diff --git a/BUILD b/BUILD
index 3bab706a9b5..6472c8bb3fc 100644
--- a/BUILD
+++ b/BUILD
@@ -467,7 +467,6 @@ grpc_cc_library(
         "src/core/lib/support/arena.cc",
         "src/core/lib/support/atm.cc",
         "src/core/lib/support/avl.cc",
-        "src/core/lib/support/backoff.cc",
         "src/core/lib/support/cmdline.cc",
         "src/core/lib/support/cpu_iphone.cc",
         "src/core/lib/support/cpu_linux.cc",
@@ -514,8 +513,6 @@ grpc_cc_library(
         "src/core/lib/support/atomic.h",
         "src/core/lib/support/atomic_with_atm.h",
         "src/core/lib/support/atomic_with_std.h",
-        "src/core/lib/support/backoff.h",
-        "src/core/lib/support/block_annotate.h",
         "src/core/lib/support/env.h",
         "src/core/lib/support/memory.h",
         "src/core/lib/support/mpscq.h",
@@ -568,6 +565,7 @@ grpc_cc_library(
 grpc_cc_library(
     name = "grpc_base_c",
     srcs = [
+        "src/core/lib/backoff/backoff.cc",
         "src/core/lib/channel/channel_args.cc",
         "src/core/lib/channel/channel_stack.cc",
         "src/core/lib/channel/channel_stack_builder.cc",
@@ -762,6 +760,7 @@ grpc_cc_library(
         "src/core/lib/iomgr/socket_utils_posix.h",
         "src/core/lib/iomgr/socket_windows.h",
         "src/core/lib/iomgr/sys_epoll_wrapper.h",
+        "src/core/lib/iomgr/block_annotate.h",
         "src/core/lib/iomgr/tcp_client.h",
         "src/core/lib/iomgr/tcp_client_posix.h",
         "src/core/lib/iomgr/tcp_posix.h",
@@ -817,6 +816,7 @@ grpc_cc_library(
         "src/core/lib/transport/timeout_encoding.h",
         "src/core/lib/transport/transport.h",
         "src/core/lib/transport/transport_impl.h",
+        "src/core/lib/backoff/backoff.h",
     ],
     external_deps = [
         "zlib",
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8114c2cfe38..d05a86ebd4a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -379,6 +379,7 @@ add_dependencies(buildtests_c algorithm_test)
 add_dependencies(buildtests_c alloc_test)
 add_dependencies(buildtests_c alpn_test)
 add_dependencies(buildtests_c arena_test)
+add_dependencies(buildtests_c backoff_test)
 add_dependencies(buildtests_c bad_server_response_test)
 add_dependencies(buildtests_c bdp_estimator_test)
 add_dependencies(buildtests_c bin_decoder_test)
@@ -428,7 +429,6 @@ if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
 add_dependencies(buildtests_c goaway_server_test)
 endif()
 add_dependencies(buildtests_c gpr_avl_test)
-add_dependencies(buildtests_c gpr_backoff_test)
 add_dependencies(buildtests_c gpr_cmdline_test)
 add_dependencies(buildtests_c gpr_cpu_test)
 add_dependencies(buildtests_c gpr_env_test)
@@ -592,7 +592,6 @@ add_dependencies(buildtests_c h2_sockpair_test)
 add_dependencies(buildtests_c h2_sockpair+trace_test)
 add_dependencies(buildtests_c h2_sockpair_1byte_test)
 add_dependencies(buildtests_c h2_ssl_test)
-add_dependencies(buildtests_c h2_ssl_cert_test)
 add_dependencies(buildtests_c h2_ssl_proxy_test)
 if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
 add_dependencies(buildtests_c h2_uds_test)
@@ -704,6 +703,7 @@ add_dependencies(buildtests_cxx grpc_tool_test)
 add_dependencies(buildtests_cxx grpclb_api_test)
 add_dependencies(buildtests_cxx grpclb_end2end_test)
 add_dependencies(buildtests_cxx grpclb_test)
+add_dependencies(buildtests_cxx h2_ssl_cert_test)
 add_dependencies(buildtests_cxx health_service_end2end_test)
 if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
 add_dependencies(buildtests_cxx http2_client)
@@ -786,7 +786,6 @@ add_library(gpr
   src/core/lib/support/arena.cc
   src/core/lib/support/atm.cc
   src/core/lib/support/avl.cc
-  src/core/lib/support/backoff.cc
   src/core/lib/support/cmdline.cc
   src/core/lib/support/cpu_iphone.cc
   src/core/lib/support/cpu_linux.cc
@@ -955,6 +954,7 @@ endif (gRPC_BUILD_TESTS)
 
 add_library(grpc
   src/core/lib/surface/init.cc
+  src/core/lib/backoff/backoff.cc
   src/core/lib/channel/channel_args.cc
   src/core/lib/channel/channel_stack.cc
   src/core/lib/channel/channel_stack_builder.cc
@@ -1307,6 +1307,7 @@ endif()
 
 add_library(grpc_cronet
   src/core/lib/surface/init.cc
+  src/core/lib/backoff/backoff.cc
   src/core/lib/channel/channel_args.cc
   src/core/lib/channel/channel_stack.cc
   src/core/lib/channel/channel_stack_builder.cc
@@ -1626,6 +1627,7 @@ add_library(grpc_test_util
   test/core/util/port_server_client.c
   test/core/util/slice_splitter.c
   test/core/util/trickle_endpoint.c
+  src/core/lib/backoff/backoff.cc
   src/core/lib/channel/channel_args.cc
   src/core/lib/channel/channel_stack.cc
   src/core/lib/channel/channel_stack_builder.cc
@@ -1889,6 +1891,7 @@ add_library(grpc_test_util_unsecure
   test/core/util/port_server_client.c
   test/core/util/slice_splitter.c
   test/core/util/trickle_endpoint.c
+  src/core/lib/backoff/backoff.cc
   src/core/lib/channel/channel_args.cc
   src/core/lib/channel/channel_stack.cc
   src/core/lib/channel/channel_stack_builder.cc
@@ -2138,6 +2141,7 @@ endif (gRPC_BUILD_TESTS)
 add_library(grpc_unsecure
   src/core/lib/surface/init.cc
   src/core/lib/surface/init_unsecure.cc
+  src/core/lib/backoff/backoff.cc
   src/core/lib/channel/channel_args.cc
   src/core/lib/channel/channel_stack.cc
   src/core/lib/channel/channel_stack_builder.cc
@@ -2896,6 +2900,7 @@ add_library(grpc++_cronet
   src/core/ext/transport/chttp2/transport/stream_map.cc
   src/core/ext/transport/chttp2/transport/varint.cc
   src/core/ext/transport/chttp2/transport/writing.cc
+  src/core/lib/backoff/backoff.cc
   src/core/lib/channel/channel_args.cc
   src/core/lib/channel/channel_stack.cc
   src/core/lib/channel/channel_stack_builder.cc
@@ -5197,6 +5202,35 @@ target_link_libraries(arena_test
 endif (gRPC_BUILD_TESTS)
 if (gRPC_BUILD_TESTS)
 
+add_executable(backoff_test
+  test/core/backoff/backoff_test.c
+)
+
+
+target_include_directories(backoff_test
+  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}
+  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/include
+  PRIVATE ${BORINGSSL_ROOT_DIR}/include
+  PRIVATE ${PROTOBUF_ROOT_DIR}/src
+  PRIVATE ${BENCHMARK_ROOT_DIR}/include
+  PRIVATE ${ZLIB_ROOT_DIR}
+  PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/third_party/zlib
+  PRIVATE ${CARES_INCLUDE_DIR}
+  PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/third_party/cares/cares
+  PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/third_party/gflags/include
+)
+
+target_link_libraries(backoff_test
+  ${_gRPC_ALLTARGETS_LIBRARIES}
+  grpc_test_util
+  grpc
+  gpr_test_util
+  gpr
+)
+
+endif (gRPC_BUILD_TESTS)
+if (gRPC_BUILD_TESTS)
+
 add_executable(bad_server_response_test
   test/core/end2end/bad_server_response_test.c
 )
@@ -6297,33 +6331,6 @@ target_link_libraries(gpr_avl_test
 endif (gRPC_BUILD_TESTS)
 if (gRPC_BUILD_TESTS)
 
-add_executable(gpr_backoff_test
-  test/core/support/backoff_test.c
-)
-
-
-target_include_directories(gpr_backoff_test
-  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}
-  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/include
-  PRIVATE ${BORINGSSL_ROOT_DIR}/include
-  PRIVATE ${PROTOBUF_ROOT_DIR}/src
-  PRIVATE ${BENCHMARK_ROOT_DIR}/include
-  PRIVATE ${ZLIB_ROOT_DIR}
-  PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/third_party/zlib
-  PRIVATE ${CARES_INCLUDE_DIR}
-  PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/third_party/cares/cares
-  PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/third_party/gflags/include
-)
-
-target_link_libraries(gpr_backoff_test
-  ${_gRPC_ALLTARGETS_LIBRARIES}
-  gpr_test_util
-  gpr
-)
-
-endif (gRPC_BUILD_TESTS)
-if (gRPC_BUILD_TESTS)
-
 add_executable(gpr_cmdline_test
   test/core/support/cmdline_test.c
 )
@@ -11158,6 +11165,45 @@ target_link_libraries(grpclb_test
 endif (gRPC_BUILD_TESTS)
 if (gRPC_BUILD_TESTS)
 
+add_executable(h2_ssl_cert_test
+  test/core/end2end/h2_ssl_cert_test.cc
+  third_party/googletest/googletest/src/gtest-all.cc
+  third_party/googletest/googlemock/src/gmock-all.cc
+)
+
+
+target_include_directories(h2_ssl_cert_test
+  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}
+  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/include
+  PRIVATE ${BORINGSSL_ROOT_DIR}/include
+  PRIVATE ${PROTOBUF_ROOT_DIR}/src
+  PRIVATE ${BENCHMARK_ROOT_DIR}/include
+  PRIVATE ${ZLIB_ROOT_DIR}
+  PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/third_party/zlib
+  PRIVATE ${CARES_INCLUDE_DIR}
+  PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/third_party/cares/cares
+  PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/third_party/gflags/include
+  PRIVATE third_party/googletest/googletest/include
+  PRIVATE third_party/googletest/googletest
+  PRIVATE third_party/googletest/googlemock/include
+  PRIVATE third_party/googletest/googlemock
+  PRIVATE ${_gRPC_PROTO_GENS_DIR}
+)
+
+target_link_libraries(h2_ssl_cert_test
+  ${_gRPC_PROTOBUF_LIBRARIES}
+  ${_gRPC_ALLTARGETS_LIBRARIES}
+  grpc_test_util
+  grpc++
+  grpc
+  gpr_test_util
+  gpr
+  ${_gRPC_GFLAGS_LIBRARIES}
+)
+
+endif (gRPC_BUILD_TESTS)
+if (gRPC_BUILD_TESTS)
+
 add_executable(health_service_end2end_test
   test/cpp/end2end/health_service_end2end_test.cc
   third_party/googletest/googletest/src/gtest-all.cc
@@ -13580,36 +13626,6 @@ target_link_libraries(h2_ssl_test
 endif (gRPC_BUILD_TESTS)
 if (gRPC_BUILD_TESTS)
 
-add_executable(h2_ssl_cert_test
-  test/core/end2end/fixtures/h2_ssl_cert.c
-)
-
-
-target_include_directories(h2_ssl_cert_test
-  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}
-  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/include
-  PRIVATE ${BORINGSSL_ROOT_DIR}/include
-  PRIVATE ${PROTOBUF_ROOT_DIR}/src
-  PRIVATE ${BENCHMARK_ROOT_DIR}/include
-  PRIVATE ${ZLIB_ROOT_DIR}
-  PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/third_party/zlib
-  PRIVATE ${CARES_INCLUDE_DIR}
-  PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/third_party/cares/cares
-  PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/third_party/gflags/include
-)
-
-target_link_libraries(h2_ssl_cert_test
-  ${_gRPC_ALLTARGETS_LIBRARIES}
-  end2end_tests
-  grpc_test_util
-  grpc
-  gpr_test_util
-  gpr
-)
-
-endif (gRPC_BUILD_TESTS)
-if (gRPC_BUILD_TESTS)
-
 add_executable(h2_ssl_proxy_test
   test/core/end2end/fixtures/h2_ssl_proxy.c
 )
diff --git a/INSTALL.md b/INSTALL.md
index ea613f321de..15725bd188e 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -94,6 +94,7 @@ on experience with the tools involved.
 ### Building using CMake (RECOMMENDED)
 
 Builds gRPC C and C++ with boringssl.
+- Install Visual Studio 2015 or 2017 (Visual C++ compiler will be used).
 - Install [CMake](https://cmake.org/download/).
 - Install [Active State Perl](https://www.activestate.com/activeperl/) (`choco install activeperl`)
 - Install [Ninja](https://ninja-build.org/) (`choco install ninja`)
@@ -101,7 +102,9 @@ Builds gRPC C and C++ with boringssl.
 - Install [yasm](http://yasm.tortall.net/) and add it to `PATH` (`choco install yasm`)
 - Run these commands in the repo root directory
 
-Using Ninja (faster build, supports boringssl's assembly optimizations)
+#### cmake: Using Ninja (faster build, supports boringssl's assembly optimizations).
+Please note that when using Ninja, you'll still need Visual C++ (part of Visual Studio)
+installed to be able to compile the C/C++ sources.
 ```
 > md .build
 > cd .build
@@ -110,7 +113,12 @@ Using Ninja (faster build, supports boringssl's assembly optimizations)
 > cmake --build .
 ```
 
-Using Visual Studio 2015 (can only build with OPENSSL_NO_ASM)
+#### cmake: Using Visual Studio 2015 (can only build with OPENSSL_NO_ASM).
+When using the "Visual Studio" generator,
+cmake will generate a solution (`grpc.sln`) that contains a VS project for 
+every target defined in `CMakeLists.txt` (+ few extra convenience projects
+added automatically by cmake). After opening the solution with Visual Studio 
+you will be able to browse and build the code as usual.
 ```
 > md .build
 > cd .build
diff --git a/Makefile b/Makefile
index 1d68d5a93c4..4bcd8e55ce4 100644
--- a/Makefile
+++ b/Makefile
@@ -950,6 +950,7 @@ alloc_test: $(BINDIR)/$(CONFIG)/alloc_test
 alpn_test: $(BINDIR)/$(CONFIG)/alpn_test
 api_fuzzer: $(BINDIR)/$(CONFIG)/api_fuzzer
 arena_test: $(BINDIR)/$(CONFIG)/arena_test
+backoff_test: $(BINDIR)/$(CONFIG)/backoff_test
 bad_server_response_test: $(BINDIR)/$(CONFIG)/bad_server_response_test
 bdp_estimator_test: $(BINDIR)/$(CONFIG)/bdp_estimator_test
 bin_decoder_test: $(BINDIR)/$(CONFIG)/bin_decoder_test
@@ -988,7 +989,6 @@ gen_legal_metadata_characters: $(BINDIR)/$(CONFIG)/gen_legal_metadata_characters
 gen_percent_encoding_tables: $(BINDIR)/$(CONFIG)/gen_percent_encoding_tables
 goaway_server_test: $(BINDIR)/$(CONFIG)/goaway_server_test
 gpr_avl_test: $(BINDIR)/$(CONFIG)/gpr_avl_test
-gpr_backoff_test: $(BINDIR)/$(CONFIG)/gpr_backoff_test
 gpr_cmdline_test: $(BINDIR)/$(CONFIG)/gpr_cmdline_test
 gpr_cpu_test: $(BINDIR)/$(CONFIG)/gpr_cpu_test
 gpr_env_test: $(BINDIR)/$(CONFIG)/gpr_env_test
@@ -1145,6 +1145,7 @@ grpc_tool_test: $(BINDIR)/$(CONFIG)/grpc_tool_test
 grpclb_api_test: $(BINDIR)/$(CONFIG)/grpclb_api_test
 grpclb_end2end_test: $(BINDIR)/$(CONFIG)/grpclb_end2end_test
 grpclb_test: $(BINDIR)/$(CONFIG)/grpclb_test
+h2_ssl_cert_test: $(BINDIR)/$(CONFIG)/h2_ssl_cert_test
 health_service_end2end_test: $(BINDIR)/$(CONFIG)/health_service_end2end_test
 http2_client: $(BINDIR)/$(CONFIG)/http2_client
 hybrid_end2end_test: $(BINDIR)/$(CONFIG)/hybrid_end2end_test
@@ -1247,7 +1248,6 @@ h2_sockpair_test: $(BINDIR)/$(CONFIG)/h2_sockpair_test
 h2_sockpair+trace_test: $(BINDIR)/$(CONFIG)/h2_sockpair+trace_test
 h2_sockpair_1byte_test: $(BINDIR)/$(CONFIG)/h2_sockpair_1byte_test
 h2_ssl_test: $(BINDIR)/$(CONFIG)/h2_ssl_test
-h2_ssl_cert_test: $(BINDIR)/$(CONFIG)/h2_ssl_cert_test
 h2_ssl_proxy_test: $(BINDIR)/$(CONFIG)/h2_ssl_proxy_test
 h2_uds_test: $(BINDIR)/$(CONFIG)/h2_uds_test
 inproc_test: $(BINDIR)/$(CONFIG)/inproc_test
@@ -1350,6 +1350,7 @@ buildtests_c: privatelibs_c \
   $(BINDIR)/$(CONFIG)/alloc_test \
   $(BINDIR)/$(CONFIG)/alpn_test \
   $(BINDIR)/$(CONFIG)/arena_test \
+  $(BINDIR)/$(CONFIG)/backoff_test \
   $(BINDIR)/$(CONFIG)/bad_server_response_test \
   $(BINDIR)/$(CONFIG)/bdp_estimator_test \
   $(BINDIR)/$(CONFIG)/bin_decoder_test \
@@ -1383,7 +1384,6 @@ buildtests_c: privatelibs_c \
   $(BINDIR)/$(CONFIG)/fling_test \
   $(BINDIR)/$(CONFIG)/goaway_server_test \
   $(BINDIR)/$(CONFIG)/gpr_avl_test \
-  $(BINDIR)/$(CONFIG)/gpr_backoff_test \
   $(BINDIR)/$(CONFIG)/gpr_cmdline_test \
   $(BINDIR)/$(CONFIG)/gpr_cpu_test \
   $(BINDIR)/$(CONFIG)/gpr_env_test \
@@ -1507,7 +1507,6 @@ buildtests_c: privatelibs_c \
   $(BINDIR)/$(CONFIG)/h2_sockpair+trace_test \
   $(BINDIR)/$(CONFIG)/h2_sockpair_1byte_test \
   $(BINDIR)/$(CONFIG)/h2_ssl_test \
-  $(BINDIR)/$(CONFIG)/h2_ssl_cert_test \
   $(BINDIR)/$(CONFIG)/h2_ssl_proxy_test \
   $(BINDIR)/$(CONFIG)/h2_uds_test \
   $(BINDIR)/$(CONFIG)/inproc_test \
@@ -1583,6 +1582,7 @@ buildtests_cxx: privatelibs_cxx \
   $(BINDIR)/$(CONFIG)/grpclb_api_test \
   $(BINDIR)/$(CONFIG)/grpclb_end2end_test \
   $(BINDIR)/$(CONFIG)/grpclb_test \
+  $(BINDIR)/$(CONFIG)/h2_ssl_cert_test \
   $(BINDIR)/$(CONFIG)/health_service_end2end_test \
   $(BINDIR)/$(CONFIG)/http2_client \
   $(BINDIR)/$(CONFIG)/hybrid_end2end_test \
@@ -1703,6 +1703,7 @@ buildtests_cxx: privatelibs_cxx \
   $(BINDIR)/$(CONFIG)/grpclb_api_test \
   $(BINDIR)/$(CONFIG)/grpclb_end2end_test \
   $(BINDIR)/$(CONFIG)/grpclb_test \
+  $(BINDIR)/$(CONFIG)/h2_ssl_cert_test \
   $(BINDIR)/$(CONFIG)/health_service_end2end_test \
   $(BINDIR)/$(CONFIG)/http2_client \
   $(BINDIR)/$(CONFIG)/hybrid_end2end_test \
@@ -1761,6 +1762,8 @@ test_c: buildtests_c
 	$(Q) $(BINDIR)/$(CONFIG)/alpn_test || ( echo test alpn_test failed ; exit 1 )
 	$(E) "[RUN]     Testing arena_test"
 	$(Q) $(BINDIR)/$(CONFIG)/arena_test || ( echo test arena_test failed ; exit 1 )
+	$(E) "[RUN]     Testing backoff_test"
+	$(Q) $(BINDIR)/$(CONFIG)/backoff_test || ( echo test backoff_test failed ; exit 1 )
 	$(E) "[RUN]     Testing bad_server_response_test"
 	$(Q) $(BINDIR)/$(CONFIG)/bad_server_response_test || ( echo test bad_server_response_test failed ; exit 1 )
 	$(E) "[RUN]     Testing bdp_estimator_test"
@@ -1823,8 +1826,6 @@ test_c: buildtests_c
 	$(Q) $(BINDIR)/$(CONFIG)/goaway_server_test || ( echo test goaway_server_test failed ; exit 1 )
 	$(E) "[RUN]     Testing gpr_avl_test"
 	$(Q) $(BINDIR)/$(CONFIG)/gpr_avl_test || ( echo test gpr_avl_test failed ; exit 1 )
-	$(E) "[RUN]     Testing gpr_backoff_test"
-	$(Q) $(BINDIR)/$(CONFIG)/gpr_backoff_test || ( echo test gpr_backoff_test failed ; exit 1 )
 	$(E) "[RUN]     Testing gpr_cmdline_test"
 	$(Q) $(BINDIR)/$(CONFIG)/gpr_cmdline_test || ( echo test gpr_cmdline_test failed ; exit 1 )
 	$(E) "[RUN]     Testing gpr_cpu_test"
@@ -2109,6 +2110,8 @@ test_cxx: buildtests_cxx
 	$(Q) $(BINDIR)/$(CONFIG)/grpclb_end2end_test || ( echo test grpclb_end2end_test failed ; exit 1 )
 	$(E) "[RUN]     Testing grpclb_test"
 	$(Q) $(BINDIR)/$(CONFIG)/grpclb_test || ( echo test grpclb_test failed ; exit 1 )
+	$(E) "[RUN]     Testing h2_ssl_cert_test"
+	$(Q) $(BINDIR)/$(CONFIG)/h2_ssl_cert_test || ( echo test h2_ssl_cert_test failed ; exit 1 )
 	$(E) "[RUN]     Testing health_service_end2end_test"
 	$(Q) $(BINDIR)/$(CONFIG)/health_service_end2end_test || ( echo test health_service_end2end_test failed ; exit 1 )
 	$(E) "[RUN]     Testing interop_test"
@@ -2800,7 +2803,6 @@ LIBGPR_SRC = \
     src/core/lib/support/arena.cc \
     src/core/lib/support/atm.cc \
     src/core/lib/support/avl.cc \
-    src/core/lib/support/backoff.cc \
     src/core/lib/support/cmdline.cc \
     src/core/lib/support/cpu_iphone.cc \
     src/core/lib/support/cpu_linux.cc \
@@ -2946,6 +2948,7 @@ endif
 
 LIBGRPC_SRC = \
     src/core/lib/surface/init.cc \
+    src/core/lib/backoff/backoff.cc \
     src/core/lib/channel/channel_args.cc \
     src/core/lib/channel/channel_stack.cc \
     src/core/lib/channel/channel_stack_builder.cc \
@@ -3298,6 +3301,7 @@ endif
 
 LIBGRPC_CRONET_SRC = \
     src/core/lib/surface/init.cc \
+    src/core/lib/backoff/backoff.cc \
     src/core/lib/channel/channel_args.cc \
     src/core/lib/channel/channel_stack.cc \
     src/core/lib/channel/channel_stack_builder.cc \
@@ -3616,6 +3620,7 @@ LIBGRPC_TEST_UTIL_SRC = \
     test/core/util/port_server_client.c \
     test/core/util/slice_splitter.c \
     test/core/util/trickle_endpoint.c \
+    src/core/lib/backoff/backoff.cc \
     src/core/lib/channel/channel_args.cc \
     src/core/lib/channel/channel_stack.cc \
     src/core/lib/channel/channel_stack_builder.cc \
@@ -3870,6 +3875,7 @@ LIBGRPC_TEST_UTIL_UNSECURE_SRC = \
     test/core/util/port_server_client.c \
     test/core/util/slice_splitter.c \
     test/core/util/trickle_endpoint.c \
+    src/core/lib/backoff/backoff.cc \
     src/core/lib/channel/channel_args.cc \
     src/core/lib/channel/channel_stack.cc \
     src/core/lib/channel/channel_stack_builder.cc \
@@ -4097,6 +4103,7 @@ endif
 LIBGRPC_UNSECURE_SRC = \
     src/core/lib/surface/init.cc \
     src/core/lib/surface/init_unsecure.cc \
+    src/core/lib/backoff/backoff.cc \
     src/core/lib/channel/channel_args.cc \
     src/core/lib/channel/channel_stack.cc \
     src/core/lib/channel/channel_stack_builder.cc \
@@ -4838,6 +4845,7 @@ LIBGRPC++_CRONET_SRC = \
     src/core/ext/transport/chttp2/transport/stream_map.cc \
     src/core/ext/transport/chttp2/transport/varint.cc \
     src/core/ext/transport/chttp2/transport/writing.cc \
+    src/core/lib/backoff/backoff.cc \
     src/core/lib/channel/channel_args.cc \
     src/core/lib/channel/channel_stack.cc \
     src/core/lib/channel/channel_stack_builder.cc \
@@ -8894,6 +8902,38 @@ endif
 endif
 
 
+BACKOFF_TEST_SRC = \
+    test/core/backoff/backoff_test.c \
+
+BACKOFF_TEST_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(BACKOFF_TEST_SRC))))
+ifeq ($(NO_SECURE),true)
+
+# You can't build secure targets if you don't have OpenSSL.
+
+$(BINDIR)/$(CONFIG)/backoff_test: openssl_dep_error
+
+else
+
+
+
+$(BINDIR)/$(CONFIG)/backoff_test: $(BACKOFF_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a
+	$(E) "[LD]      Linking $@"
+	$(Q) mkdir -p `dirname $@`
+	$(Q) $(LD) $(LDFLAGS) $(BACKOFF_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LDLIBS) $(LDLIBS_SECURE) -o $(BINDIR)/$(CONFIG)/backoff_test
+
+endif
+
+$(OBJDIR)/$(CONFIG)/test/core/backoff/backoff_test.o:  $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a
+
+deps_backoff_test: $(BACKOFF_TEST_OBJS:.o=.dep)
+
+ifneq ($(NO_SECURE),true)
+ifneq ($(NO_DEPS),true)
+-include $(BACKOFF_TEST_OBJS:.o=.dep)
+endif
+endif
+
+
 BAD_SERVER_RESPONSE_TEST_SRC = \
     test/core/end2end/bad_server_response_test.c \
 
@@ -10113,38 +10153,6 @@ endif
 endif
 
 
-GPR_BACKOFF_TEST_SRC = \
-    test/core/support/backoff_test.c \
-
-GPR_BACKOFF_TEST_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(GPR_BACKOFF_TEST_SRC))))
-ifeq ($(NO_SECURE),true)
-
-# You can't build secure targets if you don't have OpenSSL.
-
-$(BINDIR)/$(CONFIG)/gpr_backoff_test: openssl_dep_error
-
-else
-
-
-
-$(BINDIR)/$(CONFIG)/gpr_backoff_test: $(GPR_BACKOFF_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a
-	$(E) "[LD]      Linking $@"
-	$(Q) mkdir -p `dirname $@`
-	$(Q) $(LD) $(LDFLAGS) $(GPR_BACKOFF_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LDLIBS) $(LDLIBS_SECURE) -o $(BINDIR)/$(CONFIG)/gpr_backoff_test
-
-endif
-
-$(OBJDIR)/$(CONFIG)/test/core/support/backoff_test.o:  $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a
-
-deps_gpr_backoff_test: $(GPR_BACKOFF_TEST_OBJS:.o=.dep)
-
-ifneq ($(NO_SECURE),true)
-ifneq ($(NO_DEPS),true)
--include $(GPR_BACKOFF_TEST_OBJS:.o=.dep)
-endif
-endif
-
-
 GPR_CMDLINE_TEST_SRC = \
     test/core/support/cmdline_test.c \
 
@@ -15650,6 +15658,49 @@ endif
 $(OBJDIR)/$(CONFIG)/test/cpp/grpclb/grpclb_test.o: $(GENDIR)/src/proto/grpc/lb/v1/load_balancer.pb.cc $(GENDIR)/src/proto/grpc/lb/v1/load_balancer.grpc.pb.cc
 
 
+H2_SSL_CERT_TEST_SRC = \
+    test/core/end2end/h2_ssl_cert_test.cc \
+
+H2_SSL_CERT_TEST_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(H2_SSL_CERT_TEST_SRC))))
+ifeq ($(NO_SECURE),true)
+
+# You can't build secure targets if you don't have OpenSSL.
+
+$(BINDIR)/$(CONFIG)/h2_ssl_cert_test: openssl_dep_error
+
+else
+
+
+
+
+ifeq ($(NO_PROTOBUF),true)
+
+# You can't build the protoc plugins or protobuf-enabled targets if you don't have protobuf 3.0.0+.
+
+$(BINDIR)/$(CONFIG)/h2_ssl_cert_test: protobuf_dep_error
+
+else
+
+$(BINDIR)/$(CONFIG)/h2_ssl_cert_test: $(PROTOBUF_DEP) $(H2_SSL_CERT_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a
+	$(E) "[LD]      Linking $@"
+	$(Q) mkdir -p `dirname $@`
+	$(Q) $(LDXX) $(LDFLAGS) $(H2_SSL_CERT_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LDLIBSXX) $(LDLIBS_PROTOBUF) $(LDLIBS) $(LDLIBS_SECURE) $(GTEST_LIB) -o $(BINDIR)/$(CONFIG)/h2_ssl_cert_test
+
+endif
+
+endif
+
+$(OBJDIR)/$(CONFIG)/test/core/end2end/h2_ssl_cert_test.o:  $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a
+
+deps_h2_ssl_cert_test: $(H2_SSL_CERT_TEST_OBJS:.o=.dep)
+
+ifneq ($(NO_SECURE),true)
+ifneq ($(NO_DEPS),true)
+-include $(H2_SSL_CERT_TEST_OBJS:.o=.dep)
+endif
+endif
+
+
 HEALTH_SERVICE_END2END_TEST_SRC = \
     test/cpp/end2end/health_service_end2end_test.cc \
 
@@ -19097,38 +19148,6 @@ endif
 endif
 
 
-H2_SSL_CERT_TEST_SRC = \
-    test/core/end2end/fixtures/h2_ssl_cert.c \
-
-H2_SSL_CERT_TEST_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(H2_SSL_CERT_TEST_SRC))))
-ifeq ($(NO_SECURE),true)
-
-# You can't build secure targets if you don't have OpenSSL.
-
-$(BINDIR)/$(CONFIG)/h2_ssl_cert_test: openssl_dep_error
-
-else
-
-
-
-$(BINDIR)/$(CONFIG)/h2_ssl_cert_test: $(H2_SSL_CERT_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libend2end_tests.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a
-	$(E) "[LD]      Linking $@"
-	$(Q) mkdir -p `dirname $@`
-	$(Q) $(LD) $(LDFLAGS) $(H2_SSL_CERT_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libend2end_tests.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LDLIBS) $(LDLIBS_SECURE) -o $(BINDIR)/$(CONFIG)/h2_ssl_cert_test
-
-endif
-
-$(OBJDIR)/$(CONFIG)/test/core/end2end/fixtures/h2_ssl_cert.o:  $(LIBDIR)/$(CONFIG)/libend2end_tests.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a
-
-deps_h2_ssl_cert_test: $(H2_SSL_CERT_TEST_OBJS:.o=.dep)
-
-ifneq ($(NO_SECURE),true)
-ifneq ($(NO_DEPS),true)
--include $(H2_SSL_CERT_TEST_OBJS:.o=.dep)
-endif
-endif
-
-
 H2_SSL_PROXY_TEST_SRC = \
     test/core/end2end/fixtures/h2_ssl_proxy.c \
 
diff --git a/binding.gyp b/binding.gyp
index 08c7a2ceefa..f1f1b46fb0e 100644
--- a/binding.gyp
+++ b/binding.gyp
@@ -600,7 +600,6 @@
         'src/core/lib/support/arena.cc',
         'src/core/lib/support/atm.cc',
         'src/core/lib/support/avl.cc',
-        'src/core/lib/support/backoff.cc',
         'src/core/lib/support/cmdline.cc',
         'src/core/lib/support/cpu_iphone.cc',
         'src/core/lib/support/cpu_linux.cc',
@@ -658,6 +657,7 @@
       ],
       'sources': [
         'src/core/lib/surface/init.cc',
+        'src/core/lib/backoff/backoff.cc',
         'src/core/lib/channel/channel_args.cc',
         'src/core/lib/channel/channel_stack.cc',
         'src/core/lib/channel/channel_stack_builder.cc',
diff --git a/build.yaml b/build.yaml
index 022aeb5c4c8..d6f7b742fe2 100644
--- a/build.yaml
+++ b/build.yaml
@@ -66,7 +66,6 @@ filegroups:
   - src/core/lib/support/arena.cc
   - src/core/lib/support/atm.cc
   - src/core/lib/support/avl.cc
-  - src/core/lib/support/backoff.cc
   - src/core/lib/support/cmdline.cc
   - src/core/lib/support/cpu_iphone.cc
   - src/core/lib/support/cpu_linux.cc
@@ -143,8 +142,6 @@ filegroups:
   - src/core/lib/support/atomic.h
   - src/core/lib/support/atomic_with_atm.h
   - src/core/lib/support/atomic_with_std.h
-  - src/core/lib/support/backoff.h
-  - src/core/lib/support/block_annotate.h
   - src/core/lib/support/env.h
   - src/core/lib/support/memory.h
   - src/core/lib/support/mpscq.h
@@ -185,6 +182,7 @@ filegroups:
   - grpc++_codegen_base
 - name: grpc_base
   src:
+  - src/core/lib/backoff/backoff.cc
   - src/core/lib/channel/channel_args.cc
   - src/core/lib/channel/channel_stack.cc
   - src/core/lib/channel/channel_stack_builder.cc
@@ -337,6 +335,7 @@ filegroups:
   - include/grpc/status.h
   - include/grpc/support/workaround_list.h
   headers:
+  - src/core/lib/backoff/backoff.h
   - src/core/lib/channel/channel_args.h
   - src/core/lib/channel/channel_stack.h
   - src/core/lib/channel/channel_stack_builder.h
@@ -355,6 +354,7 @@ filegroups:
   - src/core/lib/http/format_request.h
   - src/core/lib/http/httpcli.h
   - src/core/lib/http/parser.h
+  - src/core/lib/iomgr/block_annotate.h
   - src/core/lib/iomgr/call_combiner.h
   - src/core/lib/iomgr/closure.h
   - src/core/lib/iomgr/combiner.h
@@ -1785,6 +1785,16 @@ targets:
   deps:
   - gpr_test_util
   - gpr
+- name: backoff_test
+  build: test
+  language: c
+  src:
+  - test/core/backoff/backoff_test.c
+  deps:
+  - grpc_test_util
+  - grpc
+  - gpr_test_util
+  - gpr
 - name: bad_server_response_test
   build: test
   language: c
@@ -2213,14 +2223,6 @@ targets:
   deps:
   - gpr_test_util
   - gpr
-- name: gpr_backoff_test
-  build: test
-  language: c
-  src:
-  - test/core/support/backoff_test.c
-  deps:
-  - gpr_test_util
-  - gpr
 - name: gpr_cmdline_test
   build: test
   language: c
@@ -2279,6 +2281,7 @@ targets:
   deps:
   - gpr_test_util
   - gpr
+  uses_polling: false
 - name: gpr_spinlock_test
   cpu_cost: 3
   build: test
@@ -4166,6 +4169,22 @@ targets:
   excluded_poll_engines:
   - poll
   - poll-cv
+- name: h2_ssl_cert_test
+  gtest: true
+  build: test
+  language: c++
+  headers:
+  - test/core/end2end/end2end_tests.h
+  src:
+  - test/core/end2end/h2_ssl_cert_test.cc
+  deps:
+  - grpc_test_util
+  - grpc++
+  - grpc
+  - gpr_test_util
+  - gpr
+  uses:
+  - grpc++_test
 - name: health_service_end2end_test
   gtest: true
   build: test
diff --git a/config.m4 b/config.m4
index 33509512485..a297e432dde 100644
--- a/config.m4
+++ b/config.m4
@@ -45,7 +45,6 @@ if test "$PHP_GRPC" != "no"; then
     src/core/lib/support/arena.cc \
     src/core/lib/support/atm.cc \
     src/core/lib/support/avl.cc \
-    src/core/lib/support/backoff.cc \
     src/core/lib/support/cmdline.cc \
     src/core/lib/support/cpu_iphone.cc \
     src/core/lib/support/cpu_linux.cc \
@@ -86,6 +85,7 @@ if test "$PHP_GRPC" != "no"; then
     src/core/lib/support/tmpfile_windows.cc \
     src/core/lib/support/wrap_memcpy.cc \
     src/core/lib/surface/init.cc \
+    src/core/lib/backoff/backoff.cc \
     src/core/lib/channel/channel_args.cc \
     src/core/lib/channel/channel_stack.cc \
     src/core/lib/channel/channel_stack_builder.cc \
@@ -688,6 +688,7 @@ if test "$PHP_GRPC" != "no"; then
   PHP_ADD_BUILD_DIR($ext_builddir/src/core/ext/transport/chttp2/server/secure)
   PHP_ADD_BUILD_DIR($ext_builddir/src/core/ext/transport/chttp2/transport)
   PHP_ADD_BUILD_DIR($ext_builddir/src/core/ext/transport/inproc)
+  PHP_ADD_BUILD_DIR($ext_builddir/src/core/lib/backoff)
   PHP_ADD_BUILD_DIR($ext_builddir/src/core/lib/channel)
   PHP_ADD_BUILD_DIR($ext_builddir/src/core/lib/compression)
   PHP_ADD_BUILD_DIR($ext_builddir/src/core/lib/debug)
diff --git a/config.w32 b/config.w32
index 3feb06d1a39..9343fb4b499 100644
--- a/config.w32
+++ b/config.w32
@@ -22,7 +22,6 @@ if (PHP_GRPC != "no") {
     "src\\core\\lib\\support\\arena.cc " +
     "src\\core\\lib\\support\\atm.cc " +
     "src\\core\\lib\\support\\avl.cc " +
-    "src\\core\\lib\\support\\backoff.cc " +
     "src\\core\\lib\\support\\cmdline.cc " +
     "src\\core\\lib\\support\\cpu_iphone.cc " +
     "src\\core\\lib\\support\\cpu_linux.cc " +
@@ -63,6 +62,7 @@ if (PHP_GRPC != "no") {
     "src\\core\\lib\\support\\tmpfile_windows.cc " +
     "src\\core\\lib\\support\\wrap_memcpy.cc " +
     "src\\core\\lib\\surface\\init.cc " +
+    "src\\core\\lib\\backoff\\backoff.cc " +
     "src\\core\\lib\\channel\\channel_args.cc " +
     "src\\core\\lib\\channel\\channel_stack.cc " +
     "src\\core\\lib\\channel\\channel_stack_builder.cc " +
@@ -700,6 +700,7 @@ if (PHP_GRPC != "no") {
   FSO.CreateFolder(base_dir+"\\ext\\grpc\\src\\core\\ext\\transport\\chttp2\\transport");
   FSO.CreateFolder(base_dir+"\\ext\\grpc\\src\\core\\ext\\transport\\inproc");
   FSO.CreateFolder(base_dir+"\\ext\\grpc\\src\\core\\lib");
+  FSO.CreateFolder(base_dir+"\\ext\\grpc\\src\\core\\lib\\backoff");
   FSO.CreateFolder(base_dir+"\\ext\\grpc\\src\\core\\lib\\channel");
   FSO.CreateFolder(base_dir+"\\ext\\grpc\\src\\core\\lib\\compression");
   FSO.CreateFolder(base_dir+"\\ext\\grpc\\src\\core\\lib\\debug");
diff --git a/doc/core/moving-to-c++.md b/doc/core/moving-to-c++.md
new file mode 100644
index 00000000000..4c745b38a90
--- /dev/null
+++ b/doc/core/moving-to-c++.md
@@ -0,0 +1,60 @@
+# Moving gRPC core to C++
+
+October 2017
+
+ctiller, markdroth, vjpai
+
+## Background and Goal
+
+gRPC core was originally written in C89 for several reasons
+(possibility of kernel integration, ease of wrapping, compiler
+support, etc). Over time, this was changed to C99 as all relevant
+compilers in active use came to support C99 effectively.
+[Now, gRPC core is C++](https://github.com/grpc/proposal/blob/master/L6-allow-c%2B%2B-in-grpc-core.md)
+(although the code is still idiomatically C code) with C linkage for
+public functions. Throughout all of these transitions, the public
+header files are committed to remain in C89.
+
+The goal now is to make the gRPC core implementation true idiomatic
+C++ compatible with
+[Google's C++ style guide](https://google.github.io/styleguide/cppguide.html).
+
+## Constraints
+
+- No use of standard library
+  - Standard library makes wrapping difficult/impossible and also reduces platform portability
+  - This takes precedence over using C++ style guide
+- But lambdas are ok
+- As are third-party libraries that meet our build requirements (such as many parts of abseil)
+- There will be some C++ features that don't work
+  - `new` and `delete`
+  - pure virtual functions are not allowed because the message that prints out "Pure Virtual Function called" is part of the standard library
+    - Make a `#define GRPC_ABSTRACT {GPR_ASSERT(false);}` instead of `= 0;`
+- The sanity for making sure that we don't depend on libstdc++ is that at least some tests should explicitly not include it
+  - Most tests can migrate to use gtest
+    - There are tremendous # of code paths that can now be exposed to unit tests because of the use of gtest and C++
+  - But at least some tests should not use gtest
+
+
+## Roadmap
+
+- What should be the phases of getting code converted to idiomatic C++
+  - Opportunistically do leaf code that other parts don't depend on
+  - Spend a little time deciding how to do non-leaf stuff that isn't central or polymorphic (e.g., timer, call combiner)
+  - For big central or polymorphic interfaces, actually do an API review (for things like transport, filter API, endpoint, closure, exec_ctx, ...) .
+    - Core internal changes don't need a gRFC, but core surface changes do
+    - But an API review should include at least a PR with the header change and tests to use it before it gets used more broadly
+  - iomgr polling for POSIX is a gray area whether it's a leaf or central
+- What is the schedule?
+  - In Q4 2017, if some stuff happens opportunistically, great; otherwise ¯\\\_(ツ)\_/¯
+  - More updates as team time becomes available and committed to this project
+
+## Implications for C++ API and wrapped languages
+
+- For C++ structs, switch to `using` when possible (e.g., Slice,
+ByteBuffer, ...)
+- The C++ API implementation might directly start using
+`grpc_transport_stream_op_batch` rather than the core surface `grpc_op`.
+- Can we get wrapped languages to a point where we can statically link C++? This will take a year in probability but that would allow the use of `std::`
+  - Are there other environments that don't support std library, like maybe Android NDK?
+    - Probably, that might push things out to 18 months
diff --git a/doc/load-balancing.md b/doc/load-balancing.md
index 88ff35496f3..8ff94075b5f 100644
--- a/doc/load-balancing.md
+++ b/doc/load-balancing.md
@@ -129,10 +129,9 @@ works:
         by the resolver. It asks the balancer for the server addresses to
         use for the server name originally requested by the client (i.e.,
         the same one originally passed to the name resolver).
-        - Note: The `grpclb` policy currently ignores any non-balancer
-          addresses returned by the resolver. However, in the future, it
-          may be changed to use these addresses as a fallback in case no
-          balancers can be contacted.
+        - Note: In the `grpclb` policy, the non-balancer addresses returned
+          by the resolver are used as a fallback in case no balancers can be
+          contacted when the LB policy is started.
      2. The gRPC servers to which the load balancer is directing the client
         may report load to the load balancers, if that information is needed
         by the load balancer's configuration.
diff --git a/gRPC-Core.podspec b/gRPC-Core.podspec
index 0a91809e094..d486accbf77 100644
--- a/gRPC-Core.podspec
+++ b/gRPC-Core.podspec
@@ -106,6 +106,8 @@ Pod::Spec.new do |s|
     ss.source_files = 'include/grpc/support/alloc.h',
                       'include/grpc/support/atm.h',
                       'include/grpc/support/atm_gcc_atomic.h',
+                      'include/grpc/support/atm_gcc_sync.h',
+                      'include/grpc/support/atm_windows.h',
                       'include/grpc/support/avl.h',
                       'include/grpc/support/cmdline.h',
                       'include/grpc/support/cpu.h',
@@ -120,13 +122,18 @@ Pod::Spec.new do |s|
                       'include/grpc/support/sync_custom.h',
                       'include/grpc/support/sync_generic.h',
                       'include/grpc/support/sync_posix.h',
+                      'include/grpc/support/sync_windows.h',
                       'include/grpc/support/thd.h',
                       'include/grpc/support/time.h',
                       'include/grpc/support/tls.h',
+                      'include/grpc/support/tls_gcc.h',
+                      'include/grpc/support/tls_msvc.h',
                       'include/grpc/support/tls_pthread.h',
                       'include/grpc/support/useful.h',
                       'include/grpc/impl/codegen/atm.h',
                       'include/grpc/impl/codegen/atm_gcc_atomic.h',
+                      'include/grpc/impl/codegen/atm_gcc_sync.h',
+                      'include/grpc/impl/codegen/atm_windows.h',
                       'include/grpc/impl/codegen/gpr_slice.h',
                       'include/grpc/impl/codegen/gpr_types.h',
                       'include/grpc/impl/codegen/port_platform.h',
@@ -134,6 +141,7 @@ Pod::Spec.new do |s|
                       'include/grpc/impl/codegen/sync_custom.h',
                       'include/grpc/impl/codegen/sync_generic.h',
                       'include/grpc/impl/codegen/sync_posix.h',
+                      'include/grpc/impl/codegen/sync_windows.h',
                       'include/grpc/impl/codegen/byte_buffer.h',
                       'include/grpc/impl/codegen/byte_buffer_reader.h',
                       'include/grpc/impl/codegen/compression_types.h',
@@ -145,6 +153,8 @@ Pod::Spec.new do |s|
                       'include/grpc/impl/codegen/status.h',
                       'include/grpc/impl/codegen/atm.h',
                       'include/grpc/impl/codegen/atm_gcc_atomic.h',
+                      'include/grpc/impl/codegen/atm_gcc_sync.h',
+                      'include/grpc/impl/codegen/atm_windows.h',
                       'include/grpc/impl/codegen/gpr_slice.h',
                       'include/grpc/impl/codegen/gpr_types.h',
                       'include/grpc/impl/codegen/port_platform.h',
@@ -152,6 +162,7 @@ Pod::Spec.new do |s|
                       'include/grpc/impl/codegen/sync_custom.h',
                       'include/grpc/impl/codegen/sync_generic.h',
                       'include/grpc/impl/codegen/sync_posix.h',
+                      'include/grpc/impl/codegen/sync_windows.h',
                       'include/grpc/grpc_security.h',
                       'include/grpc/byte_buffer.h',
                       'include/grpc/byte_buffer_reader.h',
@@ -179,8 +190,6 @@ Pod::Spec.new do |s|
                       'src/core/lib/support/atomic.h',
                       'src/core/lib/support/atomic_with_atm.h',
                       'src/core/lib/support/atomic_with_std.h',
-                      'src/core/lib/support/backoff.h',
-                      'src/core/lib/support/block_annotate.h',
                       'src/core/lib/support/env.h',
                       'src/core/lib/support/memory.h',
                       'src/core/lib/support/mpscq.h',
@@ -197,7 +206,6 @@ Pod::Spec.new do |s|
                       'src/core/lib/support/arena.cc',
                       'src/core/lib/support/atm.cc',
                       'src/core/lib/support/avl.cc',
-                      'src/core/lib/support/backoff.cc',
                       'src/core/lib/support/cmdline.cc',
                       'src/core/lib/support/cpu_iphone.cc',
                       'src/core/lib/support/cpu_linux.cc',
@@ -309,6 +317,7 @@ Pod::Spec.new do |s|
                       'src/core/ext/filters/deadline/deadline_filter.h',
                       'src/core/ext/transport/chttp2/client/chttp2_connector.h',
                       'src/core/ext/transport/inproc/inproc_transport.h',
+                      'src/core/lib/backoff/backoff.h',
                       'src/core/lib/channel/channel_args.h',
                       'src/core/lib/channel/channel_stack.h',
                       'src/core/lib/channel/channel_stack_builder.h',
@@ -327,6 +336,7 @@ Pod::Spec.new do |s|
                       'src/core/lib/http/format_request.h',
                       'src/core/lib/http/httpcli.h',
                       'src/core/lib/http/parser.h',
+                      'src/core/lib/iomgr/block_annotate.h',
                       'src/core/lib/iomgr/call_combiner.h',
                       'src/core/lib/iomgr/closure.h',
                       'src/core/lib/iomgr/combiner.h',
@@ -462,6 +472,7 @@ Pod::Spec.new do |s|
                       'src/core/ext/filters/workarounds/workaround_cronet_compression_filter.h',
                       'src/core/ext/filters/workarounds/workaround_utils.h',
                       'src/core/lib/surface/init.cc',
+                      'src/core/lib/backoff/backoff.cc',
                       'src/core/lib/channel/channel_args.cc',
                       'src/core/lib/channel/channel_stack.cc',
                       'src/core/lib/channel/channel_stack_builder.cc',
@@ -726,8 +737,6 @@ Pod::Spec.new do |s|
                               'src/core/lib/support/atomic.h',
                               'src/core/lib/support/atomic_with_atm.h',
                               'src/core/lib/support/atomic_with_std.h',
-                              'src/core/lib/support/backoff.h',
-                              'src/core/lib/support/block_annotate.h',
                               'src/core/lib/support/env.h',
                               'src/core/lib/support/memory.h',
                               'src/core/lib/support/mpscq.h',
@@ -810,6 +819,7 @@ Pod::Spec.new do |s|
                               'src/core/ext/filters/deadline/deadline_filter.h',
                               'src/core/ext/transport/chttp2/client/chttp2_connector.h',
                               'src/core/ext/transport/inproc/inproc_transport.h',
+                              'src/core/lib/backoff/backoff.h',
                               'src/core/lib/channel/channel_args.h',
                               'src/core/lib/channel/channel_stack.h',
                               'src/core/lib/channel/channel_stack_builder.h',
@@ -828,6 +838,7 @@ Pod::Spec.new do |s|
                               'src/core/lib/http/format_request.h',
                               'src/core/lib/http/httpcli.h',
                               'src/core/lib/http/parser.h',
+                              'src/core/lib/iomgr/block_annotate.h',
                               'src/core/lib/iomgr/call_combiner.h',
                               'src/core/lib/iomgr/closure.h',
                               'src/core/lib/iomgr/combiner.h',
diff --git a/gRPC.podspec b/gRPC.podspec
index 6bec50f0de3..4c6cd3535f6 100644
--- a/gRPC.podspec
+++ b/gRPC.podspec
@@ -63,10 +63,13 @@ Pod::Spec.new do |s|
   end
 
   s.subspec 'GID' do |ss|
+    ss.ios.deployment_target = '7.0'
+
     ss.header_mappings_dir = "#{src_dir}"
 
     ss.source_files = "#{src_dir}/GRPCCall+GID.{h,m}"
 
+    ss.dependency "#{s.name}/Main", version
     ss.dependency 'Google/SignIn'
   end
 end
diff --git a/grpc.gemspec b/grpc.gemspec
index 0c0473cacf7..b678915bc13 100644
--- a/grpc.gemspec
+++ b/grpc.gemspec
@@ -88,8 +88,6 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/lib/support/atomic.h )
   s.files += %w( src/core/lib/support/atomic_with_atm.h )
   s.files += %w( src/core/lib/support/atomic_with_std.h )
-  s.files += %w( src/core/lib/support/backoff.h )
-  s.files += %w( src/core/lib/support/block_annotate.h )
   s.files += %w( src/core/lib/support/env.h )
   s.files += %w( src/core/lib/support/memory.h )
   s.files += %w( src/core/lib/support/mpscq.h )
@@ -106,7 +104,6 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/lib/support/arena.cc )
   s.files += %w( src/core/lib/support/atm.cc )
   s.files += %w( src/core/lib/support/avl.cc )
-  s.files += %w( src/core/lib/support/backoff.cc )
   s.files += %w( src/core/lib/support/cmdline.cc )
   s.files += %w( src/core/lib/support/cpu_iphone.cc )
   s.files += %w( src/core/lib/support/cpu_linux.cc )
@@ -252,6 +249,7 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/ext/filters/deadline/deadline_filter.h )
   s.files += %w( src/core/ext/transport/chttp2/client/chttp2_connector.h )
   s.files += %w( src/core/ext/transport/inproc/inproc_transport.h )
+  s.files += %w( src/core/lib/backoff/backoff.h )
   s.files += %w( src/core/lib/channel/channel_args.h )
   s.files += %w( src/core/lib/channel/channel_stack.h )
   s.files += %w( src/core/lib/channel/channel_stack_builder.h )
@@ -270,6 +268,7 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/lib/http/format_request.h )
   s.files += %w( src/core/lib/http/httpcli.h )
   s.files += %w( src/core/lib/http/parser.h )
+  s.files += %w( src/core/lib/iomgr/block_annotate.h )
   s.files += %w( src/core/lib/iomgr/call_combiner.h )
   s.files += %w( src/core/lib/iomgr/closure.h )
   s.files += %w( src/core/lib/iomgr/combiner.h )
@@ -409,6 +408,7 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/ext/filters/workarounds/workaround_cronet_compression_filter.h )
   s.files += %w( src/core/ext/filters/workarounds/workaround_utils.h )
   s.files += %w( src/core/lib/surface/init.cc )
+  s.files += %w( src/core/lib/backoff/backoff.cc )
   s.files += %w( src/core/lib/channel/channel_args.cc )
   s.files += %w( src/core/lib/channel/channel_stack.cc )
   s.files += %w( src/core/lib/channel/channel_stack_builder.cc )
diff --git a/grpc.gyp b/grpc.gyp
index 9bf33f958b5..f8970426719 100644
--- a/grpc.gyp
+++ b/grpc.gyp
@@ -164,7 +164,6 @@
         'src/core/lib/support/arena.cc',
         'src/core/lib/support/atm.cc',
         'src/core/lib/support/avl.cc',
-        'src/core/lib/support/backoff.cc',
         'src/core/lib/support/cmdline.cc',
         'src/core/lib/support/cpu_iphone.cc',
         'src/core/lib/support/cpu_linux.cc',
@@ -224,6 +223,7 @@
       ],
       'sources': [
         'src/core/lib/surface/init.cc',
+        'src/core/lib/backoff/backoff.cc',
         'src/core/lib/channel/channel_args.cc',
         'src/core/lib/channel/channel_stack.cc',
         'src/core/lib/channel/channel_stack_builder.cc',
@@ -526,6 +526,7 @@
         'test/core/util/port_server_client.c',
         'test/core/util/slice_splitter.c',
         'test/core/util/trickle_endpoint.c',
+        'src/core/lib/backoff/backoff.cc',
         'src/core/lib/channel/channel_args.cc',
         'src/core/lib/channel/channel_stack.cc',
         'src/core/lib/channel/channel_stack_builder.cc',
@@ -732,6 +733,7 @@
         'test/core/util/port_server_client.c',
         'test/core/util/slice_splitter.c',
         'test/core/util/trickle_endpoint.c',
+        'src/core/lib/backoff/backoff.cc',
         'src/core/lib/channel/channel_args.cc',
         'src/core/lib/channel/channel_stack.cc',
         'src/core/lib/channel/channel_stack_builder.cc',
@@ -923,6 +925,7 @@
       'sources': [
         'src/core/lib/surface/init.cc',
         'src/core/lib/surface/init_unsecure.cc',
+        'src/core/lib/backoff/backoff.cc',
         'src/core/lib/channel/channel_args.cc',
         'src/core/lib/channel/channel_stack.cc',
         'src/core/lib/channel/channel_stack_builder.cc',
diff --git a/include/grpc++/server_builder.h b/include/grpc++/server_builder.h
index bbf45b3e74c..a948abedb58 100644
--- a/include/grpc++/server_builder.h
+++ b/include/grpc++/server_builder.h
@@ -140,7 +140,7 @@ class ServerBuilder {
   /// please use IPv6 any, i.e., [::]:<port>, which also accepts IPv4
   /// connections.  Valid values include dns:///localhost:1234, /
   /// 192.168.1.1:31416, dns:///[::1]:27182, etc.).
-  /// \params creds The credentials associated with the server.
+  /// \param creds The credentials associated with the server.
   /// \param selected_port[out] If not `nullptr`, gets populated with the port
   /// number bound to the \a grpc::Server for the corresponding endpoint after
   /// it is successfully bound, 0 otherwise.
diff --git a/include/grpc/impl/codegen/atm_gcc_atomic.h b/include/grpc/impl/codegen/atm_gcc_atomic.h
index 1793ec22b88..76ce8639141 100644
--- a/include/grpc/impl/codegen/atm_gcc_atomic.h
+++ b/include/grpc/impl/codegen/atm_gcc_atomic.h
@@ -25,6 +25,7 @@
 
 typedef intptr_t gpr_atm;
 #define GPR_ATM_MAX INTPTR_MAX
+#define GPR_ATM_MIN INTPTR_MIN
 
 #ifdef GPR_LOW_LEVEL_COUNTERS
 extern gpr_atm gpr_counter_atm_cas;
diff --git a/include/grpc/impl/codegen/atm_gcc_sync.h b/include/grpc/impl/codegen/atm_gcc_sync.h
index 27ae0f63d52..a9e4da3a0fe 100644
--- a/include/grpc/impl/codegen/atm_gcc_sync.h
+++ b/include/grpc/impl/codegen/atm_gcc_sync.h
@@ -25,6 +25,7 @@
 
 typedef intptr_t gpr_atm;
 #define GPR_ATM_MAX INTPTR_MAX
+#define GPR_ATM_MIN INTPTR_MIN
 
 #define GPR_ATM_COMPILE_BARRIER_() __asm__ __volatile__("" : : : "memory")
 
diff --git a/include/grpc/impl/codegen/atm_windows.h b/include/grpc/impl/codegen/atm_windows.h
index dfcaa4cc377..b868d79aef7 100644
--- a/include/grpc/impl/codegen/atm_windows.h
+++ b/include/grpc/impl/codegen/atm_windows.h
@@ -24,6 +24,7 @@
 
 typedef intptr_t gpr_atm;
 #define GPR_ATM_MAX INTPTR_MAX
+#define GPR_ATM_MIN INTPTR_MIN
 
 #define gpr_atm_full_barrier MemoryBarrier
 
diff --git a/include/grpc/module.modulemap b/include/grpc/module.modulemap
index 226cc6cf871..342adc0dc93 100644
--- a/include/grpc/module.modulemap
+++ b/include/grpc/module.modulemap
@@ -4,7 +4,6 @@ framework module grpc {
 
   header "support/alloc.h"
   header "support/atm.h"
-  header "support/atm_gcc_atomic.h"
   header "support/avl.h"
   header "support/cmdline.h"
   header "support/cpu.h"
@@ -16,23 +15,17 @@ framework module grpc {
   header "support/string_util.h"
   header "support/subprocess.h"
   header "support/sync.h"
-  header "support/sync_custom.h"
   header "support/sync_generic.h"
-  header "support/sync_posix.h"
   header "support/thd.h"
   header "support/time.h"
   header "support/tls.h"
-  header "support/tls_pthread.h"
   header "support/useful.h"
   header "impl/codegen/atm.h"
-  header "impl/codegen/atm_gcc_atomic.h"
   header "impl/codegen/gpr_slice.h"
   header "impl/codegen/gpr_types.h"
   header "impl/codegen/port_platform.h"
   header "impl/codegen/sync.h"
-  header "impl/codegen/sync_custom.h"
   header "impl/codegen/sync_generic.h"
-  header "impl/codegen/sync_posix.h"
   header "impl/codegen/byte_buffer.h"
   header "impl/codegen/byte_buffer_reader.h"
   header "impl/codegen/compression_types.h"
@@ -43,14 +36,11 @@ framework module grpc {
   header "impl/codegen/slice.h"
   header "impl/codegen/status.h"
   header "impl/codegen/atm.h"
-  header "impl/codegen/atm_gcc_atomic.h"
   header "impl/codegen/gpr_slice.h"
   header "impl/codegen/gpr_types.h"
   header "impl/codegen/port_platform.h"
   header "impl/codegen/sync.h"
-  header "impl/codegen/sync_custom.h"
   header "impl/codegen/sync_generic.h"
-  header "impl/codegen/sync_posix.h"
   header "grpc_security.h"
   header "byte_buffer.h"
   header "byte_buffer_reader.h"
@@ -65,6 +55,28 @@ framework module grpc {
   header "support/workaround_list.h"
   header "census.h"
 
+  textual header "support/atm_gcc_atomic.h"
+  textual header "support/atm_gcc_sync.h"
+  textual header "support/atm_windows.h"
+  textual header "support/sync_custom.h"
+  textual header "support/sync_posix.h"
+  textual header "support/sync_windows.h"
+  textual header "support/tls_gcc.h"
+  textual header "support/tls_msvc.h"
+  textual header "support/tls_pthread.h"
+  textual header "impl/codegen/atm_gcc_atomic.h"
+  textual header "impl/codegen/atm_gcc_sync.h"
+  textual header "impl/codegen/atm_windows.h"
+  textual header "impl/codegen/sync_custom.h"
+  textual header "impl/codegen/sync_posix.h"
+  textual header "impl/codegen/sync_windows.h"
+  textual header "impl/codegen/atm_gcc_atomic.h"
+  textual header "impl/codegen/atm_gcc_sync.h"
+  textual header "impl/codegen/atm_windows.h"
+  textual header "impl/codegen/sync_custom.h"
+  textual header "impl/codegen/sync_posix.h"
+  textual header "impl/codegen/sync_windows.h"
+
   export *
   module * { export * }
 }
diff --git a/package.xml b/package.xml
index f4e7fef72cf..4961db0143a 100644
--- a/package.xml
+++ b/package.xml
@@ -100,8 +100,6 @@
     <file baseinstalldir="/" name="src/core/lib/support/atomic.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/support/atomic_with_atm.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/support/atomic_with_std.h" role="src" />
-    <file baseinstalldir="/" name="src/core/lib/support/backoff.h" role="src" />
-    <file baseinstalldir="/" name="src/core/lib/support/block_annotate.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/support/env.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/support/memory.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/support/mpscq.h" role="src" />
@@ -118,7 +116,6 @@
     <file baseinstalldir="/" name="src/core/lib/support/arena.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/support/atm.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/support/avl.cc" role="src" />
-    <file baseinstalldir="/" name="src/core/lib/support/backoff.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/support/cmdline.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/support/cpu_iphone.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/support/cpu_linux.cc" role="src" />
@@ -264,6 +261,7 @@
     <file baseinstalldir="/" name="src/core/ext/filters/deadline/deadline_filter.h" role="src" />
     <file baseinstalldir="/" name="src/core/ext/transport/chttp2/client/chttp2_connector.h" role="src" />
     <file baseinstalldir="/" name="src/core/ext/transport/inproc/inproc_transport.h" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/backoff/backoff.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/channel/channel_args.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/channel/channel_stack.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/channel/channel_stack_builder.h" role="src" />
@@ -282,6 +280,7 @@
     <file baseinstalldir="/" name="src/core/lib/http/format_request.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/http/httpcli.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/http/parser.h" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/iomgr/block_annotate.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/call_combiner.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/closure.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/combiner.h" role="src" />
@@ -421,6 +420,7 @@
     <file baseinstalldir="/" name="src/core/ext/filters/workarounds/workaround_cronet_compression_filter.h" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/workarounds/workaround_utils.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/surface/init.cc" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/backoff/backoff.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/channel/channel_args.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/channel/channel_stack.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/channel/channel_stack_builder.cc" role="src" />
diff --git a/src/core/ext/census/base_resources.h b/src/core/ext/census/base_resources.h
index 4b1b988e3f7..d24923b5970 100644
--- a/src/core/ext/census/base_resources.h
+++ b/src/core/ext/census/base_resources.h
@@ -29,4 +29,4 @@ void define_base_resources();
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_CENSUS_BASE_RESOURCES_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_CENSUS_BASE_RESOURCES_H */
diff --git a/src/core/ext/census/census_interface.h b/src/core/ext/census/census_interface.h
index 12438e3c0a6..113c2b16efb 100644
--- a/src/core/ext/census/census_interface.h
+++ b/src/core/ext/census/census_interface.h
@@ -66,4 +66,4 @@ void census_tracing_end_op(census_op_id op_id);
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_CENSUS_CENSUS_INTERFACE_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_CENSUS_CENSUS_INTERFACE_H */
diff --git a/src/core/ext/census/census_log.h b/src/core/ext/census/census_log.h
index cc9e008907f..ee336ae733d 100644
--- a/src/core/ext/census/census_log.h
+++ b/src/core/ext/census/census_log.h
@@ -81,4 +81,4 @@ int census_log_out_of_space_count(void);
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_CENSUS_CENSUS_LOG_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_CENSUS_CENSUS_LOG_H */
diff --git a/src/core/ext/census/hash_table.h b/src/core/ext/census/hash_table.h
index c22ba8df9de..c3ed94ea14c 100644
--- a/src/core/ext/census/hash_table.h
+++ b/src/core/ext/census/hash_table.h
@@ -121,4 +121,4 @@ uint64_t census_ht_for_all(const census_ht *ht, census_ht_itr_cb);
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_CENSUS_HASH_TABLE_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_CENSUS_HASH_TABLE_H */
diff --git a/src/core/ext/census/mlog.h b/src/core/ext/census/mlog.h
index 7b4d39272b3..8f74ba231db 100644
--- a/src/core/ext/census/mlog.h
+++ b/src/core/ext/census/mlog.h
@@ -85,4 +85,4 @@ int64_t census_log_out_of_space_count(void);
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_CENSUS_MLOG_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_CENSUS_MLOG_H */
diff --git a/src/core/ext/census/resource.h b/src/core/ext/census/resource.h
index 5f7ac2ad27a..56aaaaf750e 100644
--- a/src/core/ext/census/resource.h
+++ b/src/core/ext/census/resource.h
@@ -53,4 +53,4 @@ int32_t define_resource(const resource *base);
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_CENSUS_RESOURCE_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_CENSUS_RESOURCE_H */
diff --git a/src/core/ext/census/trace_context.h b/src/core/ext/census/trace_context.h
index c707c632633..2b828ba4da1 100644
--- a/src/core/ext/census/trace_context.h
+++ b/src/core/ext/census/trace_context.h
@@ -61,4 +61,4 @@ bool decode_trace_context(google_trace_TraceContext *ctxt, uint8_t *buffer,
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_CENSUS_TRACE_CONTEXT_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_CENSUS_TRACE_CONTEXT_H */
diff --git a/src/core/ext/census/trace_propagation.h b/src/core/ext/census/trace_propagation.h
index 3394e9e0fd3..e05fd23a1fb 100644
--- a/src/core/ext/census/trace_propagation.h
+++ b/src/core/ext/census/trace_propagation.h
@@ -53,4 +53,4 @@ size_t http_format_to_trace_span_context(const char *buf, size_t buf_size,
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_CENSUS_TRACE_PROPAGATION_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_CENSUS_TRACE_PROPAGATION_H */
diff --git a/src/core/ext/census/tracing.h b/src/core/ext/census/tracing.h
index 5fcbb1e1f76..0690de8655c 100644
--- a/src/core/ext/census/tracing.h
+++ b/src/core/ext/census/tracing.h
@@ -114,4 +114,4 @@ void trace_end_span(const trace_status *status, trace_span_context *span_ctxt);
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_CENSUS_TRACING_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_CENSUS_TRACING_H */
diff --git a/src/core/ext/census/window_stats.h b/src/core/ext/census/window_stats.h
index 3b1d197f76a..2a1d6d0d167 100644
--- a/src/core/ext/census/window_stats.h
+++ b/src/core/ext/census/window_stats.h
@@ -163,4 +163,4 @@ void census_window_stats_destroy(struct census_window_stats *wstats);
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_CENSUS_WINDOW_STATS_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_CENSUS_WINDOW_STATS_H */
diff --git a/src/core/ext/filters/client_channel/channel_connectivity.cc b/src/core/ext/filters/client_channel/channel_connectivity.cc
index a05a11dad15..31a8fc39ce6 100644
--- a/src/core/ext/filters/client_channel/channel_connectivity.cc
+++ b/src/core/ext/filters/client_channel/channel_connectivity.cc
@@ -188,8 +188,8 @@ static void watcher_timer_init(grpc_exec_ctx *exec_ctx, void *arg,
   watcher_timer_init_arg *wa = (watcher_timer_init_arg *)arg;
 
   grpc_timer_init(exec_ctx, &wa->w->alarm,
-                  gpr_convert_clock_type(wa->deadline, GPR_CLOCK_MONOTONIC),
-                  &wa->w->on_timeout, gpr_now(GPR_CLOCK_MONOTONIC));
+                  grpc_timespec_to_millis_round_up(wa->deadline),
+                  &wa->w->on_timeout);
   gpr_free(wa);
 }
 
diff --git a/src/core/ext/filters/client_channel/client_channel.cc b/src/core/ext/filters/client_channel/client_channel.cc
index 8bff7548ac8..22c2bc88804 100644
--- a/src/core/ext/filters/client_channel/client_channel.cc
+++ b/src/core/ext/filters/client_channel/client_channel.cc
@@ -71,7 +71,7 @@ typedef enum {
 
 typedef struct {
   gpr_refcount refs;
-  gpr_timespec timeout;
+  grpc_millis timeout;
   wait_for_ready_value wait_for_ready;
 } method_parameters;
 
@@ -101,17 +101,18 @@ static bool parse_wait_for_ready(grpc_json *field,
   return true;
 }
 
-static bool parse_timeout(grpc_json *field, gpr_timespec *timeout) {
+static bool parse_timeout(grpc_json *field, grpc_millis *timeout) {
   if (field->type != GRPC_JSON_STRING) return false;
   size_t len = strlen(field->value);
   if (field->value[len - 1] != 's') return false;
   char *buf = gpr_strdup(field->value);
   buf[len - 1] = '\0';  // Remove trailing 's'.
   char *decimal_point = strchr(buf, '.');
+  int nanos = 0;
   if (decimal_point != NULL) {
     *decimal_point = '\0';
-    timeout->tv_nsec = gpr_parse_nonnegative_int(decimal_point + 1);
-    if (timeout->tv_nsec == -1) {
+    nanos = gpr_parse_nonnegative_int(decimal_point + 1);
+    if (nanos == -1) {
       gpr_free(buf);
       return false;
     }
@@ -130,24 +131,25 @@ static bool parse_timeout(grpc_json *field, gpr_timespec *timeout) {
         gpr_free(buf);
         return false;
     }
-    timeout->tv_nsec *= multiplier;
+    nanos *= multiplier;
   }
-  timeout->tv_sec = gpr_parse_nonnegative_int(buf);
+  int seconds = gpr_parse_nonnegative_int(buf);
   gpr_free(buf);
-  if (timeout->tv_sec == -1) return false;
+  if (seconds == -1) return false;
+  *timeout = seconds * GPR_MS_PER_SEC + nanos / GPR_NS_PER_MS;
   return true;
 }
 
 static void *method_parameters_create_from_json(const grpc_json *json) {
   wait_for_ready_value wait_for_ready = WAIT_FOR_READY_UNSET;
-  gpr_timespec timeout = {0, 0, GPR_TIMESPAN};
+  grpc_millis timeout = 0;
   for (grpc_json *field = json->child; field != NULL; field = field->next) {
     if (field->key == NULL) continue;
     if (strcmp(field->key, "waitForReady") == 0) {
       if (wait_for_ready != WAIT_FOR_READY_UNSET) return NULL;  // Duplicate.
       if (!parse_wait_for_ready(field, &wait_for_ready)) return NULL;
     } else if (strcmp(field->key, "timeout") == 0) {
-      if (timeout.tv_sec > 0 || timeout.tv_nsec > 0) return NULL;  // Duplicate.
+      if (timeout > 0) return NULL;  // Duplicate.
       if (!parse_timeout(field, &timeout)) return NULL;
     }
   }
@@ -826,7 +828,7 @@ typedef struct client_channel_call_data {
 
   grpc_slice path;  // Request path.
   gpr_timespec call_start_time;
-  gpr_timespec deadline;
+  grpc_millis deadline;
   gpr_arena *arena;
   grpc_call_stack *owning_call;
   grpc_call_combiner *call_combiner;
@@ -979,11 +981,11 @@ static void apply_service_config_to_call_locked(grpc_exec_ctx *exec_ctx,
       // If the deadline from the service config is shorter than the one
       // from the client API, reset the deadline timer.
       if (chand->deadline_checking_enabled &&
-          gpr_time_cmp(calld->method_params->timeout,
-                       gpr_time_0(GPR_TIMESPAN)) != 0) {
-        const gpr_timespec per_method_deadline =
-            gpr_time_add(calld->call_start_time, calld->method_params->timeout);
-        if (gpr_time_cmp(per_method_deadline, calld->deadline) < 0) {
+          calld->method_params->timeout != 0) {
+        const grpc_millis per_method_deadline =
+            grpc_timespec_to_millis_round_up(calld->call_start_time) +
+            calld->method_params->timeout;
+        if (per_method_deadline < calld->deadline) {
           calld->deadline = per_method_deadline;
           grpc_deadline_state_reset(exec_ctx, elem, calld->deadline);
         }
@@ -1422,7 +1424,7 @@ static grpc_error *cc_init_call_elem(grpc_exec_ctx *exec_ctx,
   // Initialize data members.
   calld->path = grpc_slice_ref_internal(args->path);
   calld->call_start_time = args->start_time;
-  calld->deadline = gpr_convert_clock_type(args->deadline, GPR_CLOCK_MONOTONIC);
+  calld->deadline = args->deadline;
   calld->arena = args->arena;
   calld->owning_call = args->call_stack;
   calld->call_combiner = args->call_combiner;
diff --git a/src/core/ext/filters/client_channel/client_channel.h b/src/core/ext/filters/client_channel/client_channel.h
index b32f378c6ca..152fe2365af 100644
--- a/src/core/ext/filters/client_channel/client_channel.h
+++ b/src/core/ext/filters/client_channel/client_channel.h
@@ -60,4 +60,4 @@ grpc_subchannel_call *grpc_client_channel_get_subchannel_call(
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_CLIENT_CHANNEL_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_CLIENT_CHANNEL_H */
diff --git a/src/core/ext/filters/client_channel/client_channel_factory.h b/src/core/ext/filters/client_channel/client_channel_factory.h
index bad8b970425..4273c900583 100644
--- a/src/core/ext/filters/client_channel/client_channel_factory.h
+++ b/src/core/ext/filters/client_channel/client_channel_factory.h
@@ -82,4 +82,4 @@ grpc_arg grpc_client_channel_factory_create_channel_arg(
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_CLIENT_CHANNEL_FACTORY_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_CLIENT_CHANNEL_FACTORY_H */
diff --git a/src/core/ext/filters/client_channel/connector.h b/src/core/ext/filters/client_channel/connector.h
index 79ccb0d9bf0..b71e0aab004 100644
--- a/src/core/ext/filters/client_channel/connector.h
+++ b/src/core/ext/filters/client_channel/connector.h
@@ -38,7 +38,7 @@ typedef struct {
   /** set of pollsets interested in this connection */
   grpc_pollset_set *interested_parties;
   /** deadline for connection */
-  gpr_timespec deadline;
+  grpc_millis deadline;
   /** channel arguments (to be passed to transport) */
   const grpc_channel_args *channel_args;
 } grpc_connect_in_args;
@@ -78,4 +78,4 @@ void grpc_connector_shutdown(grpc_exec_ctx *exec_ctx, grpc_connector *connector,
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_CONNECTOR_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_CONNECTOR_H */
diff --git a/src/core/ext/filters/client_channel/http_connect_handshaker.h b/src/core/ext/filters/client_channel/http_connect_handshaker.h
index 5042c61becd..05a23cdba34 100644
--- a/src/core/ext/filters/client_channel/http_connect_handshaker.h
+++ b/src/core/ext/filters/client_channel/http_connect_handshaker.h
@@ -39,4 +39,4 @@ void grpc_http_connect_register_handshaker_factory();
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_HTTP_CONNECT_HANDSHAKER_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_HTTP_CONNECT_HANDSHAKER_H */
diff --git a/src/core/ext/filters/client_channel/http_proxy.h b/src/core/ext/filters/client_channel/http_proxy.h
index 65d52334af2..bdad03def31 100644
--- a/src/core/ext/filters/client_channel/http_proxy.h
+++ b/src/core/ext/filters/client_channel/http_proxy.h
@@ -29,4 +29,4 @@ void grpc_register_http_proxy_mapper();
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_HTTP_PROXY_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_HTTP_PROXY_H */
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc
index d8e314d1f9a..ffd58129c6e 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc
@@ -103,6 +103,7 @@
 #include "src/core/ext/filters/client_channel/parse_address.h"
 #include "src/core/ext/filters/client_channel/resolver/fake/fake_resolver.h"
 #include "src/core/ext/filters/client_channel/subchannel_index.h"
+#include "src/core/lib/backoff/backoff.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/channel_stack.h"
 #include "src/core/lib/iomgr/combiner.h"
@@ -112,7 +113,6 @@
 #include "src/core/lib/slice/slice_hash_table.h"
 #include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/slice/slice_string_helpers.h"
-#include "src/core/lib/support/backoff.h"
 #include "src/core/lib/support/string.h"
 #include "src/core/lib/surface/call.h"
 #include "src/core/lib/surface/channel.h"
@@ -345,9 +345,6 @@ typedef struct glb_lb_policy {
   /** are we currently updating lb_call? */
   bool updating_lb_call;
 
-  /** are we currently updating lb_channel? */
-  bool updating_lb_channel;
-
   /** are we already watching the LB channel's connectivity? */
   bool watching_lb_channel;
 
@@ -360,9 +357,6 @@ typedef struct glb_lb_policy {
   /** called upon changes to the LB channel's connectivity. */
   grpc_closure lb_channel_on_connectivity_changed;
 
-  /** args from the latest update received while already updating, or NULL */
-  grpc_lb_policy_args *pending_update_args;
-
   /************************************************************/
   /*  client data associated with the LB server communication */
   /************************************************************/
@@ -397,7 +391,7 @@ typedef struct glb_lb_policy {
   grpc_slice lb_call_status_details;
 
   /** LB call retry backoff state */
-  gpr_backoff lb_call_backoff_state;
+  grpc_backoff lb_call_backoff_state;
 
   /** LB call retry timer */
   grpc_timer lb_call_retry_timer;
@@ -411,7 +405,7 @@ typedef struct glb_lb_policy {
    * recreated whenever lb_call is replaced. */
   grpc_grpclb_client_stats *client_stats;
   /* Interval and timer for next client load report. */
-  gpr_timespec client_stats_report_interval;
+  grpc_millis client_stats_report_interval;
   grpc_timer client_load_report_timer;
   bool client_load_report_timer_pending;
   bool last_client_load_report_counters_were_zero;
@@ -982,10 +976,6 @@ static void glb_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   }
   grpc_fake_resolver_response_generator_unref(glb_policy->response_generator);
   grpc_subchannel_index_unref();
-  if (glb_policy->pending_update_args != NULL) {
-    grpc_channel_args_destroy(exec_ctx, glb_policy->pending_update_args->args);
-    gpr_free(glb_policy->pending_update_args);
-  }
   gpr_free(glb_policy);
 }
 
@@ -1010,6 +1000,10 @@ static void glb_shutdown_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
     grpc_timer_cancel(exec_ctx, &glb_policy->lb_call_retry_timer);
     glb_policy->retry_timer_active = false;
   }
+  if (glb_policy->fallback_timer_active) {
+    grpc_timer_cancel(exec_ctx, &glb_policy->lb_fallback_timer);
+    glb_policy->fallback_timer_active = false;
+  }
 
   pending_pick *pp = glb_policy->pending_picks;
   glb_policy->pending_picks = NULL;
@@ -1130,21 +1124,19 @@ static void start_picking_locked(grpc_exec_ctx *exec_ctx,
   /* start a timer to fall back */
   if (glb_policy->lb_fallback_timeout_ms > 0 &&
       glb_policy->serverlist == NULL && !glb_policy->fallback_timer_active) {
-    gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
-    gpr_timespec deadline = gpr_time_add(
-        now,
-        gpr_time_from_millis(glb_policy->lb_fallback_timeout_ms, GPR_TIMESPAN));
+    grpc_millis deadline =
+        grpc_exec_ctx_now(exec_ctx) + glb_policy->lb_fallback_timeout_ms;
     GRPC_LB_POLICY_WEAK_REF(&glb_policy->base, "grpclb_fallback_timer");
     GRPC_CLOSURE_INIT(&glb_policy->lb_on_fallback, lb_on_fallback_timer_locked,
                       glb_policy,
                       grpc_combiner_scheduler(glb_policy->base.combiner));
     glb_policy->fallback_timer_active = true;
     grpc_timer_init(exec_ctx, &glb_policy->lb_fallback_timer, deadline,
-                    &glb_policy->lb_on_fallback, now);
+                    &glb_policy->lb_on_fallback);
   }
 
   glb_policy->started_picking = true;
-  gpr_backoff_reset(&glb_policy->lb_call_backoff_state);
+  grpc_backoff_reset(&glb_policy->lb_call_backoff_state);
   query_for_backends_locked(exec_ctx, glb_policy);
 }
 
@@ -1270,17 +1262,15 @@ static void maybe_restart_lb_call(grpc_exec_ctx *exec_ctx,
     glb_policy->updating_lb_call = false;
   } else if (!glb_policy->shutting_down) {
     /* if we aren't shutting down, restart the LB client call after some time */
-    gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
-    gpr_timespec next_try =
-        gpr_backoff_step(&glb_policy->lb_call_backoff_state, now);
+    grpc_millis next_try =
+        grpc_backoff_step(exec_ctx, &glb_policy->lb_call_backoff_state);
     if (GRPC_TRACER_ON(grpc_lb_glb_trace)) {
       gpr_log(GPR_DEBUG, "Connection to LB server lost (grpclb: %p)...",
               (void *)glb_policy);
-      gpr_timespec timeout = gpr_time_sub(next_try, now);
-      if (gpr_time_cmp(timeout, gpr_time_0(timeout.clock_type)) > 0) {
-        gpr_log(GPR_DEBUG,
-                "... retry_timer_active in %" PRId64 ".%09d seconds.",
-                timeout.tv_sec, timeout.tv_nsec);
+      grpc_millis timeout = next_try - grpc_exec_ctx_now(exec_ctx);
+      if (timeout > 0) {
+        gpr_log(GPR_DEBUG, "... retry_timer_active in %" PRIdPTR "ms.",
+                timeout);
       } else {
         gpr_log(GPR_DEBUG, "... retry_timer_active immediately.");
       }
@@ -1291,7 +1281,7 @@ static void maybe_restart_lb_call(grpc_exec_ctx *exec_ctx,
                       grpc_combiner_scheduler(glb_policy->base.combiner));
     glb_policy->retry_timer_active = true;
     grpc_timer_init(exec_ctx, &glb_policy->lb_call_retry_timer, next_try,
-                    &glb_policy->lb_on_call_retry, now);
+                    &glb_policy->lb_on_call_retry);
   }
   GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &glb_policy->base,
                             "lb_on_server_status_received_locked");
@@ -1302,15 +1292,14 @@ static void send_client_load_report_locked(grpc_exec_ctx *exec_ctx, void *arg,
 
 static void schedule_next_client_load_report(grpc_exec_ctx *exec_ctx,
                                              glb_lb_policy *glb_policy) {
-  const gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
-  const gpr_timespec next_client_load_report_time =
-      gpr_time_add(now, glb_policy->client_stats_report_interval);
+  const grpc_millis next_client_load_report_time =
+      grpc_exec_ctx_now(exec_ctx) + glb_policy->client_stats_report_interval;
   GRPC_CLOSURE_INIT(&glb_policy->client_load_report_closure,
                     send_client_load_report_locked, glb_policy,
                     grpc_combiner_scheduler(glb_policy->base.combiner));
   grpc_timer_init(exec_ctx, &glb_policy->client_load_report_timer,
                   next_client_load_report_time,
-                  &glb_policy->client_load_report_closure, now);
+                  &glb_policy->client_load_report_closure);
 }
 
 static void client_load_report_done_locked(grpc_exec_ctx *exec_ctx, void *arg,
@@ -1404,12 +1393,10 @@ static void lb_call_init_locked(grpc_exec_ctx *exec_ctx,
    * glb_policy->base.interested_parties, which is comprised of the polling
    * entities from \a client_channel. */
   grpc_slice host = grpc_slice_from_copied_string(glb_policy->server_name);
-  gpr_timespec deadline =
+  grpc_millis deadline =
       glb_policy->lb_call_timeout_ms == 0
-          ? gpr_inf_future(GPR_CLOCK_MONOTONIC)
-          : gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC),
-                         gpr_time_from_millis(glb_policy->lb_call_timeout_ms,
-                                              GPR_TIMESPAN));
+          ? GRPC_MILLIS_INF_FUTURE
+          : grpc_exec_ctx_now(exec_ctx) + glb_policy->lb_call_timeout_ms;
   glb_policy->lb_call = grpc_channel_create_pollset_set_call(
       exec_ctx, glb_policy->lb_channel, NULL, GRPC_PROPAGATE_DEFAULTS,
       glb_policy->base.interested_parties,
@@ -1440,12 +1427,12 @@ static void lb_call_init_locked(grpc_exec_ctx *exec_ctx,
                     lb_on_response_received_locked, glb_policy,
                     grpc_combiner_scheduler(glb_policy->base.combiner));
 
-  gpr_backoff_init(&glb_policy->lb_call_backoff_state,
-                   GRPC_GRPCLB_INITIAL_CONNECT_BACKOFF_SECONDS,
-                   GRPC_GRPCLB_RECONNECT_BACKOFF_MULTIPLIER,
-                   GRPC_GRPCLB_RECONNECT_JITTER,
-                   GRPC_GRPCLB_MIN_CONNECT_TIMEOUT_SECONDS * 1000,
-                   GRPC_GRPCLB_RECONNECT_MAX_BACKOFF_SECONDS * 1000);
+  grpc_backoff_init(&glb_policy->lb_call_backoff_state,
+                    GRPC_GRPCLB_INITIAL_CONNECT_BACKOFF_SECONDS,
+                    GRPC_GRPCLB_RECONNECT_BACKOFF_MULTIPLIER,
+                    GRPC_GRPCLB_RECONNECT_JITTER,
+                    GRPC_GRPCLB_MIN_CONNECT_TIMEOUT_SECONDS * 1000,
+                    GRPC_GRPCLB_RECONNECT_MAX_BACKOFF_SECONDS * 1000);
 
   glb_policy->seen_initial_response = false;
   glb_policy->last_client_load_report_counters_were_zero = false;
@@ -1553,7 +1540,7 @@ static void lb_on_response_received_locked(grpc_exec_ctx *exec_ctx, void *arg,
   memset(ops, 0, sizeof(ops));
   grpc_op *op = ops;
   if (glb_policy->lb_response_payload != NULL) {
-    gpr_backoff_reset(&glb_policy->lb_call_backoff_state);
+    grpc_backoff_reset(&glb_policy->lb_call_backoff_state);
     /* Received data from the LB server. Look inside
      * glb_policy->lb_response_payload, for a serverlist. */
     grpc_byte_buffer_reader bbr;
@@ -1567,16 +1554,14 @@ static void lb_on_response_received_locked(grpc_exec_ctx *exec_ctx, void *arg,
         (response = grpc_grpclb_initial_response_parse(response_slice)) !=
             NULL) {
       if (response->has_client_stats_report_interval) {
-        glb_policy->client_stats_report_interval =
-            gpr_time_max(gpr_time_from_seconds(1, GPR_TIMESPAN),
-                         grpc_grpclb_duration_to_timespec(
-                             &response->client_stats_report_interval));
+        glb_policy->client_stats_report_interval = GPR_MAX(
+            GPR_MS_PER_SEC, grpc_grpclb_duration_to_millis(
+                                &response->client_stats_report_interval));
         if (GRPC_TRACER_ON(grpc_lb_glb_trace)) {
           gpr_log(GPR_INFO,
                   "received initial LB response message; "
-                  "client load reporting interval = %" PRId64 ".%09d sec",
-                  glb_policy->client_stats_report_interval.tv_sec,
-                  glb_policy->client_stats_report_interval.tv_nsec);
+                  "client load reporting interval = %" PRIdPTR " milliseconds",
+                  glb_policy->client_stats_report_interval);
         }
         /* take a weak ref (won't prevent calling of \a glb_shutdown() if the
          * strong ref count goes to zero) to be unref'd in
@@ -1757,45 +1742,22 @@ static void glb_update_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
   }
   const grpc_lb_addresses *addresses =
       (const grpc_lb_addresses *)arg->value.pointer.p;
-
+  // If a non-empty serverlist hasn't been received from the balancer,
+  // propagate the update to fallback_backend_addresses.
   if (glb_policy->serverlist == NULL) {
-    // If a non-empty serverlist hasn't been received from the balancer,
-    // propagate the update to fallback_backend_addresses.
     fallback_update_locked(exec_ctx, glb_policy, addresses);
-  } else if (glb_policy->updating_lb_channel) {
-    // If we have recieved serverlist from the balancer, we need to defer update
-    // when there is an in-progress one.
-    if (GRPC_TRACER_ON(grpc_lb_glb_trace)) {
-      gpr_log(GPR_INFO,
-              "Update already in progress for grpclb %p. Deferring update.",
-              (void *)glb_policy);
-    }
-    if (glb_policy->pending_update_args != NULL) {
-      grpc_channel_args_destroy(exec_ctx,
-                                glb_policy->pending_update_args->args);
-      gpr_free(glb_policy->pending_update_args);
-    }
-    glb_policy->pending_update_args = (grpc_lb_policy_args *)gpr_zalloc(
-        sizeof(*glb_policy->pending_update_args));
-    glb_policy->pending_update_args->client_channel_factory =
-        args->client_channel_factory;
-    glb_policy->pending_update_args->args = grpc_channel_args_copy(args->args);
-    glb_policy->pending_update_args->combiner = args->combiner;
-    return;
   }
-
-  glb_policy->updating_lb_channel = true;
   GPR_ASSERT(glb_policy->lb_channel != NULL);
+  // Propagate updates to the LB channel (pick_first) through the fake
+  // resolver.
   grpc_channel_args *lb_channel_args = build_lb_channel_args(
       exec_ctx, addresses, glb_policy->response_generator, args->args);
-  /* Propagate updates to the LB channel (pick first) through the fake resolver
-   */
   grpc_fake_resolver_response_generator_set_response(
       exec_ctx, glb_policy->response_generator, lb_channel_args);
   grpc_channel_args_destroy(exec_ctx, lb_channel_args);
-
+  // Start watching the LB channel connectivity for connection, if not
+  // already doing so.
   if (!glb_policy->watching_lb_channel) {
-    // Watch the LB channel connectivity for connection.
     glb_policy->lb_channel_connectivity = grpc_channel_check_connectivity_state(
         glb_policy->lb_channel, true /* try to connect */);
     grpc_channel_element *client_channel_elem = grpc_channel_stack_last_element(
@@ -1847,18 +1809,10 @@ static void glb_lb_channel_on_connectivity_changed_cb(grpc_exec_ctx *exec_ctx,
     /* fallthrough */
     case GRPC_CHANNEL_READY:
       if (glb_policy->lb_call != NULL) {
-        glb_policy->updating_lb_channel = false;
         glb_policy->updating_lb_call = true;
         grpc_call_cancel(glb_policy->lb_call, NULL);
-        // lb_on_server_status_received will pick up the cancel and reinit
+        // lb_on_server_status_received() will pick up the cancel and reinit
         // lb_call.
-        if (glb_policy->pending_update_args != NULL) {
-          grpc_lb_policy_args *args = glb_policy->pending_update_args;
-          glb_policy->pending_update_args = NULL;
-          glb_update_locked(exec_ctx, &glb_policy->base, args);
-          grpc_channel_args_destroy(exec_ctx, args->args);
-          gpr_free(args);
-        }
       } else if (glb_policy->started_picking && !glb_policy->shutting_down) {
         if (glb_policy->retry_timer_active) {
           grpc_timer_cancel(exec_ctx, &glb_policy->lb_call_retry_timer);
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.h b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.h
index c67df609fc2..15c8a680b73 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.h
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.h
@@ -34,4 +34,4 @@ grpc_lb_policy_factory *grpc_glb_lb_factory_create();
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_GRPCLB_GRPCLB_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_GRPCLB_GRPCLB_H */
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.cc b/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.cc
index 8ef6dfc6f40..4d5fb2081cc 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.cc
@@ -299,13 +299,10 @@ int grpc_grpclb_duration_compare(const grpc_grpclb_duration *lhs,
   return 0;
 }
 
-gpr_timespec grpc_grpclb_duration_to_timespec(
-    grpc_grpclb_duration *duration_pb) {
-  gpr_timespec duration;
-  duration.tv_sec = duration_pb->has_seconds ? duration_pb->seconds : 0;
-  duration.tv_nsec = duration_pb->has_nanos ? duration_pb->nanos : 0;
-  duration.clock_type = GPR_TIMESPAN;
-  return duration;
+grpc_millis grpc_grpclb_duration_to_millis(grpc_grpclb_duration *duration_pb) {
+  return (grpc_millis)(
+      (duration_pb->has_seconds ? duration_pb->seconds : 0) * GPR_MS_PER_SEC +
+      (duration_pb->has_nanos ? duration_pb->nanos : 0) / GPR_NS_PER_MS);
 }
 
 void grpc_grpclb_initial_response_destroy(
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.h b/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.h
index c4a98492c9b..56b9c096d06 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.h
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.h
@@ -81,8 +81,7 @@ void grpc_grpclb_destroy_serverlist(grpc_grpclb_serverlist *serverlist);
 int grpc_grpclb_duration_compare(const grpc_grpclb_duration *lhs,
                                  const grpc_grpclb_duration *rhs);
 
-gpr_timespec grpc_grpclb_duration_to_timespec(
-    grpc_grpclb_duration *duration_pb);
+grpc_millis grpc_grpclb_duration_to_millis(grpc_grpclb_duration *duration_pb);
 
 /** Destroy \a initial_response */
 void grpc_grpclb_initial_response_destroy(
diff --git a/src/core/ext/filters/client_channel/lb_policy_factory.h b/src/core/ext/filters/client_channel/lb_policy_factory.h
index 69bcba42323..8790ffdda31 100644
--- a/src/core/ext/filters/client_channel/lb_policy_factory.h
+++ b/src/core/ext/filters/client_channel/lb_policy_factory.h
@@ -138,4 +138,4 @@ grpc_lb_policy *grpc_lb_policy_factory_create_lb_policy(
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_FACTORY_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_FACTORY_H */
diff --git a/src/core/ext/filters/client_channel/lb_policy_registry.h b/src/core/ext/filters/client_channel/lb_policy_registry.h
index 0867844c371..55154cb02a1 100644
--- a/src/core/ext/filters/client_channel/lb_policy_registry.h
+++ b/src/core/ext/filters/client_channel/lb_policy_registry.h
@@ -45,4 +45,4 @@ grpc_lb_policy *grpc_lb_policy_create(grpc_exec_ctx *exec_ctx, const char *name,
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_REGISTRY_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_REGISTRY_H */
diff --git a/src/core/ext/filters/client_channel/parse_address.h b/src/core/ext/filters/client_channel/parse_address.h
index 742df380b7e..27d06a1cb3d 100644
--- a/src/core/ext/filters/client_channel/parse_address.h
+++ b/src/core/ext/filters/client_channel/parse_address.h
@@ -53,4 +53,4 @@ bool grpc_parse_ipv6_hostport(const char *hostport, grpc_resolved_address *addr,
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_PARSE_ADDRESS_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_PARSE_ADDRESS_H */
diff --git a/src/core/ext/filters/client_channel/proxy_mapper.h b/src/core/ext/filters/client_channel/proxy_mapper.h
index 1325a9f1f62..bb8259f8545 100644
--- a/src/core/ext/filters/client_channel/proxy_mapper.h
+++ b/src/core/ext/filters/client_channel/proxy_mapper.h
@@ -79,4 +79,4 @@ void grpc_proxy_mapper_destroy(grpc_proxy_mapper* mapper);
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_PROXY_MAPPER_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_PROXY_MAPPER_H */
diff --git a/src/core/ext/filters/client_channel/proxy_mapper_registry.h b/src/core/ext/filters/client_channel/proxy_mapper_registry.h
index 2d389f1c21d..39c607cefcf 100644
--- a/src/core/ext/filters/client_channel/proxy_mapper_registry.h
+++ b/src/core/ext/filters/client_channel/proxy_mapper_registry.h
@@ -49,4 +49,4 @@ bool grpc_proxy_mappers_map_address(grpc_exec_ctx* exec_ctx,
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_PROXY_MAPPER_REGISTRY_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_PROXY_MAPPER_REGISTRY_H */
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc b/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
index 69f5877b006..5f7ab987cbd 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
@@ -32,13 +32,13 @@
 #include "src/core/ext/filters/client_channel/lb_policy_registry.h"
 #include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
 #include "src/core/ext/filters/client_channel/resolver_registry.h"
+#include "src/core/lib/backoff/backoff.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/iomgr/combiner.h"
 #include "src/core/lib/iomgr/gethostname.h"
 #include "src/core/lib/iomgr/resolve_address.h"
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/json/json.h"
-#include "src/core/lib/support/backoff.h"
 #include "src/core/lib/support/env.h"
 #include "src/core/lib/support/string.h"
 #include "src/core/lib/transport/service_config.h"
@@ -89,7 +89,7 @@ typedef struct {
   bool have_retry_timer;
   grpc_timer retry_timer;
   /** retry backoff state */
-  gpr_backoff backoff_state;
+  grpc_backoff backoff_state;
 
   /** currently resolving addresses */
   grpc_lb_addresses *lb_addresses;
@@ -137,7 +137,7 @@ static void dns_ares_channel_saw_error_locked(grpc_exec_ctx *exec_ctx,
                                               grpc_resolver *resolver) {
   ares_dns_resolver *r = (ares_dns_resolver *)resolver;
   if (!r->resolving) {
-    gpr_backoff_reset(&r->backoff_state);
+    grpc_backoff_reset(&r->backoff_state);
     dns_ares_start_resolving_locked(exec_ctx, r);
   }
 }
@@ -271,22 +271,20 @@ static void dns_ares_on_resolved_locked(grpc_exec_ctx *exec_ctx, void *arg,
   } else {
     const char *msg = grpc_error_string(error);
     gpr_log(GPR_DEBUG, "dns resolution failed: %s", msg);
-    gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
-    gpr_timespec next_try = gpr_backoff_step(&r->backoff_state, now);
-    gpr_timespec timeout = gpr_time_sub(next_try, now);
+    grpc_millis next_try = grpc_backoff_step(exec_ctx, &r->backoff_state);
+    grpc_millis timeout = next_try - grpc_exec_ctx_now(exec_ctx);
     gpr_log(GPR_INFO, "dns resolution failed (will retry): %s",
             grpc_error_string(error));
     GPR_ASSERT(!r->have_retry_timer);
     r->have_retry_timer = true;
     GRPC_RESOLVER_REF(&r->base, "retry-timer");
-    if (gpr_time_cmp(timeout, gpr_time_0(timeout.clock_type)) > 0) {
-      gpr_log(GPR_DEBUG, "retrying in %" PRId64 ".%09d seconds", timeout.tv_sec,
-              timeout.tv_nsec);
+    if (timeout > 0) {
+      gpr_log(GPR_DEBUG, "retrying in %" PRIdPTR " milliseconds", timeout);
     } else {
       gpr_log(GPR_DEBUG, "retrying immediately");
     }
     grpc_timer_init(exec_ctx, &r->retry_timer, next_try,
-                    &r->dns_ares_on_retry_timer_locked, now);
+                    &r->dns_ares_on_retry_timer_locked);
   }
   if (r->resolved_result != NULL) {
     grpc_channel_args_destroy(exec_ctx, r->resolved_result);
@@ -307,7 +305,7 @@ static void dns_ares_next_locked(grpc_exec_ctx *exec_ctx,
   r->next_completion = on_complete;
   r->target_result = target_result;
   if (r->resolved_version == 0 && !r->resolving) {
-    gpr_backoff_reset(&r->backoff_state);
+    grpc_backoff_reset(&r->backoff_state);
     dns_ares_start_resolving_locked(exec_ctx, r);
   } else {
     dns_ares_maybe_finish_next_locked(exec_ctx, r);
@@ -381,11 +379,11 @@ static grpc_resolver *dns_ares_create(grpc_exec_ctx *exec_ctx,
     grpc_pollset_set_add_pollset_set(exec_ctx, r->interested_parties,
                                      args->pollset_set);
   }
-  gpr_backoff_init(&r->backoff_state, GRPC_DNS_INITIAL_CONNECT_BACKOFF_SECONDS,
-                   GRPC_DNS_RECONNECT_BACKOFF_MULTIPLIER,
-                   GRPC_DNS_RECONNECT_JITTER,
-                   GRPC_DNS_MIN_CONNECT_TIMEOUT_SECONDS * 1000,
-                   GRPC_DNS_RECONNECT_MAX_BACKOFF_SECONDS * 1000);
+  grpc_backoff_init(&r->backoff_state, GRPC_DNS_INITIAL_CONNECT_BACKOFF_SECONDS,
+                    GRPC_DNS_RECONNECT_BACKOFF_MULTIPLIER,
+                    GRPC_DNS_RECONNECT_JITTER,
+                    GRPC_DNS_MIN_CONNECT_TIMEOUT_SECONDS * 1000,
+                    GRPC_DNS_RECONNECT_MAX_BACKOFF_SECONDS * 1000);
   GRPC_CLOSURE_INIT(&r->dns_ares_on_retry_timer_locked,
                     dns_ares_on_retry_timer_locked, r,
                     grpc_combiner_scheduler(r->base.combiner));
diff --git a/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc b/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc
index 1c093d0ad2f..e669b6dfc7d 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc
+++ b/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc
@@ -27,11 +27,11 @@
 
 #include "src/core/ext/filters/client_channel/lb_policy_registry.h"
 #include "src/core/ext/filters/client_channel/resolver_registry.h"
+#include "src/core/lib/backoff/backoff.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/iomgr/combiner.h"
 #include "src/core/lib/iomgr/resolve_address.h"
 #include "src/core/lib/iomgr/timer.h"
-#include "src/core/lib/support/backoff.h"
 #include "src/core/lib/support/env.h"
 #include "src/core/lib/support/string.h"
 
@@ -70,7 +70,7 @@ typedef struct {
   grpc_timer retry_timer;
   grpc_closure on_retry;
   /** retry backoff state */
-  gpr_backoff backoff_state;
+  grpc_backoff backoff_state;
 
   /** currently resolving addresses */
   grpc_resolved_addresses *addresses;
@@ -113,7 +113,7 @@ static void dns_channel_saw_error_locked(grpc_exec_ctx *exec_ctx,
                                          grpc_resolver *resolver) {
   dns_resolver *r = (dns_resolver *)resolver;
   if (!r->resolving) {
-    gpr_backoff_reset(&r->backoff_state);
+    grpc_backoff_reset(&r->backoff_state);
     dns_start_resolving_locked(exec_ctx, r);
   }
 }
@@ -126,7 +126,7 @@ static void dns_next_locked(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
   r->next_completion = on_complete;
   r->target_result = target_result;
   if (r->resolved_version == 0 && !r->resolving) {
-    gpr_backoff_reset(&r->backoff_state);
+    grpc_backoff_reset(&r->backoff_state);
     dns_start_resolving_locked(exec_ctx, r);
   } else {
     dns_maybe_finish_next_locked(exec_ctx, r);
@@ -153,6 +153,9 @@ static void dns_on_resolved_locked(grpc_exec_ctx *exec_ctx, void *arg,
   grpc_channel_args *result = NULL;
   GPR_ASSERT(r->resolving);
   r->resolving = false;
+  GRPC_ERROR_REF(error);
+  error = grpc_error_set_str(error, GRPC_ERROR_STR_TARGET_ADDRESS,
+                             grpc_slice_from_copied_string(r->name_to_resolve));
   if (r->addresses != NULL) {
     grpc_lb_addresses *addresses = grpc_lb_addresses_create(
         r->addresses->naddrs, NULL /* user_data_vtable */);
@@ -167,23 +170,21 @@ static void dns_on_resolved_locked(grpc_exec_ctx *exec_ctx, void *arg,
     grpc_resolved_addresses_destroy(r->addresses);
     grpc_lb_addresses_destroy(exec_ctx, addresses);
   } else {
-    gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
-    gpr_timespec next_try = gpr_backoff_step(&r->backoff_state, now);
-    gpr_timespec timeout = gpr_time_sub(next_try, now);
+    grpc_millis next_try = grpc_backoff_step(exec_ctx, &r->backoff_state);
+    grpc_millis timeout = next_try - grpc_exec_ctx_now(exec_ctx);
     gpr_log(GPR_INFO, "dns resolution failed (will retry): %s",
             grpc_error_string(error));
     GPR_ASSERT(!r->have_retry_timer);
     r->have_retry_timer = true;
     GRPC_RESOLVER_REF(&r->base, "retry-timer");
-    if (gpr_time_cmp(timeout, gpr_time_0(timeout.clock_type)) > 0) {
-      gpr_log(GPR_DEBUG, "retrying in %" PRId64 ".%09d seconds", timeout.tv_sec,
-              timeout.tv_nsec);
+    if (timeout > 0) {
+      gpr_log(GPR_DEBUG, "retrying in %" PRIdPTR " milliseconds", timeout);
     } else {
       gpr_log(GPR_DEBUG, "retrying immediately");
     }
     GRPC_CLOSURE_INIT(&r->on_retry, dns_on_retry_timer_locked, r,
                       grpc_combiner_scheduler(r->base.combiner));
-    grpc_timer_init(exec_ctx, &r->retry_timer, next_try, &r->on_retry, now);
+    grpc_timer_init(exec_ctx, &r->retry_timer, next_try, &r->on_retry);
   }
   if (r->resolved_result != NULL) {
     grpc_channel_args_destroy(exec_ctx, r->resolved_result);
@@ -191,6 +192,7 @@ static void dns_on_resolved_locked(grpc_exec_ctx *exec_ctx, void *arg,
   r->resolved_result = result;
   r->resolved_version++;
   dns_maybe_finish_next_locked(exec_ctx, r);
+  GRPC_ERROR_UNREF(error);
 
   GRPC_RESOLVER_UNREF(exec_ctx, &r->base, "dns-resolving");
 }
@@ -254,11 +256,11 @@ static grpc_resolver *dns_create(grpc_exec_ctx *exec_ctx,
     grpc_pollset_set_add_pollset_set(exec_ctx, r->interested_parties,
                                      args->pollset_set);
   }
-  gpr_backoff_init(&r->backoff_state, GRPC_DNS_INITIAL_CONNECT_BACKOFF_SECONDS,
-                   GRPC_DNS_RECONNECT_BACKOFF_MULTIPLIER,
-                   GRPC_DNS_RECONNECT_JITTER,
-                   GRPC_DNS_MIN_CONNECT_TIMEOUT_SECONDS * 1000,
-                   GRPC_DNS_RECONNECT_MAX_BACKOFF_SECONDS * 1000);
+  grpc_backoff_init(&r->backoff_state, GRPC_DNS_INITIAL_CONNECT_BACKOFF_SECONDS,
+                    GRPC_DNS_RECONNECT_BACKOFF_MULTIPLIER,
+                    GRPC_DNS_RECONNECT_JITTER,
+                    GRPC_DNS_MIN_CONNECT_TIMEOUT_SECONDS * 1000,
+                    GRPC_DNS_RECONNECT_MAX_BACKOFF_SECONDS * 1000);
   return &r->base;
 }
 
diff --git a/src/core/ext/filters/client_channel/resolver_factory.h b/src/core/ext/filters/client_channel/resolver_factory.h
index 6e533e32488..c8b2c58db3e 100644
--- a/src/core/ext/filters/client_channel/resolver_factory.h
+++ b/src/core/ext/filters/client_channel/resolver_factory.h
@@ -75,4 +75,4 @@ char *grpc_resolver_factory_get_default_authority(
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_FACTORY_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_FACTORY_H */
diff --git a/src/core/ext/filters/client_channel/resolver_registry.h b/src/core/ext/filters/client_channel/resolver_registry.h
index eb08d887b18..06d0b99a355 100644
--- a/src/core/ext/filters/client_channel/resolver_registry.h
+++ b/src/core/ext/filters/client_channel/resolver_registry.h
@@ -74,4 +74,4 @@ char *grpc_resolver_factory_add_default_prefix_if_needed(
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_REGISTRY_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_REGISTRY_H */
diff --git a/src/core/ext/filters/client_channel/retry_throttle.h b/src/core/ext/filters/client_channel/retry_throttle.h
index 3b849475b95..399383df78b 100644
--- a/src/core/ext/filters/client_channel/retry_throttle.h
+++ b/src/core/ext/filters/client_channel/retry_throttle.h
@@ -55,4 +55,4 @@ grpc_server_retry_throttle_data* grpc_retry_throttle_map_get_data_for_server(
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RETRY_THROTTLE_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RETRY_THROTTLE_H */
diff --git a/src/core/ext/filters/client_channel/subchannel.cc b/src/core/ext/filters/client_channel/subchannel.cc
index bff5001d699..5710a221784 100644
--- a/src/core/ext/filters/client_channel/subchannel.cc
+++ b/src/core/ext/filters/client_channel/subchannel.cc
@@ -31,6 +31,7 @@
 #include "src/core/ext/filters/client_channel/proxy_mapper_registry.h"
 #include "src/core/ext/filters/client_channel/subchannel_index.h"
 #include "src/core/ext/filters/client_channel/uri_parser.h"
+#include "src/core/lib/backoff/backoff.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/connected_channel.h"
 #include "src/core/lib/debug/stats.h"
@@ -38,7 +39,6 @@
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/slice/slice_internal.h"
-#include "src/core/lib/support/backoff.h"
 #include "src/core/lib/surface/channel.h"
 #include "src/core/lib/surface/channel_init.h"
 #include "src/core/lib/transport/connectivity_state.h"
@@ -118,9 +118,9 @@ struct grpc_subchannel {
   external_state_watcher root_external_state_watcher;
 
   /** next connect attempt time */
-  gpr_timespec next_attempt;
+  grpc_millis next_attempt;
   /** backoff state */
-  gpr_backoff backoff_state;
+  grpc_backoff backoff_state;
   /** do we have an active alarm? */
   bool have_alarm;
   /** have we started the backoff loop */
@@ -364,7 +364,7 @@ grpc_subchannel *grpc_subchannel_create(grpc_exec_ctx *exec_ctx,
       }
     }
   }
-  gpr_backoff_init(
+  grpc_backoff_init(
       &c->backoff_state, initial_backoff_ms,
       fixed_reconnect_backoff ? 1.0
                               : GRPC_SUBCHANNEL_RECONNECT_BACKOFF_MULTIPLIER,
@@ -428,8 +428,7 @@ static void on_alarm(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
   }
   if (error == GRPC_ERROR_NONE) {
     gpr_log(GPR_INFO, "Failed to connect to channel, retrying");
-    c->next_attempt =
-        gpr_backoff_step(&c->backoff_state, gpr_now(GPR_CLOCK_MONOTONIC));
+    c->next_attempt = grpc_backoff_step(exec_ctx, &c->backoff_state);
     continue_connect_locked(exec_ctx, c);
     gpr_mu_unlock(&c->mu);
   } else {
@@ -464,24 +463,22 @@ static void maybe_start_connecting_locked(grpc_exec_ctx *exec_ctx,
   c->connecting = true;
   GRPC_SUBCHANNEL_WEAK_REF(c, "connecting");
 
-  gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
   if (!c->backoff_begun) {
     c->backoff_begun = true;
-    c->next_attempt = gpr_backoff_begin(&c->backoff_state, now);
+    c->next_attempt = grpc_backoff_begin(exec_ctx, &c->backoff_state);
     continue_connect_locked(exec_ctx, c);
   } else {
     GPR_ASSERT(!c->have_alarm);
     c->have_alarm = true;
-    gpr_timespec time_til_next = gpr_time_sub(c->next_attempt, now);
-    if (gpr_time_cmp(time_til_next, gpr_time_0(time_til_next.clock_type)) <=
-        0) {
+    const grpc_millis time_til_next =
+        c->next_attempt - grpc_exec_ctx_now(exec_ctx);
+    if (time_til_next <= 0) {
       gpr_log(GPR_INFO, "Retry immediately");
     } else {
-      gpr_log(GPR_INFO, "Retry in %" PRId64 ".%09d seconds",
-              time_til_next.tv_sec, time_til_next.tv_nsec);
+      gpr_log(GPR_INFO, "Retry in %" PRIdPTR " milliseconds", time_til_next);
     }
     GRPC_CLOSURE_INIT(&c->on_alarm, on_alarm, c, grpc_schedule_on_exec_ctx);
-    grpc_timer_init(exec_ctx, &c->alarm, c->next_attempt, &c->on_alarm, now);
+    grpc_timer_init(exec_ctx, &c->alarm, c->next_attempt, &c->on_alarm);
   }
 }
 
diff --git a/src/core/ext/filters/client_channel/subchannel.h b/src/core/ext/filters/client_channel/subchannel.h
index c67ff97b0ba..46b29f1fe02 100644
--- a/src/core/ext/filters/client_channel/subchannel.h
+++ b/src/core/ext/filters/client_channel/subchannel.h
@@ -107,7 +107,7 @@ typedef struct {
   grpc_polling_entity *pollent;
   grpc_slice path;
   gpr_timespec start_time;
-  gpr_timespec deadline;
+  grpc_millis deadline;
   gpr_arena *arena;
   grpc_call_context_element *context;
   grpc_call_combiner *call_combiner;
diff --git a/src/core/ext/filters/client_channel/subchannel_index.h b/src/core/ext/filters/client_channel/subchannel_index.h
index 09bac3592ca..05c3878379f 100644
--- a/src/core/ext/filters/client_channel/subchannel_index.h
+++ b/src/core/ext/filters/client_channel/subchannel_index.h
@@ -86,4 +86,4 @@ void grpc_subchannel_index_test_only_set_force_creation(bool force_creation);
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_SUBCHANNEL_INDEX_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_SUBCHANNEL_INDEX_H */
diff --git a/src/core/ext/filters/client_channel/uri_parser.h b/src/core/ext/filters/client_channel/uri_parser.h
index 43e8ae64e03..e78da5928b6 100644
--- a/src/core/ext/filters/client_channel/uri_parser.h
+++ b/src/core/ext/filters/client_channel/uri_parser.h
@@ -55,4 +55,4 @@ void grpc_uri_destroy(grpc_uri *uri);
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_URI_PARSER_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_URI_PARSER_H */
diff --git a/src/core/ext/filters/deadline/deadline_filter.cc b/src/core/ext/filters/deadline/deadline_filter.cc
index 866ce46acf2..dc194ec0684 100644
--- a/src/core/ext/filters/deadline/deadline_filter.cc
+++ b/src/core/ext/filters/deadline/deadline_filter.cc
@@ -86,9 +86,8 @@ static void timer_callback(grpc_exec_ctx* exec_ctx, void* arg,
 // synchronized.
 static void start_timer_if_needed(grpc_exec_ctx* exec_ctx,
                                   grpc_call_element* elem,
-                                  gpr_timespec deadline) {
-  deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC);
-  if (gpr_time_cmp(deadline, gpr_inf_future(GPR_CLOCK_MONOTONIC)) == 0) {
+                                  grpc_millis deadline) {
+  if (deadline == GRPC_MILLIS_INF_FUTURE) {
     return;
   }
   grpc_deadline_state* deadline_state = (grpc_deadline_state*)elem->call_data;
@@ -114,8 +113,7 @@ static void start_timer_if_needed(grpc_exec_ctx* exec_ctx,
   }
   GPR_ASSERT(closure != NULL);
   GRPC_CALL_STACK_REF(deadline_state->call_stack, "deadline_timer");
-  grpc_timer_init(exec_ctx, &deadline_state->timer, deadline, closure,
-                  gpr_now(GPR_CLOCK_MONOTONIC));
+  grpc_timer_init(exec_ctx, &deadline_state->timer, deadline, closure);
 }
 
 // Cancels the deadline timer.
@@ -155,7 +153,7 @@ static void inject_on_complete_cb(grpc_deadline_state* deadline_state,
 struct start_timer_after_init_state {
   bool in_call_combiner;
   grpc_call_element* elem;
-  gpr_timespec deadline;
+  grpc_millis deadline;
   grpc_closure closure;
 };
 static void start_timer_after_init(grpc_exec_ctx* exec_ctx, void* arg,
@@ -182,14 +180,13 @@ static void start_timer_after_init(grpc_exec_ctx* exec_ctx, void* arg,
 void grpc_deadline_state_init(grpc_exec_ctx* exec_ctx, grpc_call_element* elem,
                               grpc_call_stack* call_stack,
                               grpc_call_combiner* call_combiner,
-                              gpr_timespec deadline) {
+                              grpc_millis deadline) {
   grpc_deadline_state* deadline_state = (grpc_deadline_state*)elem->call_data;
   deadline_state->call_stack = call_stack;
   deadline_state->call_combiner = call_combiner;
   // Deadline will always be infinite on servers, so the timer will only be
   // set on clients with a finite deadline.
-  deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC);
-  if (gpr_time_cmp(deadline, gpr_inf_future(GPR_CLOCK_MONOTONIC)) != 0) {
+  if (deadline != GRPC_MILLIS_INF_FUTURE) {
     // When the deadline passes, we indicate the failure by sending down
     // an op with cancel_error set.  However, we can't send down any ops
     // until after the call stack is fully initialized.  If we start the
@@ -214,7 +211,7 @@ void grpc_deadline_state_destroy(grpc_exec_ctx* exec_ctx,
 }
 
 void grpc_deadline_state_reset(grpc_exec_ctx* exec_ctx, grpc_call_element* elem,
-                               gpr_timespec new_deadline) {
+                               grpc_millis new_deadline) {
   grpc_deadline_state* deadline_state = (grpc_deadline_state*)elem->call_data;
   cancel_timer_if_needed(exec_ctx, deadline_state);
   start_timer_if_needed(exec_ctx, elem, new_deadline);
diff --git a/src/core/ext/filters/deadline/deadline_filter.h b/src/core/ext/filters/deadline/deadline_filter.h
index f4a1110ee6e..e665dc53ee3 100644
--- a/src/core/ext/filters/deadline/deadline_filter.h
+++ b/src/core/ext/filters/deadline/deadline_filter.h
@@ -56,7 +56,8 @@ typedef struct grpc_deadline_state {
 void grpc_deadline_state_init(grpc_exec_ctx* exec_ctx, grpc_call_element* elem,
                               grpc_call_stack* call_stack,
                               grpc_call_combiner* call_combiner,
-                              gpr_timespec deadline);
+                              grpc_millis deadline);
+
 void grpc_deadline_state_destroy(grpc_exec_ctx* exec_ctx,
                                  grpc_call_element* elem);
 
@@ -70,7 +71,7 @@ void grpc_deadline_state_destroy(grpc_exec_ctx* exec_ctx,
 //
 // Note: Must be called while holding the call combiner.
 void grpc_deadline_state_reset(grpc_exec_ctx* exec_ctx, grpc_call_element* elem,
-                               gpr_timespec new_deadline);
+                               grpc_millis new_deadline);
 
 // To be called from the client-side filter's start_transport_stream_op_batch()
 // method.  Ensures that the deadline timer is cancelled when the call
@@ -97,4 +98,4 @@ extern const grpc_channel_filter grpc_server_deadline_filter;
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_FILTERS_DEADLINE_DEADLINE_FILTER_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_FILTERS_DEADLINE_DEADLINE_FILTER_H */
diff --git a/src/core/ext/filters/max_age/max_age_filter.cc b/src/core/ext/filters/max_age/max_age_filter.cc
index f4d5b1427e7..ade2e5bc825 100644
--- a/src/core/ext/filters/max_age/max_age_filter.cc
+++ b/src/core/ext/filters/max_age/max_age_filter.cc
@@ -56,11 +56,11 @@ typedef struct channel_data {
      max_connection_idle */
   grpc_timer max_idle_timer;
   /* Allowed max time a channel may have no outstanding rpcs */
-  gpr_timespec max_connection_idle;
+  grpc_millis max_connection_idle;
   /* Allowed max time a channel may exist */
-  gpr_timespec max_connection_age;
+  grpc_millis max_connection_age;
   /* Allowed grace period after the channel reaches its max age */
-  gpr_timespec max_connection_age_grace;
+  grpc_millis max_connection_age_grace;
   /* Closure to run when the channel's idle duration reaches max_connection_idle
      and should be closed gracefully */
   grpc_closure close_max_idle_channel;
@@ -99,10 +99,9 @@ static void increase_call_count(grpc_exec_ctx* exec_ctx, channel_data* chand) {
 static void decrease_call_count(grpc_exec_ctx* exec_ctx, channel_data* chand) {
   if (gpr_atm_full_fetch_add(&chand->call_count, -1) == 1) {
     GRPC_CHANNEL_STACK_REF(chand->channel_stack, "max_age max_idle_timer");
-    grpc_timer_init(
-        exec_ctx, &chand->max_idle_timer,
-        gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), chand->max_connection_idle),
-        &chand->close_max_idle_channel, gpr_now(GPR_CLOCK_MONOTONIC));
+    grpc_timer_init(exec_ctx, &chand->max_idle_timer,
+                    grpc_exec_ctx_now(exec_ctx) + chand->max_connection_idle,
+                    &chand->close_max_idle_channel);
   }
 }
 
@@ -123,10 +122,9 @@ static void start_max_age_timer_after_init(grpc_exec_ctx* exec_ctx, void* arg,
   gpr_mu_lock(&chand->max_age_timer_mu);
   chand->max_age_timer_pending = true;
   GRPC_CHANNEL_STACK_REF(chand->channel_stack, "max_age max_age_timer");
-  grpc_timer_init(
-      exec_ctx, &chand->max_age_timer,
-      gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), chand->max_connection_age),
-      &chand->close_max_age_channel, gpr_now(GPR_CLOCK_MONOTONIC));
+  grpc_timer_init(exec_ctx, &chand->max_age_timer,
+                  grpc_exec_ctx_now(exec_ctx) + chand->max_connection_age,
+                  &chand->close_max_age_channel);
   gpr_mu_unlock(&chand->max_age_timer_mu);
   grpc_transport_op* op = grpc_make_transport_op(NULL);
   op->on_connectivity_state_change = &chand->channel_connectivity_changed,
@@ -144,11 +142,12 @@ static void start_max_age_grace_timer_after_goaway_op(grpc_exec_ctx* exec_ctx,
   gpr_mu_lock(&chand->max_age_timer_mu);
   chand->max_age_grace_timer_pending = true;
   GRPC_CHANNEL_STACK_REF(chand->channel_stack, "max_age max_age_grace_timer");
-  grpc_timer_init(exec_ctx, &chand->max_age_grace_timer,
-                  gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC),
-                               chand->max_connection_age_grace),
-                  &chand->force_close_max_age_channel,
-                  gpr_now(GPR_CLOCK_MONOTONIC));
+  grpc_timer_init(
+      exec_ctx, &chand->max_age_grace_timer,
+      chand->max_connection_age_grace == GRPC_MILLIS_INF_FUTURE
+          ? GRPC_MILLIS_INF_FUTURE
+          : grpc_exec_ctx_now(exec_ctx) + chand->max_connection_age_grace,
+      &chand->force_close_max_age_channel);
   gpr_mu_unlock(&chand->max_age_timer_mu);
   GRPC_CHANNEL_STACK_UNREF(exec_ctx, chand->channel_stack,
                            "max_age start_max_age_grace_timer_after_goaway_op");
@@ -249,7 +248,8 @@ static void channel_connectivity_changed(grpc_exec_ctx* exec_ctx, void* arg,
    connection storms. Note that the MAX_CONNECTION_AGE option without jitter
    would not create connection storms by itself, but if there happened to be a
    connection storm it could cause it to repeat at a fixed period. */
-static int add_random_max_connection_age_jitter(int value) {
+static grpc_millis
+add_random_max_connection_age_jitter_and_convert_to_grpc_millis(int value) {
   /* generate a random number between 1 - MAX_CONNECTION_AGE_JITTER and
      1 + MAX_CONNECTION_AGE_JITTER */
   double multiplier = rand() * MAX_CONNECTION_AGE_JITTER * 2.0 / RAND_MAX +
@@ -257,7 +257,9 @@ static int add_random_max_connection_age_jitter(int value) {
   double result = multiplier * value;
   /* INT_MAX - 0.5 converts the value to float, so that result will not be
      cast to int implicitly before the comparison. */
-  return result > INT_MAX - 0.5 ? INT_MAX : (int)result;
+  return result > ((double)GRPC_MILLIS_INF_FUTURE) - 0.5
+             ? GRPC_MILLIS_INF_FUTURE
+             : (grpc_millis)result;
 }
 
 /* Constructor for call_data. */
@@ -287,45 +289,36 @@ static grpc_error* init_channel_elem(grpc_exec_ctx* exec_ctx,
   chand->max_age_grace_timer_pending = false;
   chand->channel_stack = args->channel_stack;
   chand->max_connection_age =
-      DEFAULT_MAX_CONNECTION_AGE_MS == INT_MAX
-          ? gpr_inf_future(GPR_TIMESPAN)
-          : gpr_time_from_millis(add_random_max_connection_age_jitter(
-                                     DEFAULT_MAX_CONNECTION_AGE_MS),
-                                 GPR_TIMESPAN);
+      add_random_max_connection_age_jitter_and_convert_to_grpc_millis(
+          DEFAULT_MAX_CONNECTION_AGE_MS);
   chand->max_connection_age_grace =
       DEFAULT_MAX_CONNECTION_AGE_GRACE_MS == INT_MAX
-          ? gpr_inf_future(GPR_TIMESPAN)
-          : gpr_time_from_millis(DEFAULT_MAX_CONNECTION_AGE_GRACE_MS,
-                                 GPR_TIMESPAN);
-  chand->max_connection_idle =
-      DEFAULT_MAX_CONNECTION_IDLE_MS == INT_MAX
-          ? gpr_inf_future(GPR_TIMESPAN)
-          : gpr_time_from_millis(DEFAULT_MAX_CONNECTION_IDLE_MS, GPR_TIMESPAN);
+          ? GRPC_MILLIS_INF_FUTURE
+          : DEFAULT_MAX_CONNECTION_AGE_GRACE_MS;
+  chand->max_connection_idle = DEFAULT_MAX_CONNECTION_IDLE_MS == INT_MAX
+                                   ? GRPC_MILLIS_INF_FUTURE
+                                   : DEFAULT_MAX_CONNECTION_IDLE_MS;
   for (size_t i = 0; i < args->channel_args->num_args; ++i) {
     if (0 == strcmp(args->channel_args->args[i].key,
                     GRPC_ARG_MAX_CONNECTION_AGE_MS)) {
       const int value = grpc_channel_arg_get_integer(
           &args->channel_args->args[i], MAX_CONNECTION_AGE_INTEGER_OPTIONS);
       chand->max_connection_age =
-          value == INT_MAX
-              ? gpr_inf_future(GPR_TIMESPAN)
-              : gpr_time_from_millis(
-                    add_random_max_connection_age_jitter(value), GPR_TIMESPAN);
+          add_random_max_connection_age_jitter_and_convert_to_grpc_millis(
+              value);
     } else if (0 == strcmp(args->channel_args->args[i].key,
                            GRPC_ARG_MAX_CONNECTION_AGE_GRACE_MS)) {
       const int value = grpc_channel_arg_get_integer(
           &args->channel_args->args[i],
           {DEFAULT_MAX_CONNECTION_AGE_GRACE_MS, 0, INT_MAX});
       chand->max_connection_age_grace =
-          value == INT_MAX ? gpr_inf_future(GPR_TIMESPAN)
-                           : gpr_time_from_millis(value, GPR_TIMESPAN);
+          value == INT_MAX ? GRPC_MILLIS_INF_FUTURE : value;
     } else if (0 == strcmp(args->channel_args->args[i].key,
                            GRPC_ARG_MAX_CONNECTION_IDLE_MS)) {
       const int value = grpc_channel_arg_get_integer(
           &args->channel_args->args[i], MAX_CONNECTION_IDLE_INTEGER_OPTIONS);
       chand->max_connection_idle =
-          value == INT_MAX ? gpr_inf_future(GPR_TIMESPAN)
-                           : gpr_time_from_millis(value, GPR_TIMESPAN);
+          value == INT_MAX ? GRPC_MILLIS_INF_FUTURE : value;
     }
   }
   GRPC_CLOSURE_INIT(&chand->close_max_idle_channel, close_max_idle_channel,
@@ -348,8 +341,7 @@ static grpc_error* init_channel_elem(grpc_exec_ctx* exec_ctx,
                     channel_connectivity_changed, chand,
                     grpc_schedule_on_exec_ctx);
 
-  if (gpr_time_cmp(chand->max_connection_age, gpr_inf_future(GPR_TIMESPAN)) !=
-      0) {
+  if (chand->max_connection_age != GRPC_MILLIS_INF_FUTURE) {
     /* When the channel reaches its max age, we send down an op with
        goaway_error set.  However, we can't send down any ops until after the
        channel stack is fully initialized.  If we start the timer here, we have
@@ -366,8 +358,7 @@ static grpc_error* init_channel_elem(grpc_exec_ctx* exec_ctx,
   /* Initialize the number of calls as 1, so that the max_idle_timer will not
      start until start_max_idle_timer_after_init is invoked. */
   gpr_atm_rel_store(&chand->call_count, 1);
-  if (gpr_time_cmp(chand->max_connection_idle, gpr_inf_future(GPR_TIMESPAN)) !=
-      0) {
+  if (chand->max_connection_idle != GRPC_MILLIS_INF_FUTURE) {
     GRPC_CHANNEL_STACK_REF(chand->channel_stack,
                            "max_age start_max_idle_timer_after_init");
     GRPC_CLOSURE_SCHED(exec_ctx, &chand->start_max_idle_timer_after_init,
diff --git a/src/core/ext/filters/workarounds/workaround_utils.h b/src/core/ext/filters/workarounds/workaround_utils.h
index afd5291333a..3913cae6b2b 100644
--- a/src/core/ext/filters/workarounds/workaround_utils.h
+++ b/src/core/ext/filters/workarounds/workaround_utils.h
@@ -42,4 +42,4 @@ void grpc_register_workaround(uint32_t id, user_agent_parser parser);
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_FILTERS_WORKAROUNDS_WORKAROUND_UTILS_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_FILTERS_WORKAROUNDS_WORKAROUND_UTILS_H */
diff --git a/src/core/ext/transport/chttp2/alpn/alpn.h b/src/core/ext/transport/chttp2/alpn/alpn.h
index 5842204c204..99b928ea591 100644
--- a/src/core/ext/transport/chttp2/alpn/alpn.h
+++ b/src/core/ext/transport/chttp2/alpn/alpn.h
@@ -39,4 +39,4 @@ const char *grpc_chttp2_get_alpn_version_index(size_t i);
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_ALPN_ALPN_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_ALPN_ALPN_H */
diff --git a/src/core/ext/transport/chttp2/server/chttp2_server.cc b/src/core/ext/transport/chttp2/server/chttp2_server.cc
index a51959bec7a..7ac7f4ece82 100644
--- a/src/core/ext/transport/chttp2/server/chttp2_server.cc
+++ b/src/core/ext/transport/chttp2/server/chttp2_server.cc
@@ -134,8 +134,8 @@ static void on_accept(grpc_exec_ctx *exec_ctx, void *arg, grpc_endpoint *tcp,
                        connection_state->handshake_mgr);
   // TODO(roth): We should really get this timeout value from channel
   // args instead of hard-coding it.
-  const gpr_timespec deadline = gpr_time_add(
-      gpr_now(GPR_CLOCK_MONOTONIC), gpr_time_from_seconds(120, GPR_TIMESPAN));
+  const grpc_millis deadline =
+      grpc_exec_ctx_now(exec_ctx) + 120 * GPR_MS_PER_SEC;
   grpc_handshake_manager_do_handshake(exec_ctx, connection_state->handshake_mgr,
                                       tcp, state->args, deadline, acceptor,
                                       on_handshake_done, connection_state);
diff --git a/src/core/ext/transport/chttp2/server/chttp2_server.h b/src/core/ext/transport/chttp2/server/chttp2_server.h
index e1df28ed11f..2ac155160fc 100644
--- a/src/core/ext/transport/chttp2/server/chttp2_server.h
+++ b/src/core/ext/transport/chttp2/server/chttp2_server.h
@@ -37,4 +37,4 @@ grpc_error *grpc_chttp2_server_add_port(grpc_exec_ctx *exec_ctx,
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_SERVER_CHTTP2_SERVER_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_SERVER_CHTTP2_SERVER_H */
diff --git a/src/core/ext/transport/chttp2/transport/bin_decoder.h b/src/core/ext/transport/chttp2/transport/bin_decoder.h
index f50e0a8ac42..1c0b2b7e97a 100644
--- a/src/core/ext/transport/chttp2/transport/bin_decoder.h
+++ b/src/core/ext/transport/chttp2/transport/bin_decoder.h
@@ -57,4 +57,4 @@ grpc_slice grpc_chttp2_base64_decode_with_length(grpc_exec_ctx *exec_ctx,
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_BIN_DECODER_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_BIN_DECODER_H */
diff --git a/src/core/ext/transport/chttp2/transport/bin_encoder.h b/src/core/ext/transport/chttp2/transport/bin_encoder.h
index ae8219c5ced..0be3633354e 100644
--- a/src/core/ext/transport/chttp2/transport/bin_encoder.h
+++ b/src/core/ext/transport/chttp2/transport/bin_encoder.h
@@ -44,4 +44,4 @@ grpc_slice grpc_chttp2_base64_encode_and_huffman_compress(grpc_slice input);
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_BIN_ENCODER_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_BIN_ENCODER_H */
diff --git a/src/core/ext/transport/chttp2/transport/chttp2_transport.cc b/src/core/ext/transport/chttp2/transport/chttp2_transport.cc
index 65167c03bb3..e4b19a2c4ac 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_transport.cc
+++ b/src/core/ext/transport/chttp2/transport/chttp2_transport.cc
@@ -159,11 +159,9 @@ static void finish_bdp_ping_locked(grpc_exec_ctx *exec_ctx, void *tp,
 
 static void cancel_pings(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                          grpc_error *error);
-static void send_ping_locked(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
-    grpc_chttp2_ping_type ping_type, grpc_closure *on_initiate,
-    grpc_closure *on_complete,
-    grpc_chttp2_initiate_write_reason initiate_write_reason);
+static void send_ping_locked(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
+                             grpc_closure *on_initiate,
+                             grpc_closure *on_complete);
 static void retry_initiate_ping_locked(grpc_exec_ctx *exec_ctx, void *tp,
                                        grpc_error *error);
 
@@ -279,6 +277,7 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   t->is_client = is_client;
   t->flow_control.remote_window = DEFAULT_WINDOW;
   t->flow_control.announced_window = DEFAULT_WINDOW;
+  t->flow_control.target_initial_window_size = DEFAULT_WINDOW;
   t->flow_control.t = t;
   t->deframe_state = is_client ? GRPC_DTS_FH_0 : GRPC_DTS_CLIENT_PREFIX_0;
   t->is_first_frame = true;
@@ -317,17 +316,6 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                     grpc_combiner_scheduler(t->combiner));
 
   grpc_bdp_estimator_init(&t->flow_control.bdp_estimator, t->peer_string);
-  t->flow_control.last_pid_update = gpr_now(GPR_CLOCK_MONOTONIC);
-  grpc_pid_controller_init(&t->flow_control.pid_controller,
-                           {
-                               4,                    /* gain_p */
-                               8,                    /* gain_t */
-                               0,                    /* gain_d */
-                               log2(DEFAULT_WINDOW), /* initial_control_value */
-                               -1,                   /* min_control_value */
-                               25,                   /* max_control_value */
-                               10                    /* integral_range */
-                           });
 
   grpc_chttp2_goaway_parser_init(&t->goaway_parser);
   grpc_chttp2_hpack_parser_init(exec_ctx, &t->hpack_parser);
@@ -366,43 +354,33 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
     queue_setting_update(exec_ctx, t,
                          GRPC_CHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS, 0);
   }
-  queue_setting_update(exec_ctx, t, GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE,
-                       DEFAULT_WINDOW);
   queue_setting_update(exec_ctx, t, GRPC_CHTTP2_SETTINGS_MAX_HEADER_LIST_SIZE,
                        DEFAULT_MAX_HEADER_LIST_SIZE);
   queue_setting_update(exec_ctx, t,
                        GRPC_CHTTP2_SETTINGS_GRPC_ALLOW_TRUE_BINARY_METADATA, 1);
 
   t->ping_policy.max_pings_without_data = g_default_max_pings_without_data;
-  t->ping_policy.min_sent_ping_interval_without_data = gpr_time_from_millis(
-      g_default_min_sent_ping_interval_without_data_ms, GPR_TIMESPAN);
+  t->ping_policy.min_sent_ping_interval_without_data =
+      g_default_min_sent_ping_interval_without_data_ms;
   t->ping_policy.max_ping_strikes = g_default_max_ping_strikes;
-  t->ping_policy.min_recv_ping_interval_without_data = gpr_time_from_millis(
-      g_default_min_recv_ping_interval_without_data_ms, GPR_TIMESPAN);
+  t->ping_policy.min_recv_ping_interval_without_data =
+      g_default_min_recv_ping_interval_without_data_ms;
 
   /* Keepalive setting */
   if (t->is_client) {
-    t->keepalive_time =
-        g_default_client_keepalive_time_ms == INT_MAX
-            ? gpr_inf_future(GPR_TIMESPAN)
-            : gpr_time_from_millis(g_default_client_keepalive_time_ms,
-                                   GPR_TIMESPAN);
-    t->keepalive_timeout =
-        g_default_client_keepalive_timeout_ms == INT_MAX
-            ? gpr_inf_future(GPR_TIMESPAN)
-            : gpr_time_from_millis(g_default_client_keepalive_timeout_ms,
-                                   GPR_TIMESPAN);
+    t->keepalive_time = g_default_client_keepalive_time_ms == INT_MAX
+                            ? GRPC_MILLIS_INF_FUTURE
+                            : g_default_client_keepalive_time_ms;
+    t->keepalive_timeout = g_default_client_keepalive_timeout_ms == INT_MAX
+                               ? GRPC_MILLIS_INF_FUTURE
+                               : g_default_client_keepalive_timeout_ms;
   } else {
-    t->keepalive_time =
-        g_default_server_keepalive_time_ms == INT_MAX
-            ? gpr_inf_future(GPR_TIMESPAN)
-            : gpr_time_from_millis(g_default_server_keepalive_time_ms,
-                                   GPR_TIMESPAN);
-    t->keepalive_timeout =
-        g_default_server_keepalive_timeout_ms == INT_MAX
-            ? gpr_inf_future(GPR_TIMESPAN)
-            : gpr_time_from_millis(g_default_server_keepalive_timeout_ms,
-                                   GPR_TIMESPAN);
+    t->keepalive_time = g_default_server_keepalive_time_ms == INT_MAX
+                            ? GRPC_MILLIS_INF_FUTURE
+                            : g_default_server_keepalive_time_ms;
+    t->keepalive_timeout = g_default_server_keepalive_timeout_ms == INT_MAX
+                               ? GRPC_MILLIS_INF_FUTURE
+                               : g_default_server_keepalive_timeout_ms;
   }
   t->keepalive_permit_without_calls = g_default_keepalive_permit_without_calls;
 
@@ -447,23 +425,21 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                      channel_args->args[i].key,
                      GRPC_ARG_HTTP2_MIN_SENT_PING_INTERVAL_WITHOUT_DATA_MS)) {
         t->ping_policy.min_sent_ping_interval_without_data =
-            gpr_time_from_millis(
-                grpc_channel_arg_get_integer(
-                    &channel_args->args[i],
-                    {g_default_min_sent_ping_interval_without_data_ms, 0,
-                     INT_MAX}),
-                GPR_TIMESPAN);
+            grpc_channel_arg_get_integer(
+                &channel_args->args[i],
+                grpc_integer_options{
+                    g_default_min_sent_ping_interval_without_data_ms, 0,
+                    INT_MAX});
       } else if (0 ==
                  strcmp(
                      channel_args->args[i].key,
                      GRPC_ARG_HTTP2_MIN_RECV_PING_INTERVAL_WITHOUT_DATA_MS)) {
         t->ping_policy.min_recv_ping_interval_without_data =
-            gpr_time_from_millis(
-                grpc_channel_arg_get_integer(
-                    &channel_args->args[i],
-                    {g_default_min_recv_ping_interval_without_data_ms, 0,
-                     INT_MAX}),
-                GPR_TIMESPAN);
+            grpc_channel_arg_get_integer(
+                &channel_args->args[i],
+                grpc_integer_options{
+                    g_default_min_recv_ping_interval_without_data_ms, 0,
+                    INT_MAX});
       } else if (0 == strcmp(channel_args->args[i].key,
                              GRPC_ARG_HTTP2_WRITE_BUFFER_SIZE)) {
         t->write_buffer_size = (uint32_t)grpc_channel_arg_get_integer(
@@ -476,22 +452,21 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                              GRPC_ARG_KEEPALIVE_TIME_MS)) {
         const int value = grpc_channel_arg_get_integer(
             &channel_args->args[i],
-            {t->is_client ? g_default_client_keepalive_time_ms
-                          : g_default_server_keepalive_time_ms,
-             1, INT_MAX});
-        t->keepalive_time = value == INT_MAX
-                                ? gpr_inf_future(GPR_TIMESPAN)
-                                : gpr_time_from_millis(value, GPR_TIMESPAN);
+            grpc_integer_options{t->is_client
+                                     ? g_default_client_keepalive_time_ms
+                                     : g_default_server_keepalive_time_ms,
+                                 1, INT_MAX});
+        t->keepalive_time = value == INT_MAX ? GRPC_MILLIS_INF_FUTURE : value;
       } else if (0 == strcmp(channel_args->args[i].key,
                              GRPC_ARG_KEEPALIVE_TIMEOUT_MS)) {
         const int value = grpc_channel_arg_get_integer(
             &channel_args->args[i],
-            {t->is_client ? g_default_client_keepalive_timeout_ms
-                          : g_default_server_keepalive_timeout_ms,
-             0, INT_MAX});
-        t->keepalive_timeout = value == INT_MAX
-                                   ? gpr_inf_future(GPR_TIMESPAN)
-                                   : gpr_time_from_millis(value, GPR_TIMESPAN);
+            grpc_integer_options{t->is_client
+                                     ? g_default_client_keepalive_timeout_ms
+                                     : g_default_server_keepalive_timeout_ms,
+                                 0, INT_MAX});
+        t->keepalive_timeout =
+            value == INT_MAX ? GRPC_MILLIS_INF_FUTURE : value;
       } else if (0 == strcmp(channel_args->args[i].key,
                              GRPC_ARG_KEEPALIVE_PERMIT_WITHOUT_CALLS)) {
         t->keepalive_permit_without_calls =
@@ -571,23 +546,27 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   t->ping_state.pings_before_data_required = 0;
   t->ping_state.is_delayed_ping_timer_set = false;
 
-  t->ping_recv_state.last_ping_recv_time = gpr_inf_past(GPR_CLOCK_MONOTONIC);
+  t->ping_recv_state.last_ping_recv_time = GRPC_MILLIS_INF_PAST;
   t->ping_recv_state.ping_strikes = 0;
 
   /* Start keepalive pings */
-  if (gpr_time_cmp(t->keepalive_time, gpr_inf_future(GPR_TIMESPAN)) != 0) {
+  if (t->keepalive_time != GRPC_MILLIS_INF_FUTURE) {
     t->keepalive_state = GRPC_CHTTP2_KEEPALIVE_STATE_WAITING;
     GRPC_CHTTP2_REF_TRANSPORT(t, "init keepalive ping");
-    grpc_timer_init(
-        exec_ctx, &t->keepalive_ping_timer,
-        gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), t->keepalive_time),
-        &t->init_keepalive_ping_locked, gpr_now(GPR_CLOCK_MONOTONIC));
+    grpc_timer_init(exec_ctx, &t->keepalive_ping_timer,
+                    grpc_exec_ctx_now(exec_ctx) + t->keepalive_time,
+                    &t->init_keepalive_ping_locked);
   } else {
     /* Use GRPC_CHTTP2_KEEPALIVE_STATE_DISABLED to indicate there are no
        inflight keeaplive timers */
     t->keepalive_state = GRPC_CHTTP2_KEEPALIVE_STATE_DISABLED;
   }
 
+  grpc_chttp2_act_on_flowctl_action(
+      exec_ctx,
+      grpc_chttp2_flowctl_get_action(exec_ctx, &t->flow_control, NULL), t,
+      NULL);
+
   grpc_chttp2_initiate_write(exec_ctx, t,
                              GRPC_CHTTP2_INITIATE_WRITE_INITIAL_WRITE);
   post_benign_reclaimer(exec_ctx, t);
@@ -698,7 +677,7 @@ static int init_stream(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
   grpc_chttp2_incoming_metadata_buffer_init(&s->metadata_buffer[1], arena);
   grpc_chttp2_data_parser_init(&s->data_parser);
   grpc_slice_buffer_init(&s->flow_controlled_buffer);
-  s->deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
+  s->deadline = GRPC_MILLIS_INF_FUTURE;
   GRPC_CLOSURE_INIT(&s->complete_fetch_locked, complete_fetch_locked, s,
                     grpc_schedule_on_exec_ctx);
   grpc_slice_buffer_init(&s->unprocessed_incoming_frames_buffer);
@@ -902,9 +881,6 @@ static void inc_initiate_write_reason(
     case GRPC_CHTTP2_INITIATE_WRITE_SEND_SETTINGS:
       GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_SEND_SETTINGS(exec_ctx);
       break;
-    case GRPC_CHTTP2_INITIATE_WRITE_BDP_ESTIMATOR_PING:
-      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_BDP_ESTIMATOR_PING(exec_ctx);
-      break;
     case GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_SETTING:
       GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_FLOW_CONTROL_UNSTALLED_BY_SETTING(
           exec_ctx);
@@ -1042,6 +1018,7 @@ static void write_action_begin_locked(grpc_exec_ctx *exec_ctx, void *gt,
                                                    write_action, t, scheduler),
                        GRPC_ERROR_NONE);
   } else {
+    GRPC_STATS_INC_HTTP2_SPURIOUS_WRITES_BEGUN(exec_ctx);
     set_write_state(exec_ctx, t, GRPC_CHTTP2_WRITE_STATE_IDLE,
                     "begin writing nothing");
     GRPC_CHTTP2_UNREF_TRANSPORT(exec_ctx, t, "writing");
@@ -1140,14 +1117,12 @@ void grpc_chttp2_add_incoming_goaway(grpc_exec_ctx *exec_ctx,
     gpr_log(GPR_ERROR,
             "Received a GOAWAY with error code ENHANCE_YOUR_CALM and debug "
             "data equal to \"too_many_pings\"");
-    double current_keepalive_time_ms =
-        gpr_timespec_to_micros(t->keepalive_time) / 1000;
+    double current_keepalive_time_ms = (double)t->keepalive_time;
     t->keepalive_time =
         current_keepalive_time_ms > INT_MAX / KEEPALIVE_TIME_BACKOFF_MULTIPLIER
-            ? gpr_inf_future(GPR_TIMESPAN)
-            : gpr_time_from_millis((int64_t)(current_keepalive_time_ms *
-                                             KEEPALIVE_TIME_BACKOFF_MULTIPLIER),
-                                   GPR_TIMESPAN);
+            ? GRPC_MILLIS_INF_FUTURE
+            : (grpc_millis)(current_keepalive_time_ms *
+                            KEEPALIVE_TIME_BACKOFF_MULTIPLIER);
   }
 
   /* lie: use transient failure from the transport to indicate goaway has been
@@ -1461,8 +1436,7 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
         t->settings[GRPC_PEER_SETTINGS]
                    [GRPC_CHTTP2_SETTINGS_MAX_HEADER_LIST_SIZE];
     if (t->is_client) {
-      s->deadline =
-          gpr_time_min(s->deadline, s->send_initial_metadata->deadline);
+      s->deadline = GPR_MIN(s->deadline, s->send_initial_metadata->deadline);
     }
     if (metadata_size > metadata_peer_limit) {
       grpc_chttp2_cancel_stream(
@@ -1646,8 +1620,8 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
             &t->flow_control, &s->flow_control, GRPC_HEADER_SIZE_IN_BYTES,
             already_received);
         grpc_chttp2_act_on_flowctl_action(
-            exec_ctx,
-            grpc_chttp2_flowctl_get_action(&t->flow_control, &s->flow_control),
+            exec_ctx, grpc_chttp2_flowctl_get_action(exec_ctx, &t->flow_control,
+                                                     &s->flow_control),
             t, s);
       }
     }
@@ -1680,16 +1654,14 @@ static void perform_stream_op(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
 
   if (!t->is_client) {
     if (op->send_initial_metadata) {
-      gpr_timespec deadline =
+      grpc_millis deadline =
           op->payload->send_initial_metadata.send_initial_metadata->deadline;
-      GPR_ASSERT(0 ==
-                 gpr_time_cmp(gpr_inf_future(deadline.clock_type), deadline));
+      GPR_ASSERT(deadline == GRPC_MILLIS_INF_FUTURE);
     }
     if (op->send_trailing_metadata) {
-      gpr_timespec deadline =
+      grpc_millis deadline =
           op->payload->send_trailing_metadata.send_trailing_metadata->deadline;
-      GPR_ASSERT(0 ==
-                 gpr_time_cmp(gpr_inf_future(deadline.clock_type), deadline));
+      GPR_ASSERT(deadline == GRPC_MILLIS_INF_FUTURE);
     }
   }
 
@@ -1713,28 +1685,21 @@ static void cancel_pings(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                          grpc_error *error) {
   /* callback remaining pings: they're not allowed to call into the transpot,
      and maybe they hold resources that need to be freed */
-  for (size_t i = 0; i < GRPC_CHTTP2_PING_TYPE_COUNT; i++) {
-    grpc_chttp2_ping_queue *pq = &t->ping_queues[i];
-    for (size_t j = 0; j < GRPC_CHTTP2_PCL_COUNT; j++) {
-      grpc_closure_list_fail_all(&pq->lists[j], GRPC_ERROR_REF(error));
-      GRPC_CLOSURE_LIST_SCHED(exec_ctx, &pq->lists[j]);
-    }
+  grpc_chttp2_ping_queue *pq = &t->ping_queue;
+  for (size_t j = 0; j < GRPC_CHTTP2_PCL_COUNT; j++) {
+    grpc_closure_list_fail_all(&pq->lists[j], GRPC_ERROR_REF(error));
+    GRPC_CLOSURE_LIST_SCHED(exec_ctx, &pq->lists[j]);
   }
   GRPC_ERROR_UNREF(error);
 }
 
-static void send_ping_locked(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
-    grpc_chttp2_ping_type ping_type, grpc_closure *on_initiate,
-    grpc_closure *on_ack,
-    grpc_chttp2_initiate_write_reason initiate_write_reason) {
-  grpc_chttp2_ping_queue *pq = &t->ping_queues[ping_type];
+static void send_ping_locked(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
+                             grpc_closure *on_initiate, grpc_closure *on_ack) {
+  grpc_chttp2_ping_queue *pq = &t->ping_queue;
   grpc_closure_list_append(&pq->lists[GRPC_CHTTP2_PCL_INITIATE], on_initiate,
                            GRPC_ERROR_NONE);
-  if (grpc_closure_list_append(&pq->lists[GRPC_CHTTP2_PCL_NEXT], on_ack,
-                               GRPC_ERROR_NONE)) {
-    grpc_chttp2_initiate_write(exec_ctx, t, initiate_write_reason);
-  }
+  grpc_closure_list_append(&pq->lists[GRPC_CHTTP2_PCL_NEXT], on_ack,
+                           GRPC_ERROR_NONE);
 }
 
 static void retry_initiate_ping_locked(grpc_exec_ctx *exec_ctx, void *tp,
@@ -1749,8 +1714,7 @@ static void retry_initiate_ping_locked(grpc_exec_ctx *exec_ctx, void *tp,
 
 void grpc_chttp2_ack_ping(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                           uint64_t id) {
-  grpc_chttp2_ping_queue *pq =
-      &t->ping_queues[id % GRPC_CHTTP2_PING_TYPE_COUNT];
+  grpc_chttp2_ping_queue *pq = &t->ping_queue;
   if (pq->inflight_id != id) {
     char *from = grpc_endpoint_get_peer(t->ep);
     gpr_log(GPR_DEBUG, "Unknown ping response from %s: %" PRIx64, from, id);
@@ -1769,8 +1733,8 @@ static void send_goaway(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   t->sent_goaway_state = GRPC_CHTTP2_GOAWAY_SEND_SCHEDULED;
   grpc_http2_error_code http_error;
   grpc_slice slice;
-  grpc_error_get_status(error, gpr_inf_future(GPR_CLOCK_MONOTONIC), NULL,
-                        &slice, &http_error);
+  grpc_error_get_status(exec_ctx, error, GRPC_MILLIS_INF_FUTURE, NULL, &slice,
+                        &http_error);
   grpc_chttp2_goaway_append(t->last_new_stream_id, (uint32_t)http_error,
                             grpc_slice_ref_internal(slice), &t->qbuf);
   grpc_chttp2_initiate_write(exec_ctx, t,
@@ -1780,7 +1744,7 @@ static void send_goaway(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
 
 void grpc_chttp2_add_ping_strike(grpc_exec_ctx *exec_ctx,
                                  grpc_chttp2_transport *t) {
-  gpr_log(GPR_DEBUG, "PING strike");
+  t->ping_recv_state.ping_strikes++;
   if (++t->ping_recv_state.ping_strikes > t->ping_policy.max_ping_strikes &&
       t->ping_policy.max_ping_strikes != 0) {
     send_goaway(exec_ctx, t,
@@ -1820,9 +1784,9 @@ static void perform_transport_op_locked(grpc_exec_ctx *exec_ctx,
   }
 
   if (op->send_ping) {
-    send_ping_locked(exec_ctx, t, GRPC_CHTTP2_PING_ON_NEXT_WRITE, NULL,
-                     op->send_ping,
-                     GRPC_CHTTP2_INITIATE_WRITE_APPLICATION_PING);
+    send_ping_locked(exec_ctx, t, NULL, op->send_ping);
+    grpc_chttp2_initiate_write(exec_ctx, t,
+                               GRPC_CHTTP2_INITIATE_WRITE_APPLICATION_PING);
   }
 
   if (op->on_connectivity_state_change != NULL) {
@@ -2069,7 +2033,8 @@ void grpc_chttp2_cancel_stream(grpc_exec_ctx *exec_ctx,
   if (!s->read_closed || !s->write_closed) {
     if (s->id != 0) {
       grpc_http2_error_code http_error;
-      grpc_error_get_status(due_to_error, s->deadline, NULL, NULL, &http_error);
+      grpc_error_get_status(exec_ctx, due_to_error, s->deadline, NULL, NULL,
+                            &http_error);
       grpc_slice_buffer_add(
           &t->qbuf, grpc_chttp2_rst_stream_create(s->id, (uint32_t)http_error,
                                                   &s->stats.outgoing));
@@ -2087,7 +2052,7 @@ void grpc_chttp2_fake_status(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                              grpc_chttp2_stream *s, grpc_error *error) {
   grpc_status_code status;
   grpc_slice slice;
-  grpc_error_get_status(error, s->deadline, &status, &slice, NULL);
+  grpc_error_get_status(exec_ctx, error, s->deadline, &status, &slice, NULL);
 
   if (status != GRPC_STATUS_OK) {
     s->seen_error = true;
@@ -2252,7 +2217,8 @@ static void close_from_api(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   uint32_t len = 0;
   grpc_status_code grpc_status;
   grpc_slice slice;
-  grpc_error_get_status(error, s->deadline, &grpc_status, &slice, NULL);
+  grpc_error_get_status(exec_ctx, error, s->deadline, &grpc_status, &slice,
+                        NULL);
 
   GPR_ASSERT(grpc_status >= 0 && (int)grpc_status < 100);
 
@@ -2469,10 +2435,8 @@ void grpc_chttp2_act_on_flowctl_action(grpc_exec_ctx *exec_ctx,
   if (action.need_ping) {
     GRPC_CHTTP2_REF_TRANSPORT(t, "bdp_ping");
     grpc_bdp_estimator_schedule_ping(&t->flow_control.bdp_estimator);
-    send_ping_locked(exec_ctx, t,
-                     GRPC_CHTTP2_PING_BEFORE_TRANSPORT_WINDOW_UPDATE,
-                     &t->start_bdp_ping_locked, &t->finish_bdp_ping_locked,
-                     GRPC_CHTTP2_INITIATE_WRITE_BDP_ESTIMATOR_PING);
+    send_ping_locked(exec_ctx, t, &t->start_bdp_ping_locked,
+                     &t->finish_bdp_ping_locked);
   }
 }
 
@@ -2580,7 +2544,8 @@ static void read_action_locked(grpc_exec_ctx *exec_ctx, void *tp,
     grpc_endpoint_read(exec_ctx, t->ep, &t->read_buffer,
                        &t->read_action_locked);
     grpc_chttp2_act_on_flowctl_action(
-        exec_ctx, grpc_chttp2_flowctl_get_bdp_action(&t->flow_control), t,
+        exec_ctx,
+        grpc_chttp2_flowctl_get_action(exec_ctx, &t->flow_control, NULL), t,
         NULL);
     GRPC_CHTTP2_UNREF_TRANSPORT(exec_ctx, t, "keep_reading");
   } else {
@@ -2613,7 +2578,7 @@ static void finish_bdp_ping_locked(grpc_exec_ctx *exec_ctx, void *tp,
   if (GRPC_TRACER_ON(grpc_http_trace)) {
     gpr_log(GPR_DEBUG, "%s: Complete BDP ping", t->peer_string);
   }
-  grpc_bdp_estimator_complete_ping(&t->flow_control.bdp_estimator);
+  grpc_bdp_estimator_complete_ping(exec_ctx, &t->flow_control.bdp_estimator);
 
   GRPC_CHTTP2_UNREF_TRANSPORT(exec_ctx, t, "bdp_ping");
 }
@@ -2687,24 +2652,22 @@ static void init_keepalive_ping_locked(grpc_exec_ctx *exec_ctx, void *arg,
         grpc_chttp2_stream_map_size(&t->stream_map) > 0) {
       t->keepalive_state = GRPC_CHTTP2_KEEPALIVE_STATE_PINGING;
       GRPC_CHTTP2_REF_TRANSPORT(t, "keepalive ping end");
-      send_ping_locked(exec_ctx, t, GRPC_CHTTP2_PING_ON_NEXT_WRITE,
-                       &t->start_keepalive_ping_locked,
-                       &t->finish_keepalive_ping_locked,
-                       GRPC_CHTTP2_INITIATE_WRITE_KEEPALIVE_PING);
+      send_ping_locked(exec_ctx, t, &t->start_keepalive_ping_locked,
+                       &t->finish_keepalive_ping_locked);
+      grpc_chttp2_initiate_write(exec_ctx, t,
+                                 GRPC_CHTTP2_INITIATE_WRITE_KEEPALIVE_PING);
     } else {
       GRPC_CHTTP2_REF_TRANSPORT(t, "init keepalive ping");
-      grpc_timer_init(
-          exec_ctx, &t->keepalive_ping_timer,
-          gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), t->keepalive_time),
-          &t->init_keepalive_ping_locked, gpr_now(GPR_CLOCK_MONOTONIC));
+      grpc_timer_init(exec_ctx, &t->keepalive_ping_timer,
+                      grpc_exec_ctx_now(exec_ctx) + t->keepalive_time,
+                      &t->init_keepalive_ping_locked);
     }
   } else if (error == GRPC_ERROR_CANCELLED) {
     /* The keepalive ping timer may be cancelled by bdp */
     GRPC_CHTTP2_REF_TRANSPORT(t, "init keepalive ping");
-    grpc_timer_init(
-        exec_ctx, &t->keepalive_ping_timer,
-        gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), t->keepalive_time),
-        &t->init_keepalive_ping_locked, gpr_now(GPR_CLOCK_MONOTONIC));
+    grpc_timer_init(exec_ctx, &t->keepalive_ping_timer,
+                    grpc_exec_ctx_now(exec_ctx) + t->keepalive_time,
+                    &t->init_keepalive_ping_locked);
   }
   GRPC_CHTTP2_UNREF_TRANSPORT(exec_ctx, t, "init keepalive ping");
 }
@@ -2713,10 +2676,9 @@ static void start_keepalive_ping_locked(grpc_exec_ctx *exec_ctx, void *arg,
                                         grpc_error *error) {
   grpc_chttp2_transport *t = (grpc_chttp2_transport *)arg;
   GRPC_CHTTP2_REF_TRANSPORT(t, "keepalive watchdog");
-  grpc_timer_init(
-      exec_ctx, &t->keepalive_watchdog_timer,
-      gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), t->keepalive_timeout),
-      &t->keepalive_watchdog_fired_locked, gpr_now(GPR_CLOCK_MONOTONIC));
+  grpc_timer_init(exec_ctx, &t->keepalive_watchdog_timer,
+                  grpc_exec_ctx_now(exec_ctx) + t->keepalive_time,
+                  &t->keepalive_watchdog_fired_locked);
 }
 
 static void finish_keepalive_ping_locked(grpc_exec_ctx *exec_ctx, void *arg,
@@ -2727,10 +2689,9 @@ static void finish_keepalive_ping_locked(grpc_exec_ctx *exec_ctx, void *arg,
       t->keepalive_state = GRPC_CHTTP2_KEEPALIVE_STATE_WAITING;
       grpc_timer_cancel(exec_ctx, &t->keepalive_watchdog_timer);
       GRPC_CHTTP2_REF_TRANSPORT(t, "init keepalive ping");
-      grpc_timer_init(
-          exec_ctx, &t->keepalive_ping_timer,
-          gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), t->keepalive_time),
-          &t->init_keepalive_ping_locked, gpr_now(GPR_CLOCK_MONOTONIC));
+      grpc_timer_init(exec_ctx, &t->keepalive_ping_timer,
+                      grpc_exec_ctx_now(exec_ctx) + t->keepalive_time,
+                      &t->init_keepalive_ping_locked);
     }
   }
   GRPC_CHTTP2_UNREF_TRANSPORT(exec_ctx, t, "keepalive ping end");
@@ -2830,9 +2791,9 @@ static void incoming_byte_stream_next_locked(grpc_exec_ctx *exec_ctx,
                                            bs->next_action.max_size_hint,
                                            cur_length);
     grpc_chttp2_act_on_flowctl_action(
-        exec_ctx,
-        grpc_chttp2_flowctl_get_action(&t->flow_control, &s->flow_control), t,
-        s);
+        exec_ctx, grpc_chttp2_flowctl_get_action(exec_ctx, &t->flow_control,
+                                                 &s->flow_control),
+        t, s);
   }
   GPR_ASSERT(s->unprocessed_incoming_frames_buffer.length == 0);
   if (s->frame_storage.length > 0) {
@@ -3180,8 +3141,6 @@ const char *grpc_chttp2_initiate_write_reason_string(
       return "TRANSPORT_FLOW_CONTROL";
     case GRPC_CHTTP2_INITIATE_WRITE_SEND_SETTINGS:
       return "SEND_SETTINGS";
-    case GRPC_CHTTP2_INITIATE_WRITE_BDP_ESTIMATOR_PING:
-      return "BDP_ESTIMATOR_PING";
     case GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_SETTING:
       return "FLOW_CONTROL_UNSTALLED_BY_SETTING";
     case GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_UPDATE:
diff --git a/src/core/ext/transport/chttp2/transport/flow_control.cc b/src/core/ext/transport/chttp2/transport/flow_control.cc
index 75eae1f9628..2428e2526d3 100644
--- a/src/core/ext/transport/chttp2/transport/flow_control.cc
+++ b/src/core/ext/transport/chttp2/transport/flow_control.cc
@@ -176,11 +176,9 @@ static void trace_action(grpc_chttp2_transport_flowctl* tfc,
 /* How many bytes of incoming flow control would we like to advertise */
 static uint32_t grpc_chttp2_target_announced_window(
     const grpc_chttp2_transport_flowctl* tfc) {
-  return (uint32_t)GPR_MIN(
-      (int64_t)((1u << 31) - 1),
-      tfc->announced_stream_total_over_incoming_window +
-          tfc->t->settings[GRPC_SENT_SETTINGS]
-                          [GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE]);
+  return (uint32_t)GPR_MIN((int64_t)((1u << 31) - 1),
+                           tfc->announced_stream_total_over_incoming_window +
+                               tfc->target_initial_window_size);
 }
 
 // we have sent data on the wire, we must track this in our bookkeeping for the
@@ -282,13 +280,14 @@ grpc_error* grpc_chttp2_flowctl_recv_data(grpc_chttp2_transport_flowctl* tfc,
 // Returns a non zero announce integer if we should send a transport window
 // update
 uint32_t grpc_chttp2_flowctl_maybe_send_transport_update(
-    grpc_chttp2_transport_flowctl* tfc) {
+    grpc_chttp2_transport_flowctl* tfc, bool writing_anyway) {
   PRETRACE(tfc, NULL);
   uint32_t target_announced_window = grpc_chttp2_target_announced_window(tfc);
   uint32_t threshold_to_send_transport_window_update =
       tfc->t->outbuf.count > 0 ? 3 * target_announced_window / 4
                                : target_announced_window / 2;
-  if (tfc->announced_window <= threshold_to_send_transport_window_update &&
+  if ((writing_anyway ||
+       tfc->announced_window <= threshold_to_send_transport_window_update) &&
       tfc->announced_window != target_announced_window) {
     uint32_t announce = (uint32_t)GPR_CLAMP(
         target_announced_window - tfc->announced_window, 0, UINT32_MAX);
@@ -393,15 +392,27 @@ static grpc_chttp2_flowctl_urgency delta_is_significant(
 
 // Takes in a target and uses the pid controller to return a stabilized
 // guess at the new bdp.
-static double get_pid_controller_guess(grpc_chttp2_transport_flowctl* tfc,
+static double get_pid_controller_guess(grpc_exec_ctx* exec_ctx,
+                                       grpc_chttp2_transport_flowctl* tfc,
                                        double target) {
-  double bdp_error = target - grpc_pid_controller_last(&tfc->pid_controller);
-  gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
-  gpr_timespec dt_timespec = gpr_time_sub(now, tfc->last_pid_update);
-  double dt = (double)dt_timespec.tv_sec + dt_timespec.tv_nsec * 1e-9;
-  if (dt > 0.1) {
-    dt = 0.1;
+  grpc_millis now = grpc_exec_ctx_now(exec_ctx);
+  if (!tfc->pid_controller_initialized) {
+    tfc->last_pid_update = now;
+    tfc->pid_controller_initialized = true;
+    grpc_pid_controller_args args;
+    memset(&args, 0, sizeof(args));
+    args.gain_p = 4;
+    args.gain_i = 8;
+    args.gain_d = 0;
+    args.initial_control_value = target;
+    args.min_control_value = -1;
+    args.max_control_value = 25;
+    args.integral_range = 10;
+    grpc_pid_controller_init(&tfc->pid_controller, args);
+    return pow(2, target);
   }
+  double bdp_error = target - grpc_pid_controller_last(&tfc->pid_controller);
+  double dt = (double)(now - tfc->last_pid_update) * 1e-3;
   double log2_bdp_guess =
       grpc_pid_controller_update(&tfc->pid_controller, bdp_error, dt);
   tfc->last_pid_update = now;
@@ -414,20 +425,25 @@ static double get_target_under_memory_pressure(
   // do not increase window under heavy memory pressure.
   double memory_pressure = grpc_resource_quota_get_memory_pressure(
       grpc_resource_user_quota(grpc_endpoint_get_resource_user(tfc->t->ep)));
-  if (memory_pressure > 0.8) {
-    target *= 1 - GPR_MIN(1, (memory_pressure - 0.8) / 0.1);
+  static const double kLowMemPressure = 0.1;
+  static const double kZeroTarget = 22;
+  static const double kHighMemPressure = 0.8;
+  static const double kMaxMemPressure = 0.9;
+  if (memory_pressure < kLowMemPressure && target < kZeroTarget) {
+    target = (target - kZeroTarget) * memory_pressure / kLowMemPressure +
+             kZeroTarget;
+  } else if (memory_pressure > kHighMemPressure) {
+    target *= 1 - GPR_MIN(1, (memory_pressure - kHighMemPressure) /
+                                 (kMaxMemPressure - kHighMemPressure));
   }
   return target;
 }
 
 grpc_chttp2_flowctl_action grpc_chttp2_flowctl_get_action(
-    grpc_chttp2_transport_flowctl* tfc, grpc_chttp2_stream_flowctl* sfc) {
+    grpc_exec_ctx* exec_ctx, grpc_chttp2_transport_flowctl* tfc,
+    grpc_chttp2_stream_flowctl* sfc) {
   grpc_chttp2_flowctl_action action;
   memset(&action, 0, sizeof(action));
-  uint32_t target_announced_window = grpc_chttp2_target_announced_window(tfc);
-  if (tfc->announced_window < target_announced_window / 2) {
-    action.send_transport_update = GRPC_CHTTP2_FLOWCTL_UPDATE_IMMEDIATELY;
-  }
   // TODO(ncteisen): tune this
   if (sfc != NULL && !sfc->s->read_closed) {
     uint32_t sent_init_window =
@@ -442,20 +458,12 @@ grpc_chttp2_flowctl_action grpc_chttp2_flowctl_get_action(
       action.send_stream_update = GRPC_CHTTP2_FLOWCTL_QUEUE_UPDATE;
     }
   }
-  TRACEACTION(tfc, action);
-  return action;
-}
-
-grpc_chttp2_flowctl_action grpc_chttp2_flowctl_get_bdp_action(
-    grpc_chttp2_transport_flowctl* tfc) {
-  grpc_chttp2_flowctl_action action;
-  memset(&action, 0, sizeof(action));
   if (tfc->enable_bdp_probe) {
-    action.need_ping = grpc_bdp_estimator_need_ping(&tfc->bdp_estimator);
+    action.need_ping =
+        grpc_bdp_estimator_need_ping(exec_ctx, &tfc->bdp_estimator);
 
     // get bdp estimate and update initial_window accordingly.
     int64_t estimate = -1;
-    int32_t bdp = -1;
     if (grpc_bdp_estimator_get_estimate(&tfc->bdp_estimator, &estimate)) {
       double target = 1 + log2((double)estimate);
 
@@ -466,17 +474,18 @@ grpc_chttp2_flowctl_action grpc_chttp2_flowctl_get_bdp_action(
 
       // run our target through the pid controller to stabilize change.
       // TODO(ncteisen): experiment with other controllers here.
-      double bdp_guess = get_pid_controller_guess(tfc, target);
+      double bdp_guess = get_pid_controller_guess(exec_ctx, tfc, target);
 
       // Though initial window 'could' drop to 0, we keep the floor at 128
-      bdp = GPR_MAX((int32_t)bdp_guess, 128);
+      tfc->target_initial_window_size =
+          (int32_t)GPR_CLAMP(bdp_guess, 128, INT32_MAX);
 
       grpc_chttp2_flowctl_urgency init_window_update_urgency =
-          delta_is_significant(tfc, bdp,
+          delta_is_significant(tfc, tfc->target_initial_window_size,
                                GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE);
       if (init_window_update_urgency != GRPC_CHTTP2_FLOWCTL_NO_ACTION_NEEDED) {
         action.send_setting_update = init_window_update_urgency;
-        action.initial_window_size = (uint32_t)bdp;
+        action.initial_window_size = (uint32_t)tfc->target_initial_window_size;
       }
     }
 
@@ -485,8 +494,9 @@ grpc_chttp2_flowctl_action grpc_chttp2_flowctl_get_bdp_action(
     if (grpc_bdp_estimator_get_bw(&tfc->bdp_estimator, &bw_dbl)) {
       // we target the max of BDP or bandwidth in microseconds.
       int32_t frame_size = (int32_t)GPR_CLAMP(
-          GPR_MAX((int32_t)GPR_CLAMP(bw_dbl, 0, INT_MAX) / 1000, bdp), 16384,
-          16777215);
+          GPR_MAX((int32_t)GPR_CLAMP(bw_dbl, 0, INT_MAX) / 1000,
+                  tfc->target_initial_window_size),
+          16384, 16777215);
       grpc_chttp2_flowctl_urgency frame_size_urgency = delta_is_significant(
           tfc, frame_size, GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE);
       if (frame_size_urgency != GRPC_CHTTP2_FLOWCTL_NO_ACTION_NEEDED) {
@@ -497,7 +507,10 @@ grpc_chttp2_flowctl_action grpc_chttp2_flowctl_get_bdp_action(
       }
     }
   }
-
+  uint32_t target_announced_window = grpc_chttp2_target_announced_window(tfc);
+  if (tfc->announced_window < target_announced_window / 2) {
+    action.send_transport_update = GRPC_CHTTP2_FLOWCTL_UPDATE_IMMEDIATELY;
+  }
   TRACEACTION(tfc, action);
   return action;
 }
diff --git a/src/core/ext/transport/chttp2/transport/frame_data.h b/src/core/ext/transport/chttp2/transport/frame_data.h
index 2df99ccf987..81ec5361a39 100644
--- a/src/core/ext/transport/chttp2/transport/frame_data.h
+++ b/src/core/ext/transport/chttp2/transport/frame_data.h
@@ -88,4 +88,4 @@ grpc_error *grpc_deframe_unprocessed_incoming_frames(
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_DATA_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_DATA_H */
diff --git a/src/core/ext/transport/chttp2/transport/frame_goaway.h b/src/core/ext/transport/chttp2/transport/frame_goaway.h
index ce6f18b35c3..7b3aa45f3f2 100644
--- a/src/core/ext/transport/chttp2/transport/frame_goaway.h
+++ b/src/core/ext/transport/chttp2/transport/frame_goaway.h
@@ -68,4 +68,4 @@ void grpc_chttp2_goaway_append(uint32_t last_stream_id, uint32_t error_code,
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_GOAWAY_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_GOAWAY_H */
diff --git a/src/core/ext/transport/chttp2/transport/frame_ping.cc b/src/core/ext/transport/chttp2/transport/frame_ping.cc
index d431d6b2dfa..1cfa883ee15 100644
--- a/src/core/ext/transport/chttp2/transport/frame_ping.cc
+++ b/src/core/ext/transport/chttp2/transport/frame_ping.cc
@@ -89,10 +89,10 @@ grpc_error *grpc_chttp2_ping_parser_parse(grpc_exec_ctx *exec_ctx, void *parser,
       grpc_chttp2_ack_ping(exec_ctx, t, p->opaque_8bytes);
     } else {
       if (!t->is_client) {
-        gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
-        gpr_timespec next_allowed_ping =
-            gpr_time_add(t->ping_recv_state.last_ping_recv_time,
-                         t->ping_policy.min_recv_ping_interval_without_data);
+        grpc_millis now = grpc_exec_ctx_now(exec_ctx);
+        grpc_millis next_allowed_ping =
+            t->ping_recv_state.last_ping_recv_time +
+            t->ping_policy.min_recv_ping_interval_without_data;
 
         if (t->keepalive_permit_without_calls == 0 &&
             grpc_chttp2_stream_map_size(&t->stream_map) == 0) {
@@ -100,11 +100,10 @@ grpc_error *grpc_chttp2_ping_parser_parse(grpc_exec_ctx *exec_ctx, void *parser,
              no less than two hours. When there is no outstanding streams, we
              restrict the number of PINGS equivalent to TCP Keep-Alive. */
           next_allowed_ping =
-              gpr_time_add(t->ping_recv_state.last_ping_recv_time,
-                           gpr_time_from_seconds(7200, GPR_TIMESPAN));
+              t->ping_recv_state.last_ping_recv_time + 7200 * GPR_MS_PER_SEC;
         }
 
-        if (gpr_time_cmp(next_allowed_ping, now) > 0) {
+        if (next_allowed_ping > now) {
           grpc_chttp2_add_ping_strike(exec_ctx, t);
         }
 
diff --git a/src/core/ext/transport/chttp2/transport/frame_ping.h b/src/core/ext/transport/chttp2/transport/frame_ping.h
index 91f16f050fb..ffc2f0cf2ff 100644
--- a/src/core/ext/transport/chttp2/transport/frame_ping.h
+++ b/src/core/ext/transport/chttp2/transport/frame_ping.h
@@ -49,4 +49,4 @@ void grpc_set_disable_ping_ack(bool disable_ping_ack);
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_PING_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_PING_H */
diff --git a/src/core/ext/transport/chttp2/transport/frame_rst_stream.h b/src/core/ext/transport/chttp2/transport/frame_rst_stream.h
index bdca064a917..102ffdb3f36 100644
--- a/src/core/ext/transport/chttp2/transport/frame_rst_stream.h
+++ b/src/core/ext/transport/chttp2/transport/frame_rst_stream.h
@@ -48,4 +48,4 @@ grpc_error *grpc_chttp2_rst_stream_parser_parse(grpc_exec_ctx *exec_ctx,
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_RST_STREAM_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_RST_STREAM_H */
diff --git a/src/core/ext/transport/chttp2/transport/frame_settings.h b/src/core/ext/transport/chttp2/transport/frame_settings.h
index f0793f0e737..3364da15207 100644
--- a/src/core/ext/transport/chttp2/transport/frame_settings.h
+++ b/src/core/ext/transport/chttp2/transport/frame_settings.h
@@ -66,4 +66,4 @@ grpc_error *grpc_chttp2_settings_parser_parse(grpc_exec_ctx *exec_ctx,
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_SETTINGS_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_SETTINGS_H */
diff --git a/src/core/ext/transport/chttp2/transport/frame_window_update.h b/src/core/ext/transport/chttp2/transport/frame_window_update.h
index 29cf0cc740a..400f9f53989 100644
--- a/src/core/ext/transport/chttp2/transport/frame_window_update.h
+++ b/src/core/ext/transport/chttp2/transport/frame_window_update.h
@@ -47,4 +47,4 @@ grpc_error *grpc_chttp2_window_update_parser_parse(
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_WINDOW_UPDATE_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_WINDOW_UPDATE_H */
diff --git a/src/core/ext/transport/chttp2/transport/hpack_encoder.cc b/src/core/ext/transport/chttp2/transport/hpack_encoder.cc
index 5f1a2708a56..17b8c4ab85e 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_encoder.cc
+++ b/src/core/ext/transport/chttp2/transport/hpack_encoder.cc
@@ -535,12 +535,12 @@ static void hpack_enc(grpc_exec_ctx *exec_ctx, grpc_chttp2_hpack_compressor *c,
 #define TIMEOUT_KEY "grpc-timeout"
 
 static void deadline_enc(grpc_exec_ctx *exec_ctx,
-                         grpc_chttp2_hpack_compressor *c, gpr_timespec deadline,
+                         grpc_chttp2_hpack_compressor *c, grpc_millis deadline,
                          framer_state *st) {
   char timeout_str[GRPC_HTTP2_TIMEOUT_ENCODE_MIN_BUFSIZE];
   grpc_mdelem mdelem;
-  grpc_http2_encode_timeout(
-      gpr_time_sub(deadline, gpr_now(deadline.clock_type)), timeout_str);
+  grpc_http2_encode_timeout(deadline - grpc_exec_ctx_now(exec_ctx),
+                            timeout_str);
   mdelem = grpc_mdelem_from_slices(exec_ctx, GRPC_MDSTR_GRPC_TIMEOUT,
                                    grpc_slice_from_copied_string(timeout_str));
   hpack_enc(exec_ctx, c, mdelem, st);
@@ -660,8 +660,8 @@ void grpc_chttp2_encode_header(grpc_exec_ctx *exec_ctx,
   for (grpc_linked_mdelem *l = metadata->list.head; l; l = l->next) {
     hpack_enc(exec_ctx, c, l->md, &st);
   }
-  gpr_timespec deadline = metadata->deadline;
-  if (gpr_time_cmp(deadline, gpr_inf_future(deadline.clock_type)) != 0) {
+  grpc_millis deadline = metadata->deadline;
+  if (deadline != GRPC_MILLIS_INF_FUTURE) {
     deadline_enc(exec_ctx, c, deadline, &st);
   }
 
diff --git a/src/core/ext/transport/chttp2/transport/hpack_encoder.h b/src/core/ext/transport/chttp2/transport/hpack_encoder.h
index dc28b5566a6..16316b63f7c 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_encoder.h
+++ b/src/core/ext/transport/chttp2/transport/hpack_encoder.h
@@ -99,4 +99,4 @@ void grpc_chttp2_encode_header(grpc_exec_ctx *exec_ctx,
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HPACK_ENCODER_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HPACK_ENCODER_H */
diff --git a/src/core/ext/transport/chttp2/transport/hpack_parser.h b/src/core/ext/transport/chttp2/transport/hpack_parser.h
index 6c36ebdf8d1..52014175a06 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_parser.h
+++ b/src/core/ext/transport/chttp2/transport/hpack_parser.h
@@ -119,4 +119,4 @@ grpc_error *grpc_chttp2_header_parser_parse(grpc_exec_ctx *exec_ctx,
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HPACK_PARSER_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HPACK_PARSER_H */
diff --git a/src/core/ext/transport/chttp2/transport/http2_settings.h b/src/core/ext/transport/chttp2/transport/http2_settings.h
index 01e80b8d014..0f76106dceb 100644
--- a/src/core/ext/transport/chttp2/transport/http2_settings.h
+++ b/src/core/ext/transport/chttp2/transport/http2_settings.h
@@ -64,4 +64,4 @@ extern const grpc_chttp2_setting_parameters
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HTTP2_SETTINGS_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HTTP2_SETTINGS_H */
diff --git a/src/core/ext/transport/chttp2/transport/incoming_metadata.cc b/src/core/ext/transport/chttp2/transport/incoming_metadata.cc
index ba680a89db1..187ce0ea874 100644
--- a/src/core/ext/transport/chttp2/transport/incoming_metadata.cc
+++ b/src/core/ext/transport/chttp2/transport/incoming_metadata.cc
@@ -29,7 +29,7 @@ void grpc_chttp2_incoming_metadata_buffer_init(
     grpc_chttp2_incoming_metadata_buffer *buffer, gpr_arena *arena) {
   buffer->arena = arena;
   grpc_metadata_batch_init(&buffer->batch);
-  buffer->batch.deadline = gpr_inf_future(GPR_CLOCK_REALTIME);
+  buffer->batch.deadline = GRPC_MILLIS_INF_FUTURE;
 }
 
 void grpc_chttp2_incoming_metadata_buffer_destroy(
@@ -62,7 +62,7 @@ grpc_error *grpc_chttp2_incoming_metadata_buffer_replace_or_add(
 }
 
 void grpc_chttp2_incoming_metadata_buffer_set_deadline(
-    grpc_chttp2_incoming_metadata_buffer *buffer, gpr_timespec deadline) {
+    grpc_chttp2_incoming_metadata_buffer *buffer, grpc_millis deadline) {
   buffer->batch.deadline = deadline;
 }
 
diff --git a/src/core/ext/transport/chttp2/transport/incoming_metadata.h b/src/core/ext/transport/chttp2/transport/incoming_metadata.h
index 9ffcabd0b93..a0e01f2c4d2 100644
--- a/src/core/ext/transport/chttp2/transport/incoming_metadata.h
+++ b/src/core/ext/transport/chttp2/transport/incoming_metadata.h
@@ -47,10 +47,10 @@ grpc_error *grpc_chttp2_incoming_metadata_buffer_replace_or_add(
     grpc_exec_ctx *exec_ctx, grpc_chttp2_incoming_metadata_buffer *buffer,
     grpc_mdelem elem) GRPC_MUST_USE_RESULT;
 void grpc_chttp2_incoming_metadata_buffer_set_deadline(
-    grpc_chttp2_incoming_metadata_buffer *buffer, gpr_timespec deadline);
+    grpc_chttp2_incoming_metadata_buffer *buffer, grpc_millis deadline);
 
 #ifdef __cplusplus
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_INCOMING_METADATA_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_INCOMING_METADATA_H */
diff --git a/src/core/ext/transport/chttp2/transport/internal.h b/src/core/ext/transport/chttp2/transport/internal.h
index 96af18f1d18..5d27bb8d673 100644
--- a/src/core/ext/transport/chttp2/transport/internal.h
+++ b/src/core/ext/transport/chttp2/transport/internal.h
@@ -65,12 +65,6 @@ typedef enum {
   GRPC_CHTTP2_WRITE_STATE_WRITING_WITH_MORE,
 } grpc_chttp2_write_state;
 
-typedef enum {
-  GRPC_CHTTP2_PING_ON_NEXT_WRITE = 0,
-  GRPC_CHTTP2_PING_BEFORE_TRANSPORT_WINDOW_UPDATE,
-  GRPC_CHTTP2_PING_TYPE_COUNT /* must be last */
-} grpc_chttp2_ping_type;
-
 typedef enum {
   GRPC_CHTTP2_OPTIMIZE_FOR_LATENCY,
   GRPC_CHTTP2_OPTIMIZE_FOR_THROUGHPUT,
@@ -97,7 +91,6 @@ typedef enum {
   GRPC_CHTTP2_INITIATE_WRITE_STREAM_FLOW_CONTROL,
   GRPC_CHTTP2_INITIATE_WRITE_TRANSPORT_FLOW_CONTROL,
   GRPC_CHTTP2_INITIATE_WRITE_SEND_SETTINGS,
-  GRPC_CHTTP2_INITIATE_WRITE_BDP_ESTIMATOR_PING,
   GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_SETTING,
   GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_UPDATE,
   GRPC_CHTTP2_INITIATE_WRITE_APPLICATION_PING,
@@ -118,19 +111,19 @@ typedef struct {
 typedef struct {
   int max_pings_without_data;
   int max_ping_strikes;
-  gpr_timespec min_sent_ping_interval_without_data;
-  gpr_timespec min_recv_ping_interval_without_data;
+  grpc_millis min_sent_ping_interval_without_data;
+  grpc_millis min_recv_ping_interval_without_data;
 } grpc_chttp2_repeated_ping_policy;
 
 typedef struct {
-  gpr_timespec last_ping_sent_time;
+  grpc_millis last_ping_sent_time;
   int pings_before_data_required;
   grpc_timer delayed_ping_timer;
   bool is_delayed_ping_timer_set;
 } grpc_chttp2_repeated_ping_state;
 
 typedef struct {
-  gpr_timespec last_ping_recv_time;
+  grpc_millis last_ping_recv_time;
   int ping_strikes;
 } grpc_chttp2_server_ping_recv_state;
 
@@ -269,6 +262,8 @@ typedef struct {
    * to send WINDOW_UPDATE frames. */
   int64_t announced_window;
 
+  int32_t target_initial_window_size;
+
   /** should we probe bdp? */
   bool enable_bdp_probe;
 
@@ -276,8 +271,9 @@ typedef struct {
   grpc_bdp_estimator bdp_estimator;
 
   /* pid controller */
+  bool pid_controller_initialized;
   grpc_pid_controller pid_controller;
-  gpr_timespec last_pid_update;
+  grpc_millis last_pid_update;
 
   // pointer back to transport for tracing
   const grpc_chttp2_transport *t;
@@ -374,7 +370,7 @@ struct grpc_chttp2_transport {
   uint32_t last_new_stream_id;
 
   /** ping queues for various ping insertion points */
-  grpc_chttp2_ping_queue ping_queues[GRPC_CHTTP2_PING_TYPE_COUNT];
+  grpc_chttp2_ping_queue ping_queue;
   grpc_chttp2_repeated_ping_policy ping_policy;
   grpc_chttp2_repeated_ping_state ping_state;
   uint64_t ping_ctr; /* unique id for pings */
@@ -459,9 +455,9 @@ struct grpc_chttp2_transport {
   /** watchdog to kill the transport when waiting for the keepalive ping */
   grpc_timer keepalive_watchdog_timer;
   /** time duration in between pings */
-  gpr_timespec keepalive_time;
+  grpc_millis keepalive_time;
   /** grace period for a ping to complete before watchdog kicks in */
-  gpr_timespec keepalive_timeout;
+  grpc_millis keepalive_timeout;
   /** if keepalive pings are allowed when there's no outstanding streams */
   bool keepalive_permit_without_calls;
   /** keep-alive state machine state */
@@ -570,7 +566,7 @@ struct grpc_chttp2_stream {
   grpc_error *byte_stream_error; /* protected by t combiner */
   bool received_last_frame;      /* protected by t combiner */
 
-  gpr_timespec deadline;
+  grpc_millis deadline;
 
   /** saw some stream level error */
   grpc_error *forced_close_error;
@@ -661,8 +657,8 @@ bool grpc_chttp2_list_add_writable_stream(grpc_chttp2_transport *t,
     returns non-zero if there was a stream available */
 bool grpc_chttp2_list_pop_writable_stream(grpc_chttp2_transport *t,
                                           grpc_chttp2_stream **s);
-bool grpc_chttp2_list_remove_writable_stream(
-    grpc_chttp2_transport *t, grpc_chttp2_stream *s) GRPC_MUST_USE_RESULT;
+bool grpc_chttp2_list_remove_writable_stream(grpc_chttp2_transport *t,
+                                             grpc_chttp2_stream *s);
 
 bool grpc_chttp2_list_add_writing_stream(grpc_chttp2_transport *t,
                                          grpc_chttp2_stream *s);
@@ -711,7 +707,7 @@ grpc_error *grpc_chttp2_flowctl_recv_data(grpc_chttp2_transport_flowctl *tfc,
 // returns an announce if we should send a transport update to our peer,
 // else returns zero
 uint32_t grpc_chttp2_flowctl_maybe_send_transport_update(
-    grpc_chttp2_transport_flowctl *tfc);
+    grpc_chttp2_transport_flowctl *tfc, bool writing_anyway);
 
 // returns an announce if we should send a stream update to our peer, else
 // returns zero
@@ -758,10 +754,8 @@ typedef struct {
 // Reads the flow control data and returns and actionable struct that will tell
 // chttp2 exactly what it needs to do
 grpc_chttp2_flowctl_action grpc_chttp2_flowctl_get_action(
-    grpc_chttp2_transport_flowctl *tfc, grpc_chttp2_stream_flowctl *sfc);
-
-grpc_chttp2_flowctl_action grpc_chttp2_flowctl_get_bdp_action(
-    grpc_chttp2_transport_flowctl *tfc);
+    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_flowctl *tfc,
+    grpc_chttp2_stream_flowctl *sfc);
 
 // Takes in a flow control action and performs all the needed operations.
 void grpc_chttp2_act_on_flowctl_action(grpc_exec_ctx *exec_ctx,
diff --git a/src/core/ext/transport/chttp2/transport/parsing.cc b/src/core/ext/transport/chttp2/transport/parsing.cc
index 3db1ad41231..78886b497a7 100644
--- a/src/core/ext/transport/chttp2/transport/parsing.cc
+++ b/src/core/ext/transport/chttp2/transport/parsing.cc
@@ -359,8 +359,9 @@ static grpc_error *init_data_frame_parser(grpc_exec_ctx *exec_ctx,
                                       s == NULL ? NULL : &s->flow_control,
                                       t->incoming_frame_size);
   grpc_chttp2_act_on_flowctl_action(
-      exec_ctx, grpc_chttp2_flowctl_get_action(
-                    &t->flow_control, s == NULL ? NULL : &s->flow_control),
+      exec_ctx,
+      grpc_chttp2_flowctl_get_action(exec_ctx, &t->flow_control,
+                                     s == NULL ? NULL : &s->flow_control),
       t, s);
   if (err != GRPC_ERROR_NONE) {
     goto error_handler;
@@ -385,7 +386,7 @@ error_handler:
     t->parser_data = &s->data_parser;
     t->ping_state.pings_before_data_required =
         t->ping_policy.max_pings_without_data;
-    t->ping_state.last_ping_sent_time = gpr_inf_past(GPR_CLOCK_MONOTONIC);
+    t->ping_state.last_ping_sent_time = GRPC_MILLIS_INF_PAST;
     return GRPC_ERROR_NONE;
   } else if (grpc_error_get_int(err, GRPC_ERROR_INT_STREAM_ID, NULL)) {
     /* handle stream errors by closing the stream */
@@ -430,26 +431,27 @@ static void on_initial_header(grpc_exec_ctx *exec_ctx, void *tp,
   }
 
   if (grpc_slice_eq(GRPC_MDKEY(md), GRPC_MDSTR_GRPC_TIMEOUT)) {
-    gpr_timespec *cached_timeout =
-        (gpr_timespec *)grpc_mdelem_get_user_data(md, free_timeout);
-    gpr_timespec timeout;
+    grpc_millis *cached_timeout =
+        static_cast<grpc_millis *>(grpc_mdelem_get_user_data(md, free_timeout));
+    grpc_millis timeout;
     if (cached_timeout == NULL) {
       /* not already parsed: parse it now, and store the result away */
-      cached_timeout = (gpr_timespec *)gpr_malloc(sizeof(gpr_timespec));
+      cached_timeout = (grpc_millis *)gpr_malloc(sizeof(grpc_millis));
       if (!grpc_http2_decode_timeout(GRPC_MDVALUE(md), cached_timeout)) {
         char *val = grpc_slice_to_c_string(GRPC_MDVALUE(md));
         gpr_log(GPR_ERROR, "Ignoring bad timeout value '%s'", val);
         gpr_free(val);
-        *cached_timeout = gpr_inf_future(GPR_TIMESPAN);
+        *cached_timeout = GRPC_MILLIS_INF_FUTURE;
       }
       timeout = *cached_timeout;
       grpc_mdelem_set_user_data(md, free_timeout, cached_timeout);
     } else {
       timeout = *cached_timeout;
     }
-    grpc_chttp2_incoming_metadata_buffer_set_deadline(
-        &s->metadata_buffer[0],
-        gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), timeout));
+    if (timeout != GRPC_MILLIS_INF_FUTURE) {
+      grpc_chttp2_incoming_metadata_buffer_set_deadline(
+          &s->metadata_buffer[0], grpc_exec_ctx_now(exec_ctx) + timeout);
+    }
     GRPC_MDELEM_UNREF(exec_ctx, md);
   } else {
     const size_t new_size = s->metadata_buffer[0].size + GRPC_MDELEM_LENGTH(md);
@@ -564,7 +566,7 @@ static grpc_error *init_header_frame_parser(grpc_exec_ctx *exec_ctx,
 
   t->ping_state.pings_before_data_required =
       t->ping_policy.max_pings_without_data;
-  t->ping_state.last_ping_sent_time = gpr_inf_past(GPR_CLOCK_MONOTONIC);
+  t->ping_state.last_ping_sent_time = GRPC_MILLIS_INF_PAST;
 
   /* could be a new grpc_chttp2_stream or an existing grpc_chttp2_stream */
   s = grpc_chttp2_parsing_lookup_stream(t, t->incoming_stream_id);
diff --git a/src/core/ext/transport/chttp2/transport/stream_map.h b/src/core/ext/transport/chttp2/transport/stream_map.h
index 364d37c33af..7ab6a4f5ed0 100644
--- a/src/core/ext/transport/chttp2/transport/stream_map.h
+++ b/src/core/ext/transport/chttp2/transport/stream_map.h
@@ -73,4 +73,4 @@ void grpc_chttp2_stream_map_for_each(grpc_chttp2_stream_map *map,
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_STREAM_MAP_H */
\ No newline at end of file
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_STREAM_MAP_H */
diff --git a/src/core/ext/transport/chttp2/transport/writing.cc b/src/core/ext/transport/chttp2/transport/writing.cc
index ba3d55abb3c..25c1a5ef056 100644
--- a/src/core/ext/transport/chttp2/transport/writing.cc
+++ b/src/core/ext/transport/chttp2/transport/writing.cc
@@ -42,18 +42,9 @@ static void finish_write_cb(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   t->write_cb_pool = cb;
 }
 
-static void collapse_pings_from_into(grpc_chttp2_transport *t,
-                                     grpc_chttp2_ping_type ping_type,
-                                     grpc_chttp2_ping_queue *pq) {
-  for (size_t i = 0; i < GRPC_CHTTP2_PCL_COUNT; i++) {
-    grpc_closure_list_move(&t->ping_queues[ping_type].lists[i], &pq->lists[i]);
-  }
-}
-
 static void maybe_initiate_ping(grpc_exec_ctx *exec_ctx,
-                                grpc_chttp2_transport *t,
-                                grpc_chttp2_ping_type ping_type) {
-  grpc_chttp2_ping_queue *pq = &t->ping_queues[ping_type];
+                                grpc_chttp2_transport *t) {
+  grpc_chttp2_ping_queue *pq = &t->ping_queue;
   if (grpc_closure_list_empty(pq->lists[GRPC_CHTTP2_PCL_NEXT])) {
     /* no ping needed: wait */
     return;
@@ -62,7 +53,8 @@ static void maybe_initiate_ping(grpc_exec_ctx *exec_ctx,
     /* ping already in-flight: wait */
     if (GRPC_TRACER_ON(grpc_http_trace) ||
         GRPC_TRACER_ON(grpc_bdp_estimator_trace)) {
-      gpr_log(GPR_DEBUG, "Ping delayed [%p]: already pinging", t->peer_string);
+      gpr_log(GPR_DEBUG, "%s: Ping delayed [%p]: already pinging",
+              t->is_client ? "CLIENT" : "SERVER", t->peer_string);
     }
     return;
   }
@@ -71,51 +63,38 @@ static void maybe_initiate_ping(grpc_exec_ctx *exec_ctx,
     /* need to receive something of substance before sending a ping again */
     if (GRPC_TRACER_ON(grpc_http_trace) ||
         GRPC_TRACER_ON(grpc_bdp_estimator_trace)) {
-      gpr_log(GPR_DEBUG, "Ping delayed [%p]: too many recent pings: %d/%d",
-              t->peer_string, t->ping_state.pings_before_data_required,
+      gpr_log(GPR_DEBUG, "%s: Ping delayed [%p]: too many recent pings: %d/%d",
+              t->is_client ? "CLIENT" : "SERVER", t->peer_string,
+              t->ping_state.pings_before_data_required,
               t->ping_policy.max_pings_without_data);
     }
     return;
   }
-  gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
-  gpr_timespec next_allowed_ping =
-      gpr_time_add(t->ping_state.last_ping_sent_time,
-                   t->ping_policy.min_sent_ping_interval_without_data);
+  grpc_millis now = grpc_exec_ctx_now(exec_ctx);
+  grpc_millis next_allowed_ping =
+      t->ping_state.last_ping_sent_time +
+      t->ping_policy.min_sent_ping_interval_without_data;
   if (t->keepalive_permit_without_calls == 0 &&
       grpc_chttp2_stream_map_size(&t->stream_map) == 0) {
-    next_allowed_ping = gpr_time_add(t->ping_recv_state.last_ping_recv_time,
-                                     gpr_time_from_seconds(7200, GPR_TIMESPAN));
+    next_allowed_ping =
+        t->ping_recv_state.last_ping_recv_time + 7200 * GPR_MS_PER_SEC;
   }
-  /* gpr_log(GPR_DEBUG, "next_allowed_ping:%d.%09d now:%d.%09d",
-          (int)next_allowed_ping.tv_sec, (int)next_allowed_ping.tv_nsec,
-          (int)now.tv_sec, (int)now.tv_nsec); */
-  if (gpr_time_cmp(next_allowed_ping, now) > 0) {
+  if (next_allowed_ping > now) {
     /* not enough elapsed time between successive pings */
     if (GRPC_TRACER_ON(grpc_http_trace) ||
         GRPC_TRACER_ON(grpc_bdp_estimator_trace)) {
       gpr_log(GPR_DEBUG,
-              "Ping delayed [%p]: not enough time elapsed since last ping",
-              t->peer_string);
+              "%s: Ping delayed [%p]: not enough time elapsed since last ping",
+              t->is_client ? "CLIENT" : "SERVER", t->peer_string);
     }
     if (!t->ping_state.is_delayed_ping_timer_set) {
       t->ping_state.is_delayed_ping_timer_set = true;
       grpc_timer_init(exec_ctx, &t->ping_state.delayed_ping_timer,
-                      next_allowed_ping, &t->retry_initiate_ping_locked,
-                      gpr_now(GPR_CLOCK_MONOTONIC));
+                      next_allowed_ping, &t->retry_initiate_ping_locked);
     }
     return;
   }
-  /* coalesce equivalent pings into this one */
-  switch (ping_type) {
-    case GRPC_CHTTP2_PING_BEFORE_TRANSPORT_WINDOW_UPDATE:
-      collapse_pings_from_into(t, GRPC_CHTTP2_PING_ON_NEXT_WRITE, pq);
-      break;
-    case GRPC_CHTTP2_PING_ON_NEXT_WRITE:
-      break;
-    case GRPC_CHTTP2_PING_TYPE_COUNT:
-      GPR_UNREACHABLE_CODE(break);
-  }
-  pq->inflight_id = t->ping_ctr * GRPC_CHTTP2_PING_TYPE_COUNT + ping_type;
+  pq->inflight_id = t->ping_ctr;
   t->ping_ctr++;
   GRPC_CLOSURE_LIST_SCHED(exec_ctx, &pq->lists[GRPC_CHTTP2_PCL_INITIATE]);
   grpc_closure_list_move(&pq->lists[GRPC_CHTTP2_PCL_NEXT],
@@ -126,7 +105,8 @@ static void maybe_initiate_ping(grpc_exec_ctx *exec_ctx,
   t->ping_state.last_ping_sent_time = now;
   if (GRPC_TRACER_ON(grpc_http_trace) ||
       GRPC_TRACER_ON(grpc_bdp_estimator_trace)) {
-    gpr_log(GPR_DEBUG, "Ping sent [%p]: %d/%d", t->peer_string,
+    gpr_log(GPR_DEBUG, "%s: Ping sent [%p]: %d/%d",
+            t->is_client ? "CLIENT" : "SERVER", t->peer_string,
             t->ping_state.pings_before_data_required,
             t->ping_policy.max_pings_without_data);
   }
@@ -156,6 +136,25 @@ static bool update_list(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   return sched_any;
 }
 
+static void report_stall(grpc_chttp2_transport *t, grpc_chttp2_stream *s,
+                         const char *staller) {
+  gpr_log(
+      GPR_DEBUG,
+      "%s:%p stream %d stalled by %s [fc:pending=%" PRIdPTR ":flowed=%" PRId64
+      ":peer_initwin=%d:t_win=%" PRId64 ":s_win=%d:s_delta=%" PRId64 "]",
+      t->peer_string, t, s->id, staller, s->flow_controlled_buffer.length,
+      s->flow_controlled_bytes_flowed,
+      t->settings[GRPC_ACKED_SETTINGS]
+                 [GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE],
+      t->flow_control.remote_window,
+      (uint32_t)GPR_MAX(
+          0,
+          s->flow_control.remote_window_delta +
+              (int64_t)t->settings[GRPC_PEER_SETTINGS]
+                                  [GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE]),
+      s->flow_control.remote_window_delta);
+}
+
 static bool stream_ref_if_not_destroyed(gpr_refcount *r) {
   gpr_atm count;
   do {
@@ -175,342 +174,451 @@ static bool is_default_initial_metadata(grpc_metadata_batch *initial_metadata) {
   return initial_metadata->list.default_count == initial_metadata->list.count;
 }
 
-grpc_chttp2_begin_write_result grpc_chttp2_begin_write(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t) {
-  grpc_chttp2_stream *s;
+namespace {
+class StreamWriteContext;
 
-  /* stats histogram counters: we increment these throughout this function,
-     and at the end publish to the central stats histograms */
-  int flow_control_writes = 0;
-  int initial_metadata_writes = 0;
-  int trailing_metadata_writes = 0;
-  int message_writes = 0;
+class WriteContext {
+ public:
+  WriteContext(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t) : t_(t) {
+    GRPC_STATS_INC_HTTP2_WRITES_BEGUN(exec_ctx);
+    GPR_TIMER_BEGIN("grpc_chttp2_begin_write", 0);
+  }
 
-  GRPC_STATS_INC_HTTP2_WRITES_BEGUN(exec_ctx);
+  // TODO(ctiller): make this the destructor
+  void FlushStats(grpc_exec_ctx *exec_ctx) {
+    GRPC_STATS_INC_HTTP2_SEND_INITIAL_METADATA_PER_WRITE(
+        exec_ctx, initial_metadata_writes_);
+    GRPC_STATS_INC_HTTP2_SEND_MESSAGE_PER_WRITE(exec_ctx, message_writes_);
+    GRPC_STATS_INC_HTTP2_SEND_TRAILING_METADATA_PER_WRITE(
+        exec_ctx, trailing_metadata_writes_);
+    GRPC_STATS_INC_HTTP2_SEND_FLOWCTL_PER_WRITE(exec_ctx, flow_control_writes_);
+  }
+
+  void FlushSettings(grpc_exec_ctx *exec_ctx) {
+    if (t_->dirtied_local_settings && !t_->sent_local_settings) {
+      grpc_slice_buffer_add(
+          &t_->outbuf, grpc_chttp2_settings_create(
+                           t_->settings[GRPC_SENT_SETTINGS],
+                           t_->settings[GRPC_LOCAL_SETTINGS],
+                           t_->force_send_settings, GRPC_CHTTP2_NUM_SETTINGS));
+      t_->force_send_settings = false;
+      t_->dirtied_local_settings = false;
+      t_->sent_local_settings = true;
+      GRPC_STATS_INC_HTTP2_SETTINGS_WRITES(exec_ctx);
+    }
+  }
 
-  GPR_TIMER_BEGIN("grpc_chttp2_begin_write", 0);
+  void FlushQueuedBuffers(grpc_exec_ctx *exec_ctx) {
+    /* simple writes are queued to qbuf, and flushed here */
+    grpc_slice_buffer_move_into(&t_->qbuf, &t_->outbuf);
+    GPR_ASSERT(t_->qbuf.count == 0);
+  }
 
-  if (t->dirtied_local_settings && !t->sent_local_settings) {
-    grpc_slice_buffer_add(
-        &t->outbuf,
-        grpc_chttp2_settings_create(
-            t->settings[GRPC_SENT_SETTINGS], t->settings[GRPC_LOCAL_SETTINGS],
-            t->force_send_settings, GRPC_CHTTP2_NUM_SETTINGS));
-    t->force_send_settings = 0;
-    t->dirtied_local_settings = 0;
-    t->sent_local_settings = 1;
-    GRPC_STATS_INC_HTTP2_SETTINGS_WRITES(exec_ctx);
+  void FlushWindowUpdates(grpc_exec_ctx *exec_ctx) {
+    uint32_t transport_announce =
+        grpc_chttp2_flowctl_maybe_send_transport_update(&t_->flow_control,
+                                                        t_->outbuf.count > 0);
+    if (transport_announce) {
+      grpc_transport_one_way_stats throwaway_stats;
+      grpc_slice_buffer_add(
+          &t_->outbuf, grpc_chttp2_window_update_create(0, transport_announce,
+                                                        &throwaway_stats));
+      ResetPingRecvClock();
+    }
   }
 
-  /* simple writes are queued to qbuf, and flushed here */
-  grpc_slice_buffer_move_into(&t->qbuf, &t->outbuf);
-  GPR_ASSERT(t->qbuf.count == 0);
+  void FlushPingAcks() {
+    for (size_t i = 0; i < t_->ping_ack_count; i++) {
+      grpc_slice_buffer_add(&t_->outbuf,
+                            grpc_chttp2_ping_create(true, t_->ping_acks[i]));
+    }
+    t_->ping_ack_count = 0;
+  }
 
-  grpc_chttp2_hpack_compressor_set_max_table_size(
-      &t->hpack_compressor,
-      t->settings[GRPC_PEER_SETTINGS][GRPC_CHTTP2_SETTINGS_HEADER_TABLE_SIZE]);
+  void EnactHpackSettings(grpc_exec_ctx *exec_ctx) {
+    grpc_chttp2_hpack_compressor_set_max_table_size(
+        &t_->hpack_compressor,
+        t_->settings[GRPC_PEER_SETTINGS]
+                    [GRPC_CHTTP2_SETTINGS_HEADER_TABLE_SIZE]);
+  }
 
-  if (t->flow_control.remote_window > 0) {
-    while (grpc_chttp2_list_pop_stalled_by_transport(t, &s)) {
-      if (!t->closed && grpc_chttp2_list_add_writable_stream(t, s)) {
-        stream_ref_if_not_destroyed(&s->refcount->refs);
+  void UpdateStreamsNoLongerStalled() {
+    grpc_chttp2_stream *s;
+    while (grpc_chttp2_list_pop_stalled_by_transport(t_, &s)) {
+      if (!t_->closed && grpc_chttp2_list_add_writable_stream(t_, s)) {
+        if (!stream_ref_if_not_destroyed(&s->refcount->refs)) {
+          grpc_chttp2_list_remove_writable_stream(t_, s);
+        }
       }
     }
   }
 
-  grpc_chttp2_begin_write_result result = {false, false, false};
+  grpc_chttp2_stream *NextStream() {
+    if (t_->outbuf.length > target_write_size(t_)) {
+      result_.partial = true;
+      return nullptr;
+    }
 
-  /* for each grpc_chttp2_stream that's become writable, frame it's data
-     (according to available window sizes) and add to the output buffer */
-  while (true) {
-    if (t->outbuf.length > target_write_size(t)) {
-      result.partial = true;
-      break;
+    grpc_chttp2_stream *s;
+    if (!grpc_chttp2_list_pop_writable_stream(t_, &s)) {
+      return nullptr;
     }
 
-    if (!grpc_chttp2_list_pop_writable_stream(t, &s)) {
-      break;
+    return s;
+  }
+
+  void ResetPingRecvClock() {
+    if (!t_->is_client) {
+      t_->ping_recv_state.last_ping_recv_time = GRPC_MILLIS_INF_PAST;
+      t_->ping_recv_state.ping_strikes = 0;
     }
+  }
+
+  void IncInitialMetadataWrites() { ++initial_metadata_writes_; }
+  void IncWindowUpdateWrites() { ++flow_control_writes_; }
+  void IncMessageWrites() { ++message_writes_; }
+  void IncTrailingMetadataWrites() { ++trailing_metadata_writes_; }
+
+  void NoteScheduledResults() { result_.early_results_scheduled = true; }
+
+  grpc_chttp2_transport *transport() const { return t_; }
 
-    bool sent_initial_metadata = s->sent_initial_metadata;
-    bool now_writing = false;
+  grpc_chttp2_begin_write_result Result() {
+    result_.writing = t_->outbuf.count > 0;
+    return result_;
+  }
+
+ private:
+  grpc_chttp2_transport *const t_;
 
+  /* stats histogram counters: we increment these throughout this function,
+     and at the end publish to the central stats histograms */
+  int flow_control_writes_ = 0;
+  int initial_metadata_writes_ = 0;
+  int trailing_metadata_writes_ = 0;
+  int message_writes_ = 0;
+  grpc_chttp2_begin_write_result result_ = {false, false, false};
+};
+
+class DataSendContext {
+ public:
+  DataSendContext(WriteContext *write_context, grpc_chttp2_transport *t,
+                  grpc_chttp2_stream *s)
+      : write_context_(write_context),
+        t_(t),
+        s_(s),
+        sending_bytes_before_(s_->sending_bytes) {}
+
+  uint32_t stream_remote_window() const {
+    return (uint32_t)GPR_MAX(
+        0, s_->flow_control.remote_window_delta +
+               (int64_t)t_->settings[GRPC_PEER_SETTINGS]
+                                    [GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE]);
+  }
+
+  uint32_t max_outgoing() const {
+    return (uint32_t)GPR_MIN(
+        t_->settings[GRPC_PEER_SETTINGS][GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE],
+        GPR_MIN(stream_remote_window(), t_->flow_control.remote_window));
+  }
+
+  bool AnyOutgoing() const { return max_outgoing() != 0; }
+
+  void FlushCompressedBytes() {
+    uint32_t send_bytes =
+        (uint32_t)GPR_MIN(max_outgoing(), s_->compressed_data_buffer.length);
+    bool is_last_data_frame =
+        (send_bytes == s_->compressed_data_buffer.length &&
+         s_->flow_controlled_buffer.length == 0 &&
+         s_->fetching_send_message == NULL);
+    if (is_last_data_frame && s_->send_trailing_metadata != NULL &&
+        s_->stream_compression_ctx != NULL) {
+      if (!grpc_stream_compress(s_->stream_compression_ctx,
+                                &s_->flow_controlled_buffer,
+                                &s_->compressed_data_buffer, NULL, MAX_SIZE_T,
+                                GRPC_STREAM_COMPRESSION_FLUSH_FINISH)) {
+        gpr_log(GPR_ERROR, "Stream compression failed.");
+      }
+      grpc_stream_compression_context_destroy(s_->stream_compression_ctx);
+      s_->stream_compression_ctx = NULL;
+      /* After finish, bytes in s->compressed_data_buffer may be
+       * more than max_outgoing. Start another round of the current
+       * while loop so that send_bytes and is_last_data_frame are
+       * recalculated. */
+      return;
+    }
+    is_last_frame_ = is_last_data_frame && s_->send_trailing_metadata != NULL &&
+                     grpc_metadata_batch_is_empty(s_->send_trailing_metadata);
+    grpc_chttp2_encode_data(s_->id, &s_->compressed_data_buffer, send_bytes,
+                            is_last_frame_, &s_->stats.outgoing, &t_->outbuf);
+    grpc_chttp2_flowctl_sent_data(&t_->flow_control, &s_->flow_control,
+                                  send_bytes);
+    if (s_->compressed_data_buffer.length == 0) {
+      s_->sending_bytes += s_->uncompressed_data_size;
+    }
+  }
+
+  void CompressMoreBytes() {
+    if (s_->stream_compression_ctx == NULL) {
+      s_->stream_compression_ctx =
+          grpc_stream_compression_context_create(s_->stream_compression_method);
+    }
+    s_->uncompressed_data_size = s_->flow_controlled_buffer.length;
+    if (!grpc_stream_compress(s_->stream_compression_ctx,
+                              &s_->flow_controlled_buffer,
+                              &s_->compressed_data_buffer, NULL, MAX_SIZE_T,
+                              GRPC_STREAM_COMPRESSION_FLUSH_SYNC)) {
+      gpr_log(GPR_ERROR, "Stream compression failed.");
+    }
+  }
+
+  bool is_last_frame() const { return is_last_frame_; }
+
+  void CallCallbacks(grpc_exec_ctx *exec_ctx) {
+    if (update_list(exec_ctx, t_, s_,
+                    (int64_t)(s_->sending_bytes - sending_bytes_before_),
+                    &s_->on_flow_controlled_cbs,
+                    &s_->flow_controlled_bytes_flowed, GRPC_ERROR_NONE)) {
+      write_context_->NoteScheduledResults();
+    }
+  }
+
+ private:
+  WriteContext *write_context_;
+  grpc_chttp2_transport *t_;
+  grpc_chttp2_stream *s_;
+  const size_t sending_bytes_before_;
+  bool is_last_frame_ = false;
+};
+
+class StreamWriteContext {
+ public:
+  StreamWriteContext(WriteContext *write_context, grpc_chttp2_stream *s)
+      : write_context_(write_context), t_(write_context->transport()), s_(s) {
     GRPC_CHTTP2_IF_TRACING(
-        gpr_log(GPR_DEBUG, "W:%p %s[%d] im-(sent,send)=(%d,%d) announce=%d", t,
-                t->is_client ? "CLIENT" : "SERVER", s->id,
-                sent_initial_metadata, s->send_initial_metadata != NULL,
+        gpr_log(GPR_DEBUG, "W:%p %s[%d] im-(sent,send)=(%d,%d) announce=%d", t_,
+                t_->is_client ? "CLIENT" : "SERVER", s->id,
+                s->sent_initial_metadata, s->send_initial_metadata != NULL,
                 (int)(s->flow_control.local_window_delta -
                       s->flow_control.announced_window_delta)));
+  }
 
-    grpc_mdelem *extra_headers_for_trailing_metadata[2];
-    size_t num_extra_headers_for_trailing_metadata = 0;
-
+  void FlushInitialMetadata(grpc_exec_ctx *exec_ctx) {
     /* send initial metadata if it's available */
-    if (!sent_initial_metadata && s->send_initial_metadata != NULL) {
-      // We skip this on the server side if there is no custom initial
-      // metadata, there are no messages to send, and we are also sending
-      // trailing metadata.  This results in a Trailers-Only response,
-      // which is required for retries, as per:
-      // https://github.com/grpc/proposal/blob/master/A6-client-retries.md#when-retries-are-valid
-      if (t->is_client || s->fetching_send_message != NULL ||
-          s->flow_controlled_buffer.length != 0 ||
-          s->send_trailing_metadata == NULL ||
-          !is_default_initial_metadata(s->send_initial_metadata)) {
-        grpc_encode_header_options hopt = {
-            s->id,  // stream_id
-            false,  // is_eof
-            t->settings[GRPC_PEER_SETTINGS]
-                       [GRPC_CHTTP2_SETTINGS_GRPC_ALLOW_TRUE_BINARY_METADATA] !=
-                0,  // use_true_binary_metadata
-            t->settings[GRPC_PEER_SETTINGS]
-                       [GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE],  // max_frame_size
-            &s->stats.outgoing                                 // stats
-        };
-        grpc_chttp2_encode_header(exec_ctx, &t->hpack_compressor, NULL, 0,
-                                  s->send_initial_metadata, &hopt, &t->outbuf);
-        now_writing = true;
-        if (!t->is_client) {
-          t->ping_recv_state.last_ping_recv_time =
-              gpr_inf_past(GPR_CLOCK_MONOTONIC);
-          t->ping_recv_state.ping_strikes = 0;
-        }
-        initial_metadata_writes++;
-      } else {
-        GRPC_CHTTP2_IF_TRACING(
-            gpr_log(GPR_INFO, "not sending initial_metadata (Trailers-Only)"));
-        // When sending Trailers-Only, we need to move the :status and
-        // content-type headers to the trailers.
-        if (s->send_initial_metadata->idx.named.status != NULL) {
-          extra_headers_for_trailing_metadata
-              [num_extra_headers_for_trailing_metadata++] =
-                  &s->send_initial_metadata->idx.named.status->md;
-        }
-        if (s->send_initial_metadata->idx.named.content_type != NULL) {
-          extra_headers_for_trailing_metadata
-              [num_extra_headers_for_trailing_metadata++] =
-                  &s->send_initial_metadata->idx.named.content_type->md;
-        }
-        trailing_metadata_writes++;
-      }
-      s->send_initial_metadata = NULL;
-      s->sent_initial_metadata = true;
-      sent_initial_metadata = true;
-      result.early_results_scheduled = true;
-      grpc_chttp2_complete_closure_step(
-          exec_ctx, t, s, &s->send_initial_metadata_finished, GRPC_ERROR_NONE,
-          "send_initial_metadata_finished");
+    if (s_->sent_initial_metadata) return;
+    if (s_->send_initial_metadata == nullptr) return;
+
+    // We skip this on the server side if there is no custom initial
+    // metadata, there are no messages to send, and we are also sending
+    // trailing metadata.  This results in a Trailers-Only response,
+    // which is required for retries, as per:
+    // https://github.com/grpc/proposal/blob/master/A6-client-retries.md#when-retries-are-valid
+    if (!t_->is_client && s_->fetching_send_message == nullptr &&
+        s_->flow_controlled_buffer.length == 0 &&
+        s_->compressed_data_buffer.length == 0 &&
+        s_->send_trailing_metadata != nullptr &&
+        is_default_initial_metadata(s_->send_initial_metadata)) {
+      ConvertInitialMetadataToTrailingMetadata();
+    } else {
+      grpc_encode_header_options hopt = {
+          s_->id,  // stream_id
+          false,   // is_eof
+          t_->settings[GRPC_PEER_SETTINGS]
+                      [GRPC_CHTTP2_SETTINGS_GRPC_ALLOW_TRUE_BINARY_METADATA] !=
+              0,  // use_true_binary_metadata
+          t_->settings[GRPC_PEER_SETTINGS]
+                      [GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE],  // max_frame_size
+          &s_->stats.outgoing                                 // stats
+      };
+      grpc_chttp2_encode_header(exec_ctx, &t_->hpack_compressor, NULL, 0,
+                                s_->send_initial_metadata, &hopt, &t_->outbuf);
+      write_context_->ResetPingRecvClock();
+      write_context_->IncInitialMetadataWrites();
     }
+
+    s_->send_initial_metadata = NULL;
+    s_->sent_initial_metadata = true;
+    write_context_->NoteScheduledResults();
+    grpc_chttp2_complete_closure_step(
+        exec_ctx, t_, s_, &s_->send_initial_metadata_finished, GRPC_ERROR_NONE,
+        "send_initial_metadata_finished");
+  }
+
+  void FlushWindowUpdates(grpc_exec_ctx *exec_ctx) {
     /* send any window updates */
     uint32_t stream_announce = grpc_chttp2_flowctl_maybe_send_stream_update(
-        &t->flow_control, &s->flow_control);
-    if (stream_announce > 0) {
-      grpc_slice_buffer_add(
-          &t->outbuf, grpc_chttp2_window_update_create(s->id, stream_announce,
-                                                       &s->stats.outgoing));
-      if (!t->is_client) {
-        t->ping_recv_state.last_ping_recv_time =
-            gpr_inf_past(GPR_CLOCK_MONOTONIC);
-        t->ping_recv_state.ping_strikes = 0;
+        &t_->flow_control, &s_->flow_control);
+    if (stream_announce == 0) return;
+
+    grpc_slice_buffer_add(
+        &t_->outbuf, grpc_chttp2_window_update_create(s_->id, stream_announce,
+                                                      &s_->stats.outgoing));
+    write_context_->ResetPingRecvClock();
+    write_context_->IncWindowUpdateWrites();
+  }
+
+  void FlushData(grpc_exec_ctx *exec_ctx) {
+    if (!s_->sent_initial_metadata) return;
+
+    if (s_->flow_controlled_buffer.length == 0 &&
+        s_->compressed_data_buffer.length == 0) {
+      return;  // early out: nothing to do
+    }
+
+    DataSendContext data_send_context(write_context_, t_, s_);
+
+    if (!data_send_context.AnyOutgoing()) {
+      if (t_->flow_control.remote_window == 0) {
+        report_stall(t_, s_, "transport");
+        grpc_chttp2_list_add_stalled_by_transport(t_, s_);
+      } else if (data_send_context.stream_remote_window() == 0) {
+        report_stall(t_, s_, "stream");
+        grpc_chttp2_list_add_stalled_by_stream(t_, s_);
       }
-      flow_control_writes++;
+      return;  // early out: nothing to do
     }
-    if (sent_initial_metadata) {
-      /* send any body bytes, if allowed by flow control */
-      if (s->flow_controlled_buffer.length > 0 ||
-          s->compressed_data_buffer.length > 0) {
-        uint32_t stream_remote_window = (uint32_t)GPR_MAX(
-            0,
-            s->flow_control.remote_window_delta +
-                (int64_t)t->settings[GRPC_PEER_SETTINGS]
-                                    [GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE]);
-        uint32_t max_outgoing = (uint32_t)GPR_MIN(
-            t->settings[GRPC_PEER_SETTINGS]
-                       [GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE],
-            GPR_MIN(stream_remote_window, t->flow_control.remote_window));
-        if (max_outgoing > 0) {
-          bool is_last_data_frame = false;
-          bool is_last_frame = false;
-          size_t sending_bytes_before = s->sending_bytes;
-          while ((s->flow_controlled_buffer.length > 0 ||
-                  s->compressed_data_buffer.length > 0) &&
-                 max_outgoing > 0) {
-            if (s->compressed_data_buffer.length > 0) {
-              uint32_t send_bytes = (uint32_t)GPR_MIN(
-                  max_outgoing, s->compressed_data_buffer.length);
-              is_last_data_frame =
-                  (send_bytes == s->compressed_data_buffer.length &&
-                   s->flow_controlled_buffer.length == 0 &&
-                   s->fetching_send_message == NULL);
-              if (is_last_data_frame && s->send_trailing_metadata != NULL &&
-                  s->stream_compression_ctx != NULL) {
-                if (!grpc_stream_compress(
-                        s->stream_compression_ctx, &s->flow_controlled_buffer,
-                        &s->compressed_data_buffer, NULL, MAX_SIZE_T,
-                        GRPC_STREAM_COMPRESSION_FLUSH_FINISH)) {
-                  gpr_log(GPR_ERROR, "Stream compression failed.");
-                }
-                grpc_stream_compression_context_destroy(
-                    s->stream_compression_ctx);
-                s->stream_compression_ctx = NULL;
-                /* After finish, bytes in s->compressed_data_buffer may be
-                 * more than max_outgoing. Start another round of the current
-                 * while loop so that send_bytes and is_last_data_frame are
-                 * recalculated. */
-                continue;
-              }
-              is_last_frame =
-                  is_last_data_frame && s->send_trailing_metadata != NULL &&
-                  grpc_metadata_batch_is_empty(s->send_trailing_metadata);
-              grpc_chttp2_encode_data(s->id, &s->compressed_data_buffer,
-                                      send_bytes, is_last_frame,
-                                      &s->stats.outgoing, &t->outbuf);
-              grpc_chttp2_flowctl_sent_data(&t->flow_control, &s->flow_control,
-                                            send_bytes);
-              max_outgoing -= send_bytes;
-              if (s->compressed_data_buffer.length == 0) {
-                s->sending_bytes += s->uncompressed_data_size;
-              }
-            } else {
-              if (s->stream_compression_ctx == NULL) {
-                s->stream_compression_ctx =
-                    grpc_stream_compression_context_create(
-                        s->stream_compression_method);
-              }
-              s->uncompressed_data_size = s->flow_controlled_buffer.length;
-              if (!grpc_stream_compress(
-                      s->stream_compression_ctx, &s->flow_controlled_buffer,
-                      &s->compressed_data_buffer, NULL, MAX_SIZE_T,
-                      GRPC_STREAM_COMPRESSION_FLUSH_SYNC)) {
-                gpr_log(GPR_ERROR, "Stream compression failed.");
-              }
-            }
-          }
-          if (!t->is_client) {
-            t->ping_recv_state.last_ping_recv_time =
-                gpr_inf_past(GPR_CLOCK_MONOTONIC);
-            t->ping_recv_state.ping_strikes = 0;
-          }
-          if (is_last_frame) {
-            s->send_trailing_metadata = NULL;
-            s->sent_trailing_metadata = true;
-            if (!t->is_client && !s->read_closed) {
-              grpc_slice_buffer_add(&t->outbuf, grpc_chttp2_rst_stream_create(
-                                                    s->id, GRPC_HTTP2_NO_ERROR,
-                                                    &s->stats.outgoing));
-            }
-            grpc_chttp2_mark_stream_closed(exec_ctx, t, s, !t->is_client, 1,
-                                           GRPC_ERROR_NONE);
-          }
-          result.early_results_scheduled |=
-              update_list(exec_ctx, t, s,
-                          (int64_t)(s->sending_bytes - sending_bytes_before),
-                          &s->on_flow_controlled_cbs,
-                          &s->flow_controlled_bytes_flowed, GRPC_ERROR_NONE);
-          now_writing = true;
-          if (s->flow_controlled_buffer.length > 0 ||
-              s->compressed_data_buffer.length > 0) {
-            GRPC_CHTTP2_STREAM_REF(s, "chttp2_writing:fork");
-            grpc_chttp2_list_add_writable_stream(t, s);
-          }
-          message_writes++;
-        } else if (t->flow_control.remote_window == 0) {
-          grpc_chttp2_list_add_stalled_by_transport(t, s);
-          now_writing = true;
-        } else if (stream_remote_window == 0) {
-          grpc_chttp2_list_add_stalled_by_stream(t, s);
-          now_writing = true;
-        }
+
+    while ((s_->flow_controlled_buffer.length > 0 ||
+            s_->compressed_data_buffer.length > 0) &&
+           data_send_context.max_outgoing() > 0) {
+      if (s_->compressed_data_buffer.length > 0) {
+        data_send_context.FlushCompressedBytes();
+      } else {
+        data_send_context.CompressMoreBytes();
       }
-      if (s->send_trailing_metadata != NULL &&
-          s->fetching_send_message == NULL &&
-          s->flow_controlled_buffer.length == 0 &&
-          s->compressed_data_buffer.length == 0) {
-        GRPC_CHTTP2_IF_TRACING(gpr_log(GPR_INFO, "sending trailing_metadata"));
-        if (grpc_metadata_batch_is_empty(s->send_trailing_metadata)) {
-          grpc_chttp2_encode_data(s->id, &s->flow_controlled_buffer, 0, true,
-                                  &s->stats.outgoing, &t->outbuf);
-        } else {
-          grpc_encode_header_options hopt = {
-              s->id, true,
-
-              t->settings
-                      [GRPC_PEER_SETTINGS]
+    }
+    write_context_->ResetPingRecvClock();
+    if (data_send_context.is_last_frame()) {
+      SentLastFrame(exec_ctx);
+    }
+    data_send_context.CallCallbacks(exec_ctx);
+    stream_became_writable_ = true;
+    if (s_->flow_controlled_buffer.length > 0 ||
+        s_->compressed_data_buffer.length > 0) {
+      GRPC_CHTTP2_STREAM_REF(s_, "chttp2_writing:fork");
+      grpc_chttp2_list_add_writable_stream(t_, s_);
+    }
+    write_context_->IncMessageWrites();
+  }
+
+  void FlushTrailingMetadata(grpc_exec_ctx *exec_ctx) {
+    if (!s_->sent_initial_metadata) return;
+
+    if (s_->send_trailing_metadata == NULL) return;
+    if (s_->fetching_send_message != NULL) return;
+    if (s_->flow_controlled_buffer.length != 0) return;
+    if (s_->compressed_data_buffer.length != 0) return;
+
+    GRPC_CHTTP2_IF_TRACING(gpr_log(GPR_INFO, "sending trailing_metadata"));
+    if (grpc_metadata_batch_is_empty(s_->send_trailing_metadata)) {
+      grpc_chttp2_encode_data(s_->id, &s_->flow_controlled_buffer, 0, true,
+                              &s_->stats.outgoing, &t_->outbuf);
+    } else {
+      grpc_encode_header_options hopt = {
+          s_->id, true,
+          t_->settings[GRPC_PEER_SETTINGS]
                       [GRPC_CHTTP2_SETTINGS_GRPC_ALLOW_TRUE_BINARY_METADATA] !=
-                  0,
-
-              t->settings[GRPC_PEER_SETTINGS]
-                         [GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE],
-              &s->stats.outgoing};
-          grpc_chttp2_encode_header(exec_ctx, &t->hpack_compressor,
-                                    extra_headers_for_trailing_metadata,
-                                    num_extra_headers_for_trailing_metadata,
-                                    s->send_trailing_metadata, &hopt,
-                                    &t->outbuf);
-          trailing_metadata_writes++;
-        }
-        s->send_trailing_metadata = NULL;
-        s->sent_trailing_metadata = true;
-        if (!t->is_client && !s->read_closed) {
-          grpc_slice_buffer_add(
-              &t->outbuf, grpc_chttp2_rst_stream_create(
-                              s->id, GRPC_HTTP2_NO_ERROR, &s->stats.outgoing));
-        }
-        grpc_chttp2_mark_stream_closed(exec_ctx, t, s, !t->is_client, 1,
-                                       GRPC_ERROR_NONE);
-        now_writing = true;
-        result.early_results_scheduled = true;
-        grpc_chttp2_complete_closure_step(
-            exec_ctx, t, s, &s->send_trailing_metadata_finished,
-            GRPC_ERROR_NONE, "send_trailing_metadata_finished");
-      }
+              0,
+
+          t_->settings[GRPC_PEER_SETTINGS][GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE],
+          &s_->stats.outgoing};
+      grpc_chttp2_encode_header(exec_ctx, &t_->hpack_compressor,
+                                extra_headers_for_trailing_metadata_,
+                                num_extra_headers_for_trailing_metadata_,
+                                s_->send_trailing_metadata, &hopt, &t_->outbuf);
+    }
+    write_context_->IncTrailingMetadataWrites();
+    write_context_->ResetPingRecvClock();
+    SentLastFrame(exec_ctx);
+
+    write_context_->NoteScheduledResults();
+    grpc_chttp2_complete_closure_step(
+        exec_ctx, t_, s_, &s_->send_trailing_metadata_finished, GRPC_ERROR_NONE,
+        "send_trailing_metadata_finished");
+  }
+
+  bool stream_became_writable() { return stream_became_writable_; }
+
+ private:
+  void ConvertInitialMetadataToTrailingMetadata() {
+    GRPC_CHTTP2_IF_TRACING(
+        gpr_log(GPR_INFO, "not sending initial_metadata (Trailers-Only)"));
+    // When sending Trailers-Only, we need to move the :status and
+    // content-type headers to the trailers.
+    if (s_->send_initial_metadata->idx.named.status != NULL) {
+      extra_headers_for_trailing_metadata_
+          [num_extra_headers_for_trailing_metadata_++] =
+              &s_->send_initial_metadata->idx.named.status->md;
     }
+    if (s_->send_initial_metadata->idx.named.content_type != NULL) {
+      extra_headers_for_trailing_metadata_
+          [num_extra_headers_for_trailing_metadata_++] =
+              &s_->send_initial_metadata->idx.named.content_type->md;
+    }
+  }
+
+  void SentLastFrame(grpc_exec_ctx *exec_ctx) {
+    s_->send_trailing_metadata = NULL;
+    s_->sent_trailing_metadata = true;
+
+    if (!t_->is_client && !s_->read_closed) {
+      grpc_slice_buffer_add(
+          &t_->outbuf, grpc_chttp2_rst_stream_create(
+                           s_->id, GRPC_HTTP2_NO_ERROR, &s_->stats.outgoing));
+    }
+    grpc_chttp2_mark_stream_closed(exec_ctx, t_, s_, !t_->is_client, true,
+                                   GRPC_ERROR_NONE);
+  }
 
-    if (now_writing) {
-      GRPC_STATS_INC_HTTP2_SEND_INITIAL_METADATA_PER_WRITE(
-          exec_ctx, initial_metadata_writes);
-      GRPC_STATS_INC_HTTP2_SEND_MESSAGE_PER_WRITE(exec_ctx, message_writes);
-      GRPC_STATS_INC_HTTP2_SEND_TRAILING_METADATA_PER_WRITE(
-          exec_ctx, trailing_metadata_writes);
-      GRPC_STATS_INC_HTTP2_SEND_FLOWCTL_PER_WRITE(exec_ctx,
-                                                  flow_control_writes);
+  WriteContext *const write_context_;
+  grpc_chttp2_transport *const t_;
+  grpc_chttp2_stream *const s_;
+  bool stream_became_writable_ = false;
+  grpc_mdelem *extra_headers_for_trailing_metadata_[2];
+  size_t num_extra_headers_for_trailing_metadata_ = 0;
+};
+}  // namespace
 
+grpc_chttp2_begin_write_result grpc_chttp2_begin_write(
+    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t) {
+  WriteContext ctx(exec_ctx, t);
+  ctx.FlushSettings(exec_ctx);
+  ctx.FlushPingAcks();
+  ctx.FlushQueuedBuffers(exec_ctx);
+  ctx.EnactHpackSettings(exec_ctx);
+
+  if (t->flow_control.remote_window > 0) {
+    ctx.UpdateStreamsNoLongerStalled();
+  }
+
+  /* for each grpc_chttp2_stream that's become writable, frame it's data
+     (according to available window sizes) and add to the output buffer */
+  while (grpc_chttp2_stream *s = ctx.NextStream()) {
+    StreamWriteContext stream_ctx(&ctx, s);
+    stream_ctx.FlushInitialMetadata(exec_ctx);
+    stream_ctx.FlushWindowUpdates(exec_ctx);
+    stream_ctx.FlushData(exec_ctx);
+    stream_ctx.FlushTrailingMetadata(exec_ctx);
+
+    if (stream_ctx.stream_became_writable()) {
       if (!grpc_chttp2_list_add_writing_stream(t, s)) {
         /* already in writing list: drop ref */
         GRPC_CHTTP2_STREAM_UNREF(exec_ctx, s, "chttp2_writing:already_writing");
+      } else {
+        /* ref will be dropped at end of write */
       }
     } else {
       GRPC_CHTTP2_STREAM_UNREF(exec_ctx, s, "chttp2_writing:no_write");
     }
   }
 
-  uint32_t transport_announce =
-      grpc_chttp2_flowctl_maybe_send_transport_update(&t->flow_control);
-  if (transport_announce) {
-    maybe_initiate_ping(exec_ctx, t,
-                        GRPC_CHTTP2_PING_BEFORE_TRANSPORT_WINDOW_UPDATE);
-    grpc_transport_one_way_stats throwaway_stats;
-    grpc_slice_buffer_add(
-        &t->outbuf, grpc_chttp2_window_update_create(0, transport_announce,
-                                                     &throwaway_stats));
-    if (!t->is_client) {
-      t->ping_recv_state.last_ping_recv_time =
-          gpr_inf_past(GPR_CLOCK_MONOTONIC);
-      t->ping_recv_state.ping_strikes = 0;
-    }
-  }
-
-  for (size_t i = 0; i < t->ping_ack_count; i++) {
-    grpc_slice_buffer_add(&t->outbuf,
-                          grpc_chttp2_ping_create(1, t->ping_acks[i]));
-  }
-  t->ping_ack_count = 0;
+  ctx.FlushWindowUpdates(exec_ctx);
 
-  maybe_initiate_ping(exec_ctx, t, GRPC_CHTTP2_PING_ON_NEXT_WRITE);
+  maybe_initiate_ping(exec_ctx, t);
 
   GPR_TIMER_END("grpc_chttp2_begin_write", 0);
 
-  result.writing = t->outbuf.count > 0;
-  return result;
+  return ctx.Result();
 }
 
 void grpc_chttp2_end_write(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
diff --git a/src/core/ext/transport/inproc/inproc_transport.cc b/src/core/ext/transport/inproc/inproc_transport.cc
index 31739d07dd6..67a8358927c 100644
--- a/src/core/ext/transport/inproc/inproc_transport.cc
+++ b/src/core/ext/transport/inproc/inproc_transport.cc
@@ -62,96 +62,22 @@ typedef struct inproc_transport {
   struct inproc_stream *stream_list;
 } inproc_transport;
 
-typedef struct sb_list_entry {
-  grpc_slice_buffer sb;
-  struct sb_list_entry *next;
-} sb_list_entry;
-
-// Specialize grpc_byte_stream for our use case
-typedef struct {
-  grpc_byte_stream base;
-  sb_list_entry *le;
-  grpc_error *shutdown_error;
-} inproc_slice_byte_stream;
-
-typedef struct {
-  // TODO (vjpai): Add some inlined elements to avoid alloc in simple cases
-  sb_list_entry *head;
-  sb_list_entry *tail;
-} slice_buffer_list;
-
-static void slice_buffer_list_init(slice_buffer_list *l) {
-  l->head = NULL;
-  l->tail = NULL;
-}
-
-static void sb_list_entry_destroy(grpc_exec_ctx *exec_ctx, sb_list_entry *le) {
-  grpc_slice_buffer_destroy_internal(exec_ctx, &le->sb);
-  gpr_free(le);
-}
-
-static void slice_buffer_list_destroy(grpc_exec_ctx *exec_ctx,
-                                      slice_buffer_list *l) {
-  sb_list_entry *curr = l->head;
-  while (curr != NULL) {
-    sb_list_entry *le = curr;
-    curr = curr->next;
-    sb_list_entry_destroy(exec_ctx, le);
-  }
-  l->head = NULL;
-  l->tail = NULL;
-}
-
-static bool slice_buffer_list_empty(slice_buffer_list *l) {
-  return l->head == NULL;
-}
-
-static void slice_buffer_list_append_entry(slice_buffer_list *l,
-                                           sb_list_entry *next) {
-  next->next = NULL;
-  if (l->tail) {
-    l->tail->next = next;
-    l->tail = next;
-  } else {
-    l->head = next;
-    l->tail = next;
-  }
-}
-
-static grpc_slice_buffer *slice_buffer_list_append(slice_buffer_list *l) {
-  sb_list_entry *next = (sb_list_entry *)gpr_malloc(sizeof(*next));
-  grpc_slice_buffer_init(&next->sb);
-  slice_buffer_list_append_entry(l, next);
-  return &next->sb;
-}
-
-static sb_list_entry *slice_buffer_list_pophead(slice_buffer_list *l) {
-  sb_list_entry *ret = l->head;
-  l->head = l->head->next;
-  if (l->head == NULL) {
-    l->tail = NULL;
-  }
-  return ret;
-}
-
 typedef struct inproc_stream {
   inproc_transport *t;
   grpc_metadata_batch to_read_initial_md;
   uint32_t to_read_initial_md_flags;
   bool to_read_initial_md_filled;
-  slice_buffer_list to_read_message;
   grpc_metadata_batch to_read_trailing_md;
   bool to_read_trailing_md_filled;
-  bool reads_needed;
-  bool read_closure_scheduled;
-  grpc_closure read_closure;
+  bool ops_needed;
+  bool op_closure_scheduled;
+  grpc_closure op_closure;
   // Write buffer used only during gap at init time when client-side
   // stream is set up but server side stream is not yet set up
   grpc_metadata_batch write_buffer_initial_md;
   bool write_buffer_initial_md_filled;
   uint32_t write_buffer_initial_md_flags;
-  gpr_timespec write_buffer_deadline;
-  slice_buffer_list write_buffer_message;
+  grpc_millis write_buffer_deadline;
   grpc_metadata_batch write_buffer_trailing_md;
   bool write_buffer_trailing_md_filled;
   grpc_error *write_buffer_cancel_error;
@@ -164,11 +90,15 @@ typedef struct inproc_stream {
 
   gpr_arena *arena;
 
+  grpc_transport_stream_op_batch *send_message_op;
+  grpc_transport_stream_op_batch *send_trailing_md_op;
   grpc_transport_stream_op_batch *recv_initial_md_op;
   grpc_transport_stream_op_batch *recv_message_op;
   grpc_transport_stream_op_batch *recv_trailing_md_op;
 
-  inproc_slice_byte_stream recv_message_stream;
+  grpc_slice_buffer recv_message;
+  grpc_slice_buffer_stream recv_stream;
+  bool recv_inited;
 
   bool initial_md_sent;
   bool trailing_md_sent;
@@ -180,61 +110,18 @@ typedef struct inproc_stream {
   grpc_error *cancel_self_error;
   grpc_error *cancel_other_error;
 
-  gpr_timespec deadline;
+  grpc_millis deadline;
 
   bool listed;
   struct inproc_stream *stream_list_prev;
   struct inproc_stream *stream_list_next;
 } inproc_stream;
 
-static bool inproc_slice_byte_stream_next(grpc_exec_ctx *exec_ctx,
-                                          grpc_byte_stream *bs, size_t max,
-                                          grpc_closure *on_complete) {
-  // Because inproc transport always provides the entire message atomically,
-  // the byte stream always has data available when this function is called.
-  // Thus, this function always returns true (unlike other transports) and
-  // there is never any need to schedule a closure
-  return true;
-}
-
-static grpc_error *inproc_slice_byte_stream_pull(grpc_exec_ctx *exec_ctx,
-                                                 grpc_byte_stream *bs,
-                                                 grpc_slice *slice) {
-  inproc_slice_byte_stream *stream = (inproc_slice_byte_stream *)bs;
-  if (stream->shutdown_error != GRPC_ERROR_NONE) {
-    return GRPC_ERROR_REF(stream->shutdown_error);
-  }
-  *slice = grpc_slice_buffer_take_first(&stream->le->sb);
-  return GRPC_ERROR_NONE;
-}
-
-static void inproc_slice_byte_stream_shutdown(grpc_exec_ctx *exec_ctx,
-                                              grpc_byte_stream *bs,
-                                              grpc_error *error) {
-  inproc_slice_byte_stream *stream = (inproc_slice_byte_stream *)bs;
-  GRPC_ERROR_UNREF(stream->shutdown_error);
-  stream->shutdown_error = error;
-}
-
-static void inproc_slice_byte_stream_destroy(grpc_exec_ctx *exec_ctx,
-                                             grpc_byte_stream *bs) {
-  inproc_slice_byte_stream *stream = (inproc_slice_byte_stream *)bs;
-  sb_list_entry_destroy(exec_ctx, stream->le);
-  GRPC_ERROR_UNREF(stream->shutdown_error);
-}
-
-static const grpc_byte_stream_vtable inproc_slice_byte_stream_vtable = {
-    inproc_slice_byte_stream_next, inproc_slice_byte_stream_pull,
-    inproc_slice_byte_stream_shutdown, inproc_slice_byte_stream_destroy};
-
-void inproc_slice_byte_stream_init(inproc_slice_byte_stream *s,
-                                   sb_list_entry *le) {
-  s->base.length = (uint32_t)le->sb.length;
-  s->base.flags = 0;
-  s->base.vtable = &inproc_slice_byte_stream_vtable;
-  s->le = le;
-  s->shutdown_error = GRPC_ERROR_NONE;
-}
+static grpc_closure do_nothing_closure;
+static bool cancel_stream_locked(grpc_exec_ctx *exec_ctx, inproc_stream *s,
+                                 grpc_error *error);
+static void op_state_machine(grpc_exec_ctx *exec_ctx, void *arg,
+                             grpc_error *error);
 
 static void ref_transport(inproc_transport *t) {
   INPROC_LOG(GPR_DEBUG, "ref_transport %p", t);
@@ -280,12 +167,14 @@ static void unref_stream(grpc_exec_ctx *exec_ctx, inproc_stream *s,
 static void really_destroy_stream(grpc_exec_ctx *exec_ctx, inproc_stream *s) {
   INPROC_LOG(GPR_DEBUG, "really_destroy_stream %p", s);
 
-  slice_buffer_list_destroy(exec_ctx, &s->to_read_message);
-  slice_buffer_list_destroy(exec_ctx, &s->write_buffer_message);
   GRPC_ERROR_UNREF(s->write_buffer_cancel_error);
   GRPC_ERROR_UNREF(s->cancel_self_error);
   GRPC_ERROR_UNREF(s->cancel_other_error);
 
+  if (s->recv_inited) {
+    grpc_slice_buffer_destroy_internal(exec_ctx, &s->recv_message);
+  }
+
   unref_transport(exec_ctx, s->t);
 
   if (s->closure_at_destroy) {
@@ -293,9 +182,6 @@ static void really_destroy_stream(grpc_exec_ctx *exec_ctx, inproc_stream *s) {
   }
 }
 
-static void read_state_machine(grpc_exec_ctx *exec_ctx, void *arg,
-                               grpc_error *error);
-
 static void log_metadata(const grpc_metadata_batch *md_batch, bool is_client,
                          bool is_initial) {
   for (grpc_linked_mdelem *md = md_batch->list.head; md != NULL;
@@ -359,11 +245,9 @@ static int init_stream(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
   s->write_buffer_initial_md_filled = false;
   grpc_metadata_batch_init(&s->write_buffer_trailing_md);
   s->write_buffer_trailing_md_filled = false;
-  slice_buffer_list_init(&s->to_read_message);
-  slice_buffer_list_init(&s->write_buffer_message);
-  s->reads_needed = false;
-  s->read_closure_scheduled = false;
-  GRPC_CLOSURE_INIT(&s->read_closure, read_state_machine, s,
+  s->ops_needed = false;
+  s->op_closure_scheduled = false;
+  GRPC_CLOSURE_INIT(&s->op_closure, op_state_machine, s,
                     grpc_schedule_on_exec_ctx);
   s->t = t;
   s->closure_at_destroy = NULL;
@@ -377,8 +261,8 @@ static int init_stream(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
   s->cancel_self_error = GRPC_ERROR_NONE;
   s->cancel_other_error = GRPC_ERROR_NONE;
   s->write_buffer_cancel_error = GRPC_ERROR_NONE;
-  s->deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
-  s->write_buffer_deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
+  s->deadline = GRPC_MILLIS_INF_FUTURE;
+  s->write_buffer_deadline = GRPC_MILLIS_INF_FUTURE;
 
   s->stream_list_prev = NULL;
   gpr_mu_lock(&t->mu->mu);
@@ -421,15 +305,10 @@ static int init_stream(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
                        cs->write_buffer_initial_md_flags,
                        &s->to_read_initial_md, &s->to_read_initial_md_flags,
                        &s->to_read_initial_md_filled);
-      s->deadline = gpr_time_min(s->deadline, cs->write_buffer_deadline);
+      s->deadline = GPR_MIN(s->deadline, cs->write_buffer_deadline);
       grpc_metadata_batch_clear(exec_ctx, &cs->write_buffer_initial_md);
       cs->write_buffer_initial_md_filled = false;
     }
-    while (!slice_buffer_list_empty(&cs->write_buffer_message)) {
-      slice_buffer_list_append_entry(
-          &s->to_read_message,
-          slice_buffer_list_pophead(&cs->write_buffer_message));
-    }
     if (cs->write_buffer_trailing_md_filled) {
       fill_in_metadata(exec_ctx, s, &cs->write_buffer_trailing_md, 0,
                        &s->to_read_trailing_md, NULL,
@@ -488,9 +367,39 @@ static void close_other_side_locked(grpc_exec_ctx *exec_ctx, inproc_stream *s,
   }
 }
 
+// Call the on_complete closure associated with this stream_op_batch if
+// this stream_op_batch is only one of the pending operations for this
+// stream. This is called when one of the pending operations for the stream
+// is done and about to be NULLed out
+static void complete_if_batch_end_locked(grpc_exec_ctx *exec_ctx,
+                                         inproc_stream *s, grpc_error *error,
+                                         grpc_transport_stream_op_batch *op,
+                                         const char *msg) {
+  int is_sm = (int)(op == s->send_message_op);
+  int is_stm = (int)(op == s->send_trailing_md_op);
+  int is_rim = (int)(op == s->recv_initial_md_op);
+  int is_rm = (int)(op == s->recv_message_op);
+  int is_rtm = (int)(op == s->recv_trailing_md_op);
+
+  if ((is_sm + is_stm + is_rim + is_rm + is_rtm) == 1) {
+    INPROC_LOG(GPR_DEBUG, "%s %p %p %p", msg, s, op, error);
+    GRPC_CLOSURE_SCHED(exec_ctx, op->on_complete, GRPC_ERROR_REF(error));
+  }
+}
+
+static void maybe_schedule_op_closure_locked(grpc_exec_ctx *exec_ctx,
+                                             inproc_stream *s,
+                                             grpc_error *error) {
+  if (s && s->ops_needed && !s->op_closure_scheduled) {
+    GRPC_CLOSURE_SCHED(exec_ctx, &s->op_closure, GRPC_ERROR_REF(error));
+    s->op_closure_scheduled = true;
+    s->ops_needed = false;
+  }
+}
+
 static void fail_helper_locked(grpc_exec_ctx *exec_ctx, inproc_stream *s,
                                grpc_error *error) {
-  INPROC_LOG(GPR_DEBUG, "read_state_machine %p fail_helper", s);
+  INPROC_LOG(GPR_DEBUG, "op_state_machine %p fail_helper", s);
   // If we're failing this side, we need to make sure that
   // we also send or have already sent trailing metadata
   if (!s->trailing_md_sent) {
@@ -512,14 +421,7 @@ static void fail_helper_locked(grpc_exec_ctx *exec_ctx, inproc_stream *s,
       if (other->cancel_other_error == GRPC_ERROR_NONE) {
         other->cancel_other_error = GRPC_ERROR_REF(error);
       }
-      if (other->reads_needed) {
-        if (!other->read_closure_scheduled) {
-          GRPC_CLOSURE_SCHED(exec_ctx, &other->read_closure,
-                             GRPC_ERROR_REF(error));
-          other->read_closure_scheduled = true;
-        }
-        other->reads_needed = false;
-      }
+      maybe_schedule_op_closure_locked(exec_ctx, other, error);
     } else if (s->write_buffer_cancel_error == GRPC_ERROR_NONE) {
       s->write_buffer_cancel_error = GRPC_ERROR_REF(error);
     }
@@ -564,14 +466,9 @@ static void fail_helper_locked(grpc_exec_ctx *exec_ctx, inproc_stream *s,
                        err);
     // Last use of err so no need to REF and then UNREF it
 
-    if ((s->recv_initial_md_op != s->recv_message_op) &&
-        (s->recv_initial_md_op != s->recv_trailing_md_op)) {
-      INPROC_LOG(GPR_DEBUG,
-                 "fail_helper %p scheduling initial-metadata-on-complete %p",
-                 error, s);
-      GRPC_CLOSURE_SCHED(exec_ctx, s->recv_initial_md_op->on_complete,
-                         GRPC_ERROR_REF(error));
-    }
+    complete_if_batch_end_locked(
+        exec_ctx, s, error, s->recv_initial_md_op,
+        "fail_helper scheduling recv-initial-metadata-on-complete");
     s->recv_initial_md_op = NULL;
   }
   if (s->recv_message_op) {
@@ -580,20 +477,30 @@ static void fail_helper_locked(grpc_exec_ctx *exec_ctx, inproc_stream *s,
     GRPC_CLOSURE_SCHED(
         exec_ctx, s->recv_message_op->payload->recv_message.recv_message_ready,
         GRPC_ERROR_REF(error));
-    if (s->recv_message_op != s->recv_trailing_md_op) {
-      INPROC_LOG(GPR_DEBUG, "fail_helper %p scheduling message-on-complete %p",
-                 s, error);
-      GRPC_CLOSURE_SCHED(exec_ctx, s->recv_message_op->on_complete,
-                         GRPC_ERROR_REF(error));
-    }
+    complete_if_batch_end_locked(
+        exec_ctx, s, error, s->recv_message_op,
+        "fail_helper scheduling recv-message-on-complete");
     s->recv_message_op = NULL;
   }
+  if (s->send_message_op) {
+    complete_if_batch_end_locked(
+        exec_ctx, s, error, s->send_message_op,
+        "fail_helper scheduling send-message-on-complete");
+    s->send_message_op = NULL;
+  }
+  if (s->send_trailing_md_op) {
+    complete_if_batch_end_locked(
+        exec_ctx, s, error, s->send_trailing_md_op,
+        "fail_helper scheduling send-trailng-md-on-complete");
+    s->send_trailing_md_op = NULL;
+  }
   if (s->recv_trailing_md_op) {
     INPROC_LOG(GPR_DEBUG,
                "fail_helper %p scheduling trailing-md-on-complete %p", s,
                error);
-    GRPC_CLOSURE_SCHED(exec_ctx, s->recv_trailing_md_op->on_complete,
-                       GRPC_ERROR_REF(error));
+    complete_if_batch_end_locked(
+        exec_ctx, s, error, s->recv_trailing_md_op,
+        "fail_helper scheduling recv-trailing-metadata-on-complete");
     s->recv_trailing_md_op = NULL;
   }
   close_other_side_locked(exec_ctx, s, "fail_helper:other_side");
@@ -602,12 +509,61 @@ static void fail_helper_locked(grpc_exec_ctx *exec_ctx, inproc_stream *s,
   GRPC_ERROR_UNREF(error);
 }
 
-static void read_state_machine(grpc_exec_ctx *exec_ctx, void *arg,
-                               grpc_error *error) {
+static void message_transfer_locked(grpc_exec_ctx *exec_ctx,
+                                    inproc_stream *sender,
+                                    inproc_stream *receiver) {
+  size_t remaining =
+      sender->send_message_op->payload->send_message.send_message->length;
+  if (receiver->recv_inited) {
+    grpc_slice_buffer_destroy_internal(exec_ctx, &receiver->recv_message);
+  }
+  grpc_slice_buffer_init(&receiver->recv_message);
+  receiver->recv_inited = true;
+  do {
+    grpc_slice message_slice;
+    grpc_closure unused;
+    GPR_ASSERT(grpc_byte_stream_next(
+        exec_ctx, sender->send_message_op->payload->send_message.send_message,
+        SIZE_MAX, &unused));
+    grpc_error *error = grpc_byte_stream_pull(
+        exec_ctx, sender->send_message_op->payload->send_message.send_message,
+        &message_slice);
+    if (error != GRPC_ERROR_NONE) {
+      cancel_stream_locked(exec_ctx, sender, GRPC_ERROR_REF(error));
+      break;
+    }
+    GPR_ASSERT(error == GRPC_ERROR_NONE);
+    remaining -= GRPC_SLICE_LENGTH(message_slice);
+    grpc_slice_buffer_add(&receiver->recv_message, message_slice);
+  } while (remaining > 0);
+
+  grpc_slice_buffer_stream_init(&receiver->recv_stream, &receiver->recv_message,
+                                0);
+  *receiver->recv_message_op->payload->recv_message.recv_message =
+      &receiver->recv_stream.base;
+  INPROC_LOG(GPR_DEBUG, "message_transfer_locked %p scheduling message-ready",
+             receiver);
+  GRPC_CLOSURE_SCHED(
+      exec_ctx,
+      receiver->recv_message_op->payload->recv_message.recv_message_ready,
+      GRPC_ERROR_NONE);
+  complete_if_batch_end_locked(
+      exec_ctx, sender, GRPC_ERROR_NONE, sender->send_message_op,
+      "message_transfer scheduling sender on_complete");
+  complete_if_batch_end_locked(
+      exec_ctx, receiver, GRPC_ERROR_NONE, receiver->recv_message_op,
+      "message_transfer scheduling receiver on_complete");
+
+  receiver->recv_message_op = NULL;
+  sender->send_message_op = NULL;
+}
+
+static void op_state_machine(grpc_exec_ctx *exec_ctx, void *arg,
+                             grpc_error *error) {
   // This function gets called when we have contents in the unprocessed reads
   // Get what we want based on our ops wanted
   // Schedule our appropriate closures
-  // and then return to reads_needed state if still needed
+  // and then return to ops_needed state if still needed
 
   // Since this is a closure directly invoked by the combiner, it should not
   // unref the error parameter explicitly; the combiner will do that implicitly
@@ -615,12 +571,14 @@ static void read_state_machine(grpc_exec_ctx *exec_ctx, void *arg,
 
   bool needs_close = false;
 
-  INPROC_LOG(GPR_DEBUG, "read_state_machine %p", arg);
+  INPROC_LOG(GPR_DEBUG, "op_state_machine %p", arg);
   inproc_stream *s = (inproc_stream *)arg;
   gpr_mu *mu = &s->t->mu->mu;  // keep aside in case s gets closed
   gpr_mu_lock(mu);
-  s->read_closure_scheduled = false;
+  s->op_closure_scheduled = false;
   // cancellation takes precedence
+  inproc_stream *other = s->other_side;
+
   if (s->cancel_self_error != GRPC_ERROR_NONE) {
     fail_helper_locked(exec_ctx, s, GRPC_ERROR_REF(s->cancel_self_error));
     goto done;
@@ -632,89 +590,116 @@ static void read_state_machine(grpc_exec_ctx *exec_ctx, void *arg,
     goto done;
   }
 
-  if (s->recv_initial_md_op) {
-    if (!s->to_read_initial_md_filled) {
-      // We entered the state machine on some other kind of read even though
-      // we still haven't satisfied initial md . That's an error.
-      new_err =
-          GRPC_ERROR_CREATE_FROM_STATIC_STRING("Unexpected frame sequencing");
-      INPROC_LOG(GPR_DEBUG,
-                 "read_state_machine %p scheduling on_complete errors for no "
-                 "initial md %p",
-                 s, new_err);
+  if (s->send_message_op && other) {
+    if (other->recv_message_op) {
+      message_transfer_locked(exec_ctx, s, other);
+      maybe_schedule_op_closure_locked(exec_ctx, other, GRPC_ERROR_NONE);
+    } else if (!s->t->is_client &&
+               (s->trailing_md_sent || other->recv_trailing_md_op)) {
+      // A server send will never be matched if the client is waiting
+      // for trailing metadata already
+      complete_if_batch_end_locked(
+          exec_ctx, s, GRPC_ERROR_NONE, s->send_message_op,
+          "op_state_machine scheduling send-message-on-complete");
+      s->send_message_op = NULL;
+    }
+  }
+  // Pause a send trailing metadata if there is still an outstanding
+  // send message unless we know that the send message will never get
+  // matched to a receive. This happens on the client if the server has
+  // already sent status.
+  if (s->send_trailing_md_op &&
+      (!s->send_message_op ||
+       (s->t->is_client &&
+        (s->trailing_md_recvd || s->to_read_trailing_md_filled)))) {
+    grpc_metadata_batch *dest = (other == NULL) ? &s->write_buffer_trailing_md
+                                                : &other->to_read_trailing_md;
+    bool *destfilled = (other == NULL) ? &s->write_buffer_trailing_md_filled
+                                       : &other->to_read_trailing_md_filled;
+    if (*destfilled || s->trailing_md_sent) {
+      // The buffer is already in use; that's an error!
+      INPROC_LOG(GPR_DEBUG, "Extra trailing metadata %p", s);
+      new_err = GRPC_ERROR_CREATE_FROM_STATIC_STRING("Extra trailing metadata");
       fail_helper_locked(exec_ctx, s, GRPC_ERROR_REF(new_err));
       goto done;
-    } else if (s->initial_md_recvd) {
+    } else {
+      if (other && !other->closed) {
+        fill_in_metadata(exec_ctx, s,
+                         s->send_trailing_md_op->payload->send_trailing_metadata
+                             .send_trailing_metadata,
+                         0, dest, NULL, destfilled);
+      }
+      s->trailing_md_sent = true;
+      if (!s->t->is_client && s->trailing_md_recvd && s->recv_trailing_md_op) {
+        INPROC_LOG(GPR_DEBUG,
+                   "op_state_machine %p scheduling trailing-md-on-complete", s);
+        GRPC_CLOSURE_SCHED(exec_ctx, s->recv_trailing_md_op->on_complete,
+                           GRPC_ERROR_NONE);
+        s->recv_trailing_md_op = NULL;
+        needs_close = true;
+      }
+    }
+    maybe_schedule_op_closure_locked(exec_ctx, other, GRPC_ERROR_NONE);
+    complete_if_batch_end_locked(
+        exec_ctx, s, GRPC_ERROR_NONE, s->send_trailing_md_op,
+        "op_state_machine scheduling send-trailing-metadata-on-complete");
+    s->send_trailing_md_op = NULL;
+  }
+  if (s->recv_initial_md_op) {
+    if (s->initial_md_recvd) {
       new_err =
           GRPC_ERROR_CREATE_FROM_STATIC_STRING("Already recvd initial md");
       INPROC_LOG(
           GPR_DEBUG,
-          "read_state_machine %p scheduling on_complete errors for already "
+          "op_state_machine %p scheduling on_complete errors for already "
           "recvd initial md %p",
           s, new_err);
       fail_helper_locked(exec_ctx, s, GRPC_ERROR_REF(new_err));
       goto done;
     }
 
-    s->initial_md_recvd = true;
-    new_err = fill_in_metadata(
-        exec_ctx, s, &s->to_read_initial_md, s->to_read_initial_md_flags,
-        s->recv_initial_md_op->payload->recv_initial_metadata
-            .recv_initial_metadata,
-        s->recv_initial_md_op->payload->recv_initial_metadata.recv_flags, NULL);
-    s->recv_initial_md_op->payload->recv_initial_metadata.recv_initial_metadata
-        ->deadline = s->deadline;
-    grpc_metadata_batch_clear(exec_ctx, &s->to_read_initial_md);
-    s->to_read_initial_md_filled = false;
-    INPROC_LOG(GPR_DEBUG,
-               "read_state_machine %p scheduling initial-metadata-ready %p", s,
-               new_err);
-    GRPC_CLOSURE_SCHED(exec_ctx,
-                       s->recv_initial_md_op->payload->recv_initial_metadata
-                           .recv_initial_metadata_ready,
-                       GRPC_ERROR_REF(new_err));
-    if ((s->recv_initial_md_op != s->recv_message_op) &&
-        (s->recv_initial_md_op != s->recv_trailing_md_op)) {
-      INPROC_LOG(
-          GPR_DEBUG,
-          "read_state_machine %p scheduling initial-metadata-on-complete %p", s,
-          new_err);
-      GRPC_CLOSURE_SCHED(exec_ctx, s->recv_initial_md_op->on_complete,
-                         GRPC_ERROR_REF(new_err));
-    }
-    s->recv_initial_md_op = NULL;
-
-    if (new_err != GRPC_ERROR_NONE) {
+    if (s->to_read_initial_md_filled) {
+      s->initial_md_recvd = true;
+      new_err = fill_in_metadata(
+          exec_ctx, s, &s->to_read_initial_md, s->to_read_initial_md_flags,
+          s->recv_initial_md_op->payload->recv_initial_metadata
+              .recv_initial_metadata,
+          s->recv_initial_md_op->payload->recv_initial_metadata.recv_flags,
+          NULL);
+      s->recv_initial_md_op->payload->recv_initial_metadata
+          .recv_initial_metadata->deadline = s->deadline;
+      grpc_metadata_batch_clear(exec_ctx, &s->to_read_initial_md);
+      s->to_read_initial_md_filled = false;
       INPROC_LOG(GPR_DEBUG,
-                 "read_state_machine %p scheduling on_complete errors2 %p", s,
+                 "op_state_machine %p scheduling initial-metadata-ready %p", s,
                  new_err);
-      fail_helper_locked(exec_ctx, s, GRPC_ERROR_REF(new_err));
-      goto done;
+      GRPC_CLOSURE_SCHED(exec_ctx,
+                         s->recv_initial_md_op->payload->recv_initial_metadata
+                             .recv_initial_metadata_ready,
+                         GRPC_ERROR_REF(new_err));
+      complete_if_batch_end_locked(
+          exec_ctx, s, new_err, s->recv_initial_md_op,
+          "op_state_machine scheduling recv-initial-metadata-on-complete");
+      s->recv_initial_md_op = NULL;
+
+      if (new_err != GRPC_ERROR_NONE) {
+        INPROC_LOG(GPR_DEBUG,
+                   "op_state_machine %p scheduling on_complete errors2 %p", s,
+                   new_err);
+        fail_helper_locked(exec_ctx, s, GRPC_ERROR_REF(new_err));
+        goto done;
+      }
     }
   }
-  if (s->to_read_initial_md_filled) {
-    new_err = GRPC_ERROR_CREATE_FROM_STATIC_STRING("Unexpected recv frame");
-    fail_helper_locked(exec_ctx, s, GRPC_ERROR_REF(new_err));
-    goto done;
-  }
-  if (!slice_buffer_list_empty(&s->to_read_message) && s->recv_message_op) {
-    inproc_slice_byte_stream_init(
-        &s->recv_message_stream,
-        slice_buffer_list_pophead(&s->to_read_message));
-    *s->recv_message_op->payload->recv_message.recv_message =
-        &s->recv_message_stream.base;
-    INPROC_LOG(GPR_DEBUG, "read_state_machine %p scheduling message-ready", s);
-    GRPC_CLOSURE_SCHED(
-        exec_ctx, s->recv_message_op->payload->recv_message.recv_message_ready,
-        GRPC_ERROR_NONE);
-    if (s->recv_message_op != s->recv_trailing_md_op) {
-      INPROC_LOG(GPR_DEBUG,
-                 "read_state_machine %p scheduling message-on-complete %p", s,
-                 new_err);
-      GRPC_CLOSURE_SCHED(exec_ctx, s->recv_message_op->on_complete,
-                         GRPC_ERROR_REF(new_err));
+  if (s->recv_message_op) {
+    if (other && other->send_message_op) {
+      message_transfer_locked(exec_ctx, other, s);
+      maybe_schedule_op_closure_locked(exec_ctx, other, GRPC_ERROR_NONE);
     }
-    s->recv_message_op = NULL;
+  }
+  if (s->recv_trailing_md_op && s->t->is_client && other &&
+      other->send_message_op) {
+    maybe_schedule_op_closure_locked(exec_ctx, other, GRPC_ERROR_NONE);
   }
   if (s->to_read_trailing_md_filled) {
     if (s->trailing_md_recvd) {
@@ -722,7 +707,7 @@ static void read_state_machine(grpc_exec_ctx *exec_ctx, void *arg,
           GRPC_ERROR_CREATE_FROM_STATIC_STRING("Already recvd trailing md");
       INPROC_LOG(
           GPR_DEBUG,
-          "read_state_machine %p scheduling on_complete errors for already "
+          "op_state_machine %p scheduling on_complete errors for already "
           "recvd trailing md %p",
           s, new_err);
       fail_helper_locked(exec_ctx, s, GRPC_ERROR_REF(new_err));
@@ -731,21 +716,24 @@ static void read_state_machine(grpc_exec_ctx *exec_ctx, void *arg,
     if (s->recv_message_op != NULL) {
       // This message needs to be wrapped up because it will never be
       // satisfied
-      INPROC_LOG(GPR_DEBUG, "read_state_machine %p scheduling message-ready",
-                 s);
+      INPROC_LOG(GPR_DEBUG, "op_state_machine %p scheduling message-ready", s);
       GRPC_CLOSURE_SCHED(
           exec_ctx,
           s->recv_message_op->payload->recv_message.recv_message_ready,
           GRPC_ERROR_NONE);
-      if (s->recv_message_op != s->recv_trailing_md_op) {
-        INPROC_LOG(GPR_DEBUG,
-                   "read_state_machine %p scheduling message-on-complete %p", s,
-                   new_err);
-        GRPC_CLOSURE_SCHED(exec_ctx, s->recv_message_op->on_complete,
-                           GRPC_ERROR_REF(new_err));
-      }
+      complete_if_batch_end_locked(
+          exec_ctx, s, new_err, s->recv_message_op,
+          "op_state_machine scheduling recv-message-on-complete");
       s->recv_message_op = NULL;
     }
+    if ((s->trailing_md_sent || s->t->is_client) && s->send_message_op) {
+      // Nothing further will try to receive from this stream, so finish off
+      // any outstanding send_message op
+      complete_if_batch_end_locked(
+          exec_ctx, s, new_err, s->send_message_op,
+          "op_state_machine scheduling send-message-on-complete");
+      s->send_message_op = NULL;
+    }
     if (s->recv_trailing_md_op != NULL) {
       // We wanted trailing metadata and we got it
       s->trailing_md_recvd = true;
@@ -763,61 +751,65 @@ static void read_state_machine(grpc_exec_ctx *exec_ctx, void *arg,
       //    (If the server hasn't already sent its trailing md, it doesn't have
       //     a final status, so don't mark this op complete)
       if (s->t->is_client || s->trailing_md_sent) {
-        INPROC_LOG(
-            GPR_DEBUG,
-            "read_state_machine %p scheduling trailing-md-on-complete %p", s,
-            new_err);
+        INPROC_LOG(GPR_DEBUG,
+                   "op_state_machine %p scheduling trailing-md-on-complete %p",
+                   s, new_err);
         GRPC_CLOSURE_SCHED(exec_ctx, s->recv_trailing_md_op->on_complete,
                            GRPC_ERROR_REF(new_err));
         s->recv_trailing_md_op = NULL;
         needs_close = true;
       } else {
         INPROC_LOG(GPR_DEBUG,
-                   "read_state_machine %p server needs to delay handling "
+                   "op_state_machine %p server needs to delay handling "
                    "trailing-md-on-complete %p",
                    s, new_err);
       }
     } else {
       INPROC_LOG(
           GPR_DEBUG,
-          "read_state_machine %p has trailing md but not yet waiting for it",
-          s);
+          "op_state_machine %p has trailing md but not yet waiting for it", s);
     }
   }
   if (s->trailing_md_recvd && s->recv_message_op) {
     // No further message will come on this stream, so finish off the
     // recv_message_op
-    INPROC_LOG(GPR_DEBUG, "read_state_machine %p scheduling message-ready", s);
+    INPROC_LOG(GPR_DEBUG, "op_state_machine %p scheduling message-ready", s);
     GRPC_CLOSURE_SCHED(
         exec_ctx, s->recv_message_op->payload->recv_message.recv_message_ready,
         GRPC_ERROR_NONE);
-    if (s->recv_message_op != s->recv_trailing_md_op) {
-      INPROC_LOG(GPR_DEBUG,
-                 "read_state_machine %p scheduling message-on-complete %p", s,
-                 new_err);
-      GRPC_CLOSURE_SCHED(exec_ctx, s->recv_message_op->on_complete,
-                         GRPC_ERROR_REF(new_err));
-    }
+    complete_if_batch_end_locked(
+        exec_ctx, s, new_err, s->recv_message_op,
+        "op_state_machine scheduling recv-message-on-complete");
     s->recv_message_op = NULL;
   }
-  if (s->recv_message_op || s->recv_trailing_md_op) {
+  if (s->trailing_md_recvd && (s->trailing_md_sent || s->t->is_client) &&
+      s->send_message_op) {
+    // Nothing further will try to receive from this stream, so finish off
+    // any outstanding send_message op
+    complete_if_batch_end_locked(
+        exec_ctx, s, new_err, s->send_message_op,
+        "op_state_machine scheduling send-message-on-complete");
+    s->send_message_op = NULL;
+  }
+  if (s->send_message_op || s->send_trailing_md_op || s->recv_initial_md_op ||
+      s->recv_message_op || s->recv_trailing_md_op) {
     // Didn't get the item we wanted so we still need to get
     // rescheduled
-    INPROC_LOG(GPR_DEBUG, "read_state_machine %p still needs closure %p %p", s,
-               s->recv_message_op, s->recv_trailing_md_op);
-    s->reads_needed = true;
+    INPROC_LOG(
+        GPR_DEBUG, "op_state_machine %p still needs closure %p %p %p %p %p", s,
+        s->send_message_op, s->send_trailing_md_op, s->recv_initial_md_op,
+        s->recv_message_op, s->recv_trailing_md_op);
+    s->ops_needed = true;
   }
 done:
   if (needs_close) {
-    close_other_side_locked(exec_ctx, s, "read_state_machine");
+    close_other_side_locked(exec_ctx, s, "op_state_machine");
     close_stream_locked(exec_ctx, s);
   }
   gpr_mu_unlock(mu);
   GRPC_ERROR_UNREF(new_err);
 }
 
-static grpc_closure do_nothing_closure;
-
 static bool cancel_stream_locked(grpc_exec_ctx *exec_ctx, inproc_stream *s,
                                  grpc_error *error) {
   bool ret = false;  // was the cancel accepted
@@ -826,14 +818,7 @@ static bool cancel_stream_locked(grpc_exec_ctx *exec_ctx, inproc_stream *s,
   if (s->cancel_self_error == GRPC_ERROR_NONE) {
     ret = true;
     s->cancel_self_error = GRPC_ERROR_REF(error);
-    if (s->reads_needed) {
-      if (!s->read_closure_scheduled) {
-        GRPC_CLOSURE_SCHED(exec_ctx, &s->read_closure,
-                           GRPC_ERROR_REF(s->cancel_self_error));
-        s->read_closure_scheduled = true;
-      }
-      s->reads_needed = false;
-    }
+    maybe_schedule_op_closure_locked(exec_ctx, s, s->cancel_self_error);
     // Send trailing md to the other side indicating cancellation, even if we
     // already have
     s->trailing_md_sent = true;
@@ -853,14 +838,8 @@ static bool cancel_stream_locked(grpc_exec_ctx *exec_ctx, inproc_stream *s,
       if (other->cancel_other_error == GRPC_ERROR_NONE) {
         other->cancel_other_error = GRPC_ERROR_REF(s->cancel_self_error);
       }
-      if (other->reads_needed) {
-        if (!other->read_closure_scheduled) {
-          GRPC_CLOSURE_SCHED(exec_ctx, &other->read_closure,
-                             GRPC_ERROR_REF(other->cancel_other_error));
-          other->read_closure_scheduled = true;
-        }
-        other->reads_needed = false;
-      }
+      maybe_schedule_op_closure_locked(exec_ctx, other,
+                                       other->cancel_other_error);
     } else if (s->write_buffer_cancel_error == GRPC_ERROR_NONE) {
       s->write_buffer_cancel_error = GRPC_ERROR_REF(s->cancel_self_error);
     }
@@ -869,11 +848,9 @@ static bool cancel_stream_locked(grpc_exec_ctx *exec_ctx, inproc_stream *s,
     // couldn't complete that because we hadn't yet sent out trailing
     // md, now's the chance
     if (!s->t->is_client && s->trailing_md_recvd && s->recv_trailing_md_op) {
-      INPROC_LOG(GPR_DEBUG,
-                 "cancel_stream %p scheduling trailing-md-on-complete %p", s,
-                 s->cancel_self_error);
-      GRPC_CLOSURE_SCHED(exec_ctx, s->recv_trailing_md_op->on_complete,
-                         GRPC_ERROR_REF(s->cancel_self_error));
+      complete_if_batch_end_locked(
+          exec_ctx, s, s->cancel_self_error, s->recv_trailing_md_op,
+          "cancel_stream scheduling trailing-md-on-complete");
       s->recv_trailing_md_op = NULL;
     }
   }
@@ -918,7 +895,8 @@ static void perform_stream_op(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
     // already self-canceled so still give it an error
     error = GRPC_ERROR_REF(s->cancel_self_error);
   } else {
-    INPROC_LOG(GPR_DEBUG, "perform_stream_op %p%s%s%s%s%s%s", s,
+    INPROC_LOG(GPR_DEBUG, "perform_stream_op %p %s%s%s%s%s%s%s", s,
+               s->t->is_client ? "client" : "server",
                op->send_initial_metadata ? " send_initial_metadata" : "",
                op->send_message ? " send_message" : "",
                op->send_trailing_metadata ? " send_trailing_metadata" : "",
@@ -929,10 +907,9 @@ static void perform_stream_op(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
 
   bool needs_close = false;
 
+  inproc_stream *other = s->other_side;
   if (error == GRPC_ERROR_NONE &&
-      (op->send_initial_metadata || op->send_message ||
-       op->send_trailing_metadata)) {
-    inproc_stream *other = s->other_side;
+      (op->send_initial_metadata || op->send_trailing_metadata)) {
     if (s->t->is_closed) {
       error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("Endpoint already shutdown");
     }
@@ -956,79 +933,28 @@ static void perform_stream_op(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
               dest, destflags, destfilled);
         }
         if (s->t->is_client) {
-          gpr_timespec *dl =
+          grpc_millis *dl =
               (other == NULL) ? &s->write_buffer_deadline : &other->deadline;
-          *dl = gpr_time_min(*dl, op->payload->send_initial_metadata
-                                      .send_initial_metadata->deadline);
+          *dl = GPR_MIN(*dl, op->payload->send_initial_metadata
+                                 .send_initial_metadata->deadline);
           s->initial_md_sent = true;
         }
       }
-    }
-    if (error == GRPC_ERROR_NONE && op->send_message) {
-      size_t remaining = op->payload->send_message.send_message->length;
-      grpc_slice_buffer *dest = slice_buffer_list_append(
-          (other == NULL) ? &s->write_buffer_message : &other->to_read_message);
-      do {
-        grpc_slice message_slice;
-        grpc_closure unused;
-        GPR_ASSERT(grpc_byte_stream_next(exec_ctx,
-                                         op->payload->send_message.send_message,
-                                         SIZE_MAX, &unused));
-        error = grpc_byte_stream_pull(
-            exec_ctx, op->payload->send_message.send_message, &message_slice);
-        if (error != GRPC_ERROR_NONE) {
-          cancel_stream_locked(exec_ctx, s, GRPC_ERROR_REF(error));
-          break;
-        }
-        GPR_ASSERT(error == GRPC_ERROR_NONE);
-        remaining -= GRPC_SLICE_LENGTH(message_slice);
-        grpc_slice_buffer_add(dest, message_slice);
-      } while (remaining != 0);
-      grpc_byte_stream_destroy(exec_ctx,
-                               op->payload->send_message.send_message);
-    }
-    if (error == GRPC_ERROR_NONE && op->send_trailing_metadata) {
-      grpc_metadata_batch *dest = (other == NULL) ? &s->write_buffer_trailing_md
-                                                  : &other->to_read_trailing_md;
-      bool *destfilled = (other == NULL) ? &s->write_buffer_trailing_md_filled
-                                         : &other->to_read_trailing_md_filled;
-      if (*destfilled || s->trailing_md_sent) {
-        // The buffer is already in use; that's an error!
-        INPROC_LOG(GPR_DEBUG, "Extra trailing metadata %p", s);
-        error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("Extra trailing metadata");
-      } else {
-        if (!other->closed) {
-          fill_in_metadata(
-              exec_ctx, s,
-              op->payload->send_trailing_metadata.send_trailing_metadata, 0,
-              dest, NULL, destfilled);
-        }
-        s->trailing_md_sent = true;
-        if (!s->t->is_client && s->trailing_md_recvd &&
-            s->recv_trailing_md_op) {
-          INPROC_LOG(GPR_DEBUG,
-                     "perform_stream_op %p scheduling trailing-md-on-complete",
-                     s);
-          GRPC_CLOSURE_SCHED(exec_ctx, s->recv_trailing_md_op->on_complete,
-                             GRPC_ERROR_NONE);
-          s->recv_trailing_md_op = NULL;
-          needs_close = true;
-        }
-      }
-    }
-    if (other != NULL && other->reads_needed) {
-      if (!other->read_closure_scheduled) {
-        GRPC_CLOSURE_SCHED(exec_ctx, &other->read_closure, error);
-        other->read_closure_scheduled = true;
-      }
-      other->reads_needed = false;
+      maybe_schedule_op_closure_locked(exec_ctx, other, error);
     }
   }
+
   if (error == GRPC_ERROR_NONE &&
-      (op->recv_initial_metadata || op->recv_message ||
+      (op->send_message || op->send_trailing_metadata ||
+       op->recv_initial_metadata || op->recv_message ||
        op->recv_trailing_metadata)) {
-    // If there are any reads, mark it so that the read closure will react to
-    // them
+    // Mark ops that need to be processed by the closure
+    if (op->send_message) {
+      s->send_message_op = op;
+    }
+    if (op->send_trailing_metadata) {
+      s->send_trailing_md_op = op;
+    }
     if (op->recv_initial_metadata) {
       s->recv_initial_md_op = op;
     }
@@ -1040,25 +966,28 @@ static void perform_stream_op(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
     }
 
     // We want to initiate the closure if:
-    // 1. There is initial metadata and something ready to take that
-    // 2. There is a message and something ready to take it
-    // 3. There is trailing metadata, even if nothing specifically wants
-    //    that because that can shut down the message as well
-    if ((s->to_read_initial_md_filled && op->recv_initial_metadata) ||
-        ((!slice_buffer_list_empty(&s->to_read_message) ||
-          s->trailing_md_recvd) &&
-         op->recv_message) ||
-        (s->to_read_trailing_md_filled)) {
-      if (!s->read_closure_scheduled) {
-        GRPC_CLOSURE_SCHED(exec_ctx, &s->read_closure, GRPC_ERROR_NONE);
-        s->read_closure_scheduled = true;
+    // 1. We want to send a message and the other side wants to receive or end
+    // 2. We want to send trailing metadata and there isn't an unmatched send
+    // 3. We want initial metadata and the other side has sent it
+    // 4. We want to receive a message and there is a message ready
+    // 5. There is trailing metadata, even if nothing specifically wants
+    //    that because that can shut down the receive message as well
+    if ((op->send_message && other && ((other->recv_message_op != NULL) ||
+                                       (other->recv_trailing_md_op != NULL))) ||
+        (op->send_trailing_metadata && !op->send_message) ||
+        (op->recv_initial_metadata && s->to_read_initial_md_filled) ||
+        (op->recv_message && (other && other->send_message_op != NULL)) ||
+        (s->to_read_trailing_md_filled || s->trailing_md_recvd)) {
+      if (!s->op_closure_scheduled) {
+        GRPC_CLOSURE_SCHED(exec_ctx, &s->op_closure, GRPC_ERROR_NONE);
+        s->op_closure_scheduled = true;
       }
     } else {
-      s->reads_needed = true;
+      s->ops_needed = true;
     }
   } else {
     if (error != GRPC_ERROR_NONE) {
-      // Schedule op's read closures that we didn't push to read state machine
+      // Schedule op's closures that we didn't push to op state machine
       if (op->recv_initial_metadata) {
         INPROC_LOG(
             GPR_DEBUG,
diff --git a/src/core/lib/support/backoff.cc b/src/core/lib/backoff/backoff.cc
similarity index 63%
rename from src/core/lib/support/backoff.cc
rename to src/core/lib/backoff/backoff.cc
index 6dc0df473b5..fe0a7518171 100644
--- a/src/core/lib/support/backoff.cc
+++ b/src/core/lib/backoff/backoff.cc
@@ -16,13 +16,14 @@
  *
  */
 
-#include "src/core/lib/support/backoff.h"
+#include "src/core/lib/backoff/backoff.h"
 
 #include <grpc/support/useful.h>
 
-void gpr_backoff_init(gpr_backoff *backoff, int64_t initial_connect_timeout,
-                      double multiplier, double jitter,
-                      int64_t min_timeout_millis, int64_t max_timeout_millis) {
+void grpc_backoff_init(grpc_backoff *backoff,
+                       grpc_millis initial_connect_timeout, double multiplier,
+                       double jitter, grpc_millis min_timeout_millis,
+                       grpc_millis max_timeout_millis) {
   backoff->initial_connect_timeout = initial_connect_timeout;
   backoff->multiplier = multiplier;
   backoff->jitter = jitter;
@@ -31,11 +32,11 @@ void gpr_backoff_init(gpr_backoff *backoff, int64_t initial_connect_timeout,
   backoff->rng_state = (uint32_t)gpr_now(GPR_CLOCK_REALTIME).tv_nsec;
 }
 
-gpr_timespec gpr_backoff_begin(gpr_backoff *backoff, gpr_timespec now) {
+grpc_millis grpc_backoff_begin(grpc_exec_ctx *exec_ctx, grpc_backoff *backoff) {
   backoff->current_timeout_millis = backoff->initial_connect_timeout;
-  const int64_t first_timeout =
+  const grpc_millis first_timeout =
       GPR_MAX(backoff->current_timeout_millis, backoff->min_timeout_millis);
-  return gpr_time_add(now, gpr_time_from_millis(first_timeout, GPR_TIMESPAN));
+  return grpc_exec_ctx_now(exec_ctx) + first_timeout;
 }
 
 /* Generate a random number between 0 and 1. */
@@ -44,11 +45,11 @@ static double generate_uniform_random_number(uint32_t *rng_state) {
   return *rng_state / (double)((uint32_t)1 << 31);
 }
 
-gpr_timespec gpr_backoff_step(gpr_backoff *backoff, gpr_timespec now) {
+grpc_millis grpc_backoff_step(grpc_exec_ctx *exec_ctx, grpc_backoff *backoff) {
   const double new_timeout_millis =
       backoff->multiplier * (double)backoff->current_timeout_millis;
   backoff->current_timeout_millis =
-      GPR_MIN((int64_t)new_timeout_millis, backoff->max_timeout_millis);
+      GPR_MIN((grpc_millis)new_timeout_millis, backoff->max_timeout_millis);
 
   const double jitter_range_width = backoff->jitter * new_timeout_millis;
   const double jitter =
@@ -56,17 +57,17 @@ gpr_timespec gpr_backoff_step(gpr_backoff *backoff, gpr_timespec now) {
       jitter_range_width;
 
   backoff->current_timeout_millis =
-      (int64_t)((double)(backoff->current_timeout_millis) + jitter);
+      (grpc_millis)((double)(backoff->current_timeout_millis) + jitter);
 
-  const gpr_timespec current_deadline = gpr_time_add(
-      now, gpr_time_from_millis(backoff->current_timeout_millis, GPR_TIMESPAN));
+  const grpc_millis current_deadline =
+      grpc_exec_ctx_now(exec_ctx) + backoff->current_timeout_millis;
 
-  const gpr_timespec min_deadline = gpr_time_add(
-      now, gpr_time_from_millis(backoff->min_timeout_millis, GPR_TIMESPAN));
+  const grpc_millis min_deadline =
+      grpc_exec_ctx_now(exec_ctx) + backoff->min_timeout_millis;
 
-  return gpr_time_max(current_deadline, min_deadline);
+  return GPR_MAX(current_deadline, min_deadline);
 }
 
-void gpr_backoff_reset(gpr_backoff *backoff) {
+void grpc_backoff_reset(grpc_backoff *backoff) {
   backoff->current_timeout_millis = backoff->initial_connect_timeout;
 }
diff --git a/src/core/lib/support/backoff.h b/src/core/lib/backoff/backoff.h
similarity index 60%
rename from src/core/lib/support/backoff.h
rename to src/core/lib/backoff/backoff.h
index 31ec28f6666..80e49ea52ab 100644
--- a/src/core/lib/support/backoff.h
+++ b/src/core/lib/backoff/backoff.h
@@ -16,10 +16,10 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SUPPORT_BACKOFF_H
-#define GRPC_CORE_LIB_SUPPORT_BACKOFF_H
+#ifndef GRPC_CORE_LIB_BACKOFF_BACKOFF_H
+#define GRPC_CORE_LIB_BACKOFF_BACKOFF_H
 
-#include <grpc/support/time.h>
+#include "src/core/lib/iomgr/exec_ctx.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -27,38 +27,40 @@ extern "C" {
 
 typedef struct {
   /// const:  how long to wait after the first failure before retrying
-  int64_t initial_connect_timeout;
+  grpc_millis initial_connect_timeout;
   /// const: factor with which to multiply backoff after a failed retry
   double multiplier;
   /// const: amount to randomize backoffs
   double jitter;
   /// const: minimum time between retries in milliseconds
-  int64_t min_timeout_millis;
+  grpc_millis min_timeout_millis;
   /// const: maximum time between retries in milliseconds
-  int64_t max_timeout_millis;
+  grpc_millis max_timeout_millis;
 
   /// random number generator
   uint32_t rng_state;
 
   /// current retry timeout in milliseconds
-  int64_t current_timeout_millis;
-} gpr_backoff;
+  grpc_millis current_timeout_millis;
+} grpc_backoff;
 
 /// Initialize backoff machinery - does not need to be destroyed
-void gpr_backoff_init(gpr_backoff *backoff, int64_t initial_connect_timeout,
-                      double multiplier, double jitter,
-                      int64_t min_timeout_millis, int64_t max_timeout_millis);
+void grpc_backoff_init(grpc_backoff *backoff,
+                       grpc_millis initial_connect_timeout, double multiplier,
+                       double jitter, grpc_millis min_timeout_millis,
+                       grpc_millis max_timeout_millis);
 
 /// Begin retry loop: returns a timespec for the NEXT retry
-gpr_timespec gpr_backoff_begin(gpr_backoff *backoff, gpr_timespec now);
+grpc_millis grpc_backoff_begin(grpc_exec_ctx *exec_ctx, grpc_backoff *backoff);
 /// Step a retry loop: returns a timespec for the NEXT retry
-gpr_timespec gpr_backoff_step(gpr_backoff *backoff, gpr_timespec now);
-/// Reset the backoff, so the next gpr_backoff_step will be a gpr_backoff_begin
+grpc_millis grpc_backoff_step(grpc_exec_ctx *exec_ctx, grpc_backoff *backoff);
+/// Reset the backoff, so the next grpc_backoff_step will be a
+/// grpc_backoff_begin
 /// instead
-void gpr_backoff_reset(gpr_backoff *backoff);
+void grpc_backoff_reset(grpc_backoff *backoff);
 
 #ifdef __cplusplus
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_SUPPORT_BACKOFF_H */
+#endif /* GRPC_CORE_LIB_BACKOFF_BACKOFF_H */
diff --git a/src/core/lib/channel/channel_args.h b/src/core/lib/channel/channel_args.h
index 2837174f491..1896d35cf45 100644
--- a/src/core/lib/channel/channel_args.h
+++ b/src/core/lib/channel/channel_args.h
@@ -157,4 +157,4 @@ grpc_arg grpc_channel_arg_pointer_create(char *name, void *value,
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_CHANNEL_CHANNEL_ARGS_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_CHANNEL_CHANNEL_ARGS_H */
diff --git a/src/core/lib/channel/channel_stack.h b/src/core/lib/channel/channel_stack.h
index f0de80f0c04..5c00c098894 100644
--- a/src/core/lib/channel/channel_stack.h
+++ b/src/core/lib/channel/channel_stack.h
@@ -70,7 +70,7 @@ typedef struct {
   grpc_call_context_element *context;
   grpc_slice path;
   gpr_timespec start_time;
-  gpr_timespec deadline;
+  grpc_millis deadline;
   gpr_arena *arena;
   grpc_call_combiner *call_combiner;
 } grpc_call_element_args;
diff --git a/src/core/lib/channel/connected_channel.h b/src/core/lib/channel/connected_channel.h
index b55a1089a00..4615727baa1 100644
--- a/src/core/lib/channel/connected_channel.h
+++ b/src/core/lib/channel/connected_channel.h
@@ -38,4 +38,4 @@ grpc_stream *grpc_connected_channel_get_stream(grpc_call_element *elem);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_CHANNEL_CONNECTED_CHANNEL_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_CHANNEL_CONNECTED_CHANNEL_H */
diff --git a/src/core/lib/channel/handshaker.cc b/src/core/lib/channel/handshaker.cc
index 1753da57216..b27ee37e5b3 100644
--- a/src/core/lib/channel/handshaker.cc
+++ b/src/core/lib/channel/handshaker.cc
@@ -232,7 +232,7 @@ static void on_timeout(grpc_exec_ctx* exec_ctx, void* arg, grpc_error* error) {
 void grpc_handshake_manager_do_handshake(
     grpc_exec_ctx* exec_ctx, grpc_handshake_manager* mgr,
     grpc_endpoint* endpoint, const grpc_channel_args* channel_args,
-    gpr_timespec deadline, grpc_tcp_server_acceptor* acceptor,
+    grpc_millis deadline, grpc_tcp_server_acceptor* acceptor,
     grpc_iomgr_cb_func on_handshake_done, void* user_data) {
   gpr_mu_lock(&mgr->mu);
   GPR_ASSERT(mgr->index == 0);
@@ -255,9 +255,7 @@ void grpc_handshake_manager_do_handshake(
   gpr_ref(&mgr->refs);
   GRPC_CLOSURE_INIT(&mgr->on_timeout, on_timeout, mgr,
                     grpc_schedule_on_exec_ctx);
-  grpc_timer_init(exec_ctx, &mgr->deadline_timer,
-                  gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC),
-                  &mgr->on_timeout, gpr_now(GPR_CLOCK_MONOTONIC));
+  grpc_timer_init(exec_ctx, &mgr->deadline_timer, deadline, &mgr->on_timeout);
   // Start first handshaker, which also owns a ref.
   gpr_ref(&mgr->refs);
   bool done = call_next_handshaker_locked(exec_ctx, mgr, GRPC_ERROR_NONE);
diff --git a/src/core/lib/channel/handshaker.h b/src/core/lib/channel/handshaker.h
index a857cde7914..8ed38c15ba1 100644
--- a/src/core/lib/channel/handshaker.h
+++ b/src/core/lib/channel/handshaker.h
@@ -149,7 +149,7 @@ void grpc_handshake_manager_shutdown(grpc_exec_ctx* exec_ctx,
 void grpc_handshake_manager_do_handshake(
     grpc_exec_ctx* exec_ctx, grpc_handshake_manager* mgr,
     grpc_endpoint* endpoint, const grpc_channel_args* channel_args,
-    gpr_timespec deadline, grpc_tcp_server_acceptor* acceptor,
+    grpc_millis deadline, grpc_tcp_server_acceptor* acceptor,
     grpc_iomgr_cb_func on_handshake_done, void* user_data);
 
 /// Add \a mgr to the server side list of all pending handshake managers, the
@@ -172,4 +172,4 @@ void grpc_handshake_manager_pending_list_shutdown_all(
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_CHANNEL_HANDSHAKER_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_CHANNEL_HANDSHAKER_H */
diff --git a/src/core/lib/channel/handshaker_factory.h b/src/core/lib/channel/handshaker_factory.h
index 2a130de252a..59008adf057 100644
--- a/src/core/lib/channel/handshaker_factory.h
+++ b/src/core/lib/channel/handshaker_factory.h
@@ -56,4 +56,4 @@ void grpc_handshaker_factory_destroy(
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_CHANNEL_HANDSHAKER_FACTORY_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_CHANNEL_HANDSHAKER_FACTORY_H */
diff --git a/src/core/lib/channel/handshaker_registry.h b/src/core/lib/channel/handshaker_registry.h
index e96bf06b6af..ddd280bea8a 100644
--- a/src/core/lib/channel/handshaker_registry.h
+++ b/src/core/lib/channel/handshaker_registry.h
@@ -53,4 +53,4 @@ void grpc_handshakers_add(grpc_exec_ctx* exec_ctx,
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_CHANNEL_HANDSHAKER_REGISTRY_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_CHANNEL_HANDSHAKER_REGISTRY_H */
diff --git a/src/core/lib/compression/algorithm_metadata.h b/src/core/lib/compression/algorithm_metadata.h
index 3eb7088230b..17caf58f69c 100644
--- a/src/core/lib/compression/algorithm_metadata.h
+++ b/src/core/lib/compression/algorithm_metadata.h
@@ -57,4 +57,4 @@ grpc_stream_compression_algorithm grpc_stream_compression_algorithm_from_slice(
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_COMPRESSION_ALGORITHM_METADATA_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_COMPRESSION_ALGORITHM_METADATA_H */
diff --git a/src/core/lib/compression/message_compress.h b/src/core/lib/compression/message_compress.h
index d2545a02c2e..fffe175fd22 100644
--- a/src/core/lib/compression/message_compress.h
+++ b/src/core/lib/compression/message_compress.h
@@ -44,4 +44,4 @@ int grpc_msg_decompress(grpc_exec_ctx* exec_ctx,
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_COMPRESSION_MESSAGE_COMPRESS_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_COMPRESSION_MESSAGE_COMPRESS_H */
diff --git a/src/core/lib/debug/stats_data.cc b/src/core/lib/debug/stats_data.cc
index c0aec63c1d3..5bd7884e287 100644
--- a/src/core/lib/debug/stats_data.cc
+++ b/src/core/lib/debug/stats_data.cc
@@ -77,6 +77,7 @@ const char *grpc_stats_counter_name[GRPC_STATS_COUNTER_COUNT] = {
     "http2_initiate_write_due_to_transport_flow_control_unstalled",
     "http2_initiate_write_due_to_ping_response",
     "http2_initiate_write_due_to_force_rst_stream",
+    "http2_spurious_writes_begun",
     "hpack_recv_indexed",
     "hpack_recv_lithdr_incidx",
     "hpack_recv_lithdr_incidx_v",
@@ -177,6 +178,7 @@ const char *grpc_stats_counter_doc[GRPC_STATS_COUNTER_COUNT] = {
     "'transport_flow_control_unstalled'",
     "Number of HTTP2 writes initiated due to 'ping_response'",
     "Number of HTTP2 writes initiated due to 'force_rst_stream'",
+    "Number of HTTP2 writes initiated with nothing to write",
     "Number of HPACK indexed fields received",
     "Number of HPACK literal headers received with incremental indexing",
     "Number of HPACK literal headers received with incremental indexing and "
diff --git a/src/core/lib/debug/stats_data.h b/src/core/lib/debug/stats_data.h
index cf5bafbd047..d8e4e7d264b 100644
--- a/src/core/lib/debug/stats_data.h
+++ b/src/core/lib/debug/stats_data.h
@@ -83,6 +83,7 @@ typedef enum {
   GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_TRANSPORT_FLOW_CONTROL_UNSTALLED,
   GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_PING_RESPONSE,
   GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_FORCE_RST_STREAM,
+  GRPC_STATS_COUNTER_HTTP2_SPURIOUS_WRITES_BEGUN,
   GRPC_STATS_COUNTER_HPACK_RECV_INDEXED,
   GRPC_STATS_COUNTER_HPACK_RECV_LITHDR_INCIDX,
   GRPC_STATS_COUNTER_HPACK_RECV_LITHDR_INCIDX_V,
@@ -330,6 +331,9 @@ typedef enum {
   GRPC_STATS_INC_COUNTER(                                                     \
       (exec_ctx),                                                             \
       GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_FORCE_RST_STREAM)
+#define GRPC_STATS_INC_HTTP2_SPURIOUS_WRITES_BEGUN(exec_ctx) \
+  GRPC_STATS_INC_COUNTER((exec_ctx),                         \
+                         GRPC_STATS_COUNTER_HTTP2_SPURIOUS_WRITES_BEGUN)
 #define GRPC_STATS_INC_HPACK_RECV_INDEXED(exec_ctx) \
   GRPC_STATS_INC_COUNTER((exec_ctx), GRPC_STATS_COUNTER_HPACK_RECV_INDEXED)
 #define GRPC_STATS_INC_HPACK_RECV_LITHDR_INCIDX(exec_ctx) \
diff --git a/src/core/lib/debug/stats_data.yaml b/src/core/lib/debug/stats_data.yaml
index b5c15ff55c0..5c0ab2262e5 100644
--- a/src/core/lib/debug/stats_data.yaml
+++ b/src/core/lib/debug/stats_data.yaml
@@ -189,6 +189,8 @@
   doc: Number of HTTP2 writes initiated due to 'ping_response'
 - counter: http2_initiate_write_due_to_force_rst_stream
   doc: Number of HTTP2 writes initiated due to 'force_rst_stream'
+- counter: http2_spurious_writes_begun
+  doc: Number of HTTP2 writes initiated with nothing to write
 - counter: hpack_recv_indexed
   doc: Number of HPACK indexed fields received
 - counter: hpack_recv_lithdr_incidx
@@ -270,3 +272,4 @@
 - counter: server_slowpath_requests_queued
   doc: How many times was the server slow path taken (indicates too few
        outstanding requests)
+
diff --git a/src/core/lib/debug/stats_data_bq_schema.sql b/src/core/lib/debug/stats_data_bq_schema.sql
index f96e40c00ef..54869977b0b 100644
--- a/src/core/lib/debug/stats_data_bq_schema.sql
+++ b/src/core/lib/debug/stats_data_bq_schema.sql
@@ -52,6 +52,7 @@ http2_initiate_write_due_to_keepalive_ping_per_iteration:FLOAT,
 http2_initiate_write_due_to_transport_flow_control_unstalled_per_iteration:FLOAT,
 http2_initiate_write_due_to_ping_response_per_iteration:FLOAT,
 http2_initiate_write_due_to_force_rst_stream_per_iteration:FLOAT,
+http2_spurious_writes_begun_per_iteration:FLOAT,
 hpack_recv_indexed_per_iteration:FLOAT,
 hpack_recv_lithdr_incidx_per_iteration:FLOAT,
 hpack_recv_lithdr_incidx_v_per_iteration:FLOAT,
diff --git a/src/core/lib/http/format_request.h b/src/core/lib/http/format_request.h
index a559aac6603..2e77e8661a7 100644
--- a/src/core/lib/http/format_request.h
+++ b/src/core/lib/http/format_request.h
@@ -37,4 +37,4 @@ grpc_slice grpc_httpcli_format_connect_request(
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_HTTP_FORMAT_REQUEST_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_HTTP_FORMAT_REQUEST_H */
diff --git a/src/core/lib/http/httpcli.cc b/src/core/lib/http/httpcli.cc
index db995943a96..c96800b85c7 100644
--- a/src/core/lib/http/httpcli.cc
+++ b/src/core/lib/http/httpcli.cc
@@ -44,7 +44,7 @@ typedef struct {
   grpc_endpoint *ep;
   char *host;
   char *ssl_host_override;
-  gpr_timespec deadline;
+  grpc_millis deadline;
   int have_read_byte;
   const grpc_httpcli_handshaker *handshaker;
   grpc_closure *on_done;
@@ -65,7 +65,7 @@ static grpc_httpcli_post_override g_post_override = NULL;
 
 static void plaintext_handshake(grpc_exec_ctx *exec_ctx, void *arg,
                                 grpc_endpoint *endpoint, const char *host,
-                                gpr_timespec deadline,
+                                grpc_millis deadline,
                                 void (*on_done)(grpc_exec_ctx *exec_ctx,
                                                 void *arg,
                                                 grpc_endpoint *endpoint)) {
@@ -240,7 +240,7 @@ static void internal_request_begin(grpc_exec_ctx *exec_ctx,
                                    grpc_polling_entity *pollent,
                                    grpc_resource_quota *resource_quota,
                                    const grpc_httpcli_request *request,
-                                   gpr_timespec deadline, grpc_closure *on_done,
+                                   grpc_millis deadline, grpc_closure *on_done,
                                    grpc_httpcli_response *response,
                                    const char *name, grpc_slice request_text) {
   internal_request *req =
@@ -278,9 +278,8 @@ static void internal_request_begin(grpc_exec_ctx *exec_ctx,
 void grpc_httpcli_get(grpc_exec_ctx *exec_ctx, grpc_httpcli_context *context,
                       grpc_polling_entity *pollent,
                       grpc_resource_quota *resource_quota,
-                      const grpc_httpcli_request *request,
-                      gpr_timespec deadline, grpc_closure *on_done,
-                      grpc_httpcli_response *response) {
+                      const grpc_httpcli_request *request, grpc_millis deadline,
+                      grpc_closure *on_done, grpc_httpcli_response *response) {
   char *name;
   if (g_get_override &&
       g_get_override(exec_ctx, request, deadline, on_done, response)) {
@@ -298,7 +297,7 @@ void grpc_httpcli_post(grpc_exec_ctx *exec_ctx, grpc_httpcli_context *context,
                        grpc_resource_quota *resource_quota,
                        const grpc_httpcli_request *request,
                        const char *body_bytes, size_t body_size,
-                       gpr_timespec deadline, grpc_closure *on_done,
+                       grpc_millis deadline, grpc_closure *on_done,
                        grpc_httpcli_response *response) {
   char *name;
   if (g_post_override &&
diff --git a/src/core/lib/http/httpcli.h b/src/core/lib/http/httpcli.h
index 630481da540..76b790fa8ac 100644
--- a/src/core/lib/http/httpcli.h
+++ b/src/core/lib/http/httpcli.h
@@ -46,7 +46,7 @@ typedef struct grpc_httpcli_context {
 typedef struct {
   const char *default_port;
   void (*handshake)(grpc_exec_ctx *exec_ctx, void *arg, grpc_endpoint *endpoint,
-                    const char *host, gpr_timespec deadline,
+                    const char *host, grpc_millis deadline,
                     void (*on_done)(grpc_exec_ctx *exec_ctx, void *arg,
                                     grpc_endpoint *endpoint));
 } grpc_httpcli_handshaker;
@@ -87,8 +87,8 @@ void grpc_httpcli_context_destroy(grpc_exec_ctx *exec_ctx,
 void grpc_httpcli_get(grpc_exec_ctx *exec_ctx, grpc_httpcli_context *context,
                       grpc_polling_entity *pollent,
                       grpc_resource_quota *resource_quota,
-                      const grpc_httpcli_request *request,
-                      gpr_timespec deadline, grpc_closure *on_complete,
+                      const grpc_httpcli_request *request, grpc_millis deadline,
+                      grpc_closure *on_complete,
                       grpc_httpcli_response *response);
 
 /* Asynchronously perform a HTTP POST.
@@ -110,18 +110,18 @@ void grpc_httpcli_post(grpc_exec_ctx *exec_ctx, grpc_httpcli_context *context,
                        grpc_resource_quota *resource_quota,
                        const grpc_httpcli_request *request,
                        const char *body_bytes, size_t body_size,
-                       gpr_timespec deadline, grpc_closure *on_complete,
+                       grpc_millis deadline, grpc_closure *on_complete,
                        grpc_httpcli_response *response);
 
 /* override functions return 1 if they handled the request, 0 otherwise */
 typedef int (*grpc_httpcli_get_override)(grpc_exec_ctx *exec_ctx,
                                          const grpc_httpcli_request *request,
-                                         gpr_timespec deadline,
+                                         grpc_millis deadline,
                                          grpc_closure *on_complete,
                                          grpc_httpcli_response *response);
 typedef int (*grpc_httpcli_post_override)(
     grpc_exec_ctx *exec_ctx, const grpc_httpcli_request *request,
-    const char *body_bytes, size_t body_size, gpr_timespec deadline,
+    const char *body_bytes, size_t body_size, grpc_millis deadline,
     grpc_closure *on_complete, grpc_httpcli_response *response);
 
 void grpc_httpcli_set_override(grpc_httpcli_get_override get,
@@ -131,4 +131,4 @@ void grpc_httpcli_set_override(grpc_httpcli_get_override get,
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_HTTP_HTTPCLI_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_HTTP_HTTPCLI_H */
diff --git a/src/core/lib/http/httpcli_security_connector.cc b/src/core/lib/http/httpcli_security_connector.cc
index 8a0f225ba24..ef6c4a509bd 100644
--- a/src/core/lib/http/httpcli_security_connector.cc
+++ b/src/core/lib/http/httpcli_security_connector.cc
@@ -157,7 +157,7 @@ static void on_handshake_done(grpc_exec_ctx *exec_ctx, void *arg,
 
 static void ssl_handshake(grpc_exec_ctx *exec_ctx, void *arg,
                           grpc_endpoint *tcp, const char *host,
-                          gpr_timespec deadline,
+                          grpc_millis deadline,
                           void (*on_done)(grpc_exec_ctx *exec_ctx, void *arg,
                                           grpc_endpoint *endpoint)) {
   on_done_closure *c = (on_done_closure *)gpr_malloc(sizeof(*c));
diff --git a/src/core/lib/http/parser.h b/src/core/lib/http/parser.h
index 5484948bea8..d2bda6ae0e4 100644
--- a/src/core/lib/http/parser.h
+++ b/src/core/lib/http/parser.h
@@ -117,4 +117,4 @@ extern grpc_tracer_flag grpc_http1_trace;
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_HTTP_PARSER_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_HTTP_PARSER_H */
diff --git a/src/core/lib/support/block_annotate.h b/src/core/lib/iomgr/block_annotate.h
similarity index 58%
rename from src/core/lib/support/block_annotate.h
rename to src/core/lib/iomgr/block_annotate.h
index 8e3ef7df65c..fcbfe9eb1a0 100644
--- a/src/core/lib/support/block_annotate.h
+++ b/src/core/lib/iomgr/block_annotate.h
@@ -16,8 +16,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SUPPORT_BLOCK_ANNOTATE_H
-#define GRPC_CORE_LIB_SUPPORT_BLOCK_ANNOTATE_H
+#ifndef GRPC_CORE_LIB_IOMGR_BLOCK_ANNOTATE_H
+#define GRPC_CORE_LIB_IOMGR_BLOCK_ANNOTATE_H
 
 #ifdef __cplusplus
 extern "C" {
@@ -39,17 +39,26 @@ void gpr_thd_end_blocking_region();
   do {                                        \
     gpr_thd_start_blocking_region();          \
   } while (0)
-#define GRPC_SCHEDULING_END_BLOCKING_REGION \
-  do {                                      \
-    gpr_thd_end_blocking_region();          \
+#define GRPC_SCHEDULING_END_BLOCKING_REGION_NO_EXEC_CTX \
+  do {                                                  \
+    gpr_thd_end_blocking_region();                      \
+  } while (0)
+#define GRPC_SCHEDULING_END_BLOCKING_REGION_WITH_EXEC_CTX(ec) \
+  do {                                                        \
+    gpr_thd_end_blocking_region();                            \
+    grpc_exec_ctx_invalidate_now((ec));                       \
   } while (0)
 #else
 #define GRPC_SCHEDULING_START_BLOCKING_REGION \
   do {                                        \
   } while (0)
-#define GRPC_SCHEDULING_END_BLOCKING_REGION \
-  do {                                      \
+#define GRPC_SCHEDULING_END_BLOCKING_REGION_NO_EXEC_CTX \
+  do {                                                  \
+  } while (0)
+#define GRPC_SCHEDULING_END_BLOCKING_REGION_WITH_EXEC_CTX(ec) \
+  do {                                                        \
+    grpc_exec_ctx_invalidate_now((ec));                       \
   } while (0)
 #endif
 
-#endif /* GRPC_CORE_LIB_SUPPORT_BLOCK_ANNOTATE_H */
+#endif /* GRPC_CORE_LIB_IOMGR_BLOCK_ANNOTATE_H */
diff --git a/src/core/lib/iomgr/endpoint.h b/src/core/lib/iomgr/endpoint.h
index 16ff0ab733e..21347d90230 100644
--- a/src/core/lib/iomgr/endpoint.h
+++ b/src/core/lib/iomgr/endpoint.h
@@ -103,4 +103,4 @@ struct grpc_endpoint {
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_ENDPOINT_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_ENDPOINT_H */
diff --git a/src/core/lib/iomgr/endpoint_pair.h b/src/core/lib/iomgr/endpoint_pair.h
index f8830022f4b..ee91795749b 100644
--- a/src/core/lib/iomgr/endpoint_pair.h
+++ b/src/core/lib/iomgr/endpoint_pair.h
@@ -37,4 +37,4 @@ grpc_endpoint_pair grpc_iomgr_create_endpoint_pair(const char *name,
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_ENDPOINT_PAIR_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_ENDPOINT_PAIR_H */
diff --git a/src/core/lib/iomgr/error_internal.h b/src/core/lib/iomgr/error_internal.h
index f718e06d4e5..8746d5d353f 100644
--- a/src/core/lib/iomgr/error_internal.h
+++ b/src/core/lib/iomgr/error_internal.h
@@ -65,4 +65,4 @@ bool grpc_error_is_special(grpc_error *err);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_ERROR_INTERNAL_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_ERROR_INTERNAL_H */
diff --git a/src/core/lib/iomgr/ev_epoll1_linux.cc b/src/core/lib/iomgr/ev_epoll1_linux.cc
index 689aac15bf2..6126e2771cd 100644
--- a/src/core/lib/iomgr/ev_epoll1_linux.cc
+++ b/src/core/lib/iomgr/ev_epoll1_linux.cc
@@ -24,6 +24,7 @@
 
 #include <assert.h>
 #include <errno.h>
+#include <limits.h>
 #include <poll.h>
 #include <pthread.h>
 #include <string.h>
@@ -39,12 +40,12 @@
 #include <grpc/support/useful.h>
 
 #include "src/core/lib/debug/stats.h"
+#include "src/core/lib/iomgr/block_annotate.h"
 #include "src/core/lib/iomgr/ev_posix.h"
 #include "src/core/lib/iomgr/iomgr_internal.h"
 #include "src/core/lib/iomgr/lockfree_event.h"
 #include "src/core/lib/iomgr/wakeup_fd_posix.h"
 #include "src/core/lib/profiling/timers.h"
-#include "src/core/lib/support/block_annotate.h"
 #include "src/core/lib/support/string.h"
 
 static grpc_wakeup_fd global_wakeup_fd;
@@ -561,25 +562,17 @@ static void pollset_shutdown(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
   GPR_TIMER_END("pollset_shutdown", 0);
 }
 
-static int poll_deadline_to_millis_timeout(gpr_timespec deadline,
-                                           gpr_timespec now) {
-  gpr_timespec timeout;
-  if (gpr_time_cmp(deadline, gpr_inf_future(deadline.clock_type)) == 0) {
-    return -1;
-  }
-
-  if (gpr_time_cmp(deadline, now) <= 0) {
+static int poll_deadline_to_millis_timeout(grpc_exec_ctx *exec_ctx,
+                                           grpc_millis millis) {
+  if (millis == GRPC_MILLIS_INF_FUTURE) return -1;
+  grpc_millis delta = millis - grpc_exec_ctx_now(exec_ctx);
+  if (delta > INT_MAX) {
+    return INT_MAX;
+  } else if (delta < 0) {
     return 0;
+  } else {
+    return (int)delta;
   }
-
-  static const gpr_timespec round_up = {
-      0,                 /* tv_sec */
-      GPR_NS_PER_MS - 1, /* tv_nsec */
-      GPR_TIMESPAN       /* clock_type */
-  };
-  timeout = gpr_time_sub(deadline, now);
-  int millis = gpr_time_to_millis(gpr_time_add(timeout, round_up));
-  return millis >= 1 ? millis : 1;
 }
 
 /* Process the epoll events found by do_epoll_wait() function.
@@ -636,11 +629,11 @@ static grpc_error *process_epoll_events(grpc_exec_ctx *exec_ctx,
    (i.e the designated poller thread) will be calling this function. So there is
    no need for any synchronization when accesing fields in g_epoll_set */
 static grpc_error *do_epoll_wait(grpc_exec_ctx *exec_ctx, grpc_pollset *ps,
-                                 gpr_timespec now, gpr_timespec deadline) {
+                                 grpc_millis deadline) {
   GPR_TIMER_BEGIN("do_epoll_wait", 0);
 
   int r;
-  int timeout = poll_deadline_to_millis_timeout(deadline, now);
+  int timeout = poll_deadline_to_millis_timeout(exec_ctx, deadline);
   if (timeout != 0) {
     GRPC_SCHEDULING_START_BLOCKING_REGION;
   }
@@ -650,7 +643,7 @@ static grpc_error *do_epoll_wait(grpc_exec_ctx *exec_ctx, grpc_pollset *ps,
                    timeout);
   } while (r < 0 && errno == EINTR);
   if (timeout != 0) {
-    GRPC_SCHEDULING_END_BLOCKING_REGION;
+    GRPC_SCHEDULING_END_BLOCKING_REGION_WITH_EXEC_CTX(exec_ctx);
   }
 
   if (r < 0) return GRPC_OS_ERROR(errno, "epoll_wait");
@@ -668,9 +661,10 @@ static grpc_error *do_epoll_wait(grpc_exec_ctx *exec_ctx, grpc_pollset *ps,
   return GRPC_ERROR_NONE;
 }
 
-static bool begin_worker(grpc_pollset *pollset, grpc_pollset_worker *worker,
-                         grpc_pollset_worker **worker_hdl, gpr_timespec *now,
-                         gpr_timespec deadline) {
+static bool begin_worker(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+                         grpc_pollset_worker *worker,
+                         grpc_pollset_worker **worker_hdl,
+                         grpc_millis deadline) {
   GPR_TIMER_BEGIN("begin_worker", 0);
   if (worker_hdl != NULL) *worker_hdl = worker;
   worker->initialized_cv = false;
@@ -755,14 +749,15 @@ static bool begin_worker(grpc_pollset *pollset, grpc_pollset_worker *worker,
                 pollset->shutting_down);
       }
 
-      if (gpr_cv_wait(&worker->cv, &pollset->mu, deadline) &&
+      if (gpr_cv_wait(&worker->cv, &pollset->mu,
+                      grpc_millis_to_timespec(deadline, GPR_CLOCK_REALTIME)) &&
           worker->state == UNKICKED) {
         /* If gpr_cv_wait returns true (i.e a timeout), pretend that the worker
            received a kick */
         SET_KICK_STATE(worker, KICKED);
       }
     }
-    *now = gpr_now(now->clock_type);
+    grpc_exec_ctx_invalidate_now(exec_ctx);
   }
 
   if (GRPC_TRACER_ON(grpc_polling_trace)) {
@@ -941,7 +936,7 @@ static void end_worker(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
    ensure that it is held by the time the function returns */
 static grpc_error *pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *ps,
                                 grpc_pollset_worker **worker_hdl,
-                                gpr_timespec now, gpr_timespec deadline) {
+                                grpc_millis deadline) {
   grpc_pollset_worker worker;
   grpc_error *error = GRPC_ERROR_NONE;
   static const char *err_desc = "pollset_work";
@@ -952,7 +947,7 @@ static grpc_error *pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *ps,
     return GRPC_ERROR_NONE;
   }
 
-  if (begin_worker(ps, &worker, worker_hdl, &now, deadline)) {
+  if (begin_worker(exec_ctx, ps, &worker, worker_hdl, deadline)) {
     gpr_tls_set(&g_current_thread_pollset, (intptr_t)ps);
     gpr_tls_set(&g_current_thread_worker, (intptr_t)&worker);
     GPR_ASSERT(!ps->shutting_down);
@@ -975,8 +970,7 @@ static grpc_error *pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *ps,
        designated poller */
     if (gpr_atm_acq_load(&g_epoll_set.cursor) ==
         gpr_atm_acq_load(&g_epoll_set.num_events)) {
-      append_error(&error, do_epoll_wait(exec_ctx, ps, now, deadline),
-                   err_desc);
+      append_error(&error, do_epoll_wait(exec_ctx, ps, deadline), err_desc);
     }
     append_error(&error, process_epoll_events(exec_ctx, ps), err_desc);
 
diff --git a/src/core/lib/iomgr/ev_epoll1_linux.h b/src/core/lib/iomgr/ev_epoll1_linux.h
index 66fd826b495..b437032b368 100644
--- a/src/core/lib/iomgr/ev_epoll1_linux.h
+++ b/src/core/lib/iomgr/ev_epoll1_linux.h
@@ -34,4 +34,4 @@ const grpc_event_engine_vtable *grpc_init_epoll1_linux(bool explicit_request);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_EV_EPOLL1_LINUX_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_EV_EPOLL1_LINUX_H */
diff --git a/src/core/lib/iomgr/ev_epollex_linux.cc b/src/core/lib/iomgr/ev_epollex_linux.cc
index bed47e4388a..59dd8fd2fe9 100644
--- a/src/core/lib/iomgr/ev_epollex_linux.cc
+++ b/src/core/lib/iomgr/ev_epollex_linux.cc
@@ -25,6 +25,7 @@
 
 #include <assert.h>
 #include <errno.h>
+#include <limits.h>
 #include <poll.h>
 #include <pthread.h>
 #include <string.h>
@@ -38,7 +39,7 @@
 #include <grpc/support/useful.h>
 
 #include "src/core/lib/debug/stats.h"
-#include "src/core/lib/iomgr/ev_posix.h"
+#include "src/core/lib/iomgr/block_annotate.h"
 #include "src/core/lib/iomgr/iomgr_internal.h"
 #include "src/core/lib/iomgr/is_epollexclusive_available.h"
 #include "src/core/lib/iomgr/lockfree_event.h"
@@ -46,19 +47,18 @@
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/iomgr/wakeup_fd_posix.h"
 #include "src/core/lib/profiling/timers.h"
-#include "src/core/lib/support/block_annotate.h"
 #include "src/core/lib/support/spinlock.h"
 
 /*******************************************************************************
  * Polling object
  */
-
 typedef enum {
   PO_POLLING_GROUP,
   PO_POLLSET_SET,
   PO_POLLSET,
-  PO_FD, /* ordering is important: we always want to lock pollsets before fds:
-            this guarantees that using an fd as a pollable is safe */
+  PO_FD,
+  /* ordering is important: we always want to lock pollsets before fds:
+     this guarantees that using an fd as a pollable is safe */
   PO_EMPTY_POLLABLE,
   PO_COUNT
 } polling_obj_type;
@@ -690,32 +690,16 @@ static void pollset_init(grpc_pollset *pollset, gpr_mu **mu) {
   *mu = &pollset->pollable_obj.po.mu;
 }
 
-/* Convert a timespec to milliseconds:
-   - Very small or negative poll times are clamped to zero to do a non-blocking
-     poll (which becomes spin polling)
-   - Other small values are rounded up to one millisecond
-   - Longer than a millisecond polls are rounded up to the next nearest
-     millisecond to avoid spinning
-   - Infinite timeouts are converted to -1 */
-static int poll_deadline_to_millis_timeout(gpr_timespec deadline,
-                                           gpr_timespec now) {
-  gpr_timespec timeout;
-  if (gpr_time_cmp(deadline, gpr_inf_future(deadline.clock_type)) == 0) {
-    return -1;
-  }
-
-  if (gpr_time_cmp(deadline, now) <= 0) {
+static int poll_deadline_to_millis_timeout(grpc_exec_ctx *exec_ctx,
+                                           grpc_millis millis) {
+  if (millis == GRPC_MILLIS_INF_FUTURE) return -1;
+  grpc_millis delta = millis - grpc_exec_ctx_now(exec_ctx);
+  if (delta > INT_MAX)
+    return INT_MAX;
+  else if (delta < 0)
     return 0;
-  }
-
-  static const gpr_timespec round_up = {
-      0,                 /* tv_sec */
-      GPR_NS_PER_MS - 1, /* tv_nsec */
-      GPR_TIMESPAN       /* clock_type */
-  };
-  timeout = gpr_time_sub(deadline, now);
-  int millis = gpr_time_to_millis(gpr_time_add(timeout, round_up));
-  return millis >= 1 ? millis : 1;
+  else
+    return (int)delta;
 }
 
 static void fd_become_readable(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
@@ -810,9 +794,8 @@ static void pollset_destroy(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset) {
 }
 
 static grpc_error *pollset_epoll(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
-                                 pollable *p, gpr_timespec now,
-                                 gpr_timespec deadline) {
-  int timeout = poll_deadline_to_millis_timeout(deadline, now);
+                                 pollable *p, grpc_millis deadline) {
+  int timeout = poll_deadline_to_millis_timeout(exec_ctx, deadline);
 
   if (GRPC_TRACER_ON(grpc_polling_trace)) {
     char *desc = pollable_desc(p);
@@ -829,7 +812,7 @@ static grpc_error *pollset_epoll(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
     r = epoll_wait(p->epfd, pollset->events, MAX_EPOLL_EVENTS, timeout);
   } while (r < 0 && errno == EINTR);
   if (timeout != 0) {
-    GRPC_SCHEDULING_END_BLOCKING_REGION;
+    GRPC_SCHEDULING_END_BLOCKING_REGION_WITH_EXEC_CTX(exec_ctx);
   }
 
   if (r < 0) return GRPC_OS_ERROR(errno, "epoll_wait");
@@ -884,9 +867,10 @@ static worker_remove_result worker_remove(grpc_pollset_worker **root,
 }
 
 /* Return true if this thread should poll */
-static bool begin_worker(grpc_pollset *pollset, grpc_pollset_worker *worker,
-                         grpc_pollset_worker **worker_hdl, gpr_timespec *now,
-                         gpr_timespec deadline) {
+static bool begin_worker(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+                         grpc_pollset_worker *worker,
+                         grpc_pollset_worker **worker_hdl,
+                         grpc_millis deadline) {
   bool do_poll = true;
   if (worker_hdl != NULL) *worker_hdl = worker;
   worker->initialized_cv = false;
@@ -910,10 +894,11 @@ static bool begin_worker(grpc_pollset *pollset, grpc_pollset_worker *worker,
         worker->pollable_obj->root_worker != worker) {
       gpr_log(GPR_DEBUG, "PS:%p wait %p w=%p for %dms", pollset,
               worker->pollable_obj, worker,
-              poll_deadline_to_millis_timeout(deadline, *now));
+              poll_deadline_to_millis_timeout(exec_ctx, deadline));
     }
     while (do_poll && worker->pollable_obj->root_worker != worker) {
-      if (gpr_cv_wait(&worker->cv, &worker->pollable_obj->po.mu, deadline)) {
+      if (gpr_cv_wait(&worker->cv, &worker->pollable_obj->po.mu,
+                      grpc_millis_to_timespec(deadline, GPR_CLOCK_REALTIME))) {
         if (GRPC_TRACER_ON(grpc_polling_trace)) {
           gpr_log(GPR_DEBUG, "PS:%p timeout_wait %p w=%p", pollset,
                   worker->pollable_obj, worker);
@@ -936,7 +921,7 @@ static bool begin_worker(grpc_pollset *pollset, grpc_pollset_worker *worker,
       gpr_mu_lock(&pollset->pollable_obj.po.mu);
       gpr_mu_lock(&worker->pollable_obj->po.mu);
     }
-    *now = gpr_now(now->clock_type);
+    grpc_exec_ctx_invalidate_now(exec_ctx);
   }
 
   return do_poll && pollset->shutdown_closure == NULL &&
@@ -967,14 +952,13 @@ static void end_worker(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
    ensure that it is held by the time the function returns */
 static grpc_error *pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
                                 grpc_pollset_worker **worker_hdl,
-                                gpr_timespec now, gpr_timespec deadline) {
+                                grpc_millis deadline) {
   grpc_pollset_worker worker;
   if (0 && GRPC_TRACER_ON(grpc_polling_trace)) {
-    gpr_log(GPR_DEBUG, "PS:%p work hdl=%p worker=%p now=%" PRId64
-                       ".%09d deadline=%" PRId64 ".%09d kwp=%d root_worker=%p",
-            pollset, worker_hdl, &worker, now.tv_sec, now.tv_nsec,
-            deadline.tv_sec, deadline.tv_nsec, pollset->kicked_without_poller,
-            pollset->root_worker);
+    gpr_log(GPR_DEBUG, "PS:%p work hdl=%p worker=%p now=%" PRIdPTR
+                       " deadline=%" PRIdPTR " kwp=%d root_worker=%p",
+            pollset, worker_hdl, &worker, grpc_exec_ctx_now(exec_ctx), deadline,
+            pollset->kicked_without_poller, pollset->root_worker);
   }
   grpc_error *error = GRPC_ERROR_NONE;
   static const char *err_desc = "pollset_work";
@@ -985,7 +969,7 @@ static grpc_error *pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
   if (pollset->current_pollable_obj != &pollset->pollable_obj) {
     gpr_mu_lock(&pollset->current_pollable_obj->po.mu);
   }
-  if (begin_worker(pollset, &worker, worker_hdl, &now, deadline)) {
+  if (begin_worker(exec_ctx, pollset, &worker, worker_hdl, deadline)) {
     gpr_tls_set(&g_current_thread_pollset, (intptr_t)pollset);
     gpr_tls_set(&g_current_thread_worker, (intptr_t)&worker);
     GPR_ASSERT(!pollset->shutdown_closure);
@@ -996,7 +980,7 @@ static grpc_error *pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
     gpr_mu_unlock(&pollset->pollable_obj.po.mu);
     if (pollset->event_cursor == pollset->event_count) {
       append_error(&error, pollset_epoll(exec_ctx, pollset, worker.pollable_obj,
-                                         now, deadline),
+                                         deadline),
                    err_desc);
     }
     append_error(&error, pollset_process_events(exec_ctx, pollset, false),
diff --git a/src/core/lib/iomgr/ev_epollex_linux.h b/src/core/lib/iomgr/ev_epollex_linux.h
index 58cc5a24f8f..2849a232835 100644
--- a/src/core/lib/iomgr/ev_epollex_linux.h
+++ b/src/core/lib/iomgr/ev_epollex_linux.h
@@ -33,4 +33,4 @@ const grpc_event_engine_vtable *grpc_init_epollex_linux(
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_EV_EPOLLEX_LINUX_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_EV_EPOLLEX_LINUX_H */
diff --git a/src/core/lib/iomgr/ev_epollsig_linux.cc b/src/core/lib/iomgr/ev_epollsig_linux.cc
index c8e07c6e184..035bdc4cb55 100644
--- a/src/core/lib/iomgr/ev_epollsig_linux.cc
+++ b/src/core/lib/iomgr/ev_epollsig_linux.cc
@@ -18,6 +18,8 @@
 
 #include "src/core/lib/iomgr/port.h"
 
+#include <grpc/grpc_posix.h>
+
 /* This polling engine is only relevant on linux kernels supporting epoll() */
 #ifdef GRPC_LINUX_EPOLL
 
@@ -25,6 +27,7 @@
 
 #include <assert.h>
 #include <errno.h>
+#include <limits.h>
 #include <poll.h>
 #include <pthread.h>
 #include <signal.h>
@@ -40,13 +43,13 @@
 #include <grpc/support/useful.h>
 
 #include "src/core/lib/debug/stats.h"
+#include "src/core/lib/iomgr/block_annotate.h"
 #include "src/core/lib/iomgr/ev_posix.h"
 #include "src/core/lib/iomgr/iomgr_internal.h"
 #include "src/core/lib/iomgr/lockfree_event.h"
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/iomgr/wakeup_fd_posix.h"
 #include "src/core/lib/profiling/timers.h"
-#include "src/core/lib/support/block_annotate.h"
 
 #define GRPC_POLLSET_KICK_BROADCAST ((grpc_pollset_worker *)1)
 
@@ -1089,30 +1092,16 @@ static void pollset_init(grpc_pollset *pollset, gpr_mu **mu) {
   pollset->shutdown_done = NULL;
 }
 
-/* Convert a timespec to milliseconds:
-   - Very small or negative poll times are clamped to zero to do a non-blocking
-     poll (which becomes spin polling)
-   - Other small values are rounded up to one millisecond
-   - Longer than a millisecond polls are rounded up to the next nearest
-     millisecond to avoid spinning
-   - Infinite timeouts are converted to -1 */
-static int poll_deadline_to_millis_timeout(gpr_timespec deadline,
-                                           gpr_timespec now) {
-  gpr_timespec timeout;
-  static const int64_t max_spin_polling_us = 10;
-  if (gpr_time_cmp(deadline, gpr_inf_future(deadline.clock_type)) == 0) {
-    return -1;
-  }
-
-  if (gpr_time_cmp(deadline, gpr_time_add(now, gpr_time_from_micros(
-                                                   max_spin_polling_us,
-                                                   GPR_TIMESPAN))) <= 0) {
+static int poll_deadline_to_millis_timeout(grpc_exec_ctx *exec_ctx,
+                                           grpc_millis millis) {
+  if (millis == GRPC_MILLIS_INF_FUTURE) return -1;
+  grpc_millis delta = millis - grpc_exec_ctx_now(exec_ctx);
+  if (delta > INT_MAX)
+    return INT_MAX;
+  else if (delta < 0)
     return 0;
-  }
-  timeout = gpr_time_sub(deadline, now);
-  int millis = gpr_time_to_millis(gpr_time_add(
-      timeout, gpr_time_from_nanos(GPR_NS_PER_MS - 1, GPR_TIMESPAN)));
-  return millis >= 1 ? millis : 1;
+  else
+    return (int)delta;
 }
 
 static void fd_become_readable(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
@@ -1243,7 +1232,7 @@ static void pollset_work_and_unlock(grpc_exec_ctx *exec_ctx,
   GRPC_STATS_INC_SYSCALL_POLL(exec_ctx);
   ep_rv =
       epoll_pwait(epoll_fd, ep_ev, GRPC_EPOLL_MAX_EVENTS, timeout_ms, sig_mask);
-  GRPC_SCHEDULING_END_BLOCKING_REGION;
+  GRPC_SCHEDULING_END_BLOCKING_REGION_WITH_EXEC_CTX(exec_ctx);
   if (ep_rv < 0) {
     if (errno != EINTR) {
       gpr_asprintf(&err_msg,
@@ -1310,10 +1299,10 @@ static void pollset_work_and_unlock(grpc_exec_ctx *exec_ctx,
    ensure that it is held by the time the function returns */
 static grpc_error *pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
                                 grpc_pollset_worker **worker_hdl,
-                                gpr_timespec now, gpr_timespec deadline) {
+                                grpc_millis deadline) {
   GPR_TIMER_BEGIN("pollset_work", 0);
   grpc_error *error = GRPC_ERROR_NONE;
-  int timeout_ms = poll_deadline_to_millis_timeout(deadline, now);
+  int timeout_ms = poll_deadline_to_millis_timeout(exec_ctx, deadline);
 
   sigset_t new_mask;
 
diff --git a/src/core/lib/iomgr/ev_poll_posix.cc b/src/core/lib/iomgr/ev_poll_posix.cc
index e170702dca3..036a35690c5 100644
--- a/src/core/lib/iomgr/ev_poll_posix.cc
+++ b/src/core/lib/iomgr/ev_poll_posix.cc
@@ -24,6 +24,7 @@
 
 #include <assert.h>
 #include <errno.h>
+#include <limits.h>
 #include <poll.h>
 #include <string.h>
 #include <sys/socket.h>
@@ -37,12 +38,11 @@
 #include <grpc/support/useful.h>
 
 #include "src/core/lib/debug/stats.h"
+#include "src/core/lib/iomgr/block_annotate.h"
 #include "src/core/lib/iomgr/iomgr_internal.h"
-#include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/iomgr/wakeup_fd_cv.h"
 #include "src/core/lib/iomgr/wakeup_fd_posix.h"
 #include "src/core/lib/profiling/timers.h"
-#include "src/core/lib/support/block_annotate.h"
 #include "src/core/lib/support/murmur_hash.h"
 
 #define GRPC_POLLSET_KICK_BROADCAST ((grpc_pollset_worker *)1)
@@ -50,7 +50,6 @@
 /*******************************************************************************
  * FD declarations
  */
-
 typedef struct grpc_fd_watcher {
   struct grpc_fd_watcher *next;
   struct grpc_fd_watcher *prev;
@@ -200,8 +199,8 @@ static void pollset_set_add_fd(grpc_exec_ctx *exec_ctx,
    - longer than a millisecond polls are rounded up to the next nearest
      millisecond to avoid spinning
    - infinite timeouts are converted to -1 */
-static int poll_deadline_to_millis_timeout(gpr_timespec deadline,
-                                           gpr_timespec now);
+static int poll_deadline_to_millis_timeout(grpc_exec_ctx *exec_ctx,
+                                           grpc_millis deadline);
 
 /* Allow kick to wakeup the currently polling worker */
 #define GRPC_POLLSET_CAN_KICK_SELF 1
@@ -876,7 +875,7 @@ static void work_combine_error(grpc_error **composite, grpc_error *error) {
 
 static grpc_error *pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
                                 grpc_pollset_worker **worker_hdl,
-                                gpr_timespec now, gpr_timespec deadline) {
+                                grpc_millis deadline) {
   grpc_pollset_worker worker;
   if (worker_hdl) *worker_hdl = &worker;
   grpc_error *error = GRPC_ERROR_NONE;
@@ -945,7 +944,7 @@ static grpc_error *pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
       grpc_fd_watcher *watchers;
       struct pollfd *pfds;
 
-      timeout = poll_deadline_to_millis_timeout(deadline, now);
+      timeout = poll_deadline_to_millis_timeout(exec_ctx, deadline);
 
       if (pollset->fd_count + 2 <= inline_elements) {
         pfds = pollfd_space;
@@ -991,7 +990,7 @@ static grpc_error *pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
       GRPC_SCHEDULING_START_BLOCKING_REGION;
       GRPC_STATS_INC_SYSCALL_POLL(exec_ctx);
       r = grpc_poll_function(pfds, pfd_count, timeout);
-      GRPC_SCHEDULING_END_BLOCKING_REGION;
+      GRPC_SCHEDULING_END_BLOCKING_REGION_WITH_EXEC_CTX(exec_ctx);
 
       if (GRPC_TRACER_ON(grpc_polling_trace)) {
         gpr_log(GPR_DEBUG, "%p poll=%d", pollset, r);
@@ -1068,13 +1067,10 @@ static grpc_error *pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
       if (queued_work || worker.kicked_specifically) {
         /* If there's queued work on the list, then set the deadline to be
            immediate so we get back out of the polling loop quickly */
-        deadline = gpr_inf_past(GPR_CLOCK_MONOTONIC);
+        deadline = 0;
       }
       keep_polling = 1;
     }
-    if (keep_polling) {
-      now = gpr_now(now.clock_type);
-    }
   }
   gpr_tls_set(&g_current_thread_poller, 0);
   if (added_worker) {
@@ -1126,21 +1122,14 @@ static void pollset_shutdown(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
   }
 }
 
-static int poll_deadline_to_millis_timeout(gpr_timespec deadline,
-                                           gpr_timespec now) {
-  gpr_timespec timeout;
-  static const int64_t max_spin_polling_us = 10;
-  if (gpr_time_cmp(deadline, gpr_inf_future(deadline.clock_type)) == 0) {
-    return -1;
-  }
-  if (gpr_time_cmp(deadline, gpr_time_add(now, gpr_time_from_micros(
-                                                   max_spin_polling_us,
-                                                   GPR_TIMESPAN))) <= 0) {
-    return 0;
-  }
-  timeout = gpr_time_sub(deadline, now);
-  return gpr_time_to_millis(gpr_time_add(
-      timeout, gpr_time_from_nanos(GPR_NS_PER_MS - 1, GPR_TIMESPAN)));
+static int poll_deadline_to_millis_timeout(grpc_exec_ctx *exec_ctx,
+                                           grpc_millis deadline) {
+  if (deadline == GRPC_MILLIS_INF_FUTURE) return -1;
+  if (deadline == 0) return 0;
+  grpc_millis n = deadline - grpc_exec_ctx_now(exec_ctx);
+  if (n < 0) return 0;
+  if (n > INT_MAX) return -1;
+  return (int)n;
 }
 
 /*******************************************************************************
diff --git a/src/core/lib/iomgr/ev_poll_posix.h b/src/core/lib/iomgr/ev_poll_posix.h
index 84b68155b5f..861257204b5 100644
--- a/src/core/lib/iomgr/ev_poll_posix.h
+++ b/src/core/lib/iomgr/ev_poll_posix.h
@@ -32,4 +32,4 @@ const grpc_event_engine_vtable *grpc_init_poll_cv_posix(bool explicit_request);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_EV_POLL_POSIX_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_EV_POLL_POSIX_H */
diff --git a/src/core/lib/iomgr/ev_posix.cc b/src/core/lib/iomgr/ev_posix.cc
index 4d3ae2228ed..3a1dd8d30b3 100644
--- a/src/core/lib/iomgr/ev_posix.cc
+++ b/src/core/lib/iomgr/ev_posix.cc
@@ -61,12 +61,43 @@ typedef struct {
   event_engine_factory_fn factory;
 } event_engine_factory;
 
+namespace {
+
+extern "C" {
+
+grpc_poll_function_type real_poll_function;
+
+int dummy_poll(struct pollfd fds[], nfds_t nfds, int timeout) {
+  if (timeout == 0) {
+    return real_poll_function(fds, nfds, 0);
+  } else {
+    gpr_log(GPR_ERROR, "Attempted a blocking poll when declared non-polling.");
+    GPR_ASSERT(false);
+    return -1;
+  }
+}
+}  // extern "C"
+
+const grpc_event_engine_vtable *init_non_polling(bool explicit_request) {
+  if (!explicit_request) {
+    return nullptr;
+  }
+  // return the simplest engine as a dummy but also override the poller
+  auto ret = grpc_init_poll_posix(explicit_request);
+  real_poll_function = grpc_poll_function;
+  grpc_poll_function = dummy_poll;
+
+  return ret;
+}
+}  // namespace
+
 static const event_engine_factory g_factories[] = {
     {"epoll1", grpc_init_epoll1_linux},
     {"epollsig", grpc_init_epollsig_linux},
     {"poll", grpc_init_poll_posix},
     {"poll-cv", grpc_init_poll_cv_posix},
     {"epollex", grpc_init_epollex_linux},
+    {"none", init_non_polling},
 };
 
 static void add(const char *beg, const char *end, char ***ss, size_t *ns) {
@@ -205,9 +236,9 @@ void grpc_pollset_destroy(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset) {
 }
 
 grpc_error *grpc_pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
-                              grpc_pollset_worker **worker, gpr_timespec now,
-                              gpr_timespec deadline) {
-  return g_event_engine->pollset_work(exec_ctx, pollset, worker, now, deadline);
+                              grpc_pollset_worker **worker,
+                              grpc_millis deadline) {
+  return g_event_engine->pollset_work(exec_ctx, pollset, worker, deadline);
 }
 
 grpc_error *grpc_pollset_kick(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
diff --git a/src/core/lib/iomgr/ev_posix.h b/src/core/lib/iomgr/ev_posix.h
index 5ad1c13ee66..bc4456c2a29 100644
--- a/src/core/lib/iomgr/ev_posix.h
+++ b/src/core/lib/iomgr/ev_posix.h
@@ -56,8 +56,8 @@ typedef struct grpc_event_engine_vtable {
                            grpc_closure *closure);
   void (*pollset_destroy)(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset);
   grpc_error *(*pollset_work)(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
-                              grpc_pollset_worker **worker, gpr_timespec now,
-                              gpr_timespec deadline);
+                              grpc_pollset_worker **worker,
+                              grpc_millis deadline);
   grpc_error *(*pollset_kick)(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
                               grpc_pollset_worker *specific_worker);
   void (*pollset_add_fd)(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
@@ -166,4 +166,4 @@ const grpc_event_engine_vtable *grpc_get_event_engine_test_only();
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_EV_POSIX_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_EV_POSIX_H */
diff --git a/src/core/lib/iomgr/exec_ctx.cc b/src/core/lib/iomgr/exec_ctx.cc
index 41c69add17c..3d17afcb8fb 100644
--- a/src/core/lib/iomgr/exec_ctx.cc
+++ b/src/core/lib/iomgr/exec_ctx.cc
@@ -104,9 +104,69 @@ static void exec_ctx_sched(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
   grpc_closure_list_append(&exec_ctx->closure_list, closure, error);
 }
 
-void grpc_exec_ctx_global_init(void) {}
+static gpr_timespec
+    g_start_time[GPR_TIMESPAN + 1];  // assumes GPR_TIMESPAN is the
+                                     // last enum value in
+                                     // gpr_clock_type
+
+void grpc_exec_ctx_global_init(void) {
+  for (int i = 0; i < GPR_TIMESPAN; i++) {
+    g_start_time[i] = gpr_now((gpr_clock_type)i);
+  }
+  // allows uniform treatment in conversion functions
+  g_start_time[GPR_TIMESPAN] = gpr_time_0(GPR_TIMESPAN);
+}
+
 void grpc_exec_ctx_global_shutdown(void) {}
 
+static gpr_atm timespec_to_atm_round_down(gpr_timespec ts) {
+  ts = gpr_time_sub(ts, g_start_time[ts.clock_type]);
+  double x =
+      GPR_MS_PER_SEC * (double)ts.tv_sec + (double)ts.tv_nsec / GPR_NS_PER_MS;
+  if (x < 0) return 0;
+  if (x > GPR_ATM_MAX) return GPR_ATM_MAX;
+  return (gpr_atm)x;
+}
+
+static gpr_atm timespec_to_atm_round_up(gpr_timespec ts) {
+  ts = gpr_time_sub(ts, g_start_time[ts.clock_type]);
+  double x = GPR_MS_PER_SEC * (double)ts.tv_sec +
+             (double)ts.tv_nsec / GPR_NS_PER_MS +
+             (double)(GPR_NS_PER_SEC - 1) / (double)GPR_NS_PER_SEC;
+  if (x < 0) return 0;
+  if (x > GPR_ATM_MAX) return GPR_ATM_MAX;
+  return (gpr_atm)x;
+}
+
+grpc_millis grpc_exec_ctx_now(grpc_exec_ctx *exec_ctx) {
+  if (!exec_ctx->now_is_valid) {
+    exec_ctx->now = timespec_to_atm_round_down(gpr_now(GPR_CLOCK_MONOTONIC));
+    exec_ctx->now_is_valid = true;
+  }
+  return exec_ctx->now;
+}
+
+void grpc_exec_ctx_invalidate_now(grpc_exec_ctx *exec_ctx) {
+  exec_ctx->now_is_valid = false;
+}
+
+gpr_timespec grpc_millis_to_timespec(grpc_millis millis,
+                                     gpr_clock_type clock_type) {
+  if (clock_type == GPR_TIMESPAN) {
+    return gpr_time_from_millis(millis, GPR_TIMESPAN);
+  }
+  return gpr_time_add(g_start_time[clock_type],
+                      gpr_time_from_millis(millis, GPR_TIMESPAN));
+}
+
+grpc_millis grpc_timespec_to_millis_round_down(gpr_timespec ts) {
+  return timespec_to_atm_round_down(ts);
+}
+
+grpc_millis grpc_timespec_to_millis_round_up(gpr_timespec ts) {
+  return timespec_to_atm_round_up(ts);
+}
+
 static const grpc_closure_scheduler_vtable exec_ctx_scheduler_vtable = {
     exec_ctx_run, exec_ctx_sched, "exec_ctx"};
 static grpc_closure_scheduler exec_ctx_scheduler = {&exec_ctx_scheduler_vtable};
diff --git a/src/core/lib/iomgr/exec_ctx.h b/src/core/lib/iomgr/exec_ctx.h
index a93728f0a67..44b9be7aa99 100644
--- a/src/core/lib/iomgr/exec_ctx.h
+++ b/src/core/lib/iomgr/exec_ctx.h
@@ -19,14 +19,19 @@
 #ifndef GRPC_CORE_LIB_IOMGR_EXEC_CTX_H
 #define GRPC_CORE_LIB_IOMGR_EXEC_CTX_H
 
+#include <grpc/support/atm.h>
 #include <grpc/support/cpu.h>
+
 #include "src/core/lib/iomgr/closure.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-/* #define GRPC_EXECUTION_CONTEXT_SANITIZER 1 */
+typedef gpr_atm grpc_millis;
+
+#define GRPC_MILLIS_INF_FUTURE GPR_ATM_MAX
+#define GRPC_MILLIS_INF_PAST GPR_ATM_MIN
 
 /** A workqueue represents a list of work to be executed asynchronously.
     Forward declared here to avoid a circular dependency with workqueue.h. */
@@ -70,6 +75,9 @@ struct grpc_exec_ctx {
   unsigned starting_cpu;
   void *check_ready_to_finish_arg;
   bool (*check_ready_to_finish)(grpc_exec_ctx *exec_ctx, void *arg);
+
+  bool now_is_valid;
+  grpc_millis now;
 };
 
 /* initializer for grpc_exec_ctx:
@@ -77,7 +85,7 @@ struct grpc_exec_ctx {
 #define GRPC_EXEC_CTX_INITIALIZER(flags, finish_check, finish_check_arg) \
   {                                                                      \
     GRPC_CLOSURE_LIST_INIT, NULL, NULL, flags, gpr_cpu_current_cpu(),    \
-        finish_check_arg, finish_check                                   \
+        finish_check_arg, finish_check, false, 0                         \
   }
 
 /* initialize an execution context at the top level of an API call into grpc
@@ -110,6 +118,12 @@ void grpc_exec_ctx_global_init(void);
 void grpc_exec_ctx_global_init(void);
 void grpc_exec_ctx_global_shutdown(void);
 
+grpc_millis grpc_exec_ctx_now(grpc_exec_ctx *exec_ctx);
+void grpc_exec_ctx_invalidate_now(grpc_exec_ctx *exec_ctx);
+gpr_timespec grpc_millis_to_timespec(grpc_millis millis, gpr_clock_type clock);
+grpc_millis grpc_timespec_to_millis_round_down(gpr_timespec timespec);
+grpc_millis grpc_timespec_to_millis_round_up(gpr_timespec timespec);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/core/lib/iomgr/executor.cc b/src/core/lib/iomgr/executor.cc
index ebe7f240b45..92c3e70301c 100644
--- a/src/core/lib/iomgr/executor.cc
+++ b/src/core/lib/iomgr/executor.cc
@@ -178,6 +178,7 @@ static void executor_thread(void *arg) {
       gpr_log(GPR_DEBUG, "EXECUTOR[%d]: execute", (int)(ts - g_thread_state));
     }
 
+    grpc_exec_ctx_invalidate_now(&exec_ctx);
     subtract_depth = run_closures(&exec_ctx, exec);
   }
   grpc_exec_ctx_finish(&exec_ctx);
diff --git a/src/core/lib/iomgr/executor.h b/src/core/lib/iomgr/executor.h
index ab3fc901de2..ef5ac56c832 100644
--- a/src/core/lib/iomgr/executor.h
+++ b/src/core/lib/iomgr/executor.h
@@ -53,4 +53,4 @@ void grpc_executor_set_threading(grpc_exec_ctx *exec_ctx, bool enable);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_EXECUTOR_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_EXECUTOR_H */
diff --git a/src/core/lib/iomgr/iocp_windows.cc b/src/core/lib/iomgr/iocp_windows.cc
index c082179c0b4..78185cc084e 100644
--- a/src/core/lib/iomgr/iocp_windows.cc
+++ b/src/core/lib/iomgr/iocp_windows.cc
@@ -21,11 +21,13 @@
 #ifdef GRPC_WINSOCK_SOCKET
 
 #include <winsock2.h>
+#include <limits>
 
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/log_windows.h>
 #include <grpc/support/thd.h>
+#include <grpc/support/useful.h>
 
 #include "src/core/lib/debug/stats.h"
 #include "src/core/lib/iomgr/iocp_windows.h"
@@ -40,25 +42,20 @@ static gpr_atm g_custom_events = 0;
 
 static HANDLE g_iocp;
 
-static DWORD deadline_to_millis_timeout(gpr_timespec deadline,
-                                        gpr_timespec now) {
-  gpr_timespec timeout;
-  static const int64_t max_spin_polling_us = 10;
-  if (gpr_time_cmp(deadline, gpr_inf_future(deadline.clock_type)) == 0) {
+static DWORD deadline_to_millis_timeout(grpc_exec_ctx *exec_ctx,
+                                        grpc_millis deadline) {
+  if (deadline == GRPC_MILLIS_INF_FUTURE) {
     return INFINITE;
   }
-  if (gpr_time_cmp(deadline, gpr_time_add(now, gpr_time_from_micros(
-                                                   max_spin_polling_us,
-                                                   GPR_TIMESPAN))) <= 0) {
-    return 0;
-  }
-  timeout = gpr_time_sub(deadline, now);
-  return (DWORD)gpr_time_to_millis(gpr_time_add(
-      timeout, gpr_time_from_nanos(GPR_NS_PER_MS - 1, GPR_TIMESPAN)));
+  grpc_millis now = grpc_exec_ctx_now(exec_ctx);
+  if (deadline < now) return 0;
+  grpc_millis timeout = deadline - now;
+  if (timeout > std::numeric_limits<DWORD>::max()) return INFINITE;
+  return static_cast<DWORD>(deadline - now);
 }
 
 grpc_iocp_work_status grpc_iocp_work(grpc_exec_ctx *exec_ctx,
-                                     gpr_timespec deadline) {
+                                     grpc_millis deadline) {
   BOOL success;
   DWORD bytes = 0;
   DWORD flags = 0;
@@ -67,9 +64,10 @@ grpc_iocp_work_status grpc_iocp_work(grpc_exec_ctx *exec_ctx,
   grpc_winsocket *socket;
   grpc_winsocket_callback_info *info;
   GRPC_STATS_INC_SYSCALL_POLL(exec_ctx);
-  success = GetQueuedCompletionStatus(
-      g_iocp, &bytes, &completion_key, &overlapped,
-      deadline_to_millis_timeout(deadline, gpr_now(deadline.clock_type)));
+  success =
+      GetQueuedCompletionStatus(g_iocp, &bytes, &completion_key, &overlapped,
+                                deadline_to_millis_timeout(exec_ctx, deadline));
+  grpc_exec_ctx_invalidate_now(exec_ctx);
   if (success == 0 && overlapped == NULL) {
     return GRPC_IOCP_WORK_TIMEOUT;
   }
@@ -121,7 +119,7 @@ void grpc_iocp_flush(void) {
   grpc_iocp_work_status work_status;
 
   do {
-    work_status = grpc_iocp_work(&exec_ctx, gpr_inf_past(GPR_CLOCK_MONOTONIC));
+    work_status = grpc_iocp_work(&exec_ctx, GRPC_MILLIS_INF_PAST);
   } while (work_status == GRPC_IOCP_WORK_KICK ||
            grpc_exec_ctx_flush(&exec_ctx));
 }
@@ -129,7 +127,7 @@ void grpc_iocp_flush(void) {
 void grpc_iocp_shutdown(void) {
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   while (gpr_atm_acq_load(&g_custom_events)) {
-    grpc_iocp_work(&exec_ctx, gpr_inf_future(GPR_CLOCK_MONOTONIC));
+    grpc_iocp_work(&exec_ctx, GRPC_MILLIS_INF_FUTURE);
     grpc_exec_ctx_flush(&exec_ctx);
   }
   grpc_exec_ctx_finish(&exec_ctx);
diff --git a/src/core/lib/iomgr/iocp_windows.h b/src/core/lib/iomgr/iocp_windows.h
index 341c159501b..4efbc94645a 100644
--- a/src/core/lib/iomgr/iocp_windows.h
+++ b/src/core/lib/iomgr/iocp_windows.h
@@ -34,7 +34,7 @@ typedef enum {
 } grpc_iocp_work_status;
 
 grpc_iocp_work_status grpc_iocp_work(grpc_exec_ctx *exec_ctx,
-                                     gpr_timespec deadline);
+                                     grpc_millis deadline);
 void grpc_iocp_init(void);
 void grpc_iocp_kick(void);
 void grpc_iocp_flush(void);
@@ -45,4 +45,4 @@ void grpc_iocp_add_socket(grpc_winsocket *);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_IOCP_WINDOWS_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_IOCP_WINDOWS_H */
diff --git a/src/core/lib/iomgr/iomgr.cc b/src/core/lib/iomgr/iomgr.cc
index 3a0605833ae..d6a5b4a76c7 100644
--- a/src/core/lib/iomgr/iomgr.cc
+++ b/src/core/lib/iomgr/iomgr.cc
@@ -51,7 +51,7 @@ void grpc_iomgr_init(grpc_exec_ctx *exec_ctx) {
   gpr_cv_init(&g_rcv);
   grpc_exec_ctx_global_init();
   grpc_executor_init(exec_ctx);
-  grpc_timer_list_init(gpr_now(GPR_CLOCK_MONOTONIC));
+  grpc_timer_list_init(exec_ctx);
   g_root_object.next = g_root_object.prev = &g_root_object;
   g_root_object.name = (char *)"root";
   grpc_network_status_init();
@@ -98,8 +98,9 @@ void grpc_iomgr_shutdown(grpc_exec_ctx *exec_ctx) {
       }
       last_warning_time = gpr_now(GPR_CLOCK_REALTIME);
     }
-    if (grpc_timer_check(exec_ctx, gpr_inf_future(GPR_CLOCK_MONOTONIC), NULL) ==
-        GRPC_TIMERS_FIRED) {
+    exec_ctx->now_is_valid = true;
+    exec_ctx->now = GRPC_MILLIS_INF_FUTURE;
+    if (grpc_timer_check(exec_ctx, NULL) == GRPC_TIMERS_FIRED) {
       gpr_mu_unlock(&g_mu);
       grpc_exec_ctx_flush(exec_ctx);
       grpc_iomgr_platform_flush();
diff --git a/src/core/lib/iomgr/iomgr.h b/src/core/lib/iomgr/iomgr.h
index fea08496fef..6c0a08b9183 100644
--- a/src/core/lib/iomgr/iomgr.h
+++ b/src/core/lib/iomgr/iomgr.h
@@ -40,4 +40,4 @@ void grpc_iomgr_shutdown(grpc_exec_ctx *exec_ctx);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_IOMGR_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_IOMGR_H */
diff --git a/src/core/lib/iomgr/iomgr_internal.h b/src/core/lib/iomgr/iomgr_internal.h
index 005abbed13e..52db37c89ae 100644
--- a/src/core/lib/iomgr/iomgr_internal.h
+++ b/src/core/lib/iomgr/iomgr_internal.h
@@ -48,4 +48,4 @@ bool grpc_iomgr_abort_on_leaks(void);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_IOMGR_INTERNAL_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_IOMGR_INTERNAL_H */
diff --git a/src/core/lib/iomgr/is_epollexclusive_available.h b/src/core/lib/iomgr/is_epollexclusive_available.h
index 5c3e4830655..9ae9c5c1915 100644
--- a/src/core/lib/iomgr/is_epollexclusive_available.h
+++ b/src/core/lib/iomgr/is_epollexclusive_available.h
@@ -31,4 +31,4 @@ bool grpc_is_epollexclusive_available(void);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_IS_EPOLLEXCLUSIVE_AVAILABLE_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_IS_EPOLLEXCLUSIVE_AVAILABLE_H */
diff --git a/src/core/lib/iomgr/load_file.cc b/src/core/lib/iomgr/load_file.cc
index 0b4d41ea4b1..5cb4099ea49 100644
--- a/src/core/lib/iomgr/load_file.cc
+++ b/src/core/lib/iomgr/load_file.cc
@@ -25,7 +25,7 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/lib/support/block_annotate.h"
+#include "src/core/lib/iomgr/block_annotate.h"
 #include "src/core/lib/support/string.h"
 
 grpc_error *grpc_load_file(const char *filename, int add_null_terminator,
@@ -73,6 +73,6 @@ end:
     GRPC_ERROR_UNREF(error);
     error = error_out;
   }
-  GRPC_SCHEDULING_END_BLOCKING_REGION;
+  GRPC_SCHEDULING_END_BLOCKING_REGION_NO_EXEC_CTX;
   return error;
 }
diff --git a/src/core/lib/iomgr/lockfree_event.h b/src/core/lib/iomgr/lockfree_event.h
index 925f0049458..02229e569ef 100644
--- a/src/core/lib/iomgr/lockfree_event.h
+++ b/src/core/lib/iomgr/lockfree_event.h
@@ -45,4 +45,4 @@ void grpc_lfev_set_ready(grpc_exec_ctx *exec_ctx, gpr_atm *state,
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_LOCKFREE_EVENT_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_LOCKFREE_EVENT_H */
diff --git a/src/core/lib/iomgr/network_status_tracker.h b/src/core/lib/iomgr/network_status_tracker.h
index af50d51257e..cba38d4530f 100644
--- a/src/core/lib/iomgr/network_status_tracker.h
+++ b/src/core/lib/iomgr/network_status_tracker.h
@@ -35,4 +35,4 @@ void grpc_network_status_shutdown_all_endpoints();
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_NETWORK_STATUS_TRACKER_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_NETWORK_STATUS_TRACKER_H */
diff --git a/src/core/lib/iomgr/polling_entity.h b/src/core/lib/iomgr/polling_entity.h
index 4a37acf212f..009f968fac4 100644
--- a/src/core/lib/iomgr/polling_entity.h
+++ b/src/core/lib/iomgr/polling_entity.h
@@ -72,4 +72,4 @@ void grpc_polling_entity_del_from_pollset_set(grpc_exec_ctx *exec_ctx,
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_POLLING_ENTITY_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_POLLING_ENTITY_H */
diff --git a/src/core/lib/iomgr/pollset.h b/src/core/lib/iomgr/pollset.h
index 28d63949ea7..799fae154cf 100644
--- a/src/core/lib/iomgr/pollset.h
+++ b/src/core/lib/iomgr/pollset.h
@@ -75,8 +75,8 @@ void grpc_pollset_destroy(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset);
    pollset
    lock */
 grpc_error *grpc_pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
-                              grpc_pollset_worker **worker, gpr_timespec now,
-                              gpr_timespec deadline) GRPC_MUST_USE_RESULT;
+                              grpc_pollset_worker **worker,
+                              grpc_millis deadline) GRPC_MUST_USE_RESULT;
 
 /* Break one polling thread out of polling work for this pollset.
    If specific_worker is non-NULL, then kick that worker. */
diff --git a/src/core/lib/iomgr/pollset_set.h b/src/core/lib/iomgr/pollset_set.h
index 17df86542dd..5455eda02fd 100644
--- a/src/core/lib/iomgr/pollset_set.h
+++ b/src/core/lib/iomgr/pollset_set.h
@@ -52,4 +52,4 @@ void grpc_pollset_set_del_pollset_set(grpc_exec_ctx *exec_ctx,
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_POLLSET_SET_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_POLLSET_SET_H */
diff --git a/src/core/lib/iomgr/pollset_uv.cc b/src/core/lib/iomgr/pollset_uv.cc
index 7ea5019ad55..b9901bf8efd 100644
--- a/src/core/lib/iomgr/pollset_uv.cc
+++ b/src/core/lib/iomgr/pollset_uv.cc
@@ -116,13 +116,14 @@ void grpc_pollset_destroy(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset) {
 
 grpc_error *grpc_pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
                               grpc_pollset_worker **worker_hdl,
-                              gpr_timespec now, gpr_timespec deadline) {
+                              grpc_millis deadline) {
   uint64_t timeout;
   GRPC_UV_ASSERT_SAME_THREAD();
   gpr_mu_unlock(&grpc_polling_mu);
   if (grpc_pollset_work_run_loop) {
-    if (gpr_time_cmp(deadline, now) >= 0) {
-      timeout = (uint64_t)gpr_time_to_millis(gpr_time_sub(deadline, now));
+    grpc_millis now = grpc_exec_ctx_now(exec_ctx);
+    if (deadline >= now) {
+      timeout = deadline - now;
     } else {
       timeout = 0;
     }
diff --git a/src/core/lib/iomgr/pollset_uv.h b/src/core/lib/iomgr/pollset_uv.h
index d8f72ff867b..5cc9faf4ff1 100644
--- a/src/core/lib/iomgr/pollset_uv.h
+++ b/src/core/lib/iomgr/pollset_uv.h
@@ -32,4 +32,4 @@ void grpc_pollset_global_shutdown(void);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_POLLSET_UV_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_POLLSET_UV_H */
diff --git a/src/core/lib/iomgr/pollset_windows.cc b/src/core/lib/iomgr/pollset_windows.cc
index eb295d3eebd..bb4df83fc13 100644
--- a/src/core/lib/iomgr/pollset_windows.cc
+++ b/src/core/lib/iomgr/pollset_windows.cc
@@ -110,7 +110,7 @@ void grpc_pollset_destroy(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset) {}
 
 grpc_error *grpc_pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
                               grpc_pollset_worker **worker_hdl,
-                              gpr_timespec now, gpr_timespec deadline) {
+                              grpc_millis deadline) {
   grpc_pollset_worker worker;
   if (worker_hdl) *worker_hdl = &worker;
 
@@ -159,7 +159,8 @@ grpc_error *grpc_pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
                       &worker);
     added_worker = 1;
     while (!worker.kicked) {
-      if (gpr_cv_wait(&worker.cv, &grpc_polling_mu, deadline)) {
+      if (gpr_cv_wait(&worker.cv, &grpc_polling_mu,
+                      grpc_millis_to_timespec(deadline, GPR_CLOCK_REALTIME))) {
         break;
       }
     }
diff --git a/src/core/lib/iomgr/pollset_windows.h b/src/core/lib/iomgr/pollset_windows.h
index 7733d26471c..2479b25286d 100644
--- a/src/core/lib/iomgr/pollset_windows.h
+++ b/src/core/lib/iomgr/pollset_windows.h
@@ -68,4 +68,4 @@ void grpc_pollset_global_shutdown(void);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_POLLSET_WINDOWS_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_POLLSET_WINDOWS_H */
diff --git a/src/core/lib/iomgr/resolve_address.h b/src/core/lib/iomgr/resolve_address.h
index 4a6df2cf264..5f0634299e0 100644
--- a/src/core/lib/iomgr/resolve_address.h
+++ b/src/core/lib/iomgr/resolve_address.h
@@ -60,4 +60,4 @@ extern grpc_error *(*grpc_blocking_resolve_address)(
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_RESOLVE_ADDRESS_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_RESOLVE_ADDRESS_H */
diff --git a/src/core/lib/iomgr/resolve_address_posix.cc b/src/core/lib/iomgr/resolve_address_posix.cc
index 60cfeebd47d..1b783495dfc 100644
--- a/src/core/lib/iomgr/resolve_address_posix.cc
+++ b/src/core/lib/iomgr/resolve_address_posix.cc
@@ -33,10 +33,10 @@
 #include <grpc/support/thd.h>
 #include <grpc/support/time.h>
 #include <grpc/support/useful.h>
+#include "src/core/lib/iomgr/block_annotate.h"
 #include "src/core/lib/iomgr/executor.h"
 #include "src/core/lib/iomgr/iomgr_internal.h"
 #include "src/core/lib/iomgr/unix_sockets_posix.h"
-#include "src/core/lib/support/block_annotate.h"
 #include "src/core/lib/support/string.h"
 
 static grpc_error *blocking_resolve_address_impl(
@@ -81,7 +81,7 @@ static grpc_error *blocking_resolve_address_impl(
 
   GRPC_SCHEDULING_START_BLOCKING_REGION;
   s = getaddrinfo(host, port, &hints, &result);
-  GRPC_SCHEDULING_END_BLOCKING_REGION;
+  GRPC_SCHEDULING_END_BLOCKING_REGION_NO_EXEC_CTX;
 
   if (s != 0) {
     /* Retry if well-known service name is recognized */
@@ -90,7 +90,7 @@ static grpc_error *blocking_resolve_address_impl(
       if (strcmp(port, svc[i][0]) == 0) {
         GRPC_SCHEDULING_START_BLOCKING_REGION;
         s = getaddrinfo(host, svc[i][1], &hints, &result);
-        GRPC_SCHEDULING_END_BLOCKING_REGION;
+        GRPC_SCHEDULING_END_BLOCKING_REGION_NO_EXEC_CTX;
         break;
       }
     }
diff --git a/src/core/lib/iomgr/resolve_address_windows.cc b/src/core/lib/iomgr/resolve_address_windows.cc
index abcfc2114d5..451f01a701e 100644
--- a/src/core/lib/iomgr/resolve_address_windows.cc
+++ b/src/core/lib/iomgr/resolve_address_windows.cc
@@ -34,10 +34,10 @@
 #include <grpc/support/string_util.h>
 #include <grpc/support/thd.h>
 #include <grpc/support/time.h>
+#include "src/core/lib/iomgr/block_annotate.h"
 #include "src/core/lib/iomgr/executor.h"
 #include "src/core/lib/iomgr/iomgr_internal.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
-#include "src/core/lib/support/block_annotate.h"
 #include "src/core/lib/support/string.h"
 
 typedef struct {
@@ -87,7 +87,7 @@ static grpc_error *blocking_resolve_address_impl(
 
   GRPC_SCHEDULING_START_BLOCKING_REGION;
   s = getaddrinfo(host, port, &hints, &result);
-  GRPC_SCHEDULING_END_BLOCKING_REGION;
+  GRPC_SCHEDULING_END_BLOCKING_REGION_NO_EXEC_CTX;
   if (s != 0) {
     error = GRPC_WSA_ERROR(WSAGetLastError(), "getaddrinfo");
     goto done;
diff --git a/src/core/lib/iomgr/resource_quota.cc b/src/core/lib/iomgr/resource_quota.cc
index 60262435b33..ecb5747da86 100644
--- a/src/core/lib/iomgr/resource_quota.cc
+++ b/src/core/lib/iomgr/resource_quota.cc
@@ -89,6 +89,8 @@ struct grpc_resource_user {
   grpc_closure_list on_allocated;
   /* True if we are currently trying to allocate from the quota, false if not */
   bool allocating;
+  /* How many bytes of allocations are outstanding */
+  int64_t outstanding_allocations;
   /* True if we are currently trying to add ourselves to the non-free quota
      list, false otherwise */
   bool added_to_free_pool;
@@ -153,6 +155,9 @@ struct grpc_resource_quota {
   char *name;
 };
 
+static void ru_unref_by(grpc_exec_ctx *exec_ctx,
+                        grpc_resource_user *resource_user, gpr_atm amount);
+
 /*******************************************************************************
  * list management
  */
@@ -289,6 +294,25 @@ static bool rq_alloc(grpc_exec_ctx *exec_ctx,
   while ((resource_user = rulist_pop_head(resource_quota,
                                           GRPC_RULIST_AWAITING_ALLOCATION))) {
     gpr_mu_lock(&resource_user->mu);
+    if (GRPC_TRACER_ON(grpc_resource_quota_trace)) {
+      gpr_log(GPR_DEBUG, "RQ: check allocation for user %p shutdown=%" PRIdPTR
+                         " free_pool=%" PRId64,
+              resource_user, gpr_atm_no_barrier_load(&resource_user->shutdown),
+              resource_user->free_pool);
+    }
+    if (gpr_atm_no_barrier_load(&resource_user->shutdown)) {
+      resource_user->allocating = false;
+      grpc_closure_list_fail_all(
+          &resource_user->on_allocated,
+          GRPC_ERROR_CREATE_FROM_STATIC_STRING("Resource user shutdown"));
+      int64_t aborted_allocations = resource_user->outstanding_allocations;
+      resource_user->outstanding_allocations = 0;
+      resource_user->free_pool += aborted_allocations;
+      GRPC_CLOSURE_LIST_SCHED(exec_ctx, &resource_user->on_allocated);
+      gpr_mu_unlock(&resource_user->mu);
+      ru_unref_by(exec_ctx, resource_user, (gpr_atm)aborted_allocations);
+      continue;
+    }
     if (resource_user->free_pool < 0 &&
         -resource_user->free_pool <= resource_quota->free_pool) {
       int64_t amt = -resource_user->free_pool;
@@ -308,6 +332,7 @@ static bool rq_alloc(grpc_exec_ctx *exec_ctx,
     }
     if (resource_user->free_pool >= 0) {
       resource_user->allocating = false;
+      resource_user->outstanding_allocations = 0;
       GRPC_CLOSURE_LIST_SCHED(exec_ctx, &resource_user->on_allocated);
       gpr_mu_unlock(&resource_user->mu);
     } else {
@@ -488,6 +513,9 @@ static void ru_post_destructive_reclaimer(grpc_exec_ctx *exec_ctx, void *ru,
 }
 
 static void ru_shutdown(grpc_exec_ctx *exec_ctx, void *ru, grpc_error *error) {
+  if (GRPC_TRACER_ON(grpc_resource_quota_trace)) {
+    gpr_log(GPR_DEBUG, "RU shutdown %p", ru);
+  }
   grpc_resource_user *resource_user = (grpc_resource_user *)ru;
   GRPC_CLOSURE_SCHED(exec_ctx, resource_user->reclaimers[0],
                      GRPC_ERROR_CANCELLED);
@@ -497,6 +525,9 @@ static void ru_shutdown(grpc_exec_ctx *exec_ctx, void *ru, grpc_error *error) {
   resource_user->reclaimers[1] = NULL;
   rulist_remove(resource_user, GRPC_RULIST_RECLAIMER_BENIGN);
   rulist_remove(resource_user, GRPC_RULIST_RECLAIMER_DESTRUCTIVE);
+  if (resource_user->allocating) {
+    rq_step_sched(exec_ctx, resource_user->resource_quota);
+  }
 }
 
 static void ru_destroy(grpc_exec_ctx *exec_ctx, void *ru, grpc_error *error) {
@@ -718,6 +749,7 @@ grpc_resource_user *grpc_resource_user_create(
   resource_user->reclaimers[1] = NULL;
   resource_user->new_reclaimers[0] = NULL;
   resource_user->new_reclaimers[1] = NULL;
+  resource_user->outstanding_allocations = 0;
   for (int i = 0; i < GRPC_RULIST_COUNT; i++) {
     resource_user->links[i].next = resource_user->links[i].prev = NULL;
   }
@@ -778,6 +810,7 @@ void grpc_resource_user_alloc(grpc_exec_ctx *exec_ctx,
   gpr_mu_lock(&resource_user->mu);
   ru_ref_by(resource_user, (gpr_atm)size);
   resource_user->free_pool -= (int64_t)size;
+  resource_user->outstanding_allocations += (int64_t)size;
   if (GRPC_TRACER_ON(grpc_resource_quota_trace)) {
     gpr_log(GPR_DEBUG, "RQ %s %s: alloc %" PRIdPTR "; free_pool -> %" PRId64,
             resource_user->resource_quota->name, resource_user->name, size,
@@ -792,6 +825,7 @@ void grpc_resource_user_alloc(grpc_exec_ctx *exec_ctx,
                          GRPC_ERROR_NONE);
     }
   } else {
+    resource_user->outstanding_allocations -= (int64_t)size;
     GRPC_CLOSURE_SCHED(exec_ctx, optional_on_done, GRPC_ERROR_NONE);
   }
   gpr_mu_unlock(&resource_user->mu);
diff --git a/src/core/lib/iomgr/resource_quota.h b/src/core/lib/iomgr/resource_quota.h
index 3afb5254349..1d4249b7e29 100644
--- a/src/core/lib/iomgr/resource_quota.h
+++ b/src/core/lib/iomgr/resource_quota.h
@@ -158,4 +158,4 @@ grpc_slice grpc_resource_user_slice_malloc(grpc_exec_ctx *exec_ctx,
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_RESOURCE_QUOTA_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_RESOURCE_QUOTA_H */
diff --git a/src/core/lib/iomgr/sockaddr_utils.h b/src/core/lib/iomgr/sockaddr_utils.h
index 129bb54fc9e..1fd552febbb 100644
--- a/src/core/lib/iomgr/sockaddr_utils.h
+++ b/src/core/lib/iomgr/sockaddr_utils.h
@@ -85,4 +85,4 @@ int grpc_sockaddr_get_family(const grpc_resolved_address *resolved_addr);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_SOCKADDR_UTILS_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_SOCKADDR_UTILS_H */
diff --git a/src/core/lib/iomgr/socket_utils.h b/src/core/lib/iomgr/socket_utils.h
index f319e931b61..d6c538ec6f3 100644
--- a/src/core/lib/iomgr/socket_utils.h
+++ b/src/core/lib/iomgr/socket_utils.h
@@ -32,4 +32,4 @@ const char *grpc_inet_ntop(int af, const void *src, char *dst, size_t size);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_SOCKET_UTILS_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_SOCKET_UTILS_H */
diff --git a/src/core/lib/iomgr/socket_utils_posix.h b/src/core/lib/iomgr/socket_utils_posix.h
index 623b83f08b1..73809b68d30 100644
--- a/src/core/lib/iomgr/socket_utils_posix.h
+++ b/src/core/lib/iomgr/socket_utils_posix.h
@@ -137,4 +137,4 @@ grpc_error *grpc_create_dualstack_socket_using_factory(
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_SOCKET_UTILS_POSIX_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_SOCKET_UTILS_POSIX_H */
diff --git a/src/core/lib/iomgr/socket_windows.h b/src/core/lib/iomgr/socket_windows.h
index a00a7615a37..84fa071e89a 100644
--- a/src/core/lib/iomgr/socket_windows.h
+++ b/src/core/lib/iomgr/socket_windows.h
@@ -115,4 +115,4 @@ void grpc_socket_become_ready(grpc_exec_ctx *exec_ctx,
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_SOCKET_WINDOWS_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_SOCKET_WINDOWS_H */
diff --git a/src/core/lib/iomgr/tcp_client.h b/src/core/lib/iomgr/tcp_client.h
index 18cf6114f2d..b2f365f2af6 100644
--- a/src/core/lib/iomgr/tcp_client.h
+++ b/src/core/lib/iomgr/tcp_client.h
@@ -39,10 +39,10 @@ void grpc_tcp_client_connect(grpc_exec_ctx *exec_ctx, grpc_closure *on_connect,
                              grpc_pollset_set *interested_parties,
                              const grpc_channel_args *channel_args,
                              const grpc_resolved_address *addr,
-                             gpr_timespec deadline);
+                             grpc_millis deadline);
 
 #ifdef __cplusplus
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_TCP_CLIENT_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_TCP_CLIENT_H */
diff --git a/src/core/lib/iomgr/tcp_client_posix.cc b/src/core/lib/iomgr/tcp_client_posix.cc
index 7d9e9533fda..5611dd90624 100644
--- a/src/core/lib/iomgr/tcp_client_posix.cc
+++ b/src/core/lib/iomgr/tcp_client_posix.cc
@@ -48,7 +48,6 @@ extern grpc_tracer_flag grpc_tcp_trace;
 typedef struct {
   gpr_mu mu;
   grpc_fd *fd;
-  gpr_timespec deadline;
   grpc_timer alarm;
   grpc_closure on_alarm;
   int refs;
@@ -244,7 +243,7 @@ static void tcp_client_connect_impl(grpc_exec_ctx *exec_ctx,
                                     grpc_pollset_set *interested_parties,
                                     const grpc_channel_args *channel_args,
                                     const grpc_resolved_address *addr,
-                                    gpr_timespec deadline) {
+                                    grpc_millis deadline) {
   int fd;
   grpc_dualstack_mode dsmode;
   int err;
@@ -325,9 +324,7 @@ static void tcp_client_connect_impl(grpc_exec_ctx *exec_ctx,
 
   gpr_mu_lock(&ac->mu);
   GRPC_CLOSURE_INIT(&ac->on_alarm, tc_on_alarm, ac, grpc_schedule_on_exec_ctx);
-  grpc_timer_init(exec_ctx, &ac->alarm,
-                  gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC),
-                  &ac->on_alarm, gpr_now(GPR_CLOCK_MONOTONIC));
+  grpc_timer_init(exec_ctx, &ac->alarm, deadline, &ac->on_alarm);
   grpc_fd_notify_on_write(exec_ctx, ac->fd, &ac->write_closure);
   gpr_mu_unlock(&ac->mu);
 
@@ -342,7 +339,7 @@ void (*grpc_tcp_client_connect_impl)(
     grpc_exec_ctx *exec_ctx, grpc_closure *closure, grpc_endpoint **ep,
     grpc_pollset_set *interested_parties, const grpc_channel_args *channel_args,
     const grpc_resolved_address *addr,
-    gpr_timespec deadline) = tcp_client_connect_impl;
+    grpc_millis deadline) = tcp_client_connect_impl;
 }
 
 void grpc_tcp_client_connect(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
@@ -350,7 +347,7 @@ void grpc_tcp_client_connect(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
                              grpc_pollset_set *interested_parties,
                              const grpc_channel_args *channel_args,
                              const grpc_resolved_address *addr,
-                             gpr_timespec deadline) {
+                             grpc_millis deadline) {
   grpc_tcp_client_connect_impl(exec_ctx, closure, ep, interested_parties,
                                channel_args, addr, deadline);
 }
diff --git a/src/core/lib/iomgr/tcp_client_posix.h b/src/core/lib/iomgr/tcp_client_posix.h
index 0b9775504ca..8740511804d 100644
--- a/src/core/lib/iomgr/tcp_client_posix.h
+++ b/src/core/lib/iomgr/tcp_client_posix.h
@@ -35,4 +35,4 @@ grpc_endpoint *grpc_tcp_client_create_from_fd(
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_TCP_CLIENT_POSIX_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_TCP_CLIENT_POSIX_H */
diff --git a/src/core/lib/iomgr/tcp_client_uv.cc b/src/core/lib/iomgr/tcp_client_uv.cc
index 83835978f44..f3e9366299d 100644
--- a/src/core/lib/iomgr/tcp_client_uv.cc
+++ b/src/core/lib/iomgr/tcp_client_uv.cc
@@ -119,7 +119,7 @@ static void tcp_client_connect_impl(grpc_exec_ctx *exec_ctx,
                                     grpc_pollset_set *interested_parties,
                                     const grpc_channel_args *channel_args,
                                     const grpc_resolved_address *resolved_addr,
-                                    gpr_timespec deadline) {
+                                    grpc_millis deadline) {
   grpc_uv_tcp_connect *connect;
   grpc_resource_quota *resource_quota = grpc_resource_quota_create(NULL);
   (void)channel_args;
@@ -158,9 +158,7 @@ static void tcp_client_connect_impl(grpc_exec_ctx *exec_ctx,
                  uv_tc_on_connect);
   GRPC_CLOSURE_INIT(&connect->on_alarm, uv_tc_on_alarm, connect,
                     grpc_schedule_on_exec_ctx);
-  grpc_timer_init(exec_ctx, &connect->alarm,
-                  gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC),
-                  &connect->on_alarm, gpr_now(GPR_CLOCK_MONOTONIC));
+  grpc_timer_init(exec_ctx, &connect->alarm, deadline, &connect->on_alarm);
 }
 
 // overridden by api_fuzzer.c
@@ -169,7 +167,7 @@ void (*grpc_tcp_client_connect_impl)(
     grpc_exec_ctx *exec_ctx, grpc_closure *closure, grpc_endpoint **ep,
     grpc_pollset_set *interested_parties, const grpc_channel_args *channel_args,
     const grpc_resolved_address *addr,
-    gpr_timespec deadline) = tcp_client_connect_impl;
+    grpc_millis deadline) = tcp_client_connect_impl;
 }
 
 void grpc_tcp_client_connect(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
@@ -177,7 +175,7 @@ void grpc_tcp_client_connect(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
                              grpc_pollset_set *interested_parties,
                              const grpc_channel_args *channel_args,
                              const grpc_resolved_address *addr,
-                             gpr_timespec deadline) {
+                             grpc_millis deadline) {
   grpc_tcp_client_connect_impl(exec_ctx, closure, ep, interested_parties,
                                channel_args, addr, deadline);
 }
diff --git a/src/core/lib/iomgr/tcp_client_windows.cc b/src/core/lib/iomgr/tcp_client_windows.cc
index 1154965c82f..9adf7ee4e9c 100644
--- a/src/core/lib/iomgr/tcp_client_windows.cc
+++ b/src/core/lib/iomgr/tcp_client_windows.cc
@@ -43,7 +43,6 @@ typedef struct {
   grpc_closure *on_done;
   gpr_mu mu;
   grpc_winsocket *socket;
-  gpr_timespec deadline;
   grpc_timer alarm;
   grpc_closure on_alarm;
   char *addr_name;
@@ -126,7 +125,7 @@ static void on_connect(grpc_exec_ctx *exec_ctx, void *acp, grpc_error *error) {
 static void tcp_client_connect_impl(
     grpc_exec_ctx *exec_ctx, grpc_closure *on_done, grpc_endpoint **endpoint,
     grpc_pollset_set *interested_parties, const grpc_channel_args *channel_args,
-    const grpc_resolved_address *addr, gpr_timespec deadline) {
+    const grpc_resolved_address *addr, grpc_millis deadline) {
   SOCKET sock = INVALID_SOCKET;
   BOOL success;
   int status;
@@ -206,8 +205,7 @@ static void tcp_client_connect_impl(
   GRPC_CLOSURE_INIT(&ac->on_connect, on_connect, ac, grpc_schedule_on_exec_ctx);
 
   GRPC_CLOSURE_INIT(&ac->on_alarm, on_alarm, ac, grpc_schedule_on_exec_ctx);
-  grpc_timer_init(exec_ctx, &ac->alarm, deadline, &ac->on_alarm,
-                  gpr_now(GPR_CLOCK_MONOTONIC));
+  grpc_timer_init(exec_ctx, &ac->alarm, deadline, &ac->on_alarm);
   grpc_socket_notify_on_write(exec_ctx, socket, &ac->on_connect);
   return;
 
@@ -233,7 +231,7 @@ void (*grpc_tcp_client_connect_impl)(
     grpc_exec_ctx *exec_ctx, grpc_closure *closure, grpc_endpoint **ep,
     grpc_pollset_set *interested_parties, const grpc_channel_args *channel_args,
     const grpc_resolved_address *addr,
-    gpr_timespec deadline) = tcp_client_connect_impl;
+    grpc_millis deadline) = tcp_client_connect_impl;
 }
 
 void grpc_tcp_client_connect(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
@@ -241,7 +239,7 @@ void grpc_tcp_client_connect(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
                              grpc_pollset_set *interested_parties,
                              const grpc_channel_args *channel_args,
                              const grpc_resolved_address *addr,
-                             gpr_timespec deadline) {
+                             grpc_millis deadline) {
   grpc_tcp_client_connect_impl(exec_ctx, closure, ep, interested_parties,
                                channel_args, addr, deadline);
 }
diff --git a/src/core/lib/iomgr/tcp_posix.cc b/src/core/lib/iomgr/tcp_posix.cc
index 7e271294fd6..7fcaef76792 100644
--- a/src/core/lib/iomgr/tcp_posix.cc
+++ b/src/core/lib/iomgr/tcp_posix.cc
@@ -135,13 +135,11 @@ static void run_poller(grpc_exec_ctx *exec_ctx, void *bp,
     gpr_log(GPR_DEBUG, "BACKUP_POLLER:%p run", p);
   }
   gpr_mu_lock(p->pollset_mu);
-  gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
-  gpr_timespec deadline =
-      gpr_time_add(now, gpr_time_from_seconds(10, GPR_TIMESPAN));
+  grpc_millis deadline = grpc_exec_ctx_now(exec_ctx) + 13 * GPR_MS_PER_SEC;
   GRPC_STATS_INC_TCP_BACKUP_POLLER_POLLS(exec_ctx);
-  GRPC_LOG_IF_ERROR("backup_poller:pollset_work",
-                    grpc_pollset_work(exec_ctx, BACKUP_POLLER_POLLSET(p), NULL,
-                                      now, deadline));
+  GRPC_LOG_IF_ERROR(
+      "backup_poller:pollset_work",
+      grpc_pollset_work(exec_ctx, BACKUP_POLLER_POLLSET(p), NULL, deadline));
   gpr_mu_unlock(p->pollset_mu);
   /* last "uncovered" notification is the ref that keeps us polling, if we get
    * there try a cas to release it */
diff --git a/src/core/lib/iomgr/tcp_posix.h b/src/core/lib/iomgr/tcp_posix.h
index dda78b2f8e1..47e78fa67e6 100644
--- a/src/core/lib/iomgr/tcp_posix.h
+++ b/src/core/lib/iomgr/tcp_posix.h
@@ -61,4 +61,4 @@ void grpc_tcp_destroy_and_release_fd(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_TCP_POSIX_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_TCP_POSIX_H */
diff --git a/src/core/lib/iomgr/tcp_server.h b/src/core/lib/iomgr/tcp_server.h
index 3f190ac2853..8f9ce3819e6 100644
--- a/src/core/lib/iomgr/tcp_server.h
+++ b/src/core/lib/iomgr/tcp_server.h
@@ -106,4 +106,4 @@ void grpc_tcp_server_shutdown_listeners(grpc_exec_ctx *exec_ctx,
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_TCP_SERVER_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_TCP_SERVER_H */
diff --git a/src/core/lib/iomgr/tcp_server_utils_posix.h b/src/core/lib/iomgr/tcp_server_utils_posix.h
index 4bb0660f091..67463339608 100644
--- a/src/core/lib/iomgr/tcp_server_utils_posix.h
+++ b/src/core/lib/iomgr/tcp_server_utils_posix.h
@@ -125,4 +125,4 @@ bool grpc_tcp_server_have_ifaddrs(void);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_TCP_SERVER_UTILS_POSIX_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_TCP_SERVER_UTILS_POSIX_H */
diff --git a/src/core/lib/iomgr/tcp_uv.h b/src/core/lib/iomgr/tcp_uv.h
index ba7db8a0f7f..3399535b421 100644
--- a/src/core/lib/iomgr/tcp_uv.h
+++ b/src/core/lib/iomgr/tcp_uv.h
@@ -50,4 +50,4 @@ grpc_endpoint *grpc_tcp_create(uv_tcp_t *handle,
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_TCP_UV_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_TCP_UV_H */
diff --git a/src/core/lib/iomgr/time_averaged_stats.h b/src/core/lib/iomgr/time_averaged_stats.h
index e255b58feeb..d38ed272b6d 100644
--- a/src/core/lib/iomgr/time_averaged_stats.h
+++ b/src/core/lib/iomgr/time_averaged_stats.h
@@ -78,4 +78,4 @@ double grpc_time_averaged_stats_update_average(grpc_time_averaged_stats* stats);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_TIME_AVERAGED_STATS_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_TIME_AVERAGED_STATS_H */
diff --git a/src/core/lib/iomgr/timer.h b/src/core/lib/iomgr/timer.h
index 466600d582c..419e834cf18 100644
--- a/src/core/lib/iomgr/timer.h
+++ b/src/core/lib/iomgr/timer.h
@@ -45,8 +45,7 @@ typedef struct grpc_timer grpc_timer;
    application callback is also responsible for maintaining information about
    when to free up any user-level state. */
 void grpc_timer_init(grpc_exec_ctx *exec_ctx, grpc_timer *timer,
-                     gpr_timespec deadline, grpc_closure *closure,
-                     gpr_timespec now);
+                     grpc_millis deadline, grpc_closure *closure);
 
 /* Initialize *timer without setting it. This can later be passed through
    the regular init or cancel */
@@ -96,8 +95,8 @@ typedef enum {
    with high probability at least one thread in the system will see an update
    at any time slice. */
 grpc_timer_check_result grpc_timer_check(grpc_exec_ctx *exec_ctx,
-                                         gpr_timespec now, gpr_timespec *next);
-void grpc_timer_list_init(gpr_timespec now);
+                                         grpc_millis *next);
+void grpc_timer_list_init(grpc_exec_ctx *exec_ctx);
 void grpc_timer_list_shutdown(grpc_exec_ctx *exec_ctx);
 
 /* Consume a kick issued by grpc_kick_poller */
diff --git a/src/core/lib/iomgr/timer_generic.cc b/src/core/lib/iomgr/timer_generic.cc
index 971d80d8bc5..b8e895de6f0 100644
--- a/src/core/lib/iomgr/timer_generic.cc
+++ b/src/core/lib/iomgr/timer_generic.cc
@@ -220,9 +220,6 @@ struct shared_mutables {
 
 static struct shared_mutables g_shared_mutables;
 
-static gpr_clock_type g_clock_type;
-static gpr_timespec g_start_time;
-
 static gpr_atm saturating_add(gpr_atm a, gpr_atm b) {
   if (a > GPR_ATM_MAX - b) {
     return GPR_ATM_MAX;
@@ -235,52 +232,19 @@ static grpc_timer_check_result run_some_expired_timers(grpc_exec_ctx *exec_ctx,
                                                        gpr_atm *next,
                                                        grpc_error *error);
 
-static gpr_timespec dbl_to_ts(double d) {
-  gpr_timespec ts;
-  ts.tv_sec = (int64_t)d;
-  ts.tv_nsec = (int32_t)(1e9 * (d - (double)ts.tv_sec));
-  ts.clock_type = GPR_TIMESPAN;
-  return ts;
-}
-
-static gpr_atm timespec_to_atm_round_up(gpr_timespec ts) {
-  ts = gpr_time_sub(ts, g_start_time);
-  double x = GPR_MS_PER_SEC * (double)ts.tv_sec +
-             (double)ts.tv_nsec / GPR_NS_PER_MS +
-             (double)(GPR_NS_PER_SEC - 1) / (double)GPR_NS_PER_SEC;
-  if (x < 0) return 0;
-  if (x > GPR_ATM_MAX) return GPR_ATM_MAX;
-  return (gpr_atm)x;
-}
-
-static gpr_atm timespec_to_atm_round_down(gpr_timespec ts) {
-  ts = gpr_time_sub(ts, g_start_time);
-  double x =
-      GPR_MS_PER_SEC * (double)ts.tv_sec + (double)ts.tv_nsec / GPR_NS_PER_MS;
-  if (x < 0) return 0;
-  if (x > GPR_ATM_MAX) return GPR_ATM_MAX;
-  return (gpr_atm)x;
-}
-
-static gpr_timespec atm_to_timespec(gpr_atm x) {
-  return gpr_time_add(g_start_time, dbl_to_ts((double)x / 1000.0));
-}
-
 static gpr_atm compute_min_deadline(timer_shard *shard) {
   return grpc_timer_heap_is_empty(&shard->heap)
              ? saturating_add(shard->queue_deadline_cap, 1)
              : grpc_timer_heap_top(&shard->heap)->deadline;
 }
 
-void grpc_timer_list_init(gpr_timespec now) {
+void grpc_timer_list_init(grpc_exec_ctx *exec_ctx) {
   uint32_t i;
 
   g_shared_mutables.initialized = true;
   g_shared_mutables.checker_mu = GPR_SPINLOCK_INITIALIZER;
   gpr_mu_init(&g_shared_mutables.mu);
-  g_clock_type = now.clock_type;
-  g_start_time = now;
-  g_shared_mutables.min_timer = timespec_to_atm_round_down(now);
+  g_shared_mutables.min_timer = grpc_exec_ctx_now(exec_ctx);
   gpr_tls_init(&g_last_seen_min_timer);
   gpr_tls_set(&g_last_seen_min_timer, 0);
   grpc_register_tracer(&grpc_timer_trace);
@@ -317,10 +281,6 @@ void grpc_timer_list_shutdown(grpc_exec_ctx *exec_ctx) {
   g_shared_mutables.initialized = false;
 }
 
-static double ts_to_dbl(gpr_timespec ts) {
-  return (double)ts.tv_sec + 1e-9 * ts.tv_nsec;
-}
-
 /* returns true if the first element in the list */
 static void list_join(grpc_timer *head, grpc_timer *timer) {
   timer->next = head;
@@ -361,24 +321,20 @@ static void note_deadline_change(timer_shard *shard) {
 void grpc_timer_init_unset(grpc_timer *timer) { timer->pending = false; }
 
 void grpc_timer_init(grpc_exec_ctx *exec_ctx, grpc_timer *timer,
-                     gpr_timespec deadline, grpc_closure *closure,
-                     gpr_timespec now) {
+                     grpc_millis deadline, grpc_closure *closure) {
   int is_first_timer = 0;
   timer_shard *shard = &g_shards[GPR_HASH_POINTER(timer, NUM_SHARDS)];
-  GPR_ASSERT(deadline.clock_type == g_clock_type);
-  GPR_ASSERT(now.clock_type == g_clock_type);
   timer->closure = closure;
-  gpr_atm deadline_atm = timer->deadline = timespec_to_atm_round_up(deadline);
+  timer->deadline = deadline;
 
 #ifndef NDEBUG
   timer->hash_table_next = NULL;
 #endif
 
   if (GRPC_TRACER_ON(grpc_timer_trace)) {
-    gpr_log(GPR_DEBUG, "TIMER %p: SET %" PRId64 ".%09d [%" PRIdPTR
-                       "] now %" PRId64 ".%09d [%" PRIdPTR "] call %p[%p]",
-            timer, deadline.tv_sec, deadline.tv_nsec, deadline_atm, now.tv_sec,
-            now.tv_nsec, timespec_to_atm_round_down(now), closure, closure->cb);
+    gpr_log(GPR_DEBUG,
+            "TIMER %p: SET %" PRIdPTR " now %" PRIdPTR " call %p[%p]", timer,
+            deadline, grpc_exec_ctx_now(exec_ctx), closure, closure->cb);
   }
 
   if (!g_shared_mutables.initialized) {
@@ -391,7 +347,8 @@ void grpc_timer_init(grpc_exec_ctx *exec_ctx, grpc_timer *timer,
 
   gpr_mu_lock(&shard->mu);
   timer->pending = true;
-  if (gpr_time_cmp(deadline, now) <= 0) {
+  grpc_millis now = grpc_exec_ctx_now(exec_ctx);
+  if (deadline <= now) {
     timer->pending = false;
     GRPC_CLOSURE_SCHED(exec_ctx, timer->closure, GRPC_ERROR_NONE);
     gpr_mu_unlock(&shard->mu);
@@ -400,11 +357,11 @@ void grpc_timer_init(grpc_exec_ctx *exec_ctx, grpc_timer *timer,
   }
 
   grpc_time_averaged_stats_add_sample(&shard->stats,
-                                      ts_to_dbl(gpr_time_sub(deadline, now)));
+                                      (double)(deadline - now) / 1000.0);
 
   ADD_TO_HASH_TABLE(timer);
 
-  if (deadline_atm < shard->queue_deadline_cap) {
+  if (deadline < shard->queue_deadline_cap) {
     is_first_timer = grpc_timer_heap_add(&shard->heap, timer);
   } else {
     timer->heap_index = INVALID_HEAP_INDEX;
@@ -435,12 +392,12 @@ void grpc_timer_init(grpc_exec_ctx *exec_ctx, grpc_timer *timer,
       gpr_log(GPR_DEBUG, "  .. old shard min_deadline=%" PRIdPTR,
               shard->min_deadline);
     }
-    if (deadline_atm < shard->min_deadline) {
+    if (deadline < shard->min_deadline) {
       gpr_atm old_min_deadline = g_shard_queue[0]->min_deadline;
-      shard->min_deadline = deadline_atm;
+      shard->min_deadline = deadline;
       note_deadline_change(shard);
-      if (shard->shard_queue_index == 0 && deadline_atm < old_min_deadline) {
-        gpr_atm_no_barrier_store(&g_shared_mutables.min_timer, deadline_atm);
+      if (shard->shard_queue_index == 0 && deadline < old_min_deadline) {
+        gpr_atm_no_barrier_store(&g_shared_mutables.min_timer, deadline);
         grpc_kick_poller();
       }
     }
@@ -544,8 +501,9 @@ static grpc_timer *pop_one(timer_shard *shard, gpr_atm now) {
     }
     if (timer->deadline > now) return NULL;
     if (GRPC_TRACER_ON(grpc_timer_trace)) {
-      gpr_log(GPR_DEBUG, "TIMER %p: FIRE %" PRIdPTR "ms late", timer,
-              now - timer->deadline);
+      gpr_log(GPR_DEBUG, "TIMER %p: FIRE %" PRIdPTR "ms late via %s scheduler",
+              timer, now - timer->deadline,
+              timer->closure->scheduler->vtable->name);
     }
     timer->pending = false;
     grpc_timer_heap_pop(&shard->heap);
@@ -567,6 +525,10 @@ static size_t pop_timers(grpc_exec_ctx *exec_ctx, timer_shard *shard,
   }
   *new_min_deadline = compute_min_deadline(shard);
   gpr_mu_unlock(&shard->mu);
+  if (GRPC_TRACER_ON(grpc_timer_check_trace)) {
+    gpr_log(GPR_DEBUG, "  .. shard[%d] popped %" PRIdPTR,
+            (int)(shard - g_shards), n);
+  }
   return n;
 }
 
@@ -639,29 +601,27 @@ static grpc_timer_check_result run_some_expired_timers(grpc_exec_ctx *exec_ctx,
 }
 
 grpc_timer_check_result grpc_timer_check(grpc_exec_ctx *exec_ctx,
-                                         gpr_timespec now, gpr_timespec *next) {
+                                         grpc_millis *next) {
   // prelude
-  GPR_ASSERT(now.clock_type == g_clock_type);
-  gpr_atm now_atm = timespec_to_atm_round_down(now);
+  grpc_millis now = grpc_exec_ctx_now(exec_ctx);
 
   /* fetch from a thread-local first: this avoids contention on a globally
      mutable cacheline in the common case */
-  gpr_atm min_timer = gpr_tls_get(&g_last_seen_min_timer);
-  if (now_atm < min_timer) {
+  grpc_millis min_timer = gpr_tls_get(&g_last_seen_min_timer);
+  if (now < min_timer) {
     if (next != NULL) {
-      *next =
-          atm_to_timespec(GPR_MIN(timespec_to_atm_round_up(*next), min_timer));
+      *next = GPR_MIN(*next, min_timer);
     }
     if (GRPC_TRACER_ON(grpc_timer_check_trace)) {
       gpr_log(GPR_DEBUG,
-              "TIMER CHECK SKIP: now_atm=%" PRIdPTR " min_timer=%" PRIdPTR,
-              now_atm, min_timer);
+              "TIMER CHECK SKIP: now=%" PRIdPTR " min_timer=%" PRIdPTR, now,
+              min_timer);
     }
     return GRPC_TIMERS_CHECKED_AND_EMPTY;
   }
 
   grpc_error *shutdown_error =
-      gpr_time_cmp(now, gpr_inf_future(now.clock_type)) != 0
+      now != GRPC_MILLIS_INF_FUTURE
           ? GRPC_ERROR_NONE
           : GRPC_ERROR_CREATE_FROM_STATIC_STRING("Shutting down timer system");
 
@@ -671,34 +631,24 @@ grpc_timer_check_result grpc_timer_check(grpc_exec_ctx *exec_ctx,
     if (next == NULL) {
       next_str = gpr_strdup("NULL");
     } else {
-      gpr_asprintf(&next_str, "%" PRId64 ".%09d [%" PRIdPTR "]", next->tv_sec,
-                   next->tv_nsec, timespec_to_atm_round_down(*next));
+      gpr_asprintf(&next_str, "%" PRIdPTR, *next);
     }
-    gpr_log(GPR_DEBUG, "TIMER CHECK BEGIN: now=%" PRId64 ".%09d [%" PRIdPTR
-                       "] next=%s tls_min=%" PRIdPTR " glob_min=%" PRIdPTR,
-            now.tv_sec, now.tv_nsec, now_atm, next_str,
-            gpr_tls_get(&g_last_seen_min_timer),
+    gpr_log(GPR_DEBUG, "TIMER CHECK BEGIN: now=%" PRIdPTR
+                       " next=%s tls_min=%" PRIdPTR " glob_min=%" PRIdPTR,
+            now, next_str, gpr_tls_get(&g_last_seen_min_timer),
             gpr_atm_no_barrier_load(&g_shared_mutables.min_timer));
     gpr_free(next_str);
   }
   // actual code
-  grpc_timer_check_result r;
-  gpr_atm next_atm;
-  if (next == NULL) {
-    r = run_some_expired_timers(exec_ctx, now_atm, NULL, shutdown_error);
-  } else {
-    next_atm = timespec_to_atm_round_down(*next);
-    r = run_some_expired_timers(exec_ctx, now_atm, &next_atm, shutdown_error);
-    *next = atm_to_timespec(next_atm);
-  }
+  grpc_timer_check_result r =
+      run_some_expired_timers(exec_ctx, now, next, shutdown_error);
   // tracing
   if (GRPC_TRACER_ON(grpc_timer_check_trace)) {
     char *next_str;
     if (next == NULL) {
       next_str = gpr_strdup("NULL");
     } else {
-      gpr_asprintf(&next_str, "%" PRId64 ".%09d [%" PRIdPTR "]", next->tv_sec,
-                   next->tv_nsec, next_atm);
+      gpr_asprintf(&next_str, "%" PRIdPTR, *next);
     }
     gpr_log(GPR_DEBUG, "TIMER CHECK END: r=%d; next=%s", r, next_str);
     gpr_free(next_str);
diff --git a/src/core/lib/iomgr/timer_heap.h b/src/core/lib/iomgr/timer_heap.h
index f15e8a3abb8..228d038ab38 100644
--- a/src/core/lib/iomgr/timer_heap.h
+++ b/src/core/lib/iomgr/timer_heap.h
@@ -47,4 +47,4 @@ int grpc_timer_heap_is_empty(grpc_timer_heap *heap);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_TIMER_HEAP_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_TIMER_HEAP_H */
diff --git a/src/core/lib/iomgr/timer_manager.cc b/src/core/lib/iomgr/timer_manager.cc
index 9b54fab898f..1248f82189a 100644
--- a/src/core/lib/iomgr/timer_manager.cc
+++ b/src/core/lib/iomgr/timer_manager.cc
@@ -55,7 +55,7 @@ static bool g_kicked;
 static bool g_has_timed_waiter;
 // the deadline of the current timed waiter thread (only relevant if
 // g_has_timed_waiter is true)
-static gpr_timespec g_timed_waiter_deadline;
+static grpc_millis g_timed_waiter_deadline;
 // generation counter to track which thread is waiting for the next timer
 static uint64_t g_timed_waiter_generation;
 
@@ -99,9 +99,8 @@ static void start_timer_thread_and_unlock(void) {
 
 void grpc_timer_manager_tick() {
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
-  gpr_timespec next = gpr_inf_future(GPR_CLOCK_MONOTONIC);
-  gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
-  grpc_timer_check(&exec_ctx, now, &next);
+  grpc_millis next = GRPC_MILLIS_INF_FUTURE;
+  grpc_timer_check(&exec_ctx, &next);
   grpc_exec_ctx_finish(&exec_ctx);
 }
 
@@ -124,6 +123,9 @@ static void run_some_timers(grpc_exec_ctx *exec_ctx) {
     gpr_mu_unlock(&g_mu);
   }
   // without our lock, flush the exec_ctx
+  if (GRPC_TRACER_ON(grpc_timer_check_trace)) {
+    gpr_log(GPR_DEBUG, "flush exec_ctx");
+  }
   grpc_exec_ctx_flush(exec_ctx);
   gpr_mu_lock(&g_mu);
   // garbage collect any threads hanging out that are dead
@@ -136,8 +138,7 @@ static void run_some_timers(grpc_exec_ctx *exec_ctx) {
 // wait until 'next' (or forever if there is already a timed waiter in the pool)
 // returns true if the thread should continue executing (false if it should
 // shutdown)
-static bool wait_until(gpr_timespec next) {
-  const gpr_timespec inf_future = gpr_inf_future(GPR_CLOCK_MONOTONIC);
+static bool wait_until(grpc_exec_ctx *exec_ctx, grpc_millis next) {
   gpr_mu_lock(&g_mu);
   // if we're not threaded anymore, leave
   if (!g_threaded) {
@@ -171,30 +172,29 @@ static bool wait_until(gpr_timespec next) {
        unless their 'next' is earlier than the current timed-waiter's deadline
        (in which case the thread with earlier 'next' takes over as the new timed
        waiter) */
-    if (gpr_time_cmp(next, inf_future) != 0) {
-      if (!g_has_timed_waiter ||
-          (gpr_time_cmp(next, g_timed_waiter_deadline) < 0)) {
+    if (next != GRPC_MILLIS_INF_FUTURE) {
+      if (!g_has_timed_waiter || (next < g_timed_waiter_deadline)) {
         my_timed_waiter_generation = ++g_timed_waiter_generation;
         g_has_timed_waiter = true;
         g_timed_waiter_deadline = next;
 
         if (GRPC_TRACER_ON(grpc_timer_check_trace)) {
-          gpr_timespec wait_time =
-              gpr_time_sub(next, gpr_now(GPR_CLOCK_MONOTONIC));
-          gpr_log(GPR_DEBUG, "sleep for a %" PRId64 ".%09d seconds",
-                  wait_time.tv_sec, wait_time.tv_nsec);
+          grpc_millis wait_time = next - grpc_exec_ctx_now(exec_ctx);
+          gpr_log(GPR_DEBUG, "sleep for a %" PRIdPTR " milliseconds",
+                  wait_time);
         }
       } else {  // g_timed_waiter == true && next >= g_timed_waiter_deadline
-        next = inf_future;
+        next = GRPC_MILLIS_INF_FUTURE;
       }
     }
 
     if (GRPC_TRACER_ON(grpc_timer_check_trace) &&
-        gpr_time_cmp(next, inf_future) == 0) {
+        next == GRPC_MILLIS_INF_FUTURE) {
       gpr_log(GPR_DEBUG, "sleep until kicked");
     }
 
-    gpr_cv_wait(&g_cv_wait, &g_mu, next);
+    gpr_cv_wait(&g_cv_wait, &g_mu,
+                grpc_millis_to_timespec(next, GPR_CLOCK_REALTIME));
 
     if (GRPC_TRACER_ON(grpc_timer_check_trace)) {
       gpr_log(GPR_DEBUG, "wait ended: was_timed:%d kicked:%d",
@@ -206,7 +206,7 @@ static bool wait_until(gpr_timespec next) {
     // there's work to do after checking timers (code above)
     if (my_timed_waiter_generation == g_timed_waiter_generation) {
       g_has_timed_waiter = false;
-      g_timed_waiter_deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
+      g_timed_waiter_deadline = GRPC_MILLIS_INF_FUTURE;
     }
   }
 
@@ -222,12 +222,11 @@ static bool wait_until(gpr_timespec next) {
 }
 
 static void timer_main_loop(grpc_exec_ctx *exec_ctx) {
-  const gpr_timespec inf_future = gpr_inf_future(GPR_CLOCK_MONOTONIC);
   for (;;) {
-    gpr_timespec next = inf_future;
-    gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
+    grpc_millis next = GRPC_MILLIS_INF_FUTURE;
+    grpc_exec_ctx_invalidate_now(exec_ctx);
     // check timer state, updates next to the next time to run a check
-    switch (grpc_timer_check(exec_ctx, now, &next)) {
+    switch (grpc_timer_check(exec_ctx, &next)) {
       case GRPC_TIMERS_FIRED:
         run_some_timers(exec_ctx);
         break;
@@ -244,10 +243,10 @@ static void timer_main_loop(grpc_exec_ctx *exec_ctx) {
         if (GRPC_TRACER_ON(grpc_timer_check_trace)) {
           gpr_log(GPR_DEBUG, "timers not checked: expect another thread to");
         }
-        next = inf_future;
+        next = GRPC_MILLIS_INF_FUTURE;
       /* fall through */
       case GRPC_TIMERS_CHECKED_AND_EMPTY:
-        if (!wait_until(next)) {
+        if (!wait_until(exec_ctx, next)) {
           return;
         }
         break;
@@ -303,7 +302,7 @@ void grpc_timer_manager_init(void) {
   g_completed_threads = NULL;
 
   g_has_timed_waiter = false;
-  g_timed_waiter_deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
+  g_timed_waiter_deadline = GRPC_MILLIS_INF_FUTURE;
 
   start_threads();
 }
@@ -350,7 +349,7 @@ void grpc_kick_poller(void) {
   gpr_mu_lock(&g_mu);
   g_kicked = true;
   g_has_timed_waiter = false;
-  g_timed_waiter_deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
+  g_timed_waiter_deadline = GRPC_MILLIS_INF_FUTURE;
   ++g_timed_waiter_generation;
   gpr_cv_signal(&g_cv_wait);
   gpr_mu_unlock(&g_mu);
diff --git a/src/core/lib/iomgr/timer_manager.h b/src/core/lib/iomgr/timer_manager.h
index d8a59a9477a..72960d6ffc0 100644
--- a/src/core/lib/iomgr/timer_manager.h
+++ b/src/core/lib/iomgr/timer_manager.h
@@ -42,4 +42,4 @@ void grpc_timer_manager_tick(void);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_TIMER_MANAGER_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_TIMER_MANAGER_H */
diff --git a/src/core/lib/iomgr/timer_uv.cc b/src/core/lib/iomgr/timer_uv.cc
index 53f79b545ae..ccbbe357ae9 100644
--- a/src/core/lib/iomgr/timer_uv.cc
+++ b/src/core/lib/iomgr/timer_uv.cc
@@ -55,19 +55,18 @@ void run_expired_timer(uv_timer_t *handle) {
 }
 
 void grpc_timer_init(grpc_exec_ctx *exec_ctx, grpc_timer *timer,
-                     gpr_timespec deadline, grpc_closure *closure,
-                     gpr_timespec now) {
+                     grpc_millis deadline, grpc_closure *closure) {
   uint64_t timeout;
   uv_timer_t *uv_timer;
   GRPC_UV_ASSERT_SAME_THREAD();
   timer->closure = closure;
-  if (gpr_time_cmp(deadline, now) <= 0) {
+  if (deadline <= grpc_exec_ctx_now(exec_ctx)) {
     timer->pending = 0;
     GRPC_CLOSURE_SCHED(exec_ctx, timer->closure, GRPC_ERROR_NONE);
     return;
   }
   timer->pending = 1;
-  timeout = (uint64_t)gpr_time_to_millis(gpr_time_sub(deadline, now));
+  timeout = (uint64_t)(deadline - grpc_exec_ctx_now(exec_ctx));
   uv_timer = (uv_timer_t *)gpr_malloc(sizeof(uv_timer_t));
   uv_timer_init(uv_default_loop(), uv_timer);
   uv_timer->data = timer;
@@ -91,11 +90,11 @@ void grpc_timer_cancel(grpc_exec_ctx *exec_ctx, grpc_timer *timer) {
 }
 
 grpc_timer_check_result grpc_timer_check(grpc_exec_ctx *exec_ctx,
-                                         gpr_timespec now, gpr_timespec *next) {
+                                         grpc_millis *next) {
   return GRPC_TIMERS_NOT_CHECKED;
 }
 
-void grpc_timer_list_init(gpr_timespec now) {}
+void grpc_timer_list_init(grpc_exec_ctx *exec_ctx) {}
 void grpc_timer_list_shutdown(grpc_exec_ctx *exec_ctx) {}
 
 void grpc_timer_consume_kick(void) {}
diff --git a/src/core/lib/iomgr/udp_server.h b/src/core/lib/iomgr/udp_server.h
index bcd8572260a..e887cb1bcf4 100644
--- a/src/core/lib/iomgr/udp_server.h
+++ b/src/core/lib/iomgr/udp_server.h
@@ -81,4 +81,4 @@ void grpc_udp_server_destroy(grpc_exec_ctx *exec_ctx, grpc_udp_server *server,
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_UDP_SERVER_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_UDP_SERVER_H */
diff --git a/src/core/lib/iomgr/unix_sockets_posix.h b/src/core/lib/iomgr/unix_sockets_posix.h
index b96131ae1ce..3e7f9c7d1e3 100644
--- a/src/core/lib/iomgr/unix_sockets_posix.h
+++ b/src/core/lib/iomgr/unix_sockets_posix.h
@@ -46,4 +46,4 @@ char *grpc_sockaddr_to_uri_unix_if_possible(
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_IOMGR_UNIX_SOCKETS_POSIX_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_IOMGR_UNIX_SOCKETS_POSIX_H */
diff --git a/src/core/lib/json/json.h b/src/core/lib/json/json.h
index 81b7e0c9da3..c9fdec4ecb7 100644
--- a/src/core/lib/json/json.h
+++ b/src/core/lib/json/json.h
@@ -78,4 +78,4 @@ void grpc_json_destroy(grpc_json* json);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_JSON_JSON_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_JSON_JSON_H */
diff --git a/src/core/lib/json/json_reader.h b/src/core/lib/json/json_reader.h
index ab2384f7a71..7f14a9a9c81 100644
--- a/src/core/lib/json/json_reader.h
+++ b/src/core/lib/json/json_reader.h
@@ -150,4 +150,4 @@ int grpc_json_reader_is_complete(grpc_json_reader *reader);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_JSON_JSON_READER_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_JSON_JSON_READER_H */
diff --git a/src/core/lib/json/json_writer.h b/src/core/lib/json/json_writer.h
index 18bd2a80fec..132d1f24e85 100644
--- a/src/core/lib/json/json_writer.h
+++ b/src/core/lib/json/json_writer.h
@@ -87,4 +87,4 @@ void grpc_json_writer_value_string(grpc_json_writer *writer,
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_JSON_JSON_WRITER_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_JSON_JSON_WRITER_H */
diff --git a/src/core/lib/profiling/basic_timers.cc b/src/core/lib/profiling/basic_timers.cc
index ab9d60481cc..0ae7d7f6002 100644
--- a/src/core/lib/profiling/basic_timers.cc
+++ b/src/core/lib/profiling/basic_timers.cc
@@ -209,9 +209,9 @@ static void init_output() {
 
 static void rotate_log() {
   /* Using malloc here, as this code could end up being called by gpr_malloc */
-  gpr_timer_log *new = malloc(sizeof(*new));
+  gpr_timer_log *log = static_cast<gpr_timer_log *>(malloc(sizeof(*log)));
   gpr_once_init(&g_once_init, init_output);
-  new->num_entries = 0;
+  log->num_entries = 0;
   pthread_mutex_lock(&g_mu);
   if (g_thread_log != NULL) {
     timer_log_remove(&g_in_progress_logs, g_thread_log);
@@ -221,9 +221,9 @@ static void rotate_log() {
   } else {
     g_thread_id = g_next_thread_id++;
   }
-  timer_log_push_back(&g_in_progress_logs, new);
+  timer_log_push_back(&g_in_progress_logs, log);
   pthread_mutex_unlock(&g_mu);
-  g_thread_log = new;
+  g_thread_log = log;
 }
 
 static void gpr_timers_log_add(const char *tagstr, marker_type type,
diff --git a/src/core/lib/security/credentials/fake/fake_credentials.h b/src/core/lib/security/credentials/fake/fake_credentials.h
index 64f6f439f0a..ed3f893c58f 100644
--- a/src/core/lib/security/credentials/fake/fake_credentials.h
+++ b/src/core/lib/security/credentials/fake/fake_credentials.h
@@ -64,4 +64,4 @@ typedef struct {
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_SECURITY_CREDENTIALS_FAKE_FAKE_CREDENTIALS_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_SECURITY_CREDENTIALS_FAKE_FAKE_CREDENTIALS_H */
diff --git a/src/core/lib/security/credentials/google_default/google_default_credentials.cc b/src/core/lib/security/credentials/google_default/google_default_credentials.cc
index 8fe5802d49b..5b2ddceb4a2 100644
--- a/src/core/lib/security/credentials/google_default/google_default_credentials.cc
+++ b/src/core/lib/security/credentials/google_default/google_default_credentials.cc
@@ -97,7 +97,7 @@ static int is_stack_running_on_compute_engine(grpc_exec_ctx *exec_ctx) {
 
   /* The http call is local. If it takes more than one sec, it is for sure not
      on compute engine. */
-  gpr_timespec max_detection_delay = gpr_time_from_seconds(1, GPR_TIMESPAN);
+  grpc_millis max_detection_delay = GPR_MS_PER_SEC;
 
   grpc_pollset *pollset = (grpc_pollset *)gpr_zalloc(grpc_pollset_size());
   grpc_pollset_init(pollset, &g_polling_mu);
@@ -116,7 +116,7 @@ static int is_stack_running_on_compute_engine(grpc_exec_ctx *exec_ctx) {
       grpc_resource_quota_create("google_default_credentials");
   grpc_httpcli_get(
       exec_ctx, &context, &detector.pollent, resource_quota, &request,
-      gpr_time_add(gpr_now(GPR_CLOCK_REALTIME), max_detection_delay),
+      grpc_exec_ctx_now(exec_ctx) + max_detection_delay,
       GRPC_CLOSURE_CREATE(on_compute_engine_detection_http_response, &detector,
                           grpc_schedule_on_exec_ctx),
       &detector.response);
@@ -133,8 +133,7 @@ static int is_stack_running_on_compute_engine(grpc_exec_ctx *exec_ctx) {
             "pollset_work",
             grpc_pollset_work(exec_ctx,
                               grpc_polling_entity_pollset(&detector.pollent),
-                              &worker, gpr_now(GPR_CLOCK_MONOTONIC),
-                              gpr_inf_future(GPR_CLOCK_MONOTONIC)))) {
+                              &worker, GRPC_MILLIS_INF_FUTURE))) {
       detector.is_done = 1;
       detector.success = 0;
     }
diff --git a/src/core/lib/security/credentials/jwt/jwt_credentials.h b/src/core/lib/security/credentials/jwt/jwt_credentials.h
index c09485fd55a..5cee6ed0da6 100644
--- a/src/core/lib/security/credentials/jwt/jwt_credentials.h
+++ b/src/core/lib/security/credentials/jwt/jwt_credentials.h
@@ -53,4 +53,4 @@ grpc_service_account_jwt_access_credentials_create_from_auth_json_key(
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_SECURITY_CREDENTIALS_JWT_JWT_CREDENTIALS_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_SECURITY_CREDENTIALS_JWT_JWT_CREDENTIALS_H */
diff --git a/src/core/lib/security/credentials/jwt/jwt_verifier.cc b/src/core/lib/security/credentials/jwt/jwt_verifier.cc
index aea16dee920..39e72c195ba 100644
--- a/src/core/lib/security/credentials/jwt/jwt_verifier.cc
+++ b/src/core/lib/security/credentials/jwt/jwt_verifier.cc
@@ -384,7 +384,7 @@ void verifier_cb_ctx_destroy(grpc_exec_ctx *exec_ctx, verifier_cb_ctx *ctx) {
 gpr_timespec grpc_jwt_verifier_clock_skew = {60, 0, GPR_TIMESPAN};
 
 /* Max delay defaults to one minute. */
-gpr_timespec grpc_jwt_verifier_max_delay = {60, 0, GPR_TIMESPAN};
+grpc_millis grpc_jwt_verifier_max_delay = 60 * GPR_MS_PER_SEC;
 
 typedef struct {
   char *email_domain;
@@ -711,7 +711,7 @@ static void on_openid_config_retrieved(grpc_exec_ctx *exec_ctx, void *user_data,
   resource_quota = grpc_resource_quota_create("jwt_verifier");
   grpc_httpcli_get(
       exec_ctx, &ctx->verifier->http_ctx, &ctx->pollent, resource_quota, &req,
-      gpr_time_add(gpr_now(GPR_CLOCK_REALTIME), grpc_jwt_verifier_max_delay),
+      grpc_exec_ctx_now(exec_ctx) + grpc_jwt_verifier_max_delay,
       GRPC_CLOSURE_CREATE(on_keys_retrieved, ctx, grpc_schedule_on_exec_ctx),
       &ctx->responses[HTTP_RESPONSE_KEYS]);
   grpc_resource_quota_unref_internal(exec_ctx, resource_quota);
@@ -838,10 +838,10 @@ static void retrieve_key_and_verify(grpc_exec_ctx *exec_ctx,
      channel. This would allow us to cancel an authentication query when under
      extreme memory pressure. */
   resource_quota = grpc_resource_quota_create("jwt_verifier");
-  grpc_httpcli_get(
-      exec_ctx, &ctx->verifier->http_ctx, &ctx->pollent, resource_quota, &req,
-      gpr_time_add(gpr_now(GPR_CLOCK_REALTIME), grpc_jwt_verifier_max_delay),
-      http_cb, &ctx->responses[rsp_idx]);
+  grpc_httpcli_get(exec_ctx, &ctx->verifier->http_ctx, &ctx->pollent,
+                   resource_quota, &req,
+                   grpc_exec_ctx_now(exec_ctx) + grpc_jwt_verifier_max_delay,
+                   http_cb, &ctx->responses[rsp_idx]);
   grpc_resource_quota_unref_internal(exec_ctx, resource_quota);
   gpr_free(req.host);
   gpr_free(req.http.path);
diff --git a/src/core/lib/security/credentials/jwt/jwt_verifier.h b/src/core/lib/security/credentials/jwt/jwt_verifier.h
index 06038116270..998365e75c8 100644
--- a/src/core/lib/security/credentials/jwt/jwt_verifier.h
+++ b/src/core/lib/security/credentials/jwt/jwt_verifier.h
@@ -85,7 +85,7 @@ typedef struct {
 
 /* Globals to control the verifier. Not thread-safe. */
 extern gpr_timespec grpc_jwt_verifier_clock_skew;
-extern gpr_timespec grpc_jwt_verifier_max_delay;
+extern grpc_millis grpc_jwt_verifier_max_delay;
 
 /* The verifier can be created with some custom mappings to help with key
    discovery in the case where the issuer is an email address.
diff --git a/src/core/lib/security/credentials/oauth2/oauth2_credentials.cc b/src/core/lib/security/credentials/oauth2/oauth2_credentials.cc
index 0a801bec82b..f52a424e363 100644
--- a/src/core/lib/security/credentials/oauth2/oauth2_credentials.cc
+++ b/src/core/lib/security/credentials/oauth2/oauth2_credentials.cc
@@ -117,7 +117,7 @@ static void oauth2_token_fetcher_destruct(grpc_exec_ctx *exec_ctx,
 grpc_credentials_status
 grpc_oauth2_token_fetcher_credentials_parse_server_response(
     grpc_exec_ctx *exec_ctx, const grpc_http_response *response,
-    grpc_mdelem *token_md, gpr_timespec *token_lifetime) {
+    grpc_mdelem *token_md, grpc_millis *token_lifetime) {
   char *null_terminated_body = NULL;
   char *new_access_token = NULL;
   grpc_credentials_status status = GRPC_CREDENTIALS_OK;
@@ -183,9 +183,7 @@ grpc_oauth2_token_fetcher_credentials_parse_server_response(
     }
     gpr_asprintf(&new_access_token, "%s %s", token_type->value,
                  access_token->value);
-    token_lifetime->tv_sec = strtol(expires_in->value, NULL, 10);
-    token_lifetime->tv_nsec = 0;
-    token_lifetime->clock_type = GPR_TIMESPAN;
+    *token_lifetime = strtol(expires_in->value, NULL, 10) * GPR_MS_PER_SEC;
     if (!GRPC_MDISNULL(*token_md)) GRPC_MDELEM_UNREF(exec_ctx, *token_md);
     *token_md = grpc_mdelem_from_slices(
         exec_ctx,
@@ -214,7 +212,7 @@ static void on_oauth2_token_fetcher_http_response(grpc_exec_ctx *exec_ctx,
   grpc_oauth2_token_fetcher_credentials *c =
       (grpc_oauth2_token_fetcher_credentials *)r->creds;
   grpc_mdelem access_token_md = GRPC_MDNULL;
-  gpr_timespec token_lifetime;
+  grpc_millis token_lifetime;
   grpc_credentials_status status =
       grpc_oauth2_token_fetcher_credentials_parse_server_response(
           exec_ctx, &r->response, &access_token_md, &token_lifetime);
@@ -222,10 +220,9 @@ static void on_oauth2_token_fetcher_http_response(grpc_exec_ctx *exec_ctx,
   gpr_mu_lock(&c->mu);
   c->token_fetch_pending = false;
   c->access_token_md = GRPC_MDELEM_REF(access_token_md);
-  c->token_expiration =
-      status == GRPC_CREDENTIALS_OK
-          ? gpr_time_add(gpr_now(GPR_CLOCK_REALTIME), token_lifetime)
-          : gpr_inf_past(GPR_CLOCK_REALTIME);
+  c->token_expiration = status == GRPC_CREDENTIALS_OK
+                            ? grpc_exec_ctx_now(exec_ctx) + token_lifetime
+                            : 0;
   grpc_oauth2_pending_get_request_metadata *pending_request =
       c->pending_requests;
   c->pending_requests = NULL;
@@ -260,14 +257,12 @@ static bool oauth2_token_fetcher_get_request_metadata(
   grpc_oauth2_token_fetcher_credentials *c =
       (grpc_oauth2_token_fetcher_credentials *)creds;
   // Check if we can use the cached token.
-  gpr_timespec refresh_threshold = gpr_time_from_seconds(
-      GRPC_SECURE_TOKEN_REFRESH_THRESHOLD_SECS, GPR_TIMESPAN);
+  grpc_millis refresh_threshold =
+      GRPC_SECURE_TOKEN_REFRESH_THRESHOLD_SECS * GPR_MS_PER_SEC;
   grpc_mdelem cached_access_token_md = GRPC_MDNULL;
   gpr_mu_lock(&c->mu);
   if (!GRPC_MDISNULL(c->access_token_md) &&
-      (gpr_time_cmp(
-           gpr_time_sub(c->token_expiration, gpr_now(GPR_CLOCK_REALTIME)),
-           refresh_threshold) > 0)) {
+      (c->token_expiration + grpc_exec_ctx_now(exec_ctx) > refresh_threshold)) {
     cached_access_token_md = GRPC_MDELEM_REF(c->access_token_md);
   }
   if (!GRPC_MDISNULL(cached_access_token_md)) {
@@ -296,10 +291,10 @@ static bool oauth2_token_fetcher_get_request_metadata(
   gpr_mu_unlock(&c->mu);
   if (start_fetch) {
     grpc_call_credentials_ref(creds);
-    c->fetch_func(
-        exec_ctx, grpc_credentials_metadata_request_create(creds),
-        &c->httpcli_context, &c->pollent, on_oauth2_token_fetcher_http_response,
-        gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), refresh_threshold));
+    c->fetch_func(exec_ctx, grpc_credentials_metadata_request_create(creds),
+                  &c->httpcli_context, &c->pollent,
+                  on_oauth2_token_fetcher_http_response,
+                  grpc_exec_ctx_now(exec_ctx) + refresh_threshold);
   }
   return false;
 }
@@ -340,7 +335,7 @@ static void init_oauth2_token_fetcher(grpc_oauth2_token_fetcher_credentials *c,
   c->base.type = GRPC_CALL_CREDENTIALS_TYPE_OAUTH2;
   gpr_ref_init(&c->base.refcount, 1);
   gpr_mu_init(&c->mu);
-  c->token_expiration = gpr_inf_past(GPR_CLOCK_REALTIME);
+  c->token_expiration = 0;
   c->fetch_func = fetch_func;
   c->pollent =
       grpc_polling_entity_create_from_pollset_set(grpc_pollset_set_create());
@@ -358,7 +353,7 @@ static grpc_call_credentials_vtable compute_engine_vtable = {
 static void compute_engine_fetch_oauth2(
     grpc_exec_ctx *exec_ctx, grpc_credentials_metadata_request *metadata_req,
     grpc_httpcli_context *httpcli_context, grpc_polling_entity *pollent,
-    grpc_iomgr_cb_func response_cb, gpr_timespec deadline) {
+    grpc_iomgr_cb_func response_cb, grpc_millis deadline) {
   grpc_http_header header = {(char *)"Metadata-Flavor", (char *)"Google"};
   grpc_httpcli_request request;
   memset(&request, 0, sizeof(grpc_httpcli_request));
@@ -410,7 +405,7 @@ static grpc_call_credentials_vtable refresh_token_vtable = {
 static void refresh_token_fetch_oauth2(
     grpc_exec_ctx *exec_ctx, grpc_credentials_metadata_request *metadata_req,
     grpc_httpcli_context *httpcli_context, grpc_polling_entity *pollent,
-    grpc_iomgr_cb_func response_cb, gpr_timespec deadline) {
+    grpc_iomgr_cb_func response_cb, grpc_millis deadline) {
   grpc_google_refresh_token_credentials *c =
       (grpc_google_refresh_token_credentials *)metadata_req->creds;
   grpc_http_header header = {(char *)"Content-Type",
diff --git a/src/core/lib/security/credentials/oauth2/oauth2_credentials.h b/src/core/lib/security/credentials/oauth2/oauth2_credentials.h
index c8a93334174..c12db896f33 100644
--- a/src/core/lib/security/credentials/oauth2/oauth2_credentials.h
+++ b/src/core/lib/security/credentials/oauth2/oauth2_credentials.h
@@ -61,7 +61,7 @@ typedef void (*grpc_fetch_oauth2_func)(grpc_exec_ctx *exec_ctx,
                                        grpc_httpcli_context *http_context,
                                        grpc_polling_entity *pollent,
                                        grpc_iomgr_cb_func cb,
-                                       gpr_timespec deadline);
+                                       grpc_millis deadline);
 
 typedef struct grpc_oauth2_pending_get_request_metadata {
   grpc_credentials_mdelem_array *md_array;
@@ -74,7 +74,7 @@ typedef struct {
   grpc_call_credentials base;
   gpr_mu mu;
   grpc_mdelem access_token_md;
-  gpr_timespec token_expiration;
+  grpc_millis token_expiration;
   bool token_fetch_pending;
   grpc_oauth2_pending_get_request_metadata *pending_requests;
   grpc_httpcli_context httpcli_context;
@@ -104,10 +104,10 @@ grpc_refresh_token_credentials_create_from_auth_refresh_token(
 grpc_credentials_status
 grpc_oauth2_token_fetcher_credentials_parse_server_response(
     grpc_exec_ctx *exec_ctx, const struct grpc_http_response *response,
-    grpc_mdelem *token_md, gpr_timespec *token_lifetime);
+    grpc_mdelem *token_md, grpc_millis *token_lifetime);
 
 #ifdef __cplusplus
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_SECURITY_CREDENTIALS_OAUTH2_OAUTH2_CREDENTIALS_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_SECURITY_CREDENTIALS_OAUTH2_OAUTH2_CREDENTIALS_H */
diff --git a/src/core/lib/security/transport/lb_targets_info.h b/src/core/lib/security/transport/lb_targets_info.h
index 705d33b0abe..43f0e645565 100644
--- a/src/core/lib/security/transport/lb_targets_info.h
+++ b/src/core/lib/security/transport/lb_targets_info.h
@@ -37,4 +37,4 @@ grpc_slice_hash_table *grpc_lb_targets_info_find_in_args(
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_SECURITY_TRANSPORT_LB_TARGETS_INFO_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_SECURITY_TRANSPORT_LB_TARGETS_INFO_H */
diff --git a/src/core/lib/security/transport/secure_endpoint.h b/src/core/lib/security/transport/secure_endpoint.h
index 832cc1c0ce9..980449c03ee 100644
--- a/src/core/lib/security/transport/secure_endpoint.h
+++ b/src/core/lib/security/transport/secure_endpoint.h
@@ -44,4 +44,4 @@ grpc_endpoint *grpc_secure_endpoint_create(
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_SECURITY_TRANSPORT_SECURE_ENDPOINT_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_SECURITY_TRANSPORT_SECURE_ENDPOINT_H */
diff --git a/src/core/lib/security/transport/security_handshaker.h b/src/core/lib/security/transport/security_handshaker.h
index 345065f26c8..178099bb945 100644
--- a/src/core/lib/security/transport/security_handshaker.h
+++ b/src/core/lib/security/transport/security_handshaker.h
@@ -39,4 +39,4 @@ void grpc_security_register_handshaker_factories();
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_SECURITY_TRANSPORT_SECURITY_HANDSHAKER_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_SECURITY_TRANSPORT_SECURITY_HANDSHAKER_H */
diff --git a/src/core/lib/security/transport/tsi_error.h b/src/core/lib/security/transport/tsi_error.h
index 4c78b06603d..4e19daf796f 100644
--- a/src/core/lib/security/transport/tsi_error.h
+++ b/src/core/lib/security/transport/tsi_error.h
@@ -32,4 +32,4 @@ grpc_error *grpc_set_tsi_error_result(grpc_error *error, tsi_result result);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_SECURITY_TRANSPORT_TSI_ERROR_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_SECURITY_TRANSPORT_TSI_ERROR_H */
diff --git a/src/core/lib/security/util/json_util.h b/src/core/lib/security/util/json_util.h
index 43a2f6b9d18..cdd8a7198a8 100644
--- a/src/core/lib/security/util/json_util.h
+++ b/src/core/lib/security/util/json_util.h
@@ -45,4 +45,4 @@ bool grpc_copy_json_string_property(const grpc_json *json,
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_SECURITY_UTIL_JSON_UTIL_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_SECURITY_UTIL_JSON_UTIL_H */
diff --git a/src/core/lib/slice/b64.h b/src/core/lib/slice/b64.h
index c01da56575c..9b4dc65dbbb 100644
--- a/src/core/lib/slice/b64.h
+++ b/src/core/lib/slice/b64.h
@@ -55,4 +55,4 @@ grpc_slice grpc_base64_decode_with_len(grpc_exec_ctx *exec_ctx, const char *b64,
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_SLICE_B64_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_SLICE_B64_H */
diff --git a/src/core/lib/slice/percent_encoding.h b/src/core/lib/slice/percent_encoding.h
index e6f85120c3a..14a4deb44b8 100644
--- a/src/core/lib/slice/percent_encoding.h
+++ b/src/core/lib/slice/percent_encoding.h
@@ -68,4 +68,4 @@ grpc_slice grpc_permissive_percent_decode_slice(grpc_slice slice_in);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_SLICE_PERCENT_ENCODING_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_SLICE_PERCENT_ENCODING_H */
diff --git a/src/core/lib/slice/slice_hash_table.h b/src/core/lib/slice/slice_hash_table.h
index 3c3f0e61f3a..41250df7385 100644
--- a/src/core/lib/slice/slice_hash_table.h
+++ b/src/core/lib/slice/slice_hash_table.h
@@ -75,4 +75,4 @@ int grpc_slice_hash_table_cmp(const grpc_slice_hash_table *a,
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_SLICE_SLICE_HASH_TABLE_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_SLICE_SLICE_HASH_TABLE_H */
diff --git a/src/core/lib/slice/slice_internal.h b/src/core/lib/slice/slice_internal.h
index 8591185c53b..fcf70a0e55f 100644
--- a/src/core/lib/slice/slice_internal.h
+++ b/src/core/lib/slice/slice_internal.h
@@ -54,4 +54,4 @@ int grpc_static_slice_eq(grpc_slice a, grpc_slice b);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_SLICE_SLICE_INTERNAL_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_SLICE_SLICE_INTERNAL_H */
diff --git a/src/core/lib/slice/slice_traits.h b/src/core/lib/slice/slice_traits.h
index 1eda17cf00b..7fdb6752cb4 100644
--- a/src/core/lib/slice/slice_traits.h
+++ b/src/core/lib/slice/slice_traits.h
@@ -34,4 +34,4 @@ bool grpc_slice_is_bin_suffixed(grpc_slice s);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_SLICE_SLICE_TRAITS_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_SLICE_SLICE_TRAITS_H */
diff --git a/src/core/lib/support/env_windows.cc b/src/core/lib/support/env_windows.cc
index 73c643c5600..c5a25dc201d 100644
--- a/src/core/lib/support/env_windows.cc
+++ b/src/core/lib/support/env_windows.cc
@@ -43,7 +43,10 @@ char *gpr_getenv(const char *name) {
   DWORD ret;
 
   ret = GetEnvironmentVariable(tname, NULL, 0);
-  if (ret == 0) return NULL;
+  if (ret == 0) {
+    gpr_free(tname);
+    return NULL;
+  }
   size = ret * (DWORD)sizeof(TCHAR);
   tresult = (LPTSTR)gpr_malloc(size);
   ret = GetEnvironmentVariable(tname, tresult, size);
diff --git a/src/core/lib/support/log_android.cc b/src/core/lib/support/log_android.cc
index 6f1cec51f17..9e8529cbac8 100644
--- a/src/core/lib/support/log_android.cc
+++ b/src/core/lib/support/log_android.cc
@@ -39,8 +39,8 @@ static android_LogPriority severity_to_log_priority(gpr_log_severity severity) {
   return ANDROID_LOG_DEFAULT;
 }
 
-void gpr_log(const char *file, int line, gpr_log_severity severity,
-             const char *format, ...) {
+extern "C" void gpr_log(const char *file, int line, gpr_log_severity severity,
+                        const char *format, ...) {
   char *message = NULL;
   va_list args;
   va_start(args, format);
@@ -50,8 +50,8 @@ void gpr_log(const char *file, int line, gpr_log_severity severity,
   free(message);
 }
 
-void gpr_default_log(gpr_log_func_args *args) {
-  char *final_slash;
+extern "C" void gpr_default_log(gpr_log_func_args *args) {
+  const char *final_slash;
   const char *display_file;
   char *output = NULL;
 
diff --git a/src/core/lib/support/time_posix.cc b/src/core/lib/support/time_posix.cc
index deccb509752..3267ea6b541 100644
--- a/src/core/lib/support/time_posix.cc
+++ b/src/core/lib/support/time_posix.cc
@@ -30,7 +30,6 @@
 #include <grpc/support/atm.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include "src/core/lib/support/block_annotate.h"
 
 static struct timespec timespec_from_gpr(gpr_timespec gts) {
   struct timespec rv;
@@ -159,9 +158,7 @@ void gpr_sleep_until(gpr_timespec until) {
 
     delta = gpr_time_sub(until, now);
     delta_ts = timespec_from_gpr(delta);
-    GRPC_SCHEDULING_START_BLOCKING_REGION;
     ns_result = nanosleep(&delta_ts, NULL);
-    GRPC_SCHEDULING_END_BLOCKING_REGION;
     if (ns_result == 0) {
       break;
     }
diff --git a/src/core/lib/support/time_windows.cc b/src/core/lib/support/time_windows.cc
index dda7566cd8c..08c1b22964a 100644
--- a/src/core/lib/support/time_windows.cc
+++ b/src/core/lib/support/time_windows.cc
@@ -28,7 +28,6 @@
 #include <process.h>
 #include <sys/timeb.h>
 
-#include "src/core/lib/support/block_annotate.h"
 #include "src/core/lib/support/time_precise.h"
 
 static LARGE_INTEGER g_start_time;
@@ -94,9 +93,7 @@ void gpr_sleep_until(gpr_timespec until) {
     sleep_millis =
         delta.tv_sec * GPR_MS_PER_SEC + delta.tv_nsec / GPR_NS_PER_MS;
     GPR_ASSERT((sleep_millis >= 0) && (sleep_millis <= INT_MAX));
-    GRPC_SCHEDULING_START_BLOCKING_REGION;
     Sleep((DWORD)sleep_millis);
-    GRPC_SCHEDULING_END_BLOCKING_REGION;
   }
 }
 
diff --git a/src/core/lib/surface/alarm.cc b/src/core/lib/surface/alarm.cc
index 4e675431914..16a16bfd93b 100644
--- a/src/core/lib/surface/alarm.cc
+++ b/src/core/lib/surface/alarm.cc
@@ -126,8 +126,7 @@ void grpc_alarm_set(grpc_alarm *alarm, grpc_completion_queue *cq,
 
   GPR_ASSERT(grpc_cq_begin_op(cq, tag));
   grpc_timer_init(&exec_ctx, &alarm->alarm,
-                  gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC),
-                  &alarm->on_alarm, gpr_now(GPR_CLOCK_MONOTONIC));
+                  grpc_timespec_to_millis_round_up(deadline), &alarm->on_alarm);
   grpc_exec_ctx_finish(&exec_ctx);
 }
 
diff --git a/src/core/lib/surface/call.cc b/src/core/lib/surface/call.cc
index 6c97f5cc014..8216aa0ec81 100644
--- a/src/core/lib/surface/call.cc
+++ b/src/core/lib/surface/call.cc
@@ -216,7 +216,7 @@ struct grpc_call {
      server, it's trailing metadata */
   grpc_linked_mdelem send_extra_metadata[MAX_SEND_EXTRA_METADATA_COUNT];
   int send_extra_metadata_count;
-  gpr_timespec send_deadline;
+  grpc_millis send_deadline;
 
   grpc_slice_buffer_stream sending_stream;
 
@@ -283,7 +283,7 @@ static void destroy_call(grpc_exec_ctx *exec_ctx, void *call_stack,
                          grpc_error *error);
 static void receiving_slice_ready(grpc_exec_ctx *exec_ctx, void *bctlp,
                                   grpc_error *error);
-static void get_final_status(grpc_call *call,
+static void get_final_status(grpc_exec_ctx *exec_ctx, grpc_call *call,
                              void (*set_value)(grpc_status_code code,
                                                void *user_data),
                              void *set_value_user_data, grpc_slice *details);
@@ -372,11 +372,10 @@ grpc_error *grpc_call_create(grpc_exec_ctx *exec_ctx,
   }
   for (i = 0; i < 2; i++) {
     for (j = 0; j < 2; j++) {
-      call->metadata_batch[i][j].deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
+      call->metadata_batch[i][j].deadline = GRPC_MILLIS_INF_FUTURE;
     }
   }
-  gpr_timespec send_deadline =
-      gpr_convert_clock_type(args->send_deadline, GPR_CLOCK_MONOTONIC);
+  grpc_millis send_deadline = args->send_deadline;
 
   bool immediately_cancel = false;
 
@@ -394,10 +393,7 @@ grpc_error *grpc_call_create(grpc_exec_ctx *exec_ctx,
     gpr_mu_lock(&pc->child_list_mu);
 
     if (args->propagation_mask & GRPC_PROPAGATE_DEADLINE) {
-      send_deadline = gpr_time_min(
-          gpr_convert_clock_type(send_deadline,
-                                 args->parent->send_deadline.clock_type),
-          args->parent->send_deadline);
+      send_deadline = GPR_MIN(send_deadline, args->parent->send_deadline);
     }
     /* for now GRPC_PROPAGATE_TRACING_CONTEXT *MUST* be passed with
      * GRPC_PROPAGATE_STATS_CONTEXT */
@@ -551,8 +547,8 @@ static void destroy_call(grpc_exec_ctx *exec_ctx, void *call,
     GRPC_CQ_INTERNAL_UNREF(exec_ctx, c->cq, "bind");
   }
 
-  get_final_status(c, set_status_value_directly, &c->final_info.final_status,
-                   NULL);
+  get_final_status(exec_ctx, c, set_status_value_directly,
+                   &c->final_info.final_status, NULL);
   c->final_info.stats.latency =
       gpr_time_sub(gpr_now(GPR_CLOCK_MONOTONIC), c->start_time);
 
@@ -738,13 +734,16 @@ static void cancel_with_status(grpc_exec_ctx *exec_ctx, grpc_call *c,
  * FINAL STATUS CODE MANIPULATION
  */
 
-static bool get_final_status_from(
-    grpc_call *call, grpc_error *error, bool allow_ok_status,
-    void (*set_value)(grpc_status_code code, void *user_data),
-    void *set_value_user_data, grpc_slice *details) {
+static bool get_final_status_from(grpc_exec_ctx *exec_ctx, grpc_call *call,
+                                  grpc_error *error, bool allow_ok_status,
+                                  void (*set_value)(grpc_status_code code,
+                                                    void *user_data),
+                                  void *set_value_user_data,
+                                  grpc_slice *details) {
   grpc_status_code code;
   grpc_slice slice = grpc_empty_slice();
-  grpc_error_get_status(error, call->send_deadline, &code, &slice, NULL);
+  grpc_error_get_status(exec_ctx, error, call->send_deadline, &code, &slice,
+                        NULL);
   if (code == GRPC_STATUS_OK && !allow_ok_status) {
     return false;
   }
@@ -756,7 +755,7 @@ static bool get_final_status_from(
   return true;
 }
 
-static void get_final_status(grpc_call *call,
+static void get_final_status(grpc_exec_ctx *exec_ctx, grpc_call *call,
                              void (*set_value)(grpc_status_code code,
                                                void *user_data),
                              void *set_value_user_data, grpc_slice *details) {
@@ -781,8 +780,9 @@ static void get_final_status(grpc_call *call,
     for (i = 0; i < STATUS_SOURCE_COUNT; i++) {
       if (status[i].is_set &&
           grpc_error_has_clear_grpc_status(status[i].error)) {
-        if (get_final_status_from(call, status[i].error, allow_ok_status != 0,
-                                  set_value, set_value_user_data, details)) {
+        if (get_final_status_from(exec_ctx, call, status[i].error,
+                                  allow_ok_status != 0, set_value,
+                                  set_value_user_data, details)) {
           return;
         }
       }
@@ -790,8 +790,9 @@ static void get_final_status(grpc_call *call,
     /* If no clearly defined status exists, search for 'anything' */
     for (i = 0; i < STATUS_SOURCE_COUNT; i++) {
       if (status[i].is_set) {
-        if (get_final_status_from(call, status[i].error, allow_ok_status != 0,
-                                  set_value, set_value_user_data, details)) {
+        if (get_final_status_from(exec_ctx, call, status[i].error,
+                                  allow_ok_status != 0, set_value,
+                                  set_value_user_data, details)) {
           return;
         }
       }
@@ -1330,17 +1331,22 @@ static void post_batch_completion(grpc_exec_ctx *exec_ctx,
     }
 
     if (call->is_client) {
-      get_final_status(call, set_status_value_directly,
+      get_final_status(exec_ctx, call, set_status_value_directly,
                        call->final_op.client.status,
                        call->final_op.client.status_details);
     } else {
-      get_final_status(call, set_cancelled_value,
+      get_final_status(exec_ctx, call, set_cancelled_value,
                        call->final_op.server.cancelled, NULL);
     }
 
     GRPC_ERROR_UNREF(error);
     error = GRPC_ERROR_NONE;
   }
+  if (error != GRPC_ERROR_NONE && bctl->op.recv_message &&
+      *call->receiving_buffer != NULL) {
+    grpc_byte_buffer_destroy(*call->receiving_buffer);
+    *call->receiving_buffer = NULL;
+  }
 
   if (bctl->completion_data.notify_tag.is_closure) {
     /* unrefs bctl->error */
@@ -1611,11 +1617,8 @@ static void receiving_initial_metadata_ready(grpc_exec_ctx *exec_ctx,
     validate_filtered_metadata(exec_ctx, bctl);
     GPR_TIMER_END("validate_filtered_metadata", 0);
 
-    if (gpr_time_cmp(md->deadline, gpr_inf_future(md->deadline.clock_type)) !=
-            0 &&
-        !call->is_client) {
-      call->send_deadline =
-          gpr_convert_clock_type(md->deadline, GPR_CLOCK_MONOTONIC);
+    if (md->deadline != GRPC_MILLIS_INF_FUTURE && !call->is_client) {
+      call->send_deadline = md->deadline;
     }
   }
 
diff --git a/src/core/lib/surface/call.h b/src/core/lib/surface/call.h
index c680139cf68..27c2f5243ca 100644
--- a/src/core/lib/surface/call.h
+++ b/src/core/lib/surface/call.h
@@ -49,7 +49,7 @@ typedef struct grpc_call_create_args {
   grpc_mdelem *add_initial_metadata;
   size_t add_initial_metadata_count;
 
-  gpr_timespec send_deadline;
+  grpc_millis send_deadline;
 } grpc_call_create_args;
 
 /* Create a new call based on \a args.
diff --git a/src/core/lib/surface/channel.cc b/src/core/lib/surface/channel.cc
index 59fced7bc43..860dcc82db0 100644
--- a/src/core/lib/surface/channel.cc
+++ b/src/core/lib/surface/channel.cc
@@ -262,7 +262,7 @@ static grpc_call *grpc_channel_create_call_internal(
     grpc_exec_ctx *exec_ctx, grpc_channel *channel, grpc_call *parent_call,
     uint32_t propagation_mask, grpc_completion_queue *cq,
     grpc_pollset_set *pollset_set_alternative, grpc_mdelem path_mdelem,
-    grpc_mdelem authority_mdelem, gpr_timespec deadline) {
+    grpc_mdelem authority_mdelem, grpc_millis deadline) {
   grpc_mdelem send_metadata[2];
   size_t num_metadata = 0;
 
@@ -308,7 +308,7 @@ grpc_call *grpc_channel_create_call(grpc_channel *channel,
       host != NULL ? grpc_mdelem_from_slices(&exec_ctx, GRPC_MDSTR_AUTHORITY,
                                              grpc_slice_ref_internal(*host))
                    : GRPC_MDNULL,
-      deadline);
+      grpc_timespec_to_millis_round_up(deadline));
   grpc_exec_ctx_finish(&exec_ctx);
   return call;
 }
@@ -316,7 +316,7 @@ grpc_call *grpc_channel_create_call(grpc_channel *channel,
 grpc_call *grpc_channel_create_pollset_set_call(
     grpc_exec_ctx *exec_ctx, grpc_channel *channel, grpc_call *parent_call,
     uint32_t propagation_mask, grpc_pollset_set *pollset_set, grpc_slice method,
-    const grpc_slice *host, gpr_timespec deadline, void *reserved) {
+    const grpc_slice *host, grpc_millis deadline, void *reserved) {
   GPR_ASSERT(!reserved);
   return grpc_channel_create_call_internal(
       exec_ctx, channel, parent_call, propagation_mask, NULL, pollset_set,
@@ -372,7 +372,8 @@ grpc_call *grpc_channel_create_registered_call(
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_call *call = grpc_channel_create_call_internal(
       &exec_ctx, channel, parent_call, propagation_mask, completion_queue, NULL,
-      GRPC_MDELEM_REF(rc->path), GRPC_MDELEM_REF(rc->authority), deadline);
+      GRPC_MDELEM_REF(rc->path), GRPC_MDELEM_REF(rc->authority),
+      grpc_timespec_to_millis_round_up(deadline));
   grpc_exec_ctx_finish(&exec_ctx);
   return call;
 }
diff --git a/src/core/lib/surface/channel.h b/src/core/lib/surface/channel.h
index 427422b565b..4d1c7e369fd 100644
--- a/src/core/lib/surface/channel.h
+++ b/src/core/lib/surface/channel.h
@@ -47,7 +47,7 @@ grpc_channel *grpc_channel_create_with_builder(
 grpc_call *grpc_channel_create_pollset_set_call(
     grpc_exec_ctx *exec_ctx, grpc_channel *channel, grpc_call *parent_call,
     uint32_t propagation_mask, grpc_pollset_set *pollset_set, grpc_slice method,
-    const grpc_slice *host, gpr_timespec deadline, void *reserved);
+    const grpc_slice *host, grpc_millis deadline, void *reserved);
 
 /** Get a (borrowed) pointer to this channels underlying channel stack */
 grpc_channel_stack *grpc_channel_get_channel_stack(grpc_channel *channel);
diff --git a/src/core/lib/surface/channel_stack_type.h b/src/core/lib/surface/channel_stack_type.h
index 903b90a0716..c77848794cc 100644
--- a/src/core/lib/surface/channel_stack_type.h
+++ b/src/core/lib/surface/channel_stack_type.h
@@ -50,4 +50,4 @@ const char *grpc_channel_stack_type_string(grpc_channel_stack_type type);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_SURFACE_CHANNEL_STACK_TYPE_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_SURFACE_CHANNEL_STACK_TYPE_H */
diff --git a/src/core/lib/surface/completion_queue.cc b/src/core/lib/surface/completion_queue.cc
index 453646bd49c..36b4b835f82 100644
--- a/src/core/lib/surface/completion_queue.cc
+++ b/src/core/lib/surface/completion_queue.cc
@@ -61,8 +61,7 @@ typedef struct {
   grpc_error *(*kick)(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
                       grpc_pollset_worker *specific_worker);
   grpc_error *(*work)(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
-                      grpc_pollset_worker **worker, gpr_timespec now,
-                      gpr_timespec deadline);
+                      grpc_pollset_worker **worker, grpc_millis deadline);
   void (*shutdown)(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
                    grpc_closure *closure);
   void (*destroy)(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset);
@@ -100,8 +99,7 @@ static void non_polling_poller_destroy(grpc_exec_ctx *exec_ctx,
 static grpc_error *non_polling_poller_work(grpc_exec_ctx *exec_ctx,
                                            grpc_pollset *pollset,
                                            grpc_pollset_worker **worker,
-                                           gpr_timespec now,
-                                           gpr_timespec deadline) {
+                                           grpc_millis deadline) {
   non_polling_poller *npp = (non_polling_poller *)pollset;
   if (npp->shutdown) return GRPC_ERROR_NONE;
   non_polling_worker w;
@@ -115,7 +113,10 @@ static grpc_error *non_polling_poller_work(grpc_exec_ctx *exec_ctx,
     w.next->prev = w.prev->next = &w;
   }
   w.kicked = false;
-  while (!npp->shutdown && !w.kicked && !gpr_cv_wait(&w.cv, &npp->mu, deadline))
+  gpr_timespec deadline_ts =
+      grpc_millis_to_timespec(deadline, GPR_CLOCK_REALTIME);
+  while (!npp->shutdown && !w.kicked &&
+         !gpr_cv_wait(&w.cv, &npp->mu, deadline_ts))
     ;
   if (&w == npp->root) {
     npp->root = w.next;
@@ -743,7 +744,7 @@ void grpc_cq_end_op(grpc_exec_ctx *exec_ctx, grpc_completion_queue *cq,
 typedef struct {
   gpr_atm last_seen_things_queued_ever;
   grpc_completion_queue *cq;
-  gpr_timespec deadline;
+  grpc_millis deadline;
   grpc_cq_completion *stolen_completion;
   void *tag; /* for pluck */
   bool first_loop;
@@ -772,8 +773,7 @@ static bool cq_is_next_finished(grpc_exec_ctx *exec_ctx, void *arg) {
       return true;
     }
   }
-  return !a->first_loop &&
-         gpr_time_cmp(a->deadline, gpr_now(a->deadline.clock_type)) < 0;
+  return !a->first_loop && a->deadline < grpc_exec_ctx_now(exec_ctx);
 }
 
 #ifndef NDEBUG
@@ -802,7 +802,6 @@ static void dump_pending_tags(grpc_completion_queue *cq) {}
 static grpc_event cq_next(grpc_completion_queue *cq, gpr_timespec deadline,
                           void *reserved) {
   grpc_event ret;
-  gpr_timespec now;
   cq_next_data *cqd = (cq_next_data *)DATA_FROM_CQ(cq);
 
   GPR_TIMER_BEGIN("grpc_completion_queue_next", 0);
@@ -819,23 +818,20 @@ static grpc_event cq_next(grpc_completion_queue *cq, gpr_timespec deadline,
 
   dump_pending_tags(cq);
 
-  deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC);
-
   GRPC_CQ_INTERNAL_REF(cq, "next");
 
+  grpc_millis deadline_millis = grpc_timespec_to_millis_round_up(deadline);
   cq_is_finished_arg is_finished_arg = {
-
       gpr_atm_no_barrier_load(&cqd->things_queued_ever),
       cq,
-      deadline,
+      deadline_millis,
       NULL,
       NULL,
       true};
   grpc_exec_ctx exec_ctx =
       GRPC_EXEC_CTX_INITIALIZER(0, cq_is_next_finished, &is_finished_arg);
-
   for (;;) {
-    gpr_timespec iteration_deadline = deadline;
+    grpc_millis iteration_deadline = deadline_millis;
 
     if (is_finished_arg.stolen_completion != NULL) {
       grpc_cq_completion *c = is_finished_arg.stolen_completion;
@@ -862,7 +858,7 @@ static grpc_event cq_next(grpc_completion_queue *cq, gpr_timespec deadline,
          attempt at popping. Not doing this can potentially deadlock this
          thread forever (if the deadline is infinity) */
       if (cq_event_queue_num_items(&cqd->queue) > 0) {
-        iteration_deadline = gpr_time_0(GPR_CLOCK_MONOTONIC);
+        iteration_deadline = 0;
       }
     }
 
@@ -883,8 +879,8 @@ static grpc_event cq_next(grpc_completion_queue *cq, gpr_timespec deadline,
       break;
     }
 
-    now = gpr_now(GPR_CLOCK_MONOTONIC);
-    if (!is_finished_arg.first_loop && gpr_time_cmp(now, deadline) >= 0) {
+    if (!is_finished_arg.first_loop &&
+        grpc_exec_ctx_now(&exec_ctx) >= deadline_millis) {
       memset(&ret, 0, sizeof(ret));
       ret.type = GRPC_QUEUE_TIMEOUT;
       dump_pending_tags(cq);
@@ -895,7 +891,7 @@ static grpc_event cq_next(grpc_completion_queue *cq, gpr_timespec deadline,
     gpr_mu_lock(cq->mu);
     cq->num_polls++;
     grpc_error *err = cq->poller_vtable->work(&exec_ctx, POLLSET_FROM_CQ(cq),
-                                              NULL, now, iteration_deadline);
+                                              NULL, iteration_deadline);
     gpr_mu_unlock(cq->mu);
 
     if (err != GRPC_ERROR_NONE) {
@@ -1032,8 +1028,7 @@ static bool cq_is_pluck_finished(grpc_exec_ctx *exec_ctx, void *arg) {
     }
     gpr_mu_unlock(cq->mu);
   }
-  return !a->first_loop &&
-         gpr_time_cmp(a->deadline, gpr_now(a->deadline.clock_type)) < 0;
+  return !a->first_loop && a->deadline < grpc_exec_ctx_now(exec_ctx);
 }
 
 static grpc_event cq_pluck(grpc_completion_queue *cq, void *tag,
@@ -1042,7 +1037,6 @@ static grpc_event cq_pluck(grpc_completion_queue *cq, void *tag,
   grpc_cq_completion *c;
   grpc_cq_completion *prev;
   grpc_pollset_worker *worker = NULL;
-  gpr_timespec now;
   cq_pluck_data *cqd = (cq_pluck_data *)DATA_FROM_CQ(cq);
 
   GPR_TIMER_BEGIN("grpc_completion_queue_pluck", 0);
@@ -1061,14 +1055,13 @@ static grpc_event cq_pluck(grpc_completion_queue *cq, void *tag,
 
   dump_pending_tags(cq);
 
-  deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC);
-
   GRPC_CQ_INTERNAL_REF(cq, "pluck");
   gpr_mu_lock(cq->mu);
+  grpc_millis deadline_millis = grpc_timespec_to_millis_round_up(deadline);
   cq_is_finished_arg is_finished_arg = {
       gpr_atm_no_barrier_load(&cqd->things_queued_ever),
       cq,
-      deadline,
+      deadline_millis,
       NULL,
       tag,
       true};
@@ -1120,8 +1113,8 @@ static grpc_event cq_pluck(grpc_completion_queue *cq, void *tag,
       dump_pending_tags(cq);
       break;
     }
-    now = gpr_now(GPR_CLOCK_MONOTONIC);
-    if (!is_finished_arg.first_loop && gpr_time_cmp(now, deadline) >= 0) {
+    if (!is_finished_arg.first_loop &&
+        grpc_exec_ctx_now(&exec_ctx) >= deadline_millis) {
       del_plucker(cq, tag, &worker);
       gpr_mu_unlock(cq->mu);
       memset(&ret, 0, sizeof(ret));
@@ -1129,10 +1122,9 @@ static grpc_event cq_pluck(grpc_completion_queue *cq, void *tag,
       dump_pending_tags(cq);
       break;
     }
-
     cq->num_polls++;
     grpc_error *err = cq->poller_vtable->work(&exec_ctx, POLLSET_FROM_CQ(cq),
-                                              &worker, now, deadline);
+                                              &worker, deadline_millis);
     if (err != GRPC_ERROR_NONE) {
       del_plucker(cq, tag, &worker);
       gpr_mu_unlock(cq->mu);
diff --git a/src/core/lib/surface/completion_queue_factory.h b/src/core/lib/surface/completion_queue_factory.h
index cb0af6f0fb6..af8f3d60c38 100644
--- a/src/core/lib/surface/completion_queue_factory.h
+++ b/src/core/lib/surface/completion_queue_factory.h
@@ -41,4 +41,4 @@ struct grpc_completion_queue_factory {
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_SURFACE_COMPLETION_QUEUE_FACTORY_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_SURFACE_COMPLETION_QUEUE_FACTORY_H */
diff --git a/src/core/lib/surface/event_string.h b/src/core/lib/surface/event_string.h
index 127609c404f..2d53cf0facf 100644
--- a/src/core/lib/surface/event_string.h
+++ b/src/core/lib/surface/event_string.h
@@ -32,4 +32,4 @@ char *grpc_event_string(grpc_event *ev);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_SURFACE_EVENT_STRING_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_SURFACE_EVENT_STRING_H */
diff --git a/src/core/lib/surface/init.h b/src/core/lib/surface/init.h
index b2f48576e50..d429026327f 100644
--- a/src/core/lib/surface/init.h
+++ b/src/core/lib/surface/init.h
@@ -32,4 +32,4 @@ int grpc_is_initialized(void);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_SURFACE_INIT_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_SURFACE_INIT_H */
diff --git a/src/core/lib/surface/lame_client.cc b/src/core/lib/surface/lame_client.cc
index 6286f9159d9..88e26cbeb70 100644
--- a/src/core/lib/surface/lame_client.cc
+++ b/src/core/lib/surface/lame_client.cc
@@ -74,7 +74,7 @@ static void fill_metadata(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
   mdb->list.head = &calld->status;
   mdb->list.tail = &calld->details;
   mdb->list.count = 2;
-  mdb->deadline = gpr_inf_future(GPR_CLOCK_REALTIME);
+  mdb->deadline = GRPC_MILLIS_INF_FUTURE;
 }
 
 static void lame_start_transport_stream_op_batch(
diff --git a/src/core/lib/surface/server.cc b/src/core/lib/surface/server.cc
index 1d0fd472d07..dd09cb91de4 100644
--- a/src/core/lib/surface/server.cc
+++ b/src/core/lib/surface/server.cc
@@ -137,7 +137,7 @@ struct call_data {
   bool host_set;
   grpc_slice path;
   grpc_slice host;
-  gpr_timespec deadline;
+  grpc_millis deadline;
 
   grpc_completion_queue *cq_new;
 
@@ -492,11 +492,13 @@ static void publish_call(grpc_exec_ctx *exec_ctx, grpc_server *server,
       GPR_ASSERT(calld->path_set);
       rc->data.batch.details->host = grpc_slice_ref_internal(calld->host);
       rc->data.batch.details->method = grpc_slice_ref_internal(calld->path);
-      rc->data.batch.details->deadline = calld->deadline;
+      rc->data.batch.details->deadline =
+          grpc_millis_to_timespec(calld->deadline, GPR_CLOCK_MONOTONIC);
       rc->data.batch.details->flags = calld->recv_initial_metadata_flags;
       break;
     case REGISTERED_CALL:
-      *rc->data.registered.deadline = calld->deadline;
+      *rc->data.registered.deadline =
+          grpc_millis_to_timespec(calld->deadline, GPR_CLOCK_MONOTONIC);
       if (rc->data.registered.optional_payload) {
         *rc->data.registered.optional_payload = calld->payload;
         calld->payload = NULL;
@@ -739,7 +741,7 @@ static void server_on_recv_initial_metadata(grpc_exec_ctx *exec_ctx, void *ptr,
                                             grpc_error *error) {
   grpc_call_element *elem = (grpc_call_element *)ptr;
   call_data *calld = (call_data *)elem->call_data;
-  gpr_timespec op_deadline;
+  grpc_millis op_deadline;
 
   if (error == GRPC_ERROR_NONE) {
     GPR_ASSERT(calld->recv_initial_metadata->idx.named.path != NULL);
@@ -759,7 +761,7 @@ static void server_on_recv_initial_metadata(grpc_exec_ctx *exec_ctx, void *ptr,
     GRPC_ERROR_REF(error);
   }
   op_deadline = calld->recv_initial_metadata->deadline;
-  if (0 != gpr_time_cmp(op_deadline, gpr_inf_future(op_deadline.clock_type))) {
+  if (op_deadline != GRPC_MILLIS_INF_FUTURE) {
     calld->deadline = op_deadline;
   }
   if (calld->host_set && calld->path_set) {
@@ -833,7 +835,7 @@ static void accept_stream(grpc_exec_ctx *exec_ctx, void *cd,
   memset(&args, 0, sizeof(args));
   args.channel = chand->channel;
   args.server_transport_data = transport_server_data;
-  args.send_deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
+  args.send_deadline = GRPC_MILLIS_INF_FUTURE;
   grpc_call *call;
   grpc_error *error = grpc_call_create(exec_ctx, &args, &call);
   grpc_call_element *elem =
@@ -881,7 +883,7 @@ static grpc_error *init_call_elem(grpc_exec_ctx *exec_ctx,
   call_data *calld = (call_data *)elem->call_data;
   channel_data *chand = (channel_data *)elem->channel_data;
   memset(calld, 0, sizeof(call_data));
-  calld->deadline = gpr_inf_future(GPR_CLOCK_REALTIME);
+  calld->deadline = GRPC_MILLIS_INF_FUTURE;
   calld->call = grpc_call_from_top_element(elem);
   gpr_mu_init(&calld->mu_state);
 
diff --git a/src/core/lib/surface/server.h b/src/core/lib/surface/server.h
index 1114715833b..375eab4a048 100644
--- a/src/core/lib/surface/server.h
+++ b/src/core/lib/surface/server.h
@@ -62,4 +62,4 @@ void grpc_server_get_pollsets(grpc_server *server, grpc_pollset ***pollsets,
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_SURFACE_SERVER_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_SURFACE_SERVER_H */
diff --git a/src/core/lib/surface/validate_metadata.h b/src/core/lib/surface/validate_metadata.h
index aa02419d9f7..afc8be6dfda 100644
--- a/src/core/lib/surface/validate_metadata.h
+++ b/src/core/lib/surface/validate_metadata.h
@@ -33,4 +33,4 @@ grpc_error *grpc_validate_header_nonbin_value_is_legal(grpc_slice slice);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_SURFACE_VALIDATE_METADATA_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_SURFACE_VALIDATE_METADATA_H */
diff --git a/src/core/lib/transport/bdp_estimator.cc b/src/core/lib/transport/bdp_estimator.cc
index e7fa0eefe82..6ed427ce5c6 100644
--- a/src/core/lib/transport/bdp_estimator.cc
+++ b/src/core/lib/transport/bdp_estimator.cc
@@ -30,8 +30,12 @@ grpc_tracer_flag grpc_bdp_estimator_trace =
 void grpc_bdp_estimator_init(grpc_bdp_estimator *estimator, const char *name) {
   estimator->estimate = 65536;
   estimator->ping_state = GRPC_BDP_PING_UNSCHEDULED;
+  estimator->ping_start_time = gpr_time_0(GPR_CLOCK_MONOTONIC);
+  estimator->next_ping_scheduled = 0;
   estimator->name = name;
   estimator->bw_est = 0;
+  estimator->inter_ping_delay = 100.0;  // start at 100ms
+  estimator->stable_estimate_count = 0;
 }
 
 bool grpc_bdp_estimator_get_estimate(const grpc_bdp_estimator *estimator,
@@ -51,10 +55,11 @@ void grpc_bdp_estimator_add_incoming_bytes(grpc_bdp_estimator *estimator,
   estimator->accumulator += num_bytes;
 }
 
-bool grpc_bdp_estimator_need_ping(const grpc_bdp_estimator *estimator) {
+bool grpc_bdp_estimator_need_ping(grpc_exec_ctx *exec_ctx,
+                                  const grpc_bdp_estimator *estimator) {
   switch (estimator->ping_state) {
     case GRPC_BDP_PING_UNSCHEDULED:
-      return true;
+      return grpc_exec_ctx_now(exec_ctx) >= estimator->next_ping_scheduled;
     case GRPC_BDP_PING_SCHEDULED:
       return false;
     case GRPC_BDP_PING_STARTED:
@@ -84,11 +89,13 @@ void grpc_bdp_estimator_start_ping(grpc_bdp_estimator *estimator) {
   estimator->ping_start_time = gpr_now(GPR_CLOCK_MONOTONIC);
 }
 
-void grpc_bdp_estimator_complete_ping(grpc_bdp_estimator *estimator) {
-  gpr_timespec dt_ts =
-      gpr_time_sub(gpr_now(GPR_CLOCK_MONOTONIC), estimator->ping_start_time);
+void grpc_bdp_estimator_complete_ping(grpc_exec_ctx *exec_ctx,
+                                      grpc_bdp_estimator *estimator) {
+  gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
+  gpr_timespec dt_ts = gpr_time_sub(now, estimator->ping_start_time);
   double dt = (double)dt_ts.tv_sec + 1e-9 * (double)dt_ts.tv_nsec;
   double bw = dt > 0 ? ((double)estimator->accumulator / dt) : 0;
+  int start_inter_ping_delay = estimator->inter_ping_delay;
   if (GRPC_TRACER_ON(grpc_bdp_estimator_trace)) {
     gpr_log(GPR_DEBUG, "bdp[%s]:complete acc=%" PRId64 " est=%" PRId64
                        " dt=%lf bw=%lfMbs bw_est=%lfMbs",
@@ -105,7 +112,26 @@ void grpc_bdp_estimator_complete_ping(grpc_bdp_estimator *estimator) {
       gpr_log(GPR_DEBUG, "bdp[%s]: estimate increased to %" PRId64,
               estimator->name, estimator->estimate);
     }
+    estimator->inter_ping_delay /= 2;  // if the ping estimate changes,
+                                       // exponentially get faster at probing
+  } else if (estimator->inter_ping_delay < 10000) {
+    estimator->stable_estimate_count++;
+    if (estimator->stable_estimate_count >= 2) {
+      estimator->inter_ping_delay +=
+          100 +
+          (int)(rand() * 100.0 / RAND_MAX);  // if the ping estimate is steady,
+                                             // slowly ramp down the probe time
+    }
+  }
+  if (start_inter_ping_delay != estimator->inter_ping_delay) {
+    estimator->stable_estimate_count = 0;
+    if (GRPC_TRACER_ON(grpc_bdp_estimator_trace)) {
+      gpr_log(GPR_DEBUG, "bdp[%s]:update_inter_time to %dms", estimator->name,
+              estimator->inter_ping_delay);
+    }
   }
   estimator->ping_state = GRPC_BDP_PING_UNSCHEDULED;
   estimator->accumulator = 0;
+  estimator->next_ping_scheduled =
+      grpc_exec_ctx_now(exec_ctx) + estimator->inter_ping_delay;
 }
diff --git a/src/core/lib/transport/bdp_estimator.h b/src/core/lib/transport/bdp_estimator.h
index 21c27ec6afd..a9d986782ca 100644
--- a/src/core/lib/transport/bdp_estimator.h
+++ b/src/core/lib/transport/bdp_estimator.h
@@ -23,6 +23,7 @@
 #include <stdbool.h>
 #include <stdint.h>
 #include "src/core/lib/debug/trace.h"
+#include "src/core/lib/iomgr/exec_ctx.h"
 
 #define GRPC_BDP_SAMPLES 16
 #define GRPC_BDP_MIN_SAMPLES_FOR_ESTIMATE 3
@@ -43,7 +44,12 @@ typedef struct grpc_bdp_estimator {
   grpc_bdp_estimator_ping_state ping_state;
   int64_t accumulator;
   int64_t estimate;
+  // when was the current ping started?
   gpr_timespec ping_start_time;
+  // when should the next ping start?
+  grpc_millis next_ping_scheduled;
+  int inter_ping_delay;
+  int stable_estimate_count;
   double bw_est;
   const char *name;
 } grpc_bdp_estimator;
@@ -59,7 +65,8 @@ bool grpc_bdp_estimator_get_bw(const grpc_bdp_estimator *estimator, double *bw);
 void grpc_bdp_estimator_add_incoming_bytes(grpc_bdp_estimator *estimator,
                                            int64_t num_bytes);
 // Returns true if the user should schedule a ping
-bool grpc_bdp_estimator_need_ping(const grpc_bdp_estimator *estimator);
+bool grpc_bdp_estimator_need_ping(grpc_exec_ctx *exec_ctx,
+                                  const grpc_bdp_estimator *estimator);
 // Schedule a ping: call in response to receiving a true from
 // grpc_bdp_estimator_add_incoming_bytes once a ping has been scheduled by a
 // transport (but not necessarily started)
@@ -68,10 +75,11 @@ void grpc_bdp_estimator_schedule_ping(grpc_bdp_estimator *estimator);
 // the ping is on the wire
 void grpc_bdp_estimator_start_ping(grpc_bdp_estimator *estimator);
 // Completes a previously started ping
-void grpc_bdp_estimator_complete_ping(grpc_bdp_estimator *estimator);
+void grpc_bdp_estimator_complete_ping(grpc_exec_ctx *exec_ctx,
+                                      grpc_bdp_estimator *estimator);
 
 #ifdef __cplusplus
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_TRANSPORT_BDP_ESTIMATOR_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_TRANSPORT_BDP_ESTIMATOR_H */
diff --git a/src/core/lib/transport/byte_stream.h b/src/core/lib/transport/byte_stream.h
index d3e04df5c06..c1d8ee543f5 100644
--- a/src/core/lib/transport/byte_stream.h
+++ b/src/core/lib/transport/byte_stream.h
@@ -143,4 +143,4 @@ void grpc_caching_byte_stream_reset(grpc_caching_byte_stream *stream);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_TRANSPORT_BYTE_STREAM_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_TRANSPORT_BYTE_STREAM_H */
diff --git a/src/core/lib/transport/connectivity_state.h b/src/core/lib/transport/connectivity_state.h
index 1796a540a79..c0ba1881484 100644
--- a/src/core/lib/transport/connectivity_state.h
+++ b/src/core/lib/transport/connectivity_state.h
@@ -92,4 +92,4 @@ bool grpc_connectivity_state_notify_on_state_change(
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_TRANSPORT_CONNECTIVITY_STATE_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_TRANSPORT_CONNECTIVITY_STATE_H */
diff --git a/src/core/lib/transport/error_utils.cc b/src/core/lib/transport/error_utils.cc
index 5e3920b627e..2e3b61b7abc 100644
--- a/src/core/lib/transport/error_utils.cc
+++ b/src/core/lib/transport/error_utils.cc
@@ -39,8 +39,9 @@ static grpc_error *recursively_find_error_with_field(grpc_error *error,
   return NULL;
 }
 
-void grpc_error_get_status(grpc_error *error, gpr_timespec deadline,
-                           grpc_status_code *code, grpc_slice *slice,
+void grpc_error_get_status(grpc_exec_ctx *exec_ctx, grpc_error *error,
+                           grpc_millis deadline, grpc_status_code *code,
+                           grpc_slice *slice,
                            grpc_http2_error_code *http_error) {
   // Start with the parent error and recurse through the tree of children
   // until we find the first one that has a status code.
@@ -63,8 +64,8 @@ void grpc_error_get_status(grpc_error *error, gpr_timespec deadline,
     status = (grpc_status_code)integer;
   } else if (grpc_error_get_int(found_error, GRPC_ERROR_INT_HTTP2_ERROR,
                                 &integer)) {
-    status = grpc_http2_error_to_grpc_status((grpc_http2_error_code)integer,
-                                             deadline);
+    status = grpc_http2_error_to_grpc_status(
+        exec_ctx, (grpc_http2_error_code)integer, deadline);
   }
   if (code != NULL) *code = status;
 
diff --git a/src/core/lib/transport/error_utils.h b/src/core/lib/transport/error_utils.h
index 18ff54839cc..b4f9df4bf1a 100644
--- a/src/core/lib/transport/error_utils.h
+++ b/src/core/lib/transport/error_utils.h
@@ -20,6 +20,7 @@
 #define GRPC_CORE_LIB_TRANSPORT_ERROR_UTILS_H
 
 #include "src/core/lib/iomgr/error.h"
+#include "src/core/lib/iomgr/exec_ctx.h"
 #include "src/core/lib/transport/http2_errors.h"
 
 #ifdef __cplusplus
@@ -32,8 +33,9 @@ extern "C" {
 /// All attributes are pulled from the same child error. If any of the
 /// attributes (code, msg, http_status) are unneeded, they can be passed as
 /// NULL.
-void grpc_error_get_status(grpc_error *error, gpr_timespec deadline,
-                           grpc_status_code *code, grpc_slice *slice,
+void grpc_error_get_status(grpc_exec_ctx *exec_ctx, grpc_error *error,
+                           grpc_millis deadline, grpc_status_code *code,
+                           grpc_slice *slice,
                            grpc_http2_error_code *http_status);
 
 /// A utility function to check whether there is a clear status code that
@@ -46,4 +48,4 @@ bool grpc_error_has_clear_grpc_status(grpc_error *error);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_TRANSPORT_ERROR_UTILS_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_TRANSPORT_ERROR_UTILS_H */
diff --git a/src/core/lib/transport/metadata_batch.cc b/src/core/lib/transport/metadata_batch.cc
index 54388bdcda1..2df9c9189cf 100644
--- a/src/core/lib/transport/metadata_batch.cc
+++ b/src/core/lib/transport/metadata_batch.cc
@@ -74,7 +74,7 @@ void grpc_metadata_batch_assert_ok(grpc_metadata_batch *batch) {
 
 void grpc_metadata_batch_init(grpc_metadata_batch *batch) {
   memset(batch, 0, sizeof(*batch));
-  batch->deadline = gpr_inf_future(GPR_CLOCK_REALTIME);
+  batch->deadline = GRPC_MILLIS_INF_FUTURE;
 }
 
 void grpc_metadata_batch_destroy(grpc_exec_ctx *exec_ctx,
@@ -270,9 +270,7 @@ void grpc_metadata_batch_clear(grpc_exec_ctx *exec_ctx,
 }
 
 bool grpc_metadata_batch_is_empty(grpc_metadata_batch *batch) {
-  return batch->list.head == NULL &&
-         gpr_time_cmp(gpr_inf_future(batch->deadline.clock_type),
-                      batch->deadline) == 0;
+  return batch->list.head == NULL && batch->deadline == GRPC_MILLIS_INF_FUTURE;
 }
 
 size_t grpc_metadata_batch_size(grpc_metadata_batch *batch) {
diff --git a/src/core/lib/transport/metadata_batch.h b/src/core/lib/transport/metadata_batch.h
index 63f30a78d13..a2b4b92385b 100644
--- a/src/core/lib/transport/metadata_batch.h
+++ b/src/core/lib/transport/metadata_batch.h
@@ -51,9 +51,9 @@ typedef struct grpc_metadata_batch {
   grpc_mdelem_list list;
   grpc_metadata_batch_callouts idx;
   /** Used to calculate grpc-timeout at the point of sending,
-      or gpr_inf_future if this batch does not need to send a
+      or GRPC_MILLIS_INF_FUTURE if this batch does not need to send a
       grpc-timeout */
-  gpr_timespec deadline;
+  grpc_millis deadline;
 } grpc_metadata_batch;
 
 void grpc_metadata_batch_init(grpc_metadata_batch *batch);
diff --git a/src/core/lib/transport/pid_controller.h b/src/core/lib/transport/pid_controller.h
index 17feabfd393..80899e9a20f 100644
--- a/src/core/lib/transport/pid_controller.h
+++ b/src/core/lib/transport/pid_controller.h
@@ -67,4 +67,4 @@ double grpc_pid_controller_last(grpc_pid_controller *pid_controller);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_TRANSPORT_PID_CONTROLLER_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_TRANSPORT_PID_CONTROLLER_H */
diff --git a/src/core/lib/transport/service_config.h b/src/core/lib/transport/service_config.h
index c485f524723..9c430936274 100644
--- a/src/core/lib/transport/service_config.h
+++ b/src/core/lib/transport/service_config.h
@@ -67,4 +67,4 @@ void* grpc_method_config_table_get(grpc_exec_ctx* exec_ctx,
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_TRANSPORT_SERVICE_CONFIG_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_TRANSPORT_SERVICE_CONFIG_H */
diff --git a/src/core/lib/transport/status_conversion.cc b/src/core/lib/transport/status_conversion.cc
index a40d333284b..891c4427d7c 100644
--- a/src/core/lib/transport/status_conversion.cc
+++ b/src/core/lib/transport/status_conversion.cc
@@ -37,8 +37,9 @@ grpc_http2_error_code grpc_status_to_http2_error(grpc_status_code status) {
   }
 }
 
-grpc_status_code grpc_http2_error_to_grpc_status(grpc_http2_error_code error,
-                                                 gpr_timespec deadline) {
+grpc_status_code grpc_http2_error_to_grpc_status(grpc_exec_ctx *exec_ctx,
+                                                 grpc_http2_error_code error,
+                                                 grpc_millis deadline) {
   switch (error) {
     case GRPC_HTTP2_NO_ERROR:
       /* should never be received */
@@ -46,7 +47,7 @@ grpc_status_code grpc_http2_error_to_grpc_status(grpc_http2_error_code error,
     case GRPC_HTTP2_CANCEL:
       /* http2 cancel translates to STATUS_CANCELLED iff deadline hasn't been
        * exceeded */
-      return gpr_time_cmp(gpr_now(deadline.clock_type), deadline) >= 0
+      return grpc_exec_ctx_now(exec_ctx) > deadline
                  ? GRPC_STATUS_DEADLINE_EXCEEDED
                  : GRPC_STATUS_CANCELLED;
     case GRPC_HTTP2_ENHANCE_YOUR_CALM:
diff --git a/src/core/lib/transport/status_conversion.h b/src/core/lib/transport/status_conversion.h
index b257998e4d1..8ef91aecfea 100644
--- a/src/core/lib/transport/status_conversion.h
+++ b/src/core/lib/transport/status_conversion.h
@@ -20,6 +20,7 @@
 #define GRPC_CORE_LIB_TRANSPORT_STATUS_CONVERSION_H
 
 #include <grpc/grpc.h>
+#include "src/core/lib/iomgr/exec_ctx.h"
 #include "src/core/lib/transport/http2_errors.h"
 
 #ifdef __cplusplus
@@ -28,8 +29,9 @@ extern "C" {
 
 /* Conversion of grpc status codes to http2 error codes (for RST_STREAM) */
 grpc_http2_error_code grpc_status_to_http2_error(grpc_status_code status);
-grpc_status_code grpc_http2_error_to_grpc_status(grpc_http2_error_code error,
-                                                 gpr_timespec deadline);
+grpc_status_code grpc_http2_error_to_grpc_status(grpc_exec_ctx *exec_ctx,
+                                                 grpc_http2_error_code error,
+                                                 grpc_millis deadline);
 
 /* Conversion of HTTP status codes (:status) to grpc status codes */
 grpc_status_code grpc_http2_status_to_grpc_status(int status);
@@ -39,4 +41,4 @@ int grpc_status_to_http2_status(grpc_status_code status);
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_TRANSPORT_STATUS_CONVERSION_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_TRANSPORT_STATUS_CONVERSION_H */
diff --git a/src/core/lib/transport/timeout_encoding.cc b/src/core/lib/transport/timeout_encoding.cc
index 02f179d6a3a..23a9ef308f6 100644
--- a/src/core/lib/transport/timeout_encoding.cc
+++ b/src/core/lib/transport/timeout_encoding.cc
@@ -59,60 +59,27 @@ static void enc_seconds(char *buffer, int64_t sec) {
   }
 }
 
-static void enc_nanos(char *buffer, int64_t x) {
+static void enc_millis(char *buffer, int64_t x) {
   x = round_up_to_three_sig_figs(x);
-  if (x < 100000) {
-    if (x % 1000 == 0) {
-      enc_ext(buffer, x / 1000, 'u');
-    } else {
-      enc_ext(buffer, x, 'n');
-    }
-  } else if (x < 100000000) {
-    if (x % 1000000 == 0) {
-      enc_ext(buffer, x / 1000000, 'm');
-    } else {
-      enc_ext(buffer, x / 1000, 'u');
-    }
-  } else if (x < 1000000000) {
-    enc_ext(buffer, x / 1000000, 'm');
+  if (x < GPR_MS_PER_SEC) {
+    enc_ext(buffer, x, 'm');
   } else {
-    /* note that this is only ever called with times of less than one second,
-       so if we reach here the time must have been rounded up to a whole second
-       (and no more) */
-    memcpy(buffer, "1S", 3);
-  }
-}
-
-static void enc_micros(char *buffer, int64_t x) {
-  x = round_up_to_three_sig_figs(x);
-  if (x < 100000) {
-    if (x % 1000 == 0) {
-      enc_ext(buffer, x / 1000, 'm');
+    if (x % GPR_MS_PER_SEC == 0) {
+      enc_seconds(buffer, x / GPR_MS_PER_SEC);
     } else {
-      enc_ext(buffer, x, 'u');
+      enc_ext(buffer, x, 'm');
     }
-  } else if (x < 100000000) {
-    if (x % 1000000 == 0) {
-      enc_ext(buffer, x / 1000000, 'S');
-    } else {
-      enc_ext(buffer, x / 1000, 'm');
-    }
-  } else {
-    enc_ext(buffer, x / 1000000, 'S');
   }
 }
 
-void grpc_http2_encode_timeout(gpr_timespec timeout, char *buffer) {
-  if (timeout.tv_sec < 0) {
+void grpc_http2_encode_timeout(grpc_millis timeout, char *buffer) {
+  if (timeout <= 0) {
     enc_tiny(buffer);
-  } else if (timeout.tv_sec == 0) {
-    enc_nanos(buffer, timeout.tv_nsec);
-  } else if (timeout.tv_sec < 1000 && timeout.tv_nsec != 0) {
-    enc_micros(buffer,
-               (int64_t)(timeout.tv_sec * 1000000) +
-                   (timeout.tv_nsec / 1000 + (timeout.tv_nsec % 1000 != 0)));
+  } else if (timeout < 1000 * GPR_MS_PER_SEC) {
+    enc_millis(buffer, timeout);
   } else {
-    enc_seconds(buffer, timeout.tv_sec + (timeout.tv_nsec != 0));
+    enc_seconds(buffer,
+                timeout / GPR_MS_PER_SEC + (timeout % GPR_MS_PER_SEC != 0));
   }
 }
 
@@ -121,8 +88,8 @@ static int is_all_whitespace(const char *p, const char *end) {
   return p == end;
 }
 
-int grpc_http2_decode_timeout(grpc_slice text, gpr_timespec *timeout) {
-  int32_t x = 0;
+int grpc_http2_decode_timeout(grpc_slice text, grpc_millis *timeout) {
+  grpc_millis x = 0;
   const uint8_t *p = GRPC_SLICE_START_PTR(text);
   const uint8_t *end = GRPC_SLICE_END_PTR(text);
   int have_digit = 0;
@@ -136,7 +103,7 @@ int grpc_http2_decode_timeout(grpc_slice text, gpr_timespec *timeout) {
     /* spec allows max. 8 digits, but we allow values up to 1,000,000,000 */
     if (x >= (100 * 1000 * 1000)) {
       if (x != (100 * 1000 * 1000) || digit != 0) {
-        *timeout = gpr_inf_future(GPR_TIMESPAN);
+        *timeout = GRPC_MILLIS_INF_FUTURE;
         return 1;
       }
     }
@@ -150,22 +117,22 @@ int grpc_http2_decode_timeout(grpc_slice text, gpr_timespec *timeout) {
   /* decode unit specifier */
   switch (*p) {
     case 'n':
-      *timeout = gpr_time_from_nanos(x, GPR_TIMESPAN);
+      *timeout = x / GPR_NS_PER_MS + (x % GPR_NS_PER_MS != 0);
       break;
     case 'u':
-      *timeout = gpr_time_from_micros(x, GPR_TIMESPAN);
+      *timeout = x / GPR_US_PER_MS + (x % GPR_US_PER_MS != 0);
       break;
     case 'm':
-      *timeout = gpr_time_from_millis(x, GPR_TIMESPAN);
+      *timeout = x;
       break;
     case 'S':
-      *timeout = gpr_time_from_seconds(x, GPR_TIMESPAN);
+      *timeout = x * GPR_MS_PER_SEC;
       break;
     case 'M':
-      *timeout = gpr_time_from_minutes(x, GPR_TIMESPAN);
+      *timeout = x * 60 * GPR_MS_PER_SEC;
       break;
     case 'H':
-      *timeout = gpr_time_from_hours(x, GPR_TIMESPAN);
+      *timeout = x * 60 * 60 * GPR_MS_PER_SEC;
       break;
     default:
       return 0;
diff --git a/src/core/lib/transport/timeout_encoding.h b/src/core/lib/transport/timeout_encoding.h
index 1f4e206f8ae..91cdf0f728e 100644
--- a/src/core/lib/transport/timeout_encoding.h
+++ b/src/core/lib/transport/timeout_encoding.h
@@ -22,6 +22,7 @@
 #include <grpc/slice.h>
 #include <grpc/support/time.h>
 
+#include "src/core/lib/iomgr/exec_ctx.h"
 #include "src/core/lib/support/string.h"
 
 #define GRPC_HTTP2_TIMEOUT_ENCODE_MIN_BUFSIZE (GPR_LTOA_MIN_BUFSIZE + 1)
@@ -32,11 +33,11 @@ extern "C" {
 
 /* Encode/decode timeouts to the GRPC over HTTP/2 format;
    encoding may round up arbitrarily */
-void grpc_http2_encode_timeout(gpr_timespec timeout, char *buffer);
-int grpc_http2_decode_timeout(grpc_slice text, gpr_timespec *timeout);
+void grpc_http2_encode_timeout(grpc_millis timeout, char *buffer);
+int grpc_http2_decode_timeout(grpc_slice text, grpc_millis *timeout);
 
 #ifdef __cplusplus
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_TRANSPORT_TIMEOUT_ENCODING_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_TRANSPORT_TIMEOUT_ENCODING_H */
diff --git a/src/core/lib/transport/transport_impl.h b/src/core/lib/transport/transport_impl.h
index 41d34d39542..445fb41ab16 100644
--- a/src/core/lib/transport/transport_impl.h
+++ b/src/core/lib/transport/transport_impl.h
@@ -77,4 +77,4 @@ struct grpc_transport {
 }
 #endif
 
-#endif /* GRPC_CORE_LIB_TRANSPORT_TRANSPORT_IMPL_H */
\ No newline at end of file
+#endif /* GRPC_CORE_LIB_TRANSPORT_TRANSPORT_IMPL_H */
diff --git a/src/core/lib/transport/transport_op_string.cc b/src/core/lib/transport/transport_op_string.cc
index 87fdf72e298..cc11b0cc49e 100644
--- a/src/core/lib/transport/transport_op_string.cc
+++ b/src/core/lib/transport/transport_op_string.cc
@@ -51,10 +51,9 @@ static void put_metadata_list(gpr_strvec *b, grpc_metadata_batch md) {
     if (m != md.list.head) gpr_strvec_add(b, gpr_strdup(", "));
     put_metadata(b, m->md);
   }
-  if (gpr_time_cmp(md.deadline, gpr_inf_future(md.deadline.clock_type)) != 0) {
+  if (md.deadline != GRPC_MILLIS_INF_FUTURE) {
     char *tmp;
-    gpr_asprintf(&tmp, " deadline=%" PRId64 ".%09d", md.deadline.tv_sec,
-                 md.deadline.tv_nsec);
+    gpr_asprintf(&tmp, " deadline=%" PRIdPTR, md.deadline);
     gpr_strvec_add(b, tmp);
   }
 }
diff --git a/src/core/tsi/gts_transport_security.h b/src/core/tsi/gts_transport_security.h
index b988c3f8616..9590038ed00 100644
--- a/src/core/tsi/gts_transport_security.h
+++ b/src/core/tsi/gts_transport_security.h
@@ -42,4 +42,4 @@ gts_shared_resource *gts_get_shared_resource(void);
 }
 #endif
 
-#endif /* GRPC_CORE_TSI_GTS_TRANSPORT_SECURITY_H */
\ No newline at end of file
+#endif /* GRPC_CORE_TSI_GTS_TRANSPORT_SECURITY_H */
diff --git a/src/objective-c/BoringSSL.podspec b/src/objective-c/BoringSSL.podspec
index 37798ec3c6b..c61afc1a8f7 100644
--- a/src/objective-c/BoringSSL.podspec
+++ b/src/objective-c/BoringSSL.podspec
@@ -31,7 +31,7 @@
 
 Pod::Spec.new do |s|
   s.name     = 'BoringSSL'
-  version = '9.0'
+  version = '9.1'
   s.version  = version
   s.summary  = 'BoringSSL is a fork of OpenSSL that is designed to meet Google’s needs.'
   # Adapted from the homepage:
@@ -67,9 +67,10 @@ Pod::Spec.new do |s|
   # "The name and email addresses of the library maintainers, not the Podspec maintainer."
   s.authors  = 'Adam Langley', 'David Benjamin', 'Matt Braithwaite'
 
+  major_version = version[0] + '.0'
   s.source = {
     :git => 'https://boringssl.googlesource.com/boringssl',
-    :tag => "version_for_cocoapods_#{version}",
+    :tag => "version_for_cocoapods_#{major_version}",
   }
 
   name = 'openssl'
@@ -186,6 +187,7 @@ Pod::Spec.new do |s|
     cat > include/openssl/BoringSSL.modulemap <<EOF
       framework module openssl {
         umbrella header "umbrella.h"
+        textual header "arm_arch.h"
         export *
         module * { export * }
       }
diff --git a/src/objective-c/tests/RemoteTestClient/RemoteTest.podspec b/src/objective-c/tests/RemoteTestClient/RemoteTest.podspec
index 1796c6d7462..ad834815951 100644
--- a/src/objective-c/tests/RemoteTestClient/RemoteTest.podspec
+++ b/src/objective-c/tests/RemoteTestClient/RemoteTest.podspec
@@ -47,7 +47,7 @@ Pod::Spec.new do |s|
 
   s.pod_target_xcconfig = {
     # This is needed by all pods that depend on Protobuf:
-    'GCC_PREPROCESSOR_DEFINITIONS' => '$(inherited) GPB_USE_PROTOBUF_FRAMEWORK_IMPORTS=1',
+    'GCC_PREPROCESSOR_DEFINITIONS' => '$(inherited) GPB_USE_PROTOBUF_FRAMEWORK_IMPORTS=1 GPB_GRPC_FORWARD_DECLARE_MESSAGE_PROTO=1',
     # This is needed by all pods that depend on gRPC-RxLibrary:
     'CLANG_ALLOW_NON_MODULAR_INCLUDES_IN_FRAMEWORK_MODULES' => 'YES',
   }
diff --git a/src/php/lib/Grpc/BaseStub.php b/src/php/lib/Grpc/BaseStub.php
index b62c2c2fa96..67378a34a8a 100644
--- a/src/php/lib/Grpc/BaseStub.php
+++ b/src/php/lib/Grpc/BaseStub.php
@@ -218,7 +218,7 @@ class BaseStub
      *                              (optional)
      * @param array    $options     An array of options (optional)
      *
-     * @return SimpleSurfaceActiveCall The active call object
+     * @return UnaryCall The active call object
      */
     protected function _simpleRequest($method,
                                    $argument,
@@ -253,7 +253,7 @@ class BaseStub
      *                              (optional)
      * @param array    $options     An array of options (optional)
      *
-     * @return ClientStreamingSurfaceActiveCall The active call object
+     * @return ClientStreamingCall The active call object
      */
     protected function _clientStreamRequest($method,
                                          $deserialize,
@@ -288,7 +288,7 @@ class BaseStub
      *                              (optional)
      * @param array    $options     An array of options (optional)
      *
-     * @return ServerStreamingSurfaceActiveCall The active call object
+     * @return ServerStreamingCall The active call object
      */
     protected function _serverStreamRequest($method,
                                          $argument,
@@ -322,7 +322,7 @@ class BaseStub
      *                              (optional)
      * @param array    $options     An array of options (optional)
      *
-     * @return BidiStreamingSurfaceActiveCall The active call object
+     * @return BidiStreamingCall The active call object
      */
     protected function _bidiRequest($method,
                                  $deserialize,
diff --git a/src/php/tests/qps/client.php b/src/php/tests/qps/client.php
index a785d831b44..08904054eb3 100644
--- a/src/php/tests/qps/client.php
+++ b/src/php/tests/qps/client.php
@@ -37,6 +37,7 @@
  */
 
 require dirname(__FILE__).'/vendor/autoload.php';
+require dirname(__FILE__).'/histogram.php';
 
 /**
  * Assertion function that always exits with an error code if the assertion is
@@ -63,19 +64,19 @@ function hardAssertIfStatusOk($status)
 }
 
 /* Start the actual client */
-
-function qps_client_main($proxy_address) {
-    echo "Initiating php client\n";
+function qps_client_main($proxy_address, $server_ind) {
+    echo "[php-client] Initiating php client\n";
 
     $proxystubopts = [];
     $proxystubopts['credentials'] = Grpc\ChannelCredentials::createInsecure();
     $proxystub = new Grpc\Testing\ProxyClientServiceClient($proxy_address, $proxystubopts);
     list($config, $status) = $proxystub->GetConfig(new Grpc\Testing\Void())->wait();
     hardAssertIfStatusOk($status);
-    hardAssert($config->getClientChannels() == 1, "Only 1 channel supported");
     hardAssert($config->getOutstandingRpcsPerChannel() == 1, "Only 1 outstanding RPC supported");
 
-    echo "Got configuration from proxy, target is " . $config->getServerTargets()[0] . "\n";
+    echo "[php-client] Got configuration from proxy, target is '$server_ind'th server" . $config->getServerTargets()[$server_ind] . "\n";
+    $histres = $config->getHistogramParams()->getResolution();
+    $histmax = $config->getHistogramParams()->getMaxPossible();
 
     $stubopts = [];
     if ($config->getSecurityParams()) {
@@ -93,10 +94,10 @@ function qps_client_main($proxy_address) {
     } else {
         $stubopts['credentials'] = Grpc\ChannelCredentials::createInsecure();
     }
-    echo "Initiating php benchmarking client\n";
+    echo "[php-client] Initiating php benchmarking client\n";
 
     $stub = new Grpc\Testing\BenchmarkServiceClient(
-        $config->getServerTargets()[0], $stubopts);
+        $config->getServerTargets()[$server_ind], $stubopts);
     $req = new Grpc\Testing\SimpleRequest();
 
     $req->setResponseType(Grpc\Testing\PayloadType::COMPRESSABLE);
@@ -115,8 +116,11 @@ function qps_client_main($proxy_address) {
     } else {
         $poisson = false;
     }
-    $metric = new Grpc\Testing\ProxyStat;
-    $telemetry = $proxystub->ReportTime();
+    $histogram = new Histogram($histres, $histmax);
+    $histogram->clean();
+    $count = 0;
+    $histogram_result = new Grpc\Testing\HistogramData;
+    $telehist = $proxystub->ReportHist();
     if ($config->getRpcType() == Grpc\Testing\RpcType::UNARY) {
         while (1) {
             if ($poisson) {
@@ -126,8 +130,20 @@ function qps_client_main($proxy_address) {
             $startreq = microtime(true);
             list($resp,$status) = $stub->UnaryCall($req)->wait();
             hardAssertIfStatusOk($status);
-            $metric->setLatency(microtime(true)-$startreq);
-            $telemetry->write($metric);
+            $histogram->add((microtime(true)-$startreq)*1e9);
+            $count += 1;
+            if ($count == 2000) {
+              $contents = $histogram->contents();
+              $histogram_result->setBucket($contents);
+              $histogram_result->setMinSeen($histogram->minimum());
+              $histogram_result->setMaxSeen($histogram->maximum());
+              $histogram_result->setSum($histogram->sum());
+              $histogram_result->setSumOfSquares($histogram->sum_of_squares());
+              $histogram_result->setCount($histogram->count());
+              $telehist->write($histogram_result);
+              $histogram->clean();
+              $count = 0;
+            }
         }
     } else {
         $stream = $stub->StreamingCall();
@@ -139,8 +155,20 @@ function qps_client_main($proxy_address) {
             $startreq = microtime(true);
             $stream->write($req);
             $resp = $stream->read();
-            $metric->setLatency(microtime(true)-$startreq);
-            $telemetry->write($metric);
+            $histogram->add((microtime(true)-$startreq)*1e9);
+            $count += 1;
+            if ($count == 2000) {
+              $contents = $histogram->contents();
+              $histogram_result->setBucket($contents);
+              $histogram_result->setMinSeen($histogram->minimum());
+              $histogram_result->setMaxSeen($histogram->maximum());
+              $histogram_result->setSum($histogram->sum());
+              $histogram_result->setSumOfSquares($histogram->sum_of_squares());
+              $histogram_result->setCount($histogram->count());
+              $telehist->write($histogram_result);
+              $histogram->clean();
+              $count = 0;
+          }
         }
     }
 }
@@ -148,4 +176,4 @@ function qps_client_main($proxy_address) {
 ini_set('display_startup_errors', 1);
 ini_set('display_errors', 1);
 error_reporting(-1);
-qps_client_main($argv[1]);
+qps_client_main($argv[1], $argv[2]);
diff --git a/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Core/Stats.php b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Core/Stats.php
new file mode 100644
index 00000000000..f9c710cd4e0
--- /dev/null
+++ b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Core/Stats.php
@@ -0,0 +1,33 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/core/stats.proto
+
+namespace GPBMetadata\Src\Proto\Grpc\Core;
+
+class Stats
+{
+    public static $is_initialized = false;
+
+    public static function initOnce() {
+        $pool = \Google\Protobuf\Internal\DescriptorPool::getGeneratedPool();
+
+        if (static::$is_initialized == true) {
+          return;
+        }
+        $pool->internalAddGeneratedFile(hex2bin(
+            "0a97020a1f7372632f70726f746f2f677270632f636f72652f7374617473" .
+            "2e70726f746f1209677270632e636f726522260a064275636b6574120d0a" .
+            "057374617274180120012801120d0a05636f756e74180220012804222f0a" .
+            "09486973746f6772616d12220a076275636b65747318012003280b32112e" .
+            "677270632e636f72652e4275636b6574225b0a064d6574726963120c0a04" .
+            "6e616d65180120012809120f0a05636f756e74180a20012804480012290a" .
+            "09686973746f6772616d180b2001280b32142e677270632e636f72652e48" .
+            "6973746f6772616d480042070a0576616c7565222b0a0553746174731222" .
+            "0a076d65747269637318012003280b32112e677270632e636f72652e4d65" .
+            "74726963620670726f746f33"
+        ));
+
+        static::$is_initialized = true;
+    }
+}
+
diff --git a/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/Control.php b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/Control.php
index efca18a0cb3..9b3a7529ec7 100644
--- a/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/Control.php
+++ b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/Control.php
@@ -17,108 +17,119 @@ class Control
         \GPBMetadata\Src\Proto\Grpc\Testing\Payloads::initOnce();
         \GPBMetadata\Src\Proto\Grpc\Testing\Stats::initOnce();
         $pool->internalAddGeneratedFile(hex2bin(
-            "0add170a247372632f70726f746f2f677270632f74657374696e672f636f" .
-            "6e74726f6c2e70726f746f120c677270632e74657374696e671a25737263" .
-            "2f70726f746f2f677270632f74657374696e672f7061796c6f6164732e70" .
-            "726f746f1a227372632f70726f746f2f677270632f74657374696e672f73" .
-            "746174732e70726f746f22250a0d506f6973736f6e506172616d7312140a" .
-            "0c6f6666657265645f6c6f616418012001280122120a10436c6f7365644c" .
-            "6f6f70506172616d73227b0a0a4c6f6164506172616d7312350a0b636c6f" .
-            "7365645f6c6f6f7018012001280b321e2e677270632e74657374696e672e" .
-            "436c6f7365644c6f6f70506172616d734800122e0a07706f6973736f6e18" .
-            "022001280b321b2e677270632e74657374696e672e506f6973736f6e5061" .
-            "72616d73480042060a046c6f616422430a0e536563757269747950617261" .
-            "6d7312130a0b7573655f746573745f6361180120012808121c0a14736572" .
-            "7665725f686f73745f6f76657272696465180220012809224d0a0a436861" .
-            "6e6e656c417267120c0a046e616d6518012001280912130a097374725f76" .
-            "616c7565180220012809480012130a09696e745f76616c75651803200128" .
-            "05480042070a0576616c756522a0040a0c436c69656e74436f6e66696712" .
-            "160a0e7365727665725f74617267657473180120032809122d0a0b636c69" .
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-            "6f6e64180d2001280112220a1a6661696c65645f72657175657374735f70" .
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-            "4552564552100212100a0c4f544845525f53455256455210032a230a0752" .
-            "70635479706512090a05554e4152591000120d0a0953545245414d494e47" .
-            "1001620670726f746f33"
+            "0aa21a0a247372632f70726f746f2f677270632f74657374696e672f636f" .
+            "6e74726f6c2e70726f746f120c677270632e74657374696e671a22737263" .
+            "2f70726f746f2f677270632f74657374696e672f73746174732e70726f74" .
+            "6f22250a0d506f6973736f6e506172616d7312140a0c6f6666657265645f" .
+            "6c6f616418012001280122120a10436c6f7365644c6f6f70506172616d73" .
+            "227b0a0a4c6f6164506172616d7312350a0b636c6f7365645f6c6f6f7018" .
+            "012001280b321e2e677270632e74657374696e672e436c6f7365644c6f6f" .
+            "70506172616d734800122e0a07706f6973736f6e18022001280b321b2e67" .
+            "7270632e74657374696e672e506f6973736f6e506172616d73480042060a" .
+            "046c6f616422560a0e5365637572697479506172616d7312130a0b757365" .
+            "5f746573745f6361180120012808121c0a147365727665725f686f73745f" .
+            "6f7665727269646518022001280912110a09637265645f74797065180320" .
+            "012809224d0a0a4368616e6e656c417267120c0a046e616d651801200128" .
+            "0912130a097374725f76616c7565180220012809480012130a09696e745f" .
+            "76616c7565180320012805480042070a0576616c756522d5040a0c436c69" .
+            "656e74436f6e66696712160a0e7365727665725f74617267657473180120" .
+            "032809122d0a0b636c69656e745f7479706518022001280e32182e677270" .
+            "632e74657374696e672e436c69656e745479706512350a0f736563757269" .
+            "74795f706172616d7318032001280b321c2e677270632e74657374696e67" .
+            "2e5365637572697479506172616d7312240a1c6f75747374616e64696e67" .
+            "5f727063735f7065725f6368616e6e656c18042001280512170a0f636c69" .
+            "656e745f6368616e6e656c73180520012805121c0a146173796e635f636c" .
+            "69656e745f7468726561647318072001280512270a087270635f74797065" .
+            "18082001280e32152e677270632e74657374696e672e5270635479706512" .
+            "2d0a0b6c6f61645f706172616d73180a2001280b32182e677270632e7465" .
+            "7374696e672e4c6f6164506172616d7312330a0e7061796c6f61645f636f" .
+            "6e666967180b2001280b321b2e677270632e74657374696e672e5061796c" .
+            "6f6164436f6e66696712370a10686973746f6772616d5f706172616d7318" .
+            "0c2001280b321d2e677270632e74657374696e672e486973746f6772616d" .
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+            "03280b32182e677270632e74657374696e672e4368616e6e656c41726712" .
+            "160a0e746872656164735f7065725f6371181120012805121b0a136d6573" .
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+            "0a05726573657418012001280822680a0a436c69656e7441726773122b0a" .
+            "05736574757018012001280b321a2e677270632e74657374696e672e436c" .
+            "69656e74436f6e666967480012220a046d61726b18022001280b32122e67" .
+            "7270632e74657374696e672e4d61726b480042090a076172677479706522" .
+            "fd020a0c536572766572436f6e666967122d0a0b7365727665725f747970" .
+            "6518012001280e32182e677270632e74657374696e672e53657276657254" .
+            "79706512350a0f73656375726974795f706172616d7318022001280b321c" .
+            "2e677270632e74657374696e672e5365637572697479506172616d73120c" .
+            "0a04706f7274180420012805121c0a146173796e635f7365727665725f74" .
+            "68726561647318072001280512120a0a636f72655f6c696d697418082001" .
+            "280512330a0e7061796c6f61645f636f6e66696718092001280b321b2e67" .
+            "7270632e74657374696e672e5061796c6f6164436f6e66696712110a0963" .
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+            "20012805121c0a137265736f757263655f71756f74615f73697a6518e907" .
+            "20012805122f0a0c6368616e6e656c5f6172677318ea072003280b32182e" .
+            "677270632e74657374696e672e4368616e6e656c41726722680a0a536572" .
+            "76657241726773122b0a05736574757018012001280b321a2e677270632e" .
+            "74657374696e672e536572766572436f6e666967480012220a046d61726b" .
+            "18022001280b32122e677270632e74657374696e672e4d61726b48004209" .
+            "0a076172677479706522550a0c53657276657253746174757312280a0573" .
+            "7461747318012001280b32192e677270632e74657374696e672e53657276" .
+            "65725374617473120c0a04706f7274180220012805120d0a05636f726573" .
+            "180320012805220d0a0b436f726552657175657374221d0a0c436f726552" .
+            "6573706f6e7365120d0a05636f72657318012001280522060a04566f6964" .
+            "22fd010a085363656e6172696f120c0a046e616d6518012001280912310a" .
+            "0d636c69656e745f636f6e66696718022001280b321a2e677270632e7465" .
+            "7374696e672e436c69656e74436f6e66696712130a0b6e756d5f636c6965" .
+            "6e747318032001280512310a0d7365727665725f636f6e66696718042001" .
+            "280b321a2e677270632e74657374696e672e536572766572436f6e666967" .
+            "12130a0b6e756d5f7365727665727318052001280512160a0e7761726d75" .
+            "705f7365636f6e647318062001280512190a1162656e63686d61726b5f73" .
+            "65636f6e647318072001280512200a18737061776e5f6c6f63616c5f776f" .
+            "726b65725f636f756e7418082001280522360a095363656e6172696f7312" .
+            "290a097363656e6172696f7318012003280b32162e677270632e74657374" .
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+            "5f73797374656d5f74696d6518032001280112180a107365727665725f75" .
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+            "6d5f74696d6518052001280112180a10636c69656e745f757365725f7469" .
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+            "61696c65645f72657175657374735f7065725f7365636f6e64180e200128" .
+            "0112200a18636c69656e745f706f6c6c735f7065725f7265717565737418" .
+            "0f2001280112200a187365727665725f706f6c6c735f7065725f72657175" .
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+            "725f6370755f73656318112001280112220a1a636c69656e745f71756572" .
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+            "6172696f526573756c7412280a087363656e6172696f18012001280b3216" .
+            "2e677270632e74657374696e672e5363656e6172696f122e0a096c617465" .
+            "6e6369657318022001280b321b2e677270632e74657374696e672e486973" .
+            "746f6772616d44617461122f0a0c636c69656e745f737461747318032003" .
+            "280b32192e677270632e74657374696e672e436c69656e74537461747312" .
+            "2f0a0c7365727665725f737461747318042003280b32192e677270632e74" .
+            "657374696e672e536572766572537461747312140a0c7365727665725f63" .
+            "6f72657318052003280512340a0773756d6d61727918062001280b32232e" .
+            "677270632e74657374696e672e5363656e6172696f526573756c7453756d" .
+            "6d61727912160a0e636c69656e745f737563636573731807200328081216" .
+            "0a0e7365727665725f7375636365737318082003280812390a0f72657175" .
+            "6573745f726573756c747318092003280b32202e677270632e7465737469" .
+            "6e672e52657175657374526573756c74436f756e742a410a0a436c69656e" .
+            "7454797065120f0a0b53594e435f434c49454e54100012100a0c4153594e" .
+            "435f434c49454e54100112100a0c4f544845525f434c49454e5410022a5b" .
+            "0a0a53657276657254797065120f0a0b53594e435f534552564552100012" .
+            "100a0c4153594e435f534552564552100112180a144153594e435f47454e" .
+            "455249435f534552564552100212100a0c4f544845525f53455256455210" .
+            "032a720a075270635479706512090a05554e4152591000120d0a09535452" .
+            "45414d494e47100112190a1553545245414d494e475f46524f4d5f434c49" .
+            "454e54100212190a1553545245414d494e475f46524f4d5f534552564552" .
+            "100312170a1353545245414d494e475f424f54485f574159531004620670" .
+            "726f746f33"
         ));
 
         static::$is_initialized = true;
diff --git a/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/ProxyService.php b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/ProxyService.php
index e35944e1d82..e07f73679ea 100644
--- a/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/ProxyService.php
+++ b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/ProxyService.php
@@ -15,17 +15,20 @@ class ProxyService
           return;
         }
         \GPBMetadata\Src\Proto\Grpc\Testing\Control::initOnce();
+        \GPBMetadata\Src\Proto\Grpc\Testing\Stats::initOnce();
         $pool->internalAddGeneratedFile(hex2bin(
-            "0a97020a2a7372632f70726f746f2f677270632f74657374696e672f7072" .
+            "0ad6020a2a7372632f70726f746f2f677270632f74657374696e672f7072" .
             "6f78792d736572766963652e70726f746f120c677270632e74657374696e" .
-            "671a247372632f70726f746f2f677270632f74657374696e672f636f6e74" .
-            "726f6c2e70726f746f221c0a0950726f787953746174120f0a076c617465" .
-            "6e6379180120012801328e010a1250726f7879436c69656e745365727669" .
-            "6365123b0a09476574436f6e66696712122e677270632e74657374696e67" .
-            "2e566f69641a1a2e677270632e74657374696e672e436c69656e74436f6e" .
-            "666967123b0a0a5265706f727454696d6512172e677270632e7465737469" .
-            "6e672e50726f7879537461741a122e677270632e74657374696e672e566f" .
-            "69642801620670726f746f33"
+            "671a227372632f70726f746f2f677270632f74657374696e672f73746174" .
+            "732e70726f746f221c0a0950726f787953746174120f0a076c6174656e63" .
+            "7918012001280132cf010a1250726f7879436c69656e7453657276696365" .
+            "123b0a09476574436f6e66696712122e677270632e74657374696e672e56" .
+            "6f69641a1a2e677270632e74657374696e672e436c69656e74436f6e6669" .
+            "67123b0a0a5265706f727454696d6512172e677270632e74657374696e67" .
+            "2e50726f7879537461741a122e677270632e74657374696e672e566f6964" .
+            "2801123f0a0a5265706f727448697374121b2e677270632e74657374696e" .
+            "672e486973746f6772616d446174611a122e677270632e74657374696e67" .
+            "2e566f69642801620670726f746f33"
         ));
 
         static::$is_initialized = true;
diff --git a/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/Services.php b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/Services.php
index 7a9439a5b93..e4029182c74 100644
--- a/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/Services.php
+++ b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/Services.php
@@ -16,27 +16,40 @@ class Services
         }
         \GPBMetadata\Src\Proto\Grpc\Testing\Messages::initOnce();
         \GPBMetadata\Src\Proto\Grpc\Testing\Control::initOnce();
+        \GPBMetadata\Src\Proto\Grpc\Testing\Stats::initOnce();
         $pool->internalAddGeneratedFile(hex2bin(
-            "0ad1040a257372632f70726f746f2f677270632f74657374696e672f7365" .
-            "7276696365732e70726f746f120c677270632e74657374696e671a257372" .
-            "632f70726f746f2f677270632f74657374696e672f6d657373616765732e" .
-            "70726f746f1a247372632f70726f746f2f677270632f74657374696e672f" .
-            "636f6e74726f6c2e70726f746f32aa010a1042656e63686d61726b536572" .
-            "7669636512460a09556e61727943616c6c121b2e677270632e7465737469" .
-            "6e672e53696d706c65526571756573741a1c2e677270632e74657374696e" .
-            "672e53696d706c65526573706f6e7365124e0a0d53747265616d696e6743" .
-            "616c6c121b2e677270632e74657374696e672e53696d706c655265717565" .
-            "73741a1c2e677270632e74657374696e672e53696d706c65526573706f6e" .
-            "7365280130013297020a0d576f726b65725365727669636512450a095275" .
-            "6e53657276657212182e677270632e74657374696e672e53657276657241" .
-            "7267731a1a2e677270632e74657374696e672e5365727665725374617475" .
-            "732801300112450a0952756e436c69656e7412182e677270632e74657374" .
-            "696e672e436c69656e74417267731a1a2e677270632e74657374696e672e" .
-            "436c69656e745374617475732801300112420a09436f7265436f756e7412" .
-            "192e677270632e74657374696e672e436f7265526571756573741a1a2e67" .
-            "7270632e74657374696e672e436f7265526573706f6e736512340a0a5175" .
-            "6974576f726b657212122e677270632e74657374696e672e566f69641a12" .
-            "2e677270632e74657374696e672e566f6964620670726f746f33"
+            "0aaa070a257372632f70726f746f2f677270632f74657374696e672f7365" .
+            "7276696365732e70726f746f120c677270632e74657374696e671a247372" .
+            "632f70726f746f2f677270632f74657374696e672f636f6e74726f6c2e70" .
+            "726f746f1a227372632f70726f746f2f677270632f74657374696e672f73" .
+            "746174732e70726f746f32a6030a1042656e63686d61726b536572766963" .
+            "6512460a09556e61727943616c6c121b2e677270632e74657374696e672e" .
+            "53696d706c65526571756573741a1c2e677270632e74657374696e672e53" .
+            "696d706c65526573706f6e7365124e0a0d53747265616d696e6743616c6c" .
+            "121b2e677270632e74657374696e672e53696d706c65526571756573741a" .
+            "1c2e677270632e74657374696e672e53696d706c65526573706f6e736528" .
+            "01300112520a1353747265616d696e6746726f6d436c69656e74121b2e67" .
+            "7270632e74657374696e672e53696d706c65526571756573741a1c2e6772" .
+            "70632e74657374696e672e53696d706c65526573706f6e7365280112520a" .
+            "1353747265616d696e6746726f6d536572766572121b2e677270632e7465" .
+            "7374696e672e53696d706c65526571756573741a1c2e677270632e746573" .
+            "74696e672e53696d706c65526573706f6e7365300112520a115374726561" .
+            "6d696e67426f746857617973121b2e677270632e74657374696e672e5369" .
+            "6d706c65526571756573741a1c2e677270632e74657374696e672e53696d" .
+            "706c65526573706f6e7365280130013297020a0d576f726b657253657276" .
+            "69636512450a0952756e53657276657212182e677270632e74657374696e" .
+            "672e536572766572417267731a1a2e677270632e74657374696e672e5365" .
+            "727665725374617475732801300112450a0952756e436c69656e7412182e" .
+            "677270632e74657374696e672e436c69656e74417267731a1a2e67727063" .
+            "2e74657374696e672e436c69656e745374617475732801300112420a0943" .
+            "6f7265436f756e7412192e677270632e74657374696e672e436f72655265" .
+            "71756573741a1a2e677270632e74657374696e672e436f7265526573706f" .
+            "6e736512340a0a51756974576f726b657212122e677270632e7465737469" .
+            "6e672e566f69641a122e677270632e74657374696e672e566f6964325e0a" .
+            "185265706f72745170735363656e6172696f5365727669636512420a0e52" .
+            "65706f72745363656e6172696f121c2e677270632e74657374696e672e53" .
+            "63656e6172696f526573756c741a122e677270632e74657374696e672e56" .
+            "6f6964620670726f746f33"
         ));
 
         static::$is_initialized = true;
diff --git a/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/Stats.php b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/Stats.php
index 99c0000a52c..3d23b75dfa0 100644
--- a/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/Stats.php
+++ b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/Stats.php
@@ -14,28 +14,33 @@ class Stats
         if (static::$is_initialized == true) {
           return;
         }
+        \GPBMetadata\Src\Proto\Grpc\Core\Stats::initOnce();
         $pool->internalAddGeneratedFile(hex2bin(
-            "0adf040a227372632f70726f746f2f677270632f74657374696e672f7374" .
-            "6174732e70726f746f120c677270632e74657374696e67227a0a0b536572" .
-            "766572537461747312140a0c74696d655f656c6170736564180120012801" .
-            "12110a0974696d655f7573657218022001280112130a0b74696d655f7379" .
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-            "0f486973746f6772616d506172616d7312120a0a7265736f6c7574696f6e" .
-            "18012001280112140a0c6d61785f706f737369626c651802200128012277" .
-            "0a0d486973746f6772616d44617461120e0a066275636b65741801200328" .
-            "0d12100a086d696e5f7365656e18022001280112100a086d61785f736565" .
-            "6e180320012801120b0a0373756d18042001280112160a0e73756d5f6f66" .
-            "5f73717561726573180520012801120d0a05636f756e7418062001280122" .
-            "380a1252657175657374526573756c74436f756e7412130a0b7374617475" .
-            "735f636f6465180120012805120d0a05636f756e7418022001280322b601" .
-            "0a0b436c69656e745374617473122e0a096c6174656e6369657318012001" .
-            "280b321b2e677270632e74657374696e672e486973746f6772616d446174" .
-            "6112140a0c74696d655f656c617073656418022001280112110a0974696d" .
-            "655f7573657218032001280112130a0b74696d655f73797374656d180420" .
-            "01280112390a0f726571756573745f726573756c747318052003280b3220" .
-            "2e677270632e74657374696e672e52657175657374526573756c74436f75" .
-            "6e74620670726f746f33"
+            "0ada050a227372632f70726f746f2f677270632f74657374696e672f7374" .
+            "6174732e70726f746f120c677270632e74657374696e6722b7010a0b5365" .
+            "72766572537461747312140a0c74696d655f656c61707365641801200128" .
+            "0112110a0974696d655f7573657218022001280112130a0b74696d655f73" .
+            "797374656d18032001280112160a0e746f74616c5f6370755f74696d6518" .
+            "042001280412150a0d69646c655f6370755f74696d651805200128041215" .
+            "0a0d63715f706f6c6c5f636f756e7418062001280412240a0a636f72655f" .
+            "737461747318072001280b32102e677270632e636f72652e537461747322" .
+            "3b0a0f486973746f6772616d506172616d7312120a0a7265736f6c757469" .
+            "6f6e18012001280112140a0c6d61785f706f737369626c65180220012801" .
+            "22770a0d486973746f6772616d44617461120e0a066275636b6574180120" .
+            "03280d12100a086d696e5f7365656e18022001280112100a086d61785f73" .
+            "65656e180320012801120b0a0373756d18042001280112160a0e73756d5f" .
+            "6f665f73717561726573180520012801120d0a05636f756e741806200128" .
+            "0122380a1252657175657374526573756c74436f756e7412130a0b737461" .
+            "7475735f636f6465180120012805120d0a05636f756e7418022001280322" .
+            "f3010a0b436c69656e745374617473122e0a096c6174656e636965731801" .
+            "2001280b321b2e677270632e74657374696e672e486973746f6772616d44" .
+            "61746112140a0c74696d655f656c617073656418022001280112110a0974" .
+            "696d655f7573657218032001280112130a0b74696d655f73797374656d18" .
+            "042001280112390a0f726571756573745f726573756c747318052003280b" .
+            "32202e677270632e74657374696e672e52657175657374526573756c7443" .
+            "6f756e7412150a0d63715f706f6c6c5f636f756e7418062001280412240a" .
+            "0a636f72655f737461747318072001280b32102e677270632e636f72652e" .
+            "5374617473620670726f746f33"
         ));
 
         static::$is_initialized = true;
diff --git a/src/php/tests/qps/generated_code/Grpc/Core/Bucket.php b/src/php/tests/qps/generated_code/Grpc/Core/Bucket.php
new file mode 100644
index 00000000000..897d6271c28
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Core/Bucket.php
@@ -0,0 +1,75 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/core/stats.proto
+
+namespace Grpc\Core;
+
+use Google\Protobuf\Internal\GPBType;
+use Google\Protobuf\Internal\RepeatedField;
+use Google\Protobuf\Internal\GPBUtil;
+
+/**
+ * Generated from protobuf message <code>grpc.core.Bucket</code>
+ */
+class Bucket extends \Google\Protobuf\Internal\Message
+{
+    /**
+     * Generated from protobuf field <code>double start = 1;</code>
+     */
+    private $start = 0.0;
+    /**
+     * Generated from protobuf field <code>uint64 count = 2;</code>
+     */
+    private $count = 0;
+
+    public function __construct() {
+        \GPBMetadata\Src\Proto\Grpc\Core\Stats::initOnce();
+        parent::__construct();
+    }
+
+    /**
+     * Generated from protobuf field <code>double start = 1;</code>
+     * @return float
+     */
+    public function getStart()
+    {
+        return $this->start;
+    }
+
+    /**
+     * Generated from protobuf field <code>double start = 1;</code>
+     * @param float $var
+     * @return $this
+     */
+    public function setStart($var)
+    {
+        GPBUtil::checkDouble($var);
+        $this->start = $var;
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>uint64 count = 2;</code>
+     * @return int|string
+     */
+    public function getCount()
+    {
+        return $this->count;
+    }
+
+    /**
+     * Generated from protobuf field <code>uint64 count = 2;</code>
+     * @param int|string $var
+     * @return $this
+     */
+    public function setCount($var)
+    {
+        GPBUtil::checkUint64($var);
+        $this->count = $var;
+
+        return $this;
+    }
+
+}
+
diff --git a/src/php/tests/qps/generated_code/Grpc/Core/Histogram.php b/src/php/tests/qps/generated_code/Grpc/Core/Histogram.php
new file mode 100644
index 00000000000..1902be8e4ac
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Core/Histogram.php
@@ -0,0 +1,49 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/core/stats.proto
+
+namespace Grpc\Core;
+
+use Google\Protobuf\Internal\GPBType;
+use Google\Protobuf\Internal\RepeatedField;
+use Google\Protobuf\Internal\GPBUtil;
+
+/**
+ * Generated from protobuf message <code>grpc.core.Histogram</code>
+ */
+class Histogram extends \Google\Protobuf\Internal\Message
+{
+    /**
+     * Generated from protobuf field <code>repeated .grpc.core.Bucket buckets = 1;</code>
+     */
+    private $buckets;
+
+    public function __construct() {
+        \GPBMetadata\Src\Proto\Grpc\Core\Stats::initOnce();
+        parent::__construct();
+    }
+
+    /**
+     * Generated from protobuf field <code>repeated .grpc.core.Bucket buckets = 1;</code>
+     * @return \Google\Protobuf\Internal\RepeatedField
+     */
+    public function getBuckets()
+    {
+        return $this->buckets;
+    }
+
+    /**
+     * Generated from protobuf field <code>repeated .grpc.core.Bucket buckets = 1;</code>
+     * @param \Grpc\Core\Bucket[]|\Google\Protobuf\Internal\RepeatedField $var
+     * @return $this
+     */
+    public function setBuckets($var)
+    {
+        $arr = GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::MESSAGE, \Grpc\Core\Bucket::class);
+        $this->buckets = $arr;
+
+        return $this;
+    }
+
+}
+
diff --git a/src/php/tests/qps/generated_code/Grpc/Core/Metric.php b/src/php/tests/qps/generated_code/Grpc/Core/Metric.php
new file mode 100644
index 00000000000..c3581b7d21b
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Core/Metric.php
@@ -0,0 +1,102 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/core/stats.proto
+
+namespace Grpc\Core;
+
+use Google\Protobuf\Internal\GPBType;
+use Google\Protobuf\Internal\RepeatedField;
+use Google\Protobuf\Internal\GPBUtil;
+
+/**
+ * Generated from protobuf message <code>grpc.core.Metric</code>
+ */
+class Metric extends \Google\Protobuf\Internal\Message
+{
+    /**
+     * Generated from protobuf field <code>string name = 1;</code>
+     */
+    private $name = '';
+    protected $value;
+
+    public function __construct() {
+        \GPBMetadata\Src\Proto\Grpc\Core\Stats::initOnce();
+        parent::__construct();
+    }
+
+    /**
+     * Generated from protobuf field <code>string name = 1;</code>
+     * @return string
+     */
+    public function getName()
+    {
+        return $this->name;
+    }
+
+    /**
+     * Generated from protobuf field <code>string name = 1;</code>
+     * @param string $var
+     * @return $this
+     */
+    public function setName($var)
+    {
+        GPBUtil::checkString($var, True);
+        $this->name = $var;
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>uint64 count = 10;</code>
+     * @return int|string
+     */
+    public function getCount()
+    {
+        return $this->readOneof(10);
+    }
+
+    /**
+     * Generated from protobuf field <code>uint64 count = 10;</code>
+     * @param int|string $var
+     * @return $this
+     */
+    public function setCount($var)
+    {
+        GPBUtil::checkUint64($var);
+        $this->writeOneof(10, $var);
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>.grpc.core.Histogram histogram = 11;</code>
+     * @return \Grpc\Core\Histogram
+     */
+    public function getHistogram()
+    {
+        return $this->readOneof(11);
+    }
+
+    /**
+     * Generated from protobuf field <code>.grpc.core.Histogram histogram = 11;</code>
+     * @param \Grpc\Core\Histogram $var
+     * @return $this
+     */
+    public function setHistogram($var)
+    {
+        GPBUtil::checkMessage($var, \Grpc\Core\Histogram::class);
+        $this->writeOneof(11, $var);
+
+        return $this;
+    }
+
+    /**
+     * @return string
+     */
+    public function getValue()
+    {
+        return $this->whichOneof("value");
+    }
+
+}
+
diff --git a/src/php/tests/qps/generated_code/Grpc/Core/Stats.php b/src/php/tests/qps/generated_code/Grpc/Core/Stats.php
new file mode 100644
index 00000000000..e6f3fb08992
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Core/Stats.php
@@ -0,0 +1,49 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/core/stats.proto
+
+namespace Grpc\Core;
+
+use Google\Protobuf\Internal\GPBType;
+use Google\Protobuf\Internal\RepeatedField;
+use Google\Protobuf\Internal\GPBUtil;
+
+/**
+ * Generated from protobuf message <code>grpc.core.Stats</code>
+ */
+class Stats extends \Google\Protobuf\Internal\Message
+{
+    /**
+     * Generated from protobuf field <code>repeated .grpc.core.Metric metrics = 1;</code>
+     */
+    private $metrics;
+
+    public function __construct() {
+        \GPBMetadata\Src\Proto\Grpc\Core\Stats::initOnce();
+        parent::__construct();
+    }
+
+    /**
+     * Generated from protobuf field <code>repeated .grpc.core.Metric metrics = 1;</code>
+     * @return \Google\Protobuf\Internal\RepeatedField
+     */
+    public function getMetrics()
+    {
+        return $this->metrics;
+    }
+
+    /**
+     * Generated from protobuf field <code>repeated .grpc.core.Metric metrics = 1;</code>
+     * @param \Grpc\Core\Metric[]|\Google\Protobuf\Internal\RepeatedField $var
+     * @return $this
+     */
+    public function setMetrics($var)
+    {
+        $arr = GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::MESSAGE, \Grpc\Core\Metric::class);
+        $this->metrics = $arr;
+
+        return $this;
+    }
+
+}
+
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/BenchmarkServiceClient.php b/src/php/tests/qps/generated_code/Grpc/Testing/BenchmarkServiceClient.php
index ddf750a94fc..fa3e1479091 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/BenchmarkServiceClient.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/BenchmarkServiceClient.php
@@ -18,17 +18,19 @@
 //
 // An integration test service that covers all the method signature permutations
 // of unary/streaming requests/responses.
-namespace Grpc\Testing {
+namespace Grpc\Testing;
 
-  class BenchmarkServiceClient extends \Grpc\BaseStub {
+/**
+ */
+class BenchmarkServiceClient extends \Grpc\BaseStub {
 
     /**
      * @param string $hostname hostname
      * @param array $opts channel options
-     * @param Grpc\Channel $channel (optional) re-use channel object
+     * @param \Grpc\Channel $channel (optional) re-use channel object
      */
     public function __construct($hostname, $opts, $channel = null) {
-      parent::__construct($hostname, $opts, $channel);
+        parent::__construct($hostname, $opts, $channel);
     }
 
     /**
@@ -40,24 +42,62 @@ namespace Grpc\Testing {
      */
     public function UnaryCall(\Grpc\Testing\SimpleRequest $argument,
       $metadata = [], $options = []) {
-      return $this->_simpleRequest('/grpc.testing.BenchmarkService/UnaryCall',
-      $argument,
-      ['\Grpc\Testing\SimpleResponse', 'decode'],
-      $metadata, $options);
+        return $this->_simpleRequest('/grpc.testing.BenchmarkService/UnaryCall',
+        $argument,
+        ['\Grpc\Testing\SimpleResponse', 'decode'],
+        $metadata, $options);
     }
 
     /**
-     * One request followed by one response.
-     * The server returns the client payload as-is.
+     * Repeated sequence of one request followed by one response.
+     * Should be called streaming ping-pong
+     * The server returns the client payload as-is on each response
      * @param array $metadata metadata
      * @param array $options call options
      */
     public function StreamingCall($metadata = [], $options = []) {
-      return $this->_bidiRequest('/grpc.testing.BenchmarkService/StreamingCall',
-      ['\Grpc\Testing\SimpleResponse','decode'],
-      $metadata, $options);
+        return $this->_bidiRequest('/grpc.testing.BenchmarkService/StreamingCall',
+        ['\Grpc\Testing\SimpleResponse','decode'],
+        $metadata, $options);
     }
 
-  }
+    /**
+     * Single-sided unbounded streaming from client to server
+     * The server returns the client payload as-is once the client does WritesDone
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function StreamingFromClient($metadata = [], $options = []) {
+        return $this->_clientStreamRequest('/grpc.testing.BenchmarkService/StreamingFromClient',
+        ['\Grpc\Testing\SimpleResponse','decode'],
+        $metadata, $options);
+    }
+
+    /**
+     * Single-sided unbounded streaming from server to client
+     * The server repeatedly returns the client payload as-is
+     * @param \Grpc\Testing\SimpleRequest $argument input argument
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function StreamingFromServer(\Grpc\Testing\SimpleRequest $argument,
+      $metadata = [], $options = []) {
+        return $this->_serverStreamRequest('/grpc.testing.BenchmarkService/StreamingFromServer',
+        $argument,
+        ['\Grpc\Testing\SimpleResponse', 'decode'],
+        $metadata, $options);
+    }
+
+    /**
+     * Two-sided unbounded streaming between server to client
+     * Both sides send the content of their own choice to the other
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function StreamingBothWays($metadata = [], $options = []) {
+        return $this->_bidiRequest('/grpc.testing.BenchmarkService/StreamingBothWays',
+        ['\Grpc\Testing\SimpleResponse','decode'],
+        $metadata, $options);
+    }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/BoolValue.php b/src/php/tests/qps/generated_code/Grpc/Testing/BoolValue.php
index f0497accfb2..7eb364b7a0b 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/BoolValue.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/BoolValue.php
@@ -9,22 +9,18 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * <pre>
  * TODO(dgq): Go back to using well-known types once
  * https://github.com/grpc/grpc/issues/6980 has been fixed.
  * import "google/protobuf/wrappers.proto";
- * </pre>
  *
- * Protobuf type <code>grpc.testing.BoolValue</code>
+ * Generated from protobuf message <code>grpc.testing.BoolValue</code>
  */
 class BoolValue extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <pre>
      * The bool value.
-     * </pre>
      *
-     * <code>bool value = 1;</code>
+     * Generated from protobuf field <code>bool value = 1;</code>
      */
     private $value = false;
 
@@ -34,11 +30,10 @@ class BoolValue extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * The bool value.
-     * </pre>
      *
-     * <code>bool value = 1;</code>
+     * Generated from protobuf field <code>bool value = 1;</code>
+     * @return bool
      */
     public function getValue()
     {
@@ -46,16 +41,18 @@ class BoolValue extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * The bool value.
-     * </pre>
      *
-     * <code>bool value = 1;</code>
+     * Generated from protobuf field <code>bool value = 1;</code>
+     * @param bool $var
+     * @return $this
      */
     public function setValue($var)
     {
         GPBUtil::checkBool($var);
         $this->value = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ByteBufferParams.php b/src/php/tests/qps/generated_code/Grpc/Testing/ByteBufferParams.php
index 0057d387488..0511026ba74 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/ByteBufferParams.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ByteBufferParams.php
@@ -9,16 +9,16 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * Protobuf type <code>grpc.testing.ByteBufferParams</code>
+ * Generated from protobuf message <code>grpc.testing.ByteBufferParams</code>
  */
 class ByteBufferParams extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <code>int32 req_size = 1;</code>
+     * Generated from protobuf field <code>int32 req_size = 1;</code>
      */
     private $req_size = 0;
     /**
-     * <code>int32 resp_size = 2;</code>
+     * Generated from protobuf field <code>int32 resp_size = 2;</code>
      */
     private $resp_size = 0;
 
@@ -28,7 +28,8 @@ class ByteBufferParams extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>int32 req_size = 1;</code>
+     * Generated from protobuf field <code>int32 req_size = 1;</code>
+     * @return int
      */
     public function getReqSize()
     {
@@ -36,16 +37,21 @@ class ByteBufferParams extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>int32 req_size = 1;</code>
+     * Generated from protobuf field <code>int32 req_size = 1;</code>
+     * @param int $var
+     * @return $this
      */
     public function setReqSize($var)
     {
         GPBUtil::checkInt32($var);
         $this->req_size = $var;
+
+        return $this;
     }
 
     /**
-     * <code>int32 resp_size = 2;</code>
+     * Generated from protobuf field <code>int32 resp_size = 2;</code>
+     * @return int
      */
     public function getRespSize()
     {
@@ -53,12 +59,16 @@ class ByteBufferParams extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>int32 resp_size = 2;</code>
+     * Generated from protobuf field <code>int32 resp_size = 2;</code>
+     * @param int $var
+     * @return $this
      */
     public function setRespSize($var)
     {
         GPBUtil::checkInt32($var);
         $this->resp_size = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ChannelArg.php b/src/php/tests/qps/generated_code/Grpc/Testing/ChannelArg.php
index d2fe3ae5ffc..5c5fb861a40 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/ChannelArg.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ChannelArg.php
@@ -9,12 +9,12 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * Protobuf type <code>grpc.testing.ChannelArg</code>
+ * Generated from protobuf message <code>grpc.testing.ChannelArg</code>
  */
 class ChannelArg extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <code>string name = 1;</code>
+     * Generated from protobuf field <code>string name = 1;</code>
      */
     private $name = '';
     protected $value;
@@ -25,7 +25,8 @@ class ChannelArg extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>string name = 1;</code>
+     * Generated from protobuf field <code>string name = 1;</code>
+     * @return string
      */
     public function getName()
     {
@@ -33,16 +34,21 @@ class ChannelArg extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>string name = 1;</code>
+     * Generated from protobuf field <code>string name = 1;</code>
+     * @param string $var
+     * @return $this
      */
     public function setName($var)
     {
         GPBUtil::checkString($var, True);
         $this->name = $var;
+
+        return $this;
     }
 
     /**
-     * <code>string str_value = 2;</code>
+     * Generated from protobuf field <code>string str_value = 2;</code>
+     * @return string
      */
     public function getStrValue()
     {
@@ -50,16 +56,21 @@ class ChannelArg extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>string str_value = 2;</code>
+     * Generated from protobuf field <code>string str_value = 2;</code>
+     * @param string $var
+     * @return $this
      */
     public function setStrValue($var)
     {
         GPBUtil::checkString($var, True);
         $this->writeOneof(2, $var);
+
+        return $this;
     }
 
     /**
-     * <code>int32 int_value = 3;</code>
+     * Generated from protobuf field <code>int32 int_value = 3;</code>
+     * @return int
      */
     public function getIntValue()
     {
@@ -67,14 +78,21 @@ class ChannelArg extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>int32 int_value = 3;</code>
+     * Generated from protobuf field <code>int32 int_value = 3;</code>
+     * @param int $var
+     * @return $this
      */
     public function setIntValue($var)
     {
         GPBUtil::checkInt32($var);
         $this->writeOneof(3, $var);
+
+        return $this;
     }
 
+    /**
+     * @return string
+     */
     public function getValue()
     {
         return $this->whichOneof("value");
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ClientArgs.php b/src/php/tests/qps/generated_code/Grpc/Testing/ClientArgs.php
index c878c5a7bc0..ee3fd46f0f6 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/ClientArgs.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ClientArgs.php
@@ -9,7 +9,7 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * Protobuf type <code>grpc.testing.ClientArgs</code>
+ * Generated from protobuf message <code>grpc.testing.ClientArgs</code>
  */
 class ClientArgs extends \Google\Protobuf\Internal\Message
 {
@@ -21,7 +21,8 @@ class ClientArgs extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>.grpc.testing.ClientConfig setup = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.ClientConfig setup = 1;</code>
+     * @return \Grpc\Testing\ClientConfig
      */
     public function getSetup()
     {
@@ -29,16 +30,21 @@ class ClientArgs extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>.grpc.testing.ClientConfig setup = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.ClientConfig setup = 1;</code>
+     * @param \Grpc\Testing\ClientConfig $var
+     * @return $this
      */
-    public function setSetup(&$var)
+    public function setSetup($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\ClientConfig::class);
         $this->writeOneof(1, $var);
+
+        return $this;
     }
 
     /**
-     * <code>.grpc.testing.Mark mark = 2;</code>
+     * Generated from protobuf field <code>.grpc.testing.Mark mark = 2;</code>
+     * @return \Grpc\Testing\Mark
      */
     public function getMark()
     {
@@ -46,14 +52,21 @@ class ClientArgs extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>.grpc.testing.Mark mark = 2;</code>
+     * Generated from protobuf field <code>.grpc.testing.Mark mark = 2;</code>
+     * @param \Grpc\Testing\Mark $var
+     * @return $this
      */
-    public function setMark(&$var)
+    public function setMark($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\Mark::class);
         $this->writeOneof(2, $var);
+
+        return $this;
     }
 
+    /**
+     * @return string
+     */
     public function getArgtype()
     {
         return $this->whichOneof("argtype");
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ClientConfig.php b/src/php/tests/qps/generated_code/Grpc/Testing/ClientConfig.php
index 52d6a75fb0e..f7bc21587c9 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/ClientConfig.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ClientConfig.php
@@ -9,96 +9,94 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * Protobuf type <code>grpc.testing.ClientConfig</code>
+ * Generated from protobuf message <code>grpc.testing.ClientConfig</code>
  */
 class ClientConfig extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <pre>
      * List of targets to connect to. At least one target needs to be specified.
-     * </pre>
      *
-     * <code>repeated string server_targets = 1;</code>
+     * Generated from protobuf field <code>repeated string server_targets = 1;</code>
      */
     private $server_targets;
     /**
-     * <code>.grpc.testing.ClientType client_type = 2;</code>
+     * Generated from protobuf field <code>.grpc.testing.ClientType client_type = 2;</code>
      */
     private $client_type = 0;
     /**
-     * <code>.grpc.testing.SecurityParams security_params = 3;</code>
+     * Generated from protobuf field <code>.grpc.testing.SecurityParams security_params = 3;</code>
      */
     private $security_params = null;
     /**
-     * <pre>
      * How many concurrent RPCs to start for each channel.
      * For synchronous client, use a separate thread for each outstanding RPC.
-     * </pre>
      *
-     * <code>int32 outstanding_rpcs_per_channel = 4;</code>
+     * Generated from protobuf field <code>int32 outstanding_rpcs_per_channel = 4;</code>
      */
     private $outstanding_rpcs_per_channel = 0;
     /**
-     * <pre>
      * Number of independent client channels to create.
      * i-th channel will connect to server_target[i % server_targets.size()]
-     * </pre>
      *
-     * <code>int32 client_channels = 5;</code>
+     * Generated from protobuf field <code>int32 client_channels = 5;</code>
      */
     private $client_channels = 0;
     /**
-     * <pre>
      * Only for async client. Number of threads to use to start/manage RPCs.
-     * </pre>
      *
-     * <code>int32 async_client_threads = 7;</code>
+     * Generated from protobuf field <code>int32 async_client_threads = 7;</code>
      */
     private $async_client_threads = 0;
     /**
-     * <code>.grpc.testing.RpcType rpc_type = 8;</code>
+     * Generated from protobuf field <code>.grpc.testing.RpcType rpc_type = 8;</code>
      */
     private $rpc_type = 0;
     /**
-     * <pre>
      * The requested load for the entire client (aggregated over all the threads).
-     * </pre>
      *
-     * <code>.grpc.testing.LoadParams load_params = 10;</code>
+     * Generated from protobuf field <code>.grpc.testing.LoadParams load_params = 10;</code>
      */
     private $load_params = null;
     /**
-     * <code>.grpc.testing.PayloadConfig payload_config = 11;</code>
+     * Generated from protobuf field <code>.grpc.testing.PayloadConfig payload_config = 11;</code>
      */
     private $payload_config = null;
     /**
-     * <code>.grpc.testing.HistogramParams histogram_params = 12;</code>
+     * Generated from protobuf field <code>.grpc.testing.HistogramParams histogram_params = 12;</code>
      */
     private $histogram_params = null;
     /**
-     * <pre>
      * Specify the cores we should run the client on, if desired
-     * </pre>
      *
-     * <code>repeated int32 core_list = 13;</code>
+     * Generated from protobuf field <code>repeated int32 core_list = 13;</code>
      */
     private $core_list;
     /**
-     * <code>int32 core_limit = 14;</code>
+     * Generated from protobuf field <code>int32 core_limit = 14;</code>
      */
     private $core_limit = 0;
     /**
-     * <pre>
      * If we use an OTHER_CLIENT client_type, this string gives more detail
-     * </pre>
      *
-     * <code>string other_client_api = 15;</code>
+     * Generated from protobuf field <code>string other_client_api = 15;</code>
      */
     private $other_client_api = '';
     /**
-     * <code>repeated .grpc.testing.ChannelArg channel_args = 16;</code>
+     * Generated from protobuf field <code>repeated .grpc.testing.ChannelArg channel_args = 16;</code>
      */
     private $channel_args;
+    /**
+     * Number of threads that share each completion queue
+     *
+     * Generated from protobuf field <code>int32 threads_per_cq = 17;</code>
+     */
+    private $threads_per_cq = 0;
+    /**
+     * Number of messages on a stream before it gets finished/restarted
+     *
+     * Generated from protobuf field <code>int32 messages_per_stream = 18;</code>
+     */
+    private $messages_per_stream = 0;
 
     public function __construct() {
         \GPBMetadata\Src\Proto\Grpc\Testing\Control::initOnce();
@@ -106,11 +104,10 @@ class ClientConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * List of targets to connect to. At least one target needs to be specified.
-     * </pre>
      *
-     * <code>repeated string server_targets = 1;</code>
+     * Generated from protobuf field <code>repeated string server_targets = 1;</code>
+     * @return \Google\Protobuf\Internal\RepeatedField
      */
     public function getServerTargets()
     {
@@ -118,20 +115,23 @@ class ClientConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * List of targets to connect to. At least one target needs to be specified.
-     * </pre>
      *
-     * <code>repeated string server_targets = 1;</code>
+     * Generated from protobuf field <code>repeated string server_targets = 1;</code>
+     * @param string[]|\Google\Protobuf\Internal\RepeatedField $var
+     * @return $this
      */
-    public function setServerTargets(&$var)
+    public function setServerTargets($var)
     {
-        GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::STRING);
-        $this->server_targets = $var;
+        $arr = GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::STRING);
+        $this->server_targets = $arr;
+
+        return $this;
     }
 
     /**
-     * <code>.grpc.testing.ClientType client_type = 2;</code>
+     * Generated from protobuf field <code>.grpc.testing.ClientType client_type = 2;</code>
+     * @return int
      */
     public function getClientType()
     {
@@ -139,16 +139,21 @@ class ClientConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>.grpc.testing.ClientType client_type = 2;</code>
+     * Generated from protobuf field <code>.grpc.testing.ClientType client_type = 2;</code>
+     * @param int $var
+     * @return $this
      */
     public function setClientType($var)
     {
         GPBUtil::checkEnum($var, \Grpc\Testing\ClientType::class);
         $this->client_type = $var;
+
+        return $this;
     }
 
     /**
-     * <code>.grpc.testing.SecurityParams security_params = 3;</code>
+     * Generated from protobuf field <code>.grpc.testing.SecurityParams security_params = 3;</code>
+     * @return \Grpc\Testing\SecurityParams
      */
     public function getSecurityParams()
     {
@@ -156,21 +161,24 @@ class ClientConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>.grpc.testing.SecurityParams security_params = 3;</code>
+     * Generated from protobuf field <code>.grpc.testing.SecurityParams security_params = 3;</code>
+     * @param \Grpc\Testing\SecurityParams $var
+     * @return $this
      */
-    public function setSecurityParams(&$var)
+    public function setSecurityParams($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\SecurityParams::class);
         $this->security_params = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * How many concurrent RPCs to start for each channel.
      * For synchronous client, use a separate thread for each outstanding RPC.
-     * </pre>
      *
-     * <code>int32 outstanding_rpcs_per_channel = 4;</code>
+     * Generated from protobuf field <code>int32 outstanding_rpcs_per_channel = 4;</code>
+     * @return int
      */
     public function getOutstandingRpcsPerChannel()
     {
@@ -178,26 +186,27 @@ class ClientConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * How many concurrent RPCs to start for each channel.
      * For synchronous client, use a separate thread for each outstanding RPC.
-     * </pre>
      *
-     * <code>int32 outstanding_rpcs_per_channel = 4;</code>
+     * Generated from protobuf field <code>int32 outstanding_rpcs_per_channel = 4;</code>
+     * @param int $var
+     * @return $this
      */
     public function setOutstandingRpcsPerChannel($var)
     {
         GPBUtil::checkInt32($var);
         $this->outstanding_rpcs_per_channel = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Number of independent client channels to create.
      * i-th channel will connect to server_target[i % server_targets.size()]
-     * </pre>
      *
-     * <code>int32 client_channels = 5;</code>
+     * Generated from protobuf field <code>int32 client_channels = 5;</code>
+     * @return int
      */
     public function getClientChannels()
     {
@@ -205,25 +214,26 @@ class ClientConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Number of independent client channels to create.
      * i-th channel will connect to server_target[i % server_targets.size()]
-     * </pre>
      *
-     * <code>int32 client_channels = 5;</code>
+     * Generated from protobuf field <code>int32 client_channels = 5;</code>
+     * @param int $var
+     * @return $this
      */
     public function setClientChannels($var)
     {
         GPBUtil::checkInt32($var);
         $this->client_channels = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Only for async client. Number of threads to use to start/manage RPCs.
-     * </pre>
      *
-     * <code>int32 async_client_threads = 7;</code>
+     * Generated from protobuf field <code>int32 async_client_threads = 7;</code>
+     * @return int
      */
     public function getAsyncClientThreads()
     {
@@ -231,20 +241,23 @@ class ClientConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Only for async client. Number of threads to use to start/manage RPCs.
-     * </pre>
      *
-     * <code>int32 async_client_threads = 7;</code>
+     * Generated from protobuf field <code>int32 async_client_threads = 7;</code>
+     * @param int $var
+     * @return $this
      */
     public function setAsyncClientThreads($var)
     {
         GPBUtil::checkInt32($var);
         $this->async_client_threads = $var;
+
+        return $this;
     }
 
     /**
-     * <code>.grpc.testing.RpcType rpc_type = 8;</code>
+     * Generated from protobuf field <code>.grpc.testing.RpcType rpc_type = 8;</code>
+     * @return int
      */
     public function getRpcType()
     {
@@ -252,20 +265,23 @@ class ClientConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>.grpc.testing.RpcType rpc_type = 8;</code>
+     * Generated from protobuf field <code>.grpc.testing.RpcType rpc_type = 8;</code>
+     * @param int $var
+     * @return $this
      */
     public function setRpcType($var)
     {
         GPBUtil::checkEnum($var, \Grpc\Testing\RpcType::class);
         $this->rpc_type = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * The requested load for the entire client (aggregated over all the threads).
-     * </pre>
      *
-     * <code>.grpc.testing.LoadParams load_params = 10;</code>
+     * Generated from protobuf field <code>.grpc.testing.LoadParams load_params = 10;</code>
+     * @return \Grpc\Testing\LoadParams
      */
     public function getLoadParams()
     {
@@ -273,20 +289,23 @@ class ClientConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * The requested load for the entire client (aggregated over all the threads).
-     * </pre>
      *
-     * <code>.grpc.testing.LoadParams load_params = 10;</code>
+     * Generated from protobuf field <code>.grpc.testing.LoadParams load_params = 10;</code>
+     * @param \Grpc\Testing\LoadParams $var
+     * @return $this
      */
-    public function setLoadParams(&$var)
+    public function setLoadParams($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\LoadParams::class);
         $this->load_params = $var;
+
+        return $this;
     }
 
     /**
-     * <code>.grpc.testing.PayloadConfig payload_config = 11;</code>
+     * Generated from protobuf field <code>.grpc.testing.PayloadConfig payload_config = 11;</code>
+     * @return \Grpc\Testing\PayloadConfig
      */
     public function getPayloadConfig()
     {
@@ -294,16 +313,21 @@ class ClientConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>.grpc.testing.PayloadConfig payload_config = 11;</code>
+     * Generated from protobuf field <code>.grpc.testing.PayloadConfig payload_config = 11;</code>
+     * @param \Grpc\Testing\PayloadConfig $var
+     * @return $this
      */
-    public function setPayloadConfig(&$var)
+    public function setPayloadConfig($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\PayloadConfig::class);
         $this->payload_config = $var;
+
+        return $this;
     }
 
     /**
-     * <code>.grpc.testing.HistogramParams histogram_params = 12;</code>
+     * Generated from protobuf field <code>.grpc.testing.HistogramParams histogram_params = 12;</code>
+     * @return \Grpc\Testing\HistogramParams
      */
     public function getHistogramParams()
     {
@@ -311,20 +335,23 @@ class ClientConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>.grpc.testing.HistogramParams histogram_params = 12;</code>
+     * Generated from protobuf field <code>.grpc.testing.HistogramParams histogram_params = 12;</code>
+     * @param \Grpc\Testing\HistogramParams $var
+     * @return $this
      */
-    public function setHistogramParams(&$var)
+    public function setHistogramParams($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\HistogramParams::class);
         $this->histogram_params = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Specify the cores we should run the client on, if desired
-     * </pre>
      *
-     * <code>repeated int32 core_list = 13;</code>
+     * Generated from protobuf field <code>repeated int32 core_list = 13;</code>
+     * @return \Google\Protobuf\Internal\RepeatedField
      */
     public function getCoreList()
     {
@@ -332,20 +359,23 @@ class ClientConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Specify the cores we should run the client on, if desired
-     * </pre>
      *
-     * <code>repeated int32 core_list = 13;</code>
+     * Generated from protobuf field <code>repeated int32 core_list = 13;</code>
+     * @param int[]|\Google\Protobuf\Internal\RepeatedField $var
+     * @return $this
      */
-    public function setCoreList(&$var)
+    public function setCoreList($var)
     {
-        GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::INT32);
-        $this->core_list = $var;
+        $arr = GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::INT32);
+        $this->core_list = $arr;
+
+        return $this;
     }
 
     /**
-     * <code>int32 core_limit = 14;</code>
+     * Generated from protobuf field <code>int32 core_limit = 14;</code>
+     * @return int
      */
     public function getCoreLimit()
     {
@@ -353,20 +383,23 @@ class ClientConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>int32 core_limit = 14;</code>
+     * Generated from protobuf field <code>int32 core_limit = 14;</code>
+     * @param int $var
+     * @return $this
      */
     public function setCoreLimit($var)
     {
         GPBUtil::checkInt32($var);
         $this->core_limit = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * If we use an OTHER_CLIENT client_type, this string gives more detail
-     * </pre>
      *
-     * <code>string other_client_api = 15;</code>
+     * Generated from protobuf field <code>string other_client_api = 15;</code>
+     * @return string
      */
     public function getOtherClientApi()
     {
@@ -374,20 +407,23 @@ class ClientConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * If we use an OTHER_CLIENT client_type, this string gives more detail
-     * </pre>
      *
-     * <code>string other_client_api = 15;</code>
+     * Generated from protobuf field <code>string other_client_api = 15;</code>
+     * @param string $var
+     * @return $this
      */
     public function setOtherClientApi($var)
     {
         GPBUtil::checkString($var, True);
         $this->other_client_api = $var;
+
+        return $this;
     }
 
     /**
-     * <code>repeated .grpc.testing.ChannelArg channel_args = 16;</code>
+     * Generated from protobuf field <code>repeated .grpc.testing.ChannelArg channel_args = 16;</code>
+     * @return \Google\Protobuf\Internal\RepeatedField
      */
     public function getChannelArgs()
     {
@@ -395,12 +431,68 @@ class ClientConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>repeated .grpc.testing.ChannelArg channel_args = 16;</code>
+     * Generated from protobuf field <code>repeated .grpc.testing.ChannelArg channel_args = 16;</code>
+     * @param \Grpc\Testing\ChannelArg[]|\Google\Protobuf\Internal\RepeatedField $var
+     * @return $this
+     */
+    public function setChannelArgs($var)
+    {
+        $arr = GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::MESSAGE, \Grpc\Testing\ChannelArg::class);
+        $this->channel_args = $arr;
+
+        return $this;
+    }
+
+    /**
+     * Number of threads that share each completion queue
+     *
+     * Generated from protobuf field <code>int32 threads_per_cq = 17;</code>
+     * @return int
+     */
+    public function getThreadsPerCq()
+    {
+        return $this->threads_per_cq;
+    }
+
+    /**
+     * Number of threads that share each completion queue
+     *
+     * Generated from protobuf field <code>int32 threads_per_cq = 17;</code>
+     * @param int $var
+     * @return $this
+     */
+    public function setThreadsPerCq($var)
+    {
+        GPBUtil::checkInt32($var);
+        $this->threads_per_cq = $var;
+
+        return $this;
+    }
+
+    /**
+     * Number of messages on a stream before it gets finished/restarted
+     *
+     * Generated from protobuf field <code>int32 messages_per_stream = 18;</code>
+     * @return int
+     */
+    public function getMessagesPerStream()
+    {
+        return $this->messages_per_stream;
+    }
+
+    /**
+     * Number of messages on a stream before it gets finished/restarted
+     *
+     * Generated from protobuf field <code>int32 messages_per_stream = 18;</code>
+     * @param int $var
+     * @return $this
      */
-    public function setChannelArgs(&$var)
+    public function setMessagesPerStream($var)
     {
-        GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::MESSAGE, \Grpc\Testing\ChannelArg::class);
-        $this->channel_args = $var;
+        GPBUtil::checkInt32($var);
+        $this->messages_per_stream = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ClientStats.php b/src/php/tests/qps/generated_code/Grpc/Testing/ClientStats.php
index 8b9a0c33a46..f2a76217917 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/ClientStats.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ClientStats.php
@@ -9,42 +9,48 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * Protobuf type <code>grpc.testing.ClientStats</code>
+ * Generated from protobuf message <code>grpc.testing.ClientStats</code>
  */
 class ClientStats extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <pre>
      * Latency histogram. Data points are in nanoseconds.
-     * </pre>
      *
-     * <code>.grpc.testing.HistogramData latencies = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.HistogramData latencies = 1;</code>
      */
     private $latencies = null;
     /**
-     * <pre>
      * See ServerStats for details.
-     * </pre>
      *
-     * <code>double time_elapsed = 2;</code>
+     * Generated from protobuf field <code>double time_elapsed = 2;</code>
      */
     private $time_elapsed = 0.0;
     /**
-     * <code>double time_user = 3;</code>
+     * Generated from protobuf field <code>double time_user = 3;</code>
      */
     private $time_user = 0.0;
     /**
-     * <code>double time_system = 4;</code>
+     * Generated from protobuf field <code>double time_system = 4;</code>
      */
     private $time_system = 0.0;
     /**
-     * <pre>
      * Number of failed requests (one row per status code seen)
-     * </pre>
      *
-     * <code>repeated .grpc.testing.RequestResultCount request_results = 5;</code>
+     * Generated from protobuf field <code>repeated .grpc.testing.RequestResultCount request_results = 5;</code>
      */
     private $request_results;
+    /**
+     * Number of polls called inside completion queue
+     *
+     * Generated from protobuf field <code>uint64 cq_poll_count = 6;</code>
+     */
+    private $cq_poll_count = 0;
+    /**
+     * Core library stats
+     *
+     * Generated from protobuf field <code>.grpc.core.Stats core_stats = 7;</code>
+     */
+    private $core_stats = null;
 
     public function __construct() {
         \GPBMetadata\Src\Proto\Grpc\Testing\Stats::initOnce();
@@ -52,11 +58,10 @@ class ClientStats extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Latency histogram. Data points are in nanoseconds.
-     * </pre>
      *
-     * <code>.grpc.testing.HistogramData latencies = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.HistogramData latencies = 1;</code>
+     * @return \Grpc\Testing\HistogramData
      */
     public function getLatencies()
     {
@@ -64,24 +69,25 @@ class ClientStats extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Latency histogram. Data points are in nanoseconds.
-     * </pre>
      *
-     * <code>.grpc.testing.HistogramData latencies = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.HistogramData latencies = 1;</code>
+     * @param \Grpc\Testing\HistogramData $var
+     * @return $this
      */
-    public function setLatencies(&$var)
+    public function setLatencies($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\HistogramData::class);
         $this->latencies = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * See ServerStats for details.
-     * </pre>
      *
-     * <code>double time_elapsed = 2;</code>
+     * Generated from protobuf field <code>double time_elapsed = 2;</code>
+     * @return float
      */
     public function getTimeElapsed()
     {
@@ -89,20 +95,23 @@ class ClientStats extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * See ServerStats for details.
-     * </pre>
      *
-     * <code>double time_elapsed = 2;</code>
+     * Generated from protobuf field <code>double time_elapsed = 2;</code>
+     * @param float $var
+     * @return $this
      */
     public function setTimeElapsed($var)
     {
         GPBUtil::checkDouble($var);
         $this->time_elapsed = $var;
+
+        return $this;
     }
 
     /**
-     * <code>double time_user = 3;</code>
+     * Generated from protobuf field <code>double time_user = 3;</code>
+     * @return float
      */
     public function getTimeUser()
     {
@@ -110,16 +119,21 @@ class ClientStats extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>double time_user = 3;</code>
+     * Generated from protobuf field <code>double time_user = 3;</code>
+     * @param float $var
+     * @return $this
      */
     public function setTimeUser($var)
     {
         GPBUtil::checkDouble($var);
         $this->time_user = $var;
+
+        return $this;
     }
 
     /**
-     * <code>double time_system = 4;</code>
+     * Generated from protobuf field <code>double time_system = 4;</code>
+     * @return float
      */
     public function getTimeSystem()
     {
@@ -127,20 +141,23 @@ class ClientStats extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>double time_system = 4;</code>
+     * Generated from protobuf field <code>double time_system = 4;</code>
+     * @param float $var
+     * @return $this
      */
     public function setTimeSystem($var)
     {
         GPBUtil::checkDouble($var);
         $this->time_system = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Number of failed requests (one row per status code seen)
-     * </pre>
      *
-     * <code>repeated .grpc.testing.RequestResultCount request_results = 5;</code>
+     * Generated from protobuf field <code>repeated .grpc.testing.RequestResultCount request_results = 5;</code>
+     * @return \Google\Protobuf\Internal\RepeatedField
      */
     public function getRequestResults()
     {
@@ -148,16 +165,70 @@ class ClientStats extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Number of failed requests (one row per status code seen)
-     * </pre>
      *
-     * <code>repeated .grpc.testing.RequestResultCount request_results = 5;</code>
+     * Generated from protobuf field <code>repeated .grpc.testing.RequestResultCount request_results = 5;</code>
+     * @param \Grpc\Testing\RequestResultCount[]|\Google\Protobuf\Internal\RepeatedField $var
+     * @return $this
      */
-    public function setRequestResults(&$var)
+    public function setRequestResults($var)
     {
-        GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::MESSAGE, \Grpc\Testing\RequestResultCount::class);
-        $this->request_results = $var;
+        $arr = GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::MESSAGE, \Grpc\Testing\RequestResultCount::class);
+        $this->request_results = $arr;
+
+        return $this;
+    }
+
+    /**
+     * Number of polls called inside completion queue
+     *
+     * Generated from protobuf field <code>uint64 cq_poll_count = 6;</code>
+     * @return int|string
+     */
+    public function getCqPollCount()
+    {
+        return $this->cq_poll_count;
+    }
+
+    /**
+     * Number of polls called inside completion queue
+     *
+     * Generated from protobuf field <code>uint64 cq_poll_count = 6;</code>
+     * @param int|string $var
+     * @return $this
+     */
+    public function setCqPollCount($var)
+    {
+        GPBUtil::checkUint64($var);
+        $this->cq_poll_count = $var;
+
+        return $this;
+    }
+
+    /**
+     * Core library stats
+     *
+     * Generated from protobuf field <code>.grpc.core.Stats core_stats = 7;</code>
+     * @return \Grpc\Core\Stats
+     */
+    public function getCoreStats()
+    {
+        return $this->core_stats;
+    }
+
+    /**
+     * Core library stats
+     *
+     * Generated from protobuf field <code>.grpc.core.Stats core_stats = 7;</code>
+     * @param \Grpc\Core\Stats $var
+     * @return $this
+     */
+    public function setCoreStats($var)
+    {
+        GPBUtil::checkMessage($var, \Grpc\Core\Stats::class);
+        $this->core_stats = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ClientStatus.php b/src/php/tests/qps/generated_code/Grpc/Testing/ClientStatus.php
index a59f87a9628..3ea40c4dfa0 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/ClientStatus.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ClientStatus.php
@@ -9,12 +9,12 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * Protobuf type <code>grpc.testing.ClientStatus</code>
+ * Generated from protobuf message <code>grpc.testing.ClientStatus</code>
  */
 class ClientStatus extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <code>.grpc.testing.ClientStats stats = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.ClientStats stats = 1;</code>
      */
     private $stats = null;
 
@@ -24,7 +24,8 @@ class ClientStatus extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>.grpc.testing.ClientStats stats = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.ClientStats stats = 1;</code>
+     * @return \Grpc\Testing\ClientStats
      */
     public function getStats()
     {
@@ -32,12 +33,16 @@ class ClientStatus extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>.grpc.testing.ClientStats stats = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.ClientStats stats = 1;</code>
+     * @param \Grpc\Testing\ClientStats $var
+     * @return $this
      */
-    public function setStats(&$var)
+    public function setStats($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\ClientStats::class);
         $this->stats = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ClientType.php b/src/php/tests/qps/generated_code/Grpc/Testing/ClientType.php
index 4f59da992f9..d1df4f19436 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/ClientType.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ClientType.php
@@ -5,29 +5,25 @@
 namespace Grpc\Testing;
 
 /**
- * Protobuf enum <code>grpc.testing.ClientType</code>
+ * Protobuf enum <code>Grpc\Testing\ClientType</code>
  */
 class ClientType
 {
     /**
-     * <pre>
      * Many languages support a basic distinction between using
      * sync or async client, and this allows the specification
-     * </pre>
      *
-     * <code>SYNC_CLIENT = 0;</code>
+     * Generated from protobuf enum <code>SYNC_CLIENT = 0;</code>
      */
     const SYNC_CLIENT = 0;
     /**
-     * <code>ASYNC_CLIENT = 1;</code>
+     * Generated from protobuf enum <code>ASYNC_CLIENT = 1;</code>
      */
     const ASYNC_CLIENT = 1;
     /**
-     * <pre>
      * used for some language-specific variants
-     * </pre>
      *
-     * <code>OTHER_CLIENT = 2;</code>
+     * Generated from protobuf enum <code>OTHER_CLIENT = 2;</code>
      */
     const OTHER_CLIENT = 2;
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ClosedLoopParams.php b/src/php/tests/qps/generated_code/Grpc/Testing/ClosedLoopParams.php
index 53f2948af28..2772836f13d 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/ClosedLoopParams.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ClosedLoopParams.php
@@ -9,12 +9,10 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * <pre>
  * Once an RPC finishes, immediately start a new one.
  * No configuration parameters needed.
- * </pre>
  *
- * Protobuf type <code>grpc.testing.ClosedLoopParams</code>
+ * Generated from protobuf message <code>grpc.testing.ClosedLoopParams</code>
  */
 class ClosedLoopParams extends \Google\Protobuf\Internal\Message
 {
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ComplexProtoParams.php b/src/php/tests/qps/generated_code/Grpc/Testing/ComplexProtoParams.php
index 6d990f1b064..b9013cdb300 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/ComplexProtoParams.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ComplexProtoParams.php
@@ -9,12 +9,10 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * <pre>
  * TODO (vpai): Fill this in once the details of complex, representative
  *              protos are decided
- * </pre>
  *
- * Protobuf type <code>grpc.testing.ComplexProtoParams</code>
+ * Generated from protobuf message <code>grpc.testing.ComplexProtoParams</code>
  */
 class ComplexProtoParams extends \Google\Protobuf\Internal\Message
 {
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/CoreRequest.php b/src/php/tests/qps/generated_code/Grpc/Testing/CoreRequest.php
index 2e078b3fcdb..7772572f1c5 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/CoreRequest.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/CoreRequest.php
@@ -9,7 +9,7 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * Protobuf type <code>grpc.testing.CoreRequest</code>
+ * Generated from protobuf message <code>grpc.testing.CoreRequest</code>
  */
 class CoreRequest extends \Google\Protobuf\Internal\Message
 {
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/CoreResponse.php b/src/php/tests/qps/generated_code/Grpc/Testing/CoreResponse.php
index 85cb3418ada..e0b40ee3001 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/CoreResponse.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/CoreResponse.php
@@ -9,16 +9,14 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * Protobuf type <code>grpc.testing.CoreResponse</code>
+ * Generated from protobuf message <code>grpc.testing.CoreResponse</code>
  */
 class CoreResponse extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <pre>
      * Number of cores available on the server
-     * </pre>
      *
-     * <code>int32 cores = 1;</code>
+     * Generated from protobuf field <code>int32 cores = 1;</code>
      */
     private $cores = 0;
 
@@ -28,11 +26,10 @@ class CoreResponse extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Number of cores available on the server
-     * </pre>
      *
-     * <code>int32 cores = 1;</code>
+     * Generated from protobuf field <code>int32 cores = 1;</code>
+     * @return int
      */
     public function getCores()
     {
@@ -40,16 +37,18 @@ class CoreResponse extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Number of cores available on the server
-     * </pre>
      *
-     * <code>int32 cores = 1;</code>
+     * Generated from protobuf field <code>int32 cores = 1;</code>
+     * @param int $var
+     * @return $this
      */
     public function setCores($var)
     {
         GPBUtil::checkInt32($var);
         $this->cores = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/EchoStatus.php b/src/php/tests/qps/generated_code/Grpc/Testing/EchoStatus.php
index 27340fb0efe..6a6623a042d 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/EchoStatus.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/EchoStatus.php
@@ -9,21 +9,19 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * <pre>
  * A protobuf representation for grpc status. This is used by test
  * clients to specify a status that the server should attempt to return.
- * </pre>
  *
- * Protobuf type <code>grpc.testing.EchoStatus</code>
+ * Generated from protobuf message <code>grpc.testing.EchoStatus</code>
  */
 class EchoStatus extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <code>int32 code = 1;</code>
+     * Generated from protobuf field <code>int32 code = 1;</code>
      */
     private $code = 0;
     /**
-     * <code>string message = 2;</code>
+     * Generated from protobuf field <code>string message = 2;</code>
      */
     private $message = '';
 
@@ -33,7 +31,8 @@ class EchoStatus extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>int32 code = 1;</code>
+     * Generated from protobuf field <code>int32 code = 1;</code>
+     * @return int
      */
     public function getCode()
     {
@@ -41,16 +40,21 @@ class EchoStatus extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>int32 code = 1;</code>
+     * Generated from protobuf field <code>int32 code = 1;</code>
+     * @param int $var
+     * @return $this
      */
     public function setCode($var)
     {
         GPBUtil::checkInt32($var);
         $this->code = $var;
+
+        return $this;
     }
 
     /**
-     * <code>string message = 2;</code>
+     * Generated from protobuf field <code>string message = 2;</code>
+     * @return string
      */
     public function getMessage()
     {
@@ -58,12 +62,16 @@ class EchoStatus extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>string message = 2;</code>
+     * Generated from protobuf field <code>string message = 2;</code>
+     * @param string $var
+     * @return $this
      */
     public function setMessage($var)
     {
         GPBUtil::checkString($var, True);
         $this->message = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/HistogramData.php b/src/php/tests/qps/generated_code/Grpc/Testing/HistogramData.php
index 056da6e5de5..136eac75e28 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/HistogramData.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/HistogramData.php
@@ -9,36 +9,34 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * <pre>
  * Histogram data based on grpc/support/histogram.c
- * </pre>
  *
- * Protobuf type <code>grpc.testing.HistogramData</code>
+ * Generated from protobuf message <code>grpc.testing.HistogramData</code>
  */
 class HistogramData extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <code>repeated uint32 bucket = 1;</code>
+     * Generated from protobuf field <code>repeated uint32 bucket = 1;</code>
      */
     private $bucket;
     /**
-     * <code>double min_seen = 2;</code>
+     * Generated from protobuf field <code>double min_seen = 2;</code>
      */
     private $min_seen = 0.0;
     /**
-     * <code>double max_seen = 3;</code>
+     * Generated from protobuf field <code>double max_seen = 3;</code>
      */
     private $max_seen = 0.0;
     /**
-     * <code>double sum = 4;</code>
+     * Generated from protobuf field <code>double sum = 4;</code>
      */
     private $sum = 0.0;
     /**
-     * <code>double sum_of_squares = 5;</code>
+     * Generated from protobuf field <code>double sum_of_squares = 5;</code>
      */
     private $sum_of_squares = 0.0;
     /**
-     * <code>double count = 6;</code>
+     * Generated from protobuf field <code>double count = 6;</code>
      */
     private $count = 0.0;
 
@@ -48,7 +46,8 @@ class HistogramData extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>repeated uint32 bucket = 1;</code>
+     * Generated from protobuf field <code>repeated uint32 bucket = 1;</code>
+     * @return \Google\Protobuf\Internal\RepeatedField
      */
     public function getBucket()
     {
@@ -56,16 +55,21 @@ class HistogramData extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>repeated uint32 bucket = 1;</code>
+     * Generated from protobuf field <code>repeated uint32 bucket = 1;</code>
+     * @param int[]|\Google\Protobuf\Internal\RepeatedField $var
+     * @return $this
      */
-    public function setBucket(&$var)
+    public function setBucket($var)
     {
-        GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::UINT32);
-        $this->bucket = $var;
+        $arr = GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::UINT32);
+        $this->bucket = $arr;
+
+        return $this;
     }
 
     /**
-     * <code>double min_seen = 2;</code>
+     * Generated from protobuf field <code>double min_seen = 2;</code>
+     * @return float
      */
     public function getMinSeen()
     {
@@ -73,16 +77,21 @@ class HistogramData extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>double min_seen = 2;</code>
+     * Generated from protobuf field <code>double min_seen = 2;</code>
+     * @param float $var
+     * @return $this
      */
     public function setMinSeen($var)
     {
         GPBUtil::checkDouble($var);
         $this->min_seen = $var;
+
+        return $this;
     }
 
     /**
-     * <code>double max_seen = 3;</code>
+     * Generated from protobuf field <code>double max_seen = 3;</code>
+     * @return float
      */
     public function getMaxSeen()
     {
@@ -90,16 +99,21 @@ class HistogramData extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>double max_seen = 3;</code>
+     * Generated from protobuf field <code>double max_seen = 3;</code>
+     * @param float $var
+     * @return $this
      */
     public function setMaxSeen($var)
     {
         GPBUtil::checkDouble($var);
         $this->max_seen = $var;
+
+        return $this;
     }
 
     /**
-     * <code>double sum = 4;</code>
+     * Generated from protobuf field <code>double sum = 4;</code>
+     * @return float
      */
     public function getSum()
     {
@@ -107,16 +121,21 @@ class HistogramData extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>double sum = 4;</code>
+     * Generated from protobuf field <code>double sum = 4;</code>
+     * @param float $var
+     * @return $this
      */
     public function setSum($var)
     {
         GPBUtil::checkDouble($var);
         $this->sum = $var;
+
+        return $this;
     }
 
     /**
-     * <code>double sum_of_squares = 5;</code>
+     * Generated from protobuf field <code>double sum_of_squares = 5;</code>
+     * @return float
      */
     public function getSumOfSquares()
     {
@@ -124,16 +143,21 @@ class HistogramData extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>double sum_of_squares = 5;</code>
+     * Generated from protobuf field <code>double sum_of_squares = 5;</code>
+     * @param float $var
+     * @return $this
      */
     public function setSumOfSquares($var)
     {
         GPBUtil::checkDouble($var);
         $this->sum_of_squares = $var;
+
+        return $this;
     }
 
     /**
-     * <code>double count = 6;</code>
+     * Generated from protobuf field <code>double count = 6;</code>
+     * @return float
      */
     public function getCount()
     {
@@ -141,12 +165,16 @@ class HistogramData extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>double count = 6;</code>
+     * Generated from protobuf field <code>double count = 6;</code>
+     * @param float $var
+     * @return $this
      */
     public function setCount($var)
     {
         GPBUtil::checkDouble($var);
         $this->count = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/HistogramParams.php b/src/php/tests/qps/generated_code/Grpc/Testing/HistogramParams.php
index 836c94b01d8..1a1b484f144 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/HistogramParams.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/HistogramParams.php
@@ -9,28 +9,22 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * <pre>
  * Histogram params based on grpc/support/histogram.c
- * </pre>
  *
- * Protobuf type <code>grpc.testing.HistogramParams</code>
+ * Generated from protobuf message <code>grpc.testing.HistogramParams</code>
  */
 class HistogramParams extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <pre>
      * first bucket is [0, 1 + resolution)
-     * </pre>
      *
-     * <code>double resolution = 1;</code>
+     * Generated from protobuf field <code>double resolution = 1;</code>
      */
     private $resolution = 0.0;
     /**
-     * <pre>
      * use enough buckets to allow this value
-     * </pre>
      *
-     * <code>double max_possible = 2;</code>
+     * Generated from protobuf field <code>double max_possible = 2;</code>
      */
     private $max_possible = 0.0;
 
@@ -40,11 +34,10 @@ class HistogramParams extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * first bucket is [0, 1 + resolution)
-     * </pre>
      *
-     * <code>double resolution = 1;</code>
+     * Generated from protobuf field <code>double resolution = 1;</code>
+     * @return float
      */
     public function getResolution()
     {
@@ -52,24 +45,25 @@ class HistogramParams extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * first bucket is [0, 1 + resolution)
-     * </pre>
      *
-     * <code>double resolution = 1;</code>
+     * Generated from protobuf field <code>double resolution = 1;</code>
+     * @param float $var
+     * @return $this
      */
     public function setResolution($var)
     {
         GPBUtil::checkDouble($var);
         $this->resolution = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * use enough buckets to allow this value
-     * </pre>
      *
-     * <code>double max_possible = 2;</code>
+     * Generated from protobuf field <code>double max_possible = 2;</code>
+     * @return float
      */
     public function getMaxPossible()
     {
@@ -77,16 +71,18 @@ class HistogramParams extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * use enough buckets to allow this value
-     * </pre>
      *
-     * <code>double max_possible = 2;</code>
+     * Generated from protobuf field <code>double max_possible = 2;</code>
+     * @param float $var
+     * @return $this
      */
     public function setMaxPossible($var)
     {
         GPBUtil::checkDouble($var);
         $this->max_possible = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/LoadParams.php b/src/php/tests/qps/generated_code/Grpc/Testing/LoadParams.php
index 1f32e49c8aa..04c345f2421 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/LoadParams.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/LoadParams.php
@@ -9,7 +9,7 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * Protobuf type <code>grpc.testing.LoadParams</code>
+ * Generated from protobuf message <code>grpc.testing.LoadParams</code>
  */
 class LoadParams extends \Google\Protobuf\Internal\Message
 {
@@ -21,7 +21,8 @@ class LoadParams extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>.grpc.testing.ClosedLoopParams closed_loop = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.ClosedLoopParams closed_loop = 1;</code>
+     * @return \Grpc\Testing\ClosedLoopParams
      */
     public function getClosedLoop()
     {
@@ -29,16 +30,21 @@ class LoadParams extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>.grpc.testing.ClosedLoopParams closed_loop = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.ClosedLoopParams closed_loop = 1;</code>
+     * @param \Grpc\Testing\ClosedLoopParams $var
+     * @return $this
      */
-    public function setClosedLoop(&$var)
+    public function setClosedLoop($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\ClosedLoopParams::class);
         $this->writeOneof(1, $var);
+
+        return $this;
     }
 
     /**
-     * <code>.grpc.testing.PoissonParams poisson = 2;</code>
+     * Generated from protobuf field <code>.grpc.testing.PoissonParams poisson = 2;</code>
+     * @return \Grpc\Testing\PoissonParams
      */
     public function getPoisson()
     {
@@ -46,14 +52,21 @@ class LoadParams extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>.grpc.testing.PoissonParams poisson = 2;</code>
+     * Generated from protobuf field <code>.grpc.testing.PoissonParams poisson = 2;</code>
+     * @param \Grpc\Testing\PoissonParams $var
+     * @return $this
      */
-    public function setPoisson(&$var)
+    public function setPoisson($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\PoissonParams::class);
         $this->writeOneof(2, $var);
+
+        return $this;
     }
 
+    /**
+     * @return string
+     */
     public function getLoad()
     {
         return $this->whichOneof("load");
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/Mark.php b/src/php/tests/qps/generated_code/Grpc/Testing/Mark.php
index ce006efacd8..be058d51be8 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/Mark.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/Mark.php
@@ -9,20 +9,16 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * <pre>
  * Request current stats
- * </pre>
  *
- * Protobuf type <code>grpc.testing.Mark</code>
+ * Generated from protobuf message <code>grpc.testing.Mark</code>
  */
 class Mark extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <pre>
      * if true, the stats will be reset after taking their snapshot.
-     * </pre>
      *
-     * <code>bool reset = 1;</code>
+     * Generated from protobuf field <code>bool reset = 1;</code>
      */
     private $reset = false;
 
@@ -32,11 +28,10 @@ class Mark extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * if true, the stats will be reset after taking their snapshot.
-     * </pre>
      *
-     * <code>bool reset = 1;</code>
+     * Generated from protobuf field <code>bool reset = 1;</code>
+     * @return bool
      */
     public function getReset()
     {
@@ -44,16 +39,18 @@ class Mark extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * if true, the stats will be reset after taking their snapshot.
-     * </pre>
      *
-     * <code>bool reset = 1;</code>
+     * Generated from protobuf field <code>bool reset = 1;</code>
+     * @param bool $var
+     * @return $this
      */
     public function setReset($var)
     {
         GPBUtil::checkBool($var);
         $this->reset = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/Payload.php b/src/php/tests/qps/generated_code/Grpc/Testing/Payload.php
index d17c271af74..ad97890c93f 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/Payload.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/Payload.php
@@ -9,29 +9,23 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * <pre>
  * A block of data, to simply increase gRPC message size.
- * </pre>
  *
- * Protobuf type <code>grpc.testing.Payload</code>
+ * Generated from protobuf message <code>grpc.testing.Payload</code>
  */
 class Payload extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <pre>
      * DEPRECATED, don't use. To be removed shortly.
      * The type of data in body.
-     * </pre>
      *
-     * <code>.grpc.testing.PayloadType type = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.PayloadType type = 1;</code>
      */
     private $type = 0;
     /**
-     * <pre>
      * Primary contents of payload.
-     * </pre>
      *
-     * <code>bytes body = 2;</code>
+     * Generated from protobuf field <code>bytes body = 2;</code>
      */
     private $body = '';
 
@@ -41,12 +35,11 @@ class Payload extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * DEPRECATED, don't use. To be removed shortly.
      * The type of data in body.
-     * </pre>
      *
-     * <code>.grpc.testing.PayloadType type = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.PayloadType type = 1;</code>
+     * @return int
      */
     public function getType()
     {
@@ -54,25 +47,26 @@ class Payload extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * DEPRECATED, don't use. To be removed shortly.
      * The type of data in body.
-     * </pre>
      *
-     * <code>.grpc.testing.PayloadType type = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.PayloadType type = 1;</code>
+     * @param int $var
+     * @return $this
      */
     public function setType($var)
     {
         GPBUtil::checkEnum($var, \Grpc\Testing\PayloadType::class);
         $this->type = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Primary contents of payload.
-     * </pre>
      *
-     * <code>bytes body = 2;</code>
+     * Generated from protobuf field <code>bytes body = 2;</code>
+     * @return string
      */
     public function getBody()
     {
@@ -80,16 +74,18 @@ class Payload extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Primary contents of payload.
-     * </pre>
      *
-     * <code>bytes body = 2;</code>
+     * Generated from protobuf field <code>bytes body = 2;</code>
+     * @param string $var
+     * @return $this
      */
     public function setBody($var)
     {
         GPBUtil::checkString($var, False);
         $this->body = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/PayloadConfig.php b/src/php/tests/qps/generated_code/Grpc/Testing/PayloadConfig.php
index a2fe7109ba7..748f52da82d 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/PayloadConfig.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/PayloadConfig.php
@@ -9,7 +9,7 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * Protobuf type <code>grpc.testing.PayloadConfig</code>
+ * Generated from protobuf message <code>grpc.testing.PayloadConfig</code>
  */
 class PayloadConfig extends \Google\Protobuf\Internal\Message
 {
@@ -21,7 +21,8 @@ class PayloadConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>.grpc.testing.ByteBufferParams bytebuf_params = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.ByteBufferParams bytebuf_params = 1;</code>
+     * @return \Grpc\Testing\ByteBufferParams
      */
     public function getBytebufParams()
     {
@@ -29,16 +30,21 @@ class PayloadConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>.grpc.testing.ByteBufferParams bytebuf_params = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.ByteBufferParams bytebuf_params = 1;</code>
+     * @param \Grpc\Testing\ByteBufferParams $var
+     * @return $this
      */
-    public function setBytebufParams(&$var)
+    public function setBytebufParams($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\ByteBufferParams::class);
         $this->writeOneof(1, $var);
+
+        return $this;
     }
 
     /**
-     * <code>.grpc.testing.SimpleProtoParams simple_params = 2;</code>
+     * Generated from protobuf field <code>.grpc.testing.SimpleProtoParams simple_params = 2;</code>
+     * @return \Grpc\Testing\SimpleProtoParams
      */
     public function getSimpleParams()
     {
@@ -46,16 +52,21 @@ class PayloadConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>.grpc.testing.SimpleProtoParams simple_params = 2;</code>
+     * Generated from protobuf field <code>.grpc.testing.SimpleProtoParams simple_params = 2;</code>
+     * @param \Grpc\Testing\SimpleProtoParams $var
+     * @return $this
      */
-    public function setSimpleParams(&$var)
+    public function setSimpleParams($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\SimpleProtoParams::class);
         $this->writeOneof(2, $var);
+
+        return $this;
     }
 
     /**
-     * <code>.grpc.testing.ComplexProtoParams complex_params = 3;</code>
+     * Generated from protobuf field <code>.grpc.testing.ComplexProtoParams complex_params = 3;</code>
+     * @return \Grpc\Testing\ComplexProtoParams
      */
     public function getComplexParams()
     {
@@ -63,14 +74,21 @@ class PayloadConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>.grpc.testing.ComplexProtoParams complex_params = 3;</code>
+     * Generated from protobuf field <code>.grpc.testing.ComplexProtoParams complex_params = 3;</code>
+     * @param \Grpc\Testing\ComplexProtoParams $var
+     * @return $this
      */
-    public function setComplexParams(&$var)
+    public function setComplexParams($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\ComplexProtoParams::class);
         $this->writeOneof(3, $var);
+
+        return $this;
     }
 
+    /**
+     * @return string
+     */
     public function getPayload()
     {
         return $this->whichOneof("payload");
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/PayloadType.php b/src/php/tests/qps/generated_code/Grpc/Testing/PayloadType.php
index 189ef034b47..d8df1af7982 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/PayloadType.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/PayloadType.php
@@ -5,21 +5,17 @@
 namespace Grpc\Testing;
 
 /**
- * <pre>
  * DEPRECATED, don't use. To be removed shortly.
  * The type of payload that should be returned.
- * </pre>
  *
- * Protobuf enum <code>grpc.testing.PayloadType</code>
+ * Protobuf enum <code>Grpc\Testing\PayloadType</code>
  */
 class PayloadType
 {
     /**
-     * <pre>
      * Compressable text format.
-     * </pre>
      *
-     * <code>COMPRESSABLE = 0;</code>
+     * Generated from protobuf enum <code>COMPRESSABLE = 0;</code>
      */
     const COMPRESSABLE = 0;
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/PoissonParams.php b/src/php/tests/qps/generated_code/Grpc/Testing/PoissonParams.php
index d64edd45f03..6a4047f2ece 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/PoissonParams.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/PoissonParams.php
@@ -9,21 +9,17 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * <pre>
  * Parameters of poisson process distribution, which is a good representation
  * of activity coming in from independent identical stationary sources.
- * </pre>
  *
- * Protobuf type <code>grpc.testing.PoissonParams</code>
+ * Generated from protobuf message <code>grpc.testing.PoissonParams</code>
  */
 class PoissonParams extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <pre>
      * The rate of arrivals (a.k.a. lambda parameter of the exp distribution).
-     * </pre>
      *
-     * <code>double offered_load = 1;</code>
+     * Generated from protobuf field <code>double offered_load = 1;</code>
      */
     private $offered_load = 0.0;
 
@@ -33,11 +29,10 @@ class PoissonParams extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * The rate of arrivals (a.k.a. lambda parameter of the exp distribution).
-     * </pre>
      *
-     * <code>double offered_load = 1;</code>
+     * Generated from protobuf field <code>double offered_load = 1;</code>
+     * @return float
      */
     public function getOfferedLoad()
     {
@@ -45,16 +40,18 @@ class PoissonParams extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * The rate of arrivals (a.k.a. lambda parameter of the exp distribution).
-     * </pre>
      *
-     * <code>double offered_load = 1;</code>
+     * Generated from protobuf field <code>double offered_load = 1;</code>
+     * @param float $var
+     * @return $this
      */
     public function setOfferedLoad($var)
     {
         GPBUtil::checkDouble($var);
         $this->offered_load = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ProxyClientServiceClient.php b/src/php/tests/qps/generated_code/Grpc/Testing/ProxyClientServiceClient.php
index a6da2e7aefe..5510b57064f 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/ProxyClientServiceClient.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ProxyClientServiceClient.php
@@ -16,17 +16,19 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 //
-namespace Grpc\Testing {
+namespace Grpc\Testing;
 
-  class ProxyClientServiceClient extends \Grpc\BaseStub {
+/**
+ */
+class ProxyClientServiceClient extends \Grpc\BaseStub {
 
     /**
      * @param string $hostname hostname
      * @param array $opts channel options
-     * @param Grpc\Channel $channel (optional) re-use channel object
+     * @param \Grpc\Channel $channel (optional) re-use channel object
      */
     public function __construct($hostname, $opts, $channel = null) {
-      parent::__construct($hostname, $opts, $channel);
+        parent::__construct($hostname, $opts, $channel);
     }
 
     /**
@@ -36,10 +38,10 @@ namespace Grpc\Testing {
      */
     public function GetConfig(\Grpc\Testing\Void $argument,
       $metadata = [], $options = []) {
-      return $this->_simpleRequest('/grpc.testing.ProxyClientService/GetConfig',
-      $argument,
-      ['\Grpc\Testing\ClientConfig', 'decode'],
-      $metadata, $options);
+        return $this->_simpleRequest('/grpc.testing.ProxyClientService/GetConfig',
+        $argument,
+        ['\Grpc\Testing\ClientConfig', 'decode'],
+        $metadata, $options);
     }
 
     /**
@@ -47,11 +49,19 @@ namespace Grpc\Testing {
      * @param array $options call options
      */
     public function ReportTime($metadata = [], $options = []) {
-      return $this->_clientStreamRequest('/grpc.testing.ProxyClientService/ReportTime',
-      ['\Grpc\Testing\Void','decode'],
-      $metadata, $options);
+        return $this->_clientStreamRequest('/grpc.testing.ProxyClientService/ReportTime',
+        ['\Grpc\Testing\Void','decode'],
+        $metadata, $options);
     }
 
-  }
+    /**
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function ReportHist($metadata = [], $options = []) {
+        return $this->_clientStreamRequest('/grpc.testing.ProxyClientService/ReportHist',
+        ['\Grpc\Testing\Void','decode'],
+        $metadata, $options);
+    }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ProxyStat.php b/src/php/tests/qps/generated_code/Grpc/Testing/ProxyStat.php
index ed43be99cef..6fab6115342 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/ProxyStat.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ProxyStat.php
@@ -9,12 +9,12 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * Protobuf type <code>grpc.testing.ProxyStat</code>
+ * Generated from protobuf message <code>grpc.testing.ProxyStat</code>
  */
 class ProxyStat extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <code>double latency = 1;</code>
+     * Generated from protobuf field <code>double latency = 1;</code>
      */
     private $latency = 0.0;
 
@@ -24,7 +24,8 @@ class ProxyStat extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>double latency = 1;</code>
+     * Generated from protobuf field <code>double latency = 1;</code>
+     * @return float
      */
     public function getLatency()
     {
@@ -32,12 +33,16 @@ class ProxyStat extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>double latency = 1;</code>
+     * Generated from protobuf field <code>double latency = 1;</code>
+     * @param float $var
+     * @return $this
      */
     public function setLatency($var)
     {
         GPBUtil::checkDouble($var);
         $this->latency = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ReconnectInfo.php b/src/php/tests/qps/generated_code/Grpc/Testing/ReconnectInfo.php
index dfaaa606c3b..cd728705fa4 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/ReconnectInfo.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ReconnectInfo.php
@@ -9,22 +9,20 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * <pre>
  * For reconnect interop test only.
  * Server tells client whether its reconnects are following the spec and the
  * reconnect backoffs it saw.
- * </pre>
  *
- * Protobuf type <code>grpc.testing.ReconnectInfo</code>
+ * Generated from protobuf message <code>grpc.testing.ReconnectInfo</code>
  */
 class ReconnectInfo extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <code>bool passed = 1;</code>
+     * Generated from protobuf field <code>bool passed = 1;</code>
      */
     private $passed = false;
     /**
-     * <code>repeated int32 backoff_ms = 2;</code>
+     * Generated from protobuf field <code>repeated int32 backoff_ms = 2;</code>
      */
     private $backoff_ms;
 
@@ -34,7 +32,8 @@ class ReconnectInfo extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>bool passed = 1;</code>
+     * Generated from protobuf field <code>bool passed = 1;</code>
+     * @return bool
      */
     public function getPassed()
     {
@@ -42,16 +41,21 @@ class ReconnectInfo extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>bool passed = 1;</code>
+     * Generated from protobuf field <code>bool passed = 1;</code>
+     * @param bool $var
+     * @return $this
      */
     public function setPassed($var)
     {
         GPBUtil::checkBool($var);
         $this->passed = $var;
+
+        return $this;
     }
 
     /**
-     * <code>repeated int32 backoff_ms = 2;</code>
+     * Generated from protobuf field <code>repeated int32 backoff_ms = 2;</code>
+     * @return \Google\Protobuf\Internal\RepeatedField
      */
     public function getBackoffMs()
     {
@@ -59,12 +63,16 @@ class ReconnectInfo extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>repeated int32 backoff_ms = 2;</code>
+     * Generated from protobuf field <code>repeated int32 backoff_ms = 2;</code>
+     * @param int[]|\Google\Protobuf\Internal\RepeatedField $var
+     * @return $this
      */
-    public function setBackoffMs(&$var)
+    public function setBackoffMs($var)
     {
-        GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::INT32);
-        $this->backoff_ms = $var;
+        $arr = GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::INT32);
+        $this->backoff_ms = $arr;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ReconnectParams.php b/src/php/tests/qps/generated_code/Grpc/Testing/ReconnectParams.php
index 97158557836..f91dc410cb5 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/ReconnectParams.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ReconnectParams.php
@@ -9,17 +9,15 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * <pre>
  * For reconnect interop test only.
  * Client tells server what reconnection parameters it used.
- * </pre>
  *
- * Protobuf type <code>grpc.testing.ReconnectParams</code>
+ * Generated from protobuf message <code>grpc.testing.ReconnectParams</code>
  */
 class ReconnectParams extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <code>int32 max_reconnect_backoff_ms = 1;</code>
+     * Generated from protobuf field <code>int32 max_reconnect_backoff_ms = 1;</code>
      */
     private $max_reconnect_backoff_ms = 0;
 
@@ -29,7 +27,8 @@ class ReconnectParams extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>int32 max_reconnect_backoff_ms = 1;</code>
+     * Generated from protobuf field <code>int32 max_reconnect_backoff_ms = 1;</code>
+     * @return int
      */
     public function getMaxReconnectBackoffMs()
     {
@@ -37,12 +36,16 @@ class ReconnectParams extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>int32 max_reconnect_backoff_ms = 1;</code>
+     * Generated from protobuf field <code>int32 max_reconnect_backoff_ms = 1;</code>
+     * @param int $var
+     * @return $this
      */
     public function setMaxReconnectBackoffMs($var)
     {
         GPBUtil::checkInt32($var);
         $this->max_reconnect_backoff_ms = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ReportQpsScenarioServiceClient.php b/src/php/tests/qps/generated_code/Grpc/Testing/ReportQpsScenarioServiceClient.php
new file mode 100644
index 00000000000..72d44ffc667
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ReportQpsScenarioServiceClient.php
@@ -0,0 +1,50 @@
+<?php
+// GENERATED CODE -- DO NOT EDIT!
+
+// Original file comments:
+// Copyright 2015 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// An integration test service that covers all the method signature permutations
+// of unary/streaming requests/responses.
+namespace Grpc\Testing;
+
+/**
+ */
+class ReportQpsScenarioServiceClient extends \Grpc\BaseStub {
+
+    /**
+     * @param string $hostname hostname
+     * @param array $opts channel options
+     * @param \Grpc\Channel $channel (optional) re-use channel object
+     */
+    public function __construct($hostname, $opts, $channel = null) {
+        parent::__construct($hostname, $opts, $channel);
+    }
+
+    /**
+     * Report results of a QPS test benchmark scenario.
+     * @param \Grpc\Testing\ScenarioResult $argument input argument
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function ReportScenario(\Grpc\Testing\ScenarioResult $argument,
+      $metadata = [], $options = []) {
+        return $this->_simpleRequest('/grpc.testing.ReportQpsScenarioService/ReportScenario',
+        $argument,
+        ['\Grpc\Testing\Void', 'decode'],
+        $metadata, $options);
+    }
+
+}
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/RequestResultCount.php b/src/php/tests/qps/generated_code/Grpc/Testing/RequestResultCount.php
index 1be42b2ac91..75fa6cafe28 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/RequestResultCount.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/RequestResultCount.php
@@ -9,16 +9,16 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * Protobuf type <code>grpc.testing.RequestResultCount</code>
+ * Generated from protobuf message <code>grpc.testing.RequestResultCount</code>
  */
 class RequestResultCount extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <code>int32 status_code = 1;</code>
+     * Generated from protobuf field <code>int32 status_code = 1;</code>
      */
     private $status_code = 0;
     /**
-     * <code>int64 count = 2;</code>
+     * Generated from protobuf field <code>int64 count = 2;</code>
      */
     private $count = 0;
 
@@ -28,7 +28,8 @@ class RequestResultCount extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>int32 status_code = 1;</code>
+     * Generated from protobuf field <code>int32 status_code = 1;</code>
+     * @return int
      */
     public function getStatusCode()
     {
@@ -36,16 +37,21 @@ class RequestResultCount extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>int32 status_code = 1;</code>
+     * Generated from protobuf field <code>int32 status_code = 1;</code>
+     * @param int $var
+     * @return $this
      */
     public function setStatusCode($var)
     {
         GPBUtil::checkInt32($var);
         $this->status_code = $var;
+
+        return $this;
     }
 
     /**
-     * <code>int64 count = 2;</code>
+     * Generated from protobuf field <code>int64 count = 2;</code>
+     * @return int|string
      */
     public function getCount()
     {
@@ -53,12 +59,16 @@ class RequestResultCount extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>int64 count = 2;</code>
+     * Generated from protobuf field <code>int64 count = 2;</code>
+     * @param int|string $var
+     * @return $this
      */
     public function setCount($var)
     {
         GPBUtil::checkInt64($var);
         $this->count = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ResponseParameters.php b/src/php/tests/qps/generated_code/Grpc/Testing/ResponseParameters.php
index b7a8e5ece71..b2f0a827fe0 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/ResponseParameters.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ResponseParameters.php
@@ -9,40 +9,32 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * <pre>
  * Configuration for a particular response.
- * </pre>
  *
- * Protobuf type <code>grpc.testing.ResponseParameters</code>
+ * Generated from protobuf message <code>grpc.testing.ResponseParameters</code>
  */
 class ResponseParameters extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <pre>
      * Desired payload sizes in responses from the server.
-     * </pre>
      *
-     * <code>int32 size = 1;</code>
+     * Generated from protobuf field <code>int32 size = 1;</code>
      */
     private $size = 0;
     /**
-     * <pre>
      * Desired interval between consecutive responses in the response stream in
      * microseconds.
-     * </pre>
      *
-     * <code>int32 interval_us = 2;</code>
+     * Generated from protobuf field <code>int32 interval_us = 2;</code>
      */
     private $interval_us = 0;
     /**
-     * <pre>
      * Whether to request the server to compress the response. This field is
      * "nullable" in order to interoperate seamlessly with clients not able to
      * implement the full compression tests by introspecting the call to verify
      * the response's compression status.
-     * </pre>
      *
-     * <code>.grpc.testing.BoolValue compressed = 3;</code>
+     * Generated from protobuf field <code>.grpc.testing.BoolValue compressed = 3;</code>
      */
     private $compressed = null;
 
@@ -52,11 +44,10 @@ class ResponseParameters extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Desired payload sizes in responses from the server.
-     * </pre>
      *
-     * <code>int32 size = 1;</code>
+     * Generated from protobuf field <code>int32 size = 1;</code>
+     * @return int
      */
     public function getSize()
     {
@@ -64,25 +55,26 @@ class ResponseParameters extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Desired payload sizes in responses from the server.
-     * </pre>
      *
-     * <code>int32 size = 1;</code>
+     * Generated from protobuf field <code>int32 size = 1;</code>
+     * @param int $var
+     * @return $this
      */
     public function setSize($var)
     {
         GPBUtil::checkInt32($var);
         $this->size = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Desired interval between consecutive responses in the response stream in
      * microseconds.
-     * </pre>
      *
-     * <code>int32 interval_us = 2;</code>
+     * Generated from protobuf field <code>int32 interval_us = 2;</code>
+     * @return int
      */
     public function getIntervalUs()
     {
@@ -90,28 +82,29 @@ class ResponseParameters extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Desired interval between consecutive responses in the response stream in
      * microseconds.
-     * </pre>
      *
-     * <code>int32 interval_us = 2;</code>
+     * Generated from protobuf field <code>int32 interval_us = 2;</code>
+     * @param int $var
+     * @return $this
      */
     public function setIntervalUs($var)
     {
         GPBUtil::checkInt32($var);
         $this->interval_us = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Whether to request the server to compress the response. This field is
      * "nullable" in order to interoperate seamlessly with clients not able to
      * implement the full compression tests by introspecting the call to verify
      * the response's compression status.
-     * </pre>
      *
-     * <code>.grpc.testing.BoolValue compressed = 3;</code>
+     * Generated from protobuf field <code>.grpc.testing.BoolValue compressed = 3;</code>
+     * @return \Grpc\Testing\BoolValue
      */
     public function getCompressed()
     {
@@ -119,19 +112,21 @@ class ResponseParameters extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Whether to request the server to compress the response. This field is
      * "nullable" in order to interoperate seamlessly with clients not able to
      * implement the full compression tests by introspecting the call to verify
      * the response's compression status.
-     * </pre>
      *
-     * <code>.grpc.testing.BoolValue compressed = 3;</code>
+     * Generated from protobuf field <code>.grpc.testing.BoolValue compressed = 3;</code>
+     * @param \Grpc\Testing\BoolValue $var
+     * @return $this
      */
-    public function setCompressed(&$var)
+    public function setCompressed($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\BoolValue::class);
         $this->compressed = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/RpcType.php b/src/php/tests/qps/generated_code/Grpc/Testing/RpcType.php
index 2e664fff477..73a66490ea9 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/RpcType.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/RpcType.php
@@ -5,17 +5,29 @@
 namespace Grpc\Testing;
 
 /**
- * Protobuf enum <code>grpc.testing.RpcType</code>
+ * Protobuf enum <code>Grpc\Testing\RpcType</code>
  */
 class RpcType
 {
     /**
-     * <code>UNARY = 0;</code>
+     * Generated from protobuf enum <code>UNARY = 0;</code>
      */
     const UNARY = 0;
     /**
-     * <code>STREAMING = 1;</code>
+     * Generated from protobuf enum <code>STREAMING = 1;</code>
      */
     const STREAMING = 1;
+    /**
+     * Generated from protobuf enum <code>STREAMING_FROM_CLIENT = 2;</code>
+     */
+    const STREAMING_FROM_CLIENT = 2;
+    /**
+     * Generated from protobuf enum <code>STREAMING_FROM_SERVER = 3;</code>
+     */
+    const STREAMING_FROM_SERVER = 3;
+    /**
+     * Generated from protobuf enum <code>STREAMING_BOTH_WAYS = 4;</code>
+     */
+    const STREAMING_BOTH_WAYS = 4;
 }
 
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/Scenario.php b/src/php/tests/qps/generated_code/Grpc/Testing/Scenario.php
index 136ed299ea8..9ec284b71f2 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/Scenario.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/Scenario.php
@@ -9,76 +9,58 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * <pre>
  * A single performance scenario: input to qps_json_driver
- * </pre>
  *
- * Protobuf type <code>grpc.testing.Scenario</code>
+ * Generated from protobuf message <code>grpc.testing.Scenario</code>
  */
 class Scenario extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <pre>
      * Human readable name for this scenario
-     * </pre>
      *
-     * <code>string name = 1;</code>
+     * Generated from protobuf field <code>string name = 1;</code>
      */
     private $name = '';
     /**
-     * <pre>
      * Client configuration
-     * </pre>
      *
-     * <code>.grpc.testing.ClientConfig client_config = 2;</code>
+     * Generated from protobuf field <code>.grpc.testing.ClientConfig client_config = 2;</code>
      */
     private $client_config = null;
     /**
-     * <pre>
      * Number of clients to start for the test
-     * </pre>
      *
-     * <code>int32 num_clients = 3;</code>
+     * Generated from protobuf field <code>int32 num_clients = 3;</code>
      */
     private $num_clients = 0;
     /**
-     * <pre>
      * Server configuration
-     * </pre>
      *
-     * <code>.grpc.testing.ServerConfig server_config = 4;</code>
+     * Generated from protobuf field <code>.grpc.testing.ServerConfig server_config = 4;</code>
      */
     private $server_config = null;
     /**
-     * <pre>
      * Number of servers to start for the test
-     * </pre>
      *
-     * <code>int32 num_servers = 5;</code>
+     * Generated from protobuf field <code>int32 num_servers = 5;</code>
      */
     private $num_servers = 0;
     /**
-     * <pre>
      * Warmup period, in seconds
-     * </pre>
      *
-     * <code>int32 warmup_seconds = 6;</code>
+     * Generated from protobuf field <code>int32 warmup_seconds = 6;</code>
      */
     private $warmup_seconds = 0;
     /**
-     * <pre>
      * Benchmark time, in seconds
-     * </pre>
      *
-     * <code>int32 benchmark_seconds = 7;</code>
+     * Generated from protobuf field <code>int32 benchmark_seconds = 7;</code>
      */
     private $benchmark_seconds = 0;
     /**
-     * <pre>
      * Number of workers to spawn locally (usually zero)
-     * </pre>
      *
-     * <code>int32 spawn_local_worker_count = 8;</code>
+     * Generated from protobuf field <code>int32 spawn_local_worker_count = 8;</code>
      */
     private $spawn_local_worker_count = 0;
 
@@ -88,11 +70,10 @@ class Scenario extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Human readable name for this scenario
-     * </pre>
      *
-     * <code>string name = 1;</code>
+     * Generated from protobuf field <code>string name = 1;</code>
+     * @return string
      */
     public function getName()
     {
@@ -100,24 +81,25 @@ class Scenario extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Human readable name for this scenario
-     * </pre>
      *
-     * <code>string name = 1;</code>
+     * Generated from protobuf field <code>string name = 1;</code>
+     * @param string $var
+     * @return $this
      */
     public function setName($var)
     {
         GPBUtil::checkString($var, True);
         $this->name = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Client configuration
-     * </pre>
      *
-     * <code>.grpc.testing.ClientConfig client_config = 2;</code>
+     * Generated from protobuf field <code>.grpc.testing.ClientConfig client_config = 2;</code>
+     * @return \Grpc\Testing\ClientConfig
      */
     public function getClientConfig()
     {
@@ -125,24 +107,25 @@ class Scenario extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Client configuration
-     * </pre>
      *
-     * <code>.grpc.testing.ClientConfig client_config = 2;</code>
+     * Generated from protobuf field <code>.grpc.testing.ClientConfig client_config = 2;</code>
+     * @param \Grpc\Testing\ClientConfig $var
+     * @return $this
      */
-    public function setClientConfig(&$var)
+    public function setClientConfig($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\ClientConfig::class);
         $this->client_config = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Number of clients to start for the test
-     * </pre>
      *
-     * <code>int32 num_clients = 3;</code>
+     * Generated from protobuf field <code>int32 num_clients = 3;</code>
+     * @return int
      */
     public function getNumClients()
     {
@@ -150,24 +133,25 @@ class Scenario extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Number of clients to start for the test
-     * </pre>
      *
-     * <code>int32 num_clients = 3;</code>
+     * Generated from protobuf field <code>int32 num_clients = 3;</code>
+     * @param int $var
+     * @return $this
      */
     public function setNumClients($var)
     {
         GPBUtil::checkInt32($var);
         $this->num_clients = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Server configuration
-     * </pre>
      *
-     * <code>.grpc.testing.ServerConfig server_config = 4;</code>
+     * Generated from protobuf field <code>.grpc.testing.ServerConfig server_config = 4;</code>
+     * @return \Grpc\Testing\ServerConfig
      */
     public function getServerConfig()
     {
@@ -175,24 +159,25 @@ class Scenario extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Server configuration
-     * </pre>
      *
-     * <code>.grpc.testing.ServerConfig server_config = 4;</code>
+     * Generated from protobuf field <code>.grpc.testing.ServerConfig server_config = 4;</code>
+     * @param \Grpc\Testing\ServerConfig $var
+     * @return $this
      */
-    public function setServerConfig(&$var)
+    public function setServerConfig($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\ServerConfig::class);
         $this->server_config = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Number of servers to start for the test
-     * </pre>
      *
-     * <code>int32 num_servers = 5;</code>
+     * Generated from protobuf field <code>int32 num_servers = 5;</code>
+     * @return int
      */
     public function getNumServers()
     {
@@ -200,24 +185,25 @@ class Scenario extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Number of servers to start for the test
-     * </pre>
      *
-     * <code>int32 num_servers = 5;</code>
+     * Generated from protobuf field <code>int32 num_servers = 5;</code>
+     * @param int $var
+     * @return $this
      */
     public function setNumServers($var)
     {
         GPBUtil::checkInt32($var);
         $this->num_servers = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Warmup period, in seconds
-     * </pre>
      *
-     * <code>int32 warmup_seconds = 6;</code>
+     * Generated from protobuf field <code>int32 warmup_seconds = 6;</code>
+     * @return int
      */
     public function getWarmupSeconds()
     {
@@ -225,24 +211,25 @@ class Scenario extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Warmup period, in seconds
-     * </pre>
      *
-     * <code>int32 warmup_seconds = 6;</code>
+     * Generated from protobuf field <code>int32 warmup_seconds = 6;</code>
+     * @param int $var
+     * @return $this
      */
     public function setWarmupSeconds($var)
     {
         GPBUtil::checkInt32($var);
         $this->warmup_seconds = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Benchmark time, in seconds
-     * </pre>
      *
-     * <code>int32 benchmark_seconds = 7;</code>
+     * Generated from protobuf field <code>int32 benchmark_seconds = 7;</code>
+     * @return int
      */
     public function getBenchmarkSeconds()
     {
@@ -250,24 +237,25 @@ class Scenario extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Benchmark time, in seconds
-     * </pre>
      *
-     * <code>int32 benchmark_seconds = 7;</code>
+     * Generated from protobuf field <code>int32 benchmark_seconds = 7;</code>
+     * @param int $var
+     * @return $this
      */
     public function setBenchmarkSeconds($var)
     {
         GPBUtil::checkInt32($var);
         $this->benchmark_seconds = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Number of workers to spawn locally (usually zero)
-     * </pre>
      *
-     * <code>int32 spawn_local_worker_count = 8;</code>
+     * Generated from protobuf field <code>int32 spawn_local_worker_count = 8;</code>
+     * @return int
      */
     public function getSpawnLocalWorkerCount()
     {
@@ -275,16 +263,18 @@ class Scenario extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Number of workers to spawn locally (usually zero)
-     * </pre>
      *
-     * <code>int32 spawn_local_worker_count = 8;</code>
+     * Generated from protobuf field <code>int32 spawn_local_worker_count = 8;</code>
+     * @param int $var
+     * @return $this
      */
     public function setSpawnLocalWorkerCount($var)
     {
         GPBUtil::checkInt32($var);
         $this->spawn_local_worker_count = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ScenarioResult.php b/src/php/tests/qps/generated_code/Grpc/Testing/ScenarioResult.php
index 809cd96244d..31d9a39a1fc 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/ScenarioResult.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ScenarioResult.php
@@ -9,80 +9,62 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * <pre>
  * Results of a single benchmark scenario.
- * </pre>
  *
- * Protobuf type <code>grpc.testing.ScenarioResult</code>
+ * Generated from protobuf message <code>grpc.testing.ScenarioResult</code>
  */
 class ScenarioResult extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <pre>
      * Inputs used to run the scenario.
-     * </pre>
      *
-     * <code>.grpc.testing.Scenario scenario = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.Scenario scenario = 1;</code>
      */
     private $scenario = null;
     /**
-     * <pre>
      * Histograms from all clients merged into one histogram.
-     * </pre>
      *
-     * <code>.grpc.testing.HistogramData latencies = 2;</code>
+     * Generated from protobuf field <code>.grpc.testing.HistogramData latencies = 2;</code>
      */
     private $latencies = null;
     /**
-     * <pre>
      * Client stats for each client
-     * </pre>
      *
-     * <code>repeated .grpc.testing.ClientStats client_stats = 3;</code>
+     * Generated from protobuf field <code>repeated .grpc.testing.ClientStats client_stats = 3;</code>
      */
     private $client_stats;
     /**
-     * <pre>
      * Server stats for each server
-     * </pre>
      *
-     * <code>repeated .grpc.testing.ServerStats server_stats = 4;</code>
+     * Generated from protobuf field <code>repeated .grpc.testing.ServerStats server_stats = 4;</code>
      */
     private $server_stats;
     /**
-     * <pre>
      * Number of cores available to each server
-     * </pre>
      *
-     * <code>repeated int32 server_cores = 5;</code>
+     * Generated from protobuf field <code>repeated int32 server_cores = 5;</code>
      */
     private $server_cores;
     /**
-     * <pre>
      * An after-the-fact computed summary
-     * </pre>
      *
-     * <code>.grpc.testing.ScenarioResultSummary summary = 6;</code>
+     * Generated from protobuf field <code>.grpc.testing.ScenarioResultSummary summary = 6;</code>
      */
     private $summary = null;
     /**
-     * <pre>
      * Information on success or failure of each worker
-     * </pre>
      *
-     * <code>repeated bool client_success = 7;</code>
+     * Generated from protobuf field <code>repeated bool client_success = 7;</code>
      */
     private $client_success;
     /**
-     * <code>repeated bool server_success = 8;</code>
+     * Generated from protobuf field <code>repeated bool server_success = 8;</code>
      */
     private $server_success;
     /**
-     * <pre>
      * Number of failed requests (one row per status code seen)
-     * </pre>
      *
-     * <code>repeated .grpc.testing.RequestResultCount request_results = 9;</code>
+     * Generated from protobuf field <code>repeated .grpc.testing.RequestResultCount request_results = 9;</code>
      */
     private $request_results;
 
@@ -92,11 +74,10 @@ class ScenarioResult extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Inputs used to run the scenario.
-     * </pre>
      *
-     * <code>.grpc.testing.Scenario scenario = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.Scenario scenario = 1;</code>
+     * @return \Grpc\Testing\Scenario
      */
     public function getScenario()
     {
@@ -104,24 +85,25 @@ class ScenarioResult extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Inputs used to run the scenario.
-     * </pre>
      *
-     * <code>.grpc.testing.Scenario scenario = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.Scenario scenario = 1;</code>
+     * @param \Grpc\Testing\Scenario $var
+     * @return $this
      */
-    public function setScenario(&$var)
+    public function setScenario($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\Scenario::class);
         $this->scenario = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Histograms from all clients merged into one histogram.
-     * </pre>
      *
-     * <code>.grpc.testing.HistogramData latencies = 2;</code>
+     * Generated from protobuf field <code>.grpc.testing.HistogramData latencies = 2;</code>
+     * @return \Grpc\Testing\HistogramData
      */
     public function getLatencies()
     {
@@ -129,24 +111,25 @@ class ScenarioResult extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Histograms from all clients merged into one histogram.
-     * </pre>
      *
-     * <code>.grpc.testing.HistogramData latencies = 2;</code>
+     * Generated from protobuf field <code>.grpc.testing.HistogramData latencies = 2;</code>
+     * @param \Grpc\Testing\HistogramData $var
+     * @return $this
      */
-    public function setLatencies(&$var)
+    public function setLatencies($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\HistogramData::class);
         $this->latencies = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Client stats for each client
-     * </pre>
      *
-     * <code>repeated .grpc.testing.ClientStats client_stats = 3;</code>
+     * Generated from protobuf field <code>repeated .grpc.testing.ClientStats client_stats = 3;</code>
+     * @return \Google\Protobuf\Internal\RepeatedField
      */
     public function getClientStats()
     {
@@ -154,24 +137,25 @@ class ScenarioResult extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Client stats for each client
-     * </pre>
      *
-     * <code>repeated .grpc.testing.ClientStats client_stats = 3;</code>
+     * Generated from protobuf field <code>repeated .grpc.testing.ClientStats client_stats = 3;</code>
+     * @param \Grpc\Testing\ClientStats[]|\Google\Protobuf\Internal\RepeatedField $var
+     * @return $this
      */
-    public function setClientStats(&$var)
+    public function setClientStats($var)
     {
-        GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::MESSAGE, \Grpc\Testing\ClientStats::class);
-        $this->client_stats = $var;
+        $arr = GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::MESSAGE, \Grpc\Testing\ClientStats::class);
+        $this->client_stats = $arr;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Server stats for each server
-     * </pre>
      *
-     * <code>repeated .grpc.testing.ServerStats server_stats = 4;</code>
+     * Generated from protobuf field <code>repeated .grpc.testing.ServerStats server_stats = 4;</code>
+     * @return \Google\Protobuf\Internal\RepeatedField
      */
     public function getServerStats()
     {
@@ -179,24 +163,25 @@ class ScenarioResult extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Server stats for each server
-     * </pre>
      *
-     * <code>repeated .grpc.testing.ServerStats server_stats = 4;</code>
+     * Generated from protobuf field <code>repeated .grpc.testing.ServerStats server_stats = 4;</code>
+     * @param \Grpc\Testing\ServerStats[]|\Google\Protobuf\Internal\RepeatedField $var
+     * @return $this
      */
-    public function setServerStats(&$var)
+    public function setServerStats($var)
     {
-        GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::MESSAGE, \Grpc\Testing\ServerStats::class);
-        $this->server_stats = $var;
+        $arr = GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::MESSAGE, \Grpc\Testing\ServerStats::class);
+        $this->server_stats = $arr;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Number of cores available to each server
-     * </pre>
      *
-     * <code>repeated int32 server_cores = 5;</code>
+     * Generated from protobuf field <code>repeated int32 server_cores = 5;</code>
+     * @return \Google\Protobuf\Internal\RepeatedField
      */
     public function getServerCores()
     {
@@ -204,24 +189,25 @@ class ScenarioResult extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Number of cores available to each server
-     * </pre>
      *
-     * <code>repeated int32 server_cores = 5;</code>
+     * Generated from protobuf field <code>repeated int32 server_cores = 5;</code>
+     * @param int[]|\Google\Protobuf\Internal\RepeatedField $var
+     * @return $this
      */
-    public function setServerCores(&$var)
+    public function setServerCores($var)
     {
-        GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::INT32);
-        $this->server_cores = $var;
+        $arr = GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::INT32);
+        $this->server_cores = $arr;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * An after-the-fact computed summary
-     * </pre>
      *
-     * <code>.grpc.testing.ScenarioResultSummary summary = 6;</code>
+     * Generated from protobuf field <code>.grpc.testing.ScenarioResultSummary summary = 6;</code>
+     * @return \Grpc\Testing\ScenarioResultSummary
      */
     public function getSummary()
     {
@@ -229,24 +215,25 @@ class ScenarioResult extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * An after-the-fact computed summary
-     * </pre>
      *
-     * <code>.grpc.testing.ScenarioResultSummary summary = 6;</code>
+     * Generated from protobuf field <code>.grpc.testing.ScenarioResultSummary summary = 6;</code>
+     * @param \Grpc\Testing\ScenarioResultSummary $var
+     * @return $this
      */
-    public function setSummary(&$var)
+    public function setSummary($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\ScenarioResultSummary::class);
         $this->summary = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Information on success or failure of each worker
-     * </pre>
      *
-     * <code>repeated bool client_success = 7;</code>
+     * Generated from protobuf field <code>repeated bool client_success = 7;</code>
+     * @return \Google\Protobuf\Internal\RepeatedField
      */
     public function getClientSuccess()
     {
@@ -254,20 +241,23 @@ class ScenarioResult extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Information on success or failure of each worker
-     * </pre>
      *
-     * <code>repeated bool client_success = 7;</code>
+     * Generated from protobuf field <code>repeated bool client_success = 7;</code>
+     * @param bool[]|\Google\Protobuf\Internal\RepeatedField $var
+     * @return $this
      */
-    public function setClientSuccess(&$var)
+    public function setClientSuccess($var)
     {
-        GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::BOOL);
-        $this->client_success = $var;
+        $arr = GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::BOOL);
+        $this->client_success = $arr;
+
+        return $this;
     }
 
     /**
-     * <code>repeated bool server_success = 8;</code>
+     * Generated from protobuf field <code>repeated bool server_success = 8;</code>
+     * @return \Google\Protobuf\Internal\RepeatedField
      */
     public function getServerSuccess()
     {
@@ -275,20 +265,23 @@ class ScenarioResult extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>repeated bool server_success = 8;</code>
+     * Generated from protobuf field <code>repeated bool server_success = 8;</code>
+     * @param bool[]|\Google\Protobuf\Internal\RepeatedField $var
+     * @return $this
      */
-    public function setServerSuccess(&$var)
+    public function setServerSuccess($var)
     {
-        GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::BOOL);
-        $this->server_success = $var;
+        $arr = GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::BOOL);
+        $this->server_success = $arr;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Number of failed requests (one row per status code seen)
-     * </pre>
      *
-     * <code>repeated .grpc.testing.RequestResultCount request_results = 9;</code>
+     * Generated from protobuf field <code>repeated .grpc.testing.RequestResultCount request_results = 9;</code>
+     * @return \Google\Protobuf\Internal\RepeatedField
      */
     public function getRequestResults()
     {
@@ -296,16 +289,18 @@ class ScenarioResult extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Number of failed requests (one row per status code seen)
-     * </pre>
      *
-     * <code>repeated .grpc.testing.RequestResultCount request_results = 9;</code>
+     * Generated from protobuf field <code>repeated .grpc.testing.RequestResultCount request_results = 9;</code>
+     * @param \Grpc\Testing\RequestResultCount[]|\Google\Protobuf\Internal\RepeatedField $var
+     * @return $this
      */
-    public function setRequestResults(&$var)
+    public function setRequestResults($var)
     {
-        GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::MESSAGE, \Grpc\Testing\RequestResultCount::class);
-        $this->request_results = $var;
+        $arr = GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::MESSAGE, \Grpc\Testing\RequestResultCount::class);
+        $this->request_results = $arr;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ScenarioResultSummary.php b/src/php/tests/qps/generated_code/Grpc/Testing/ScenarioResultSummary.php
index 7520cff78e8..f7f1c987b53 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/ScenarioResultSummary.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ScenarioResultSummary.php
@@ -9,107 +9,107 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * <pre>
  * Basic summary that can be computed from ClientStats and ServerStats
  * once the scenario has finished.
- * </pre>
  *
- * Protobuf type <code>grpc.testing.ScenarioResultSummary</code>
+ * Generated from protobuf message <code>grpc.testing.ScenarioResultSummary</code>
  */
 class ScenarioResultSummary extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <pre>
      * Total number of operations per second over all clients.
-     * </pre>
      *
-     * <code>double qps = 1;</code>
+     * Generated from protobuf field <code>double qps = 1;</code>
      */
     private $qps = 0.0;
     /**
-     * <pre>
      * QPS per one server core.
-     * </pre>
      *
-     * <code>double qps_per_server_core = 2;</code>
+     * Generated from protobuf field <code>double qps_per_server_core = 2;</code>
      */
     private $qps_per_server_core = 0.0;
     /**
-     * <pre>
-     * server load based on system_time (0.85 =&gt; 85%)
-     * </pre>
+     * server load based on system_time (0.85 => 85%)
      *
-     * <code>double server_system_time = 3;</code>
+     * Generated from protobuf field <code>double server_system_time = 3;</code>
      */
     private $server_system_time = 0.0;
     /**
-     * <pre>
-     * server load based on user_time (0.85 =&gt; 85%)
-     * </pre>
+     * server load based on user_time (0.85 => 85%)
      *
-     * <code>double server_user_time = 4;</code>
+     * Generated from protobuf field <code>double server_user_time = 4;</code>
      */
     private $server_user_time = 0.0;
     /**
-     * <pre>
-     * client load based on system_time (0.85 =&gt; 85%)
-     * </pre>
+     * client load based on system_time (0.85 => 85%)
      *
-     * <code>double client_system_time = 5;</code>
+     * Generated from protobuf field <code>double client_system_time = 5;</code>
      */
     private $client_system_time = 0.0;
     /**
-     * <pre>
-     * client load based on user_time (0.85 =&gt; 85%)
-     * </pre>
+     * client load based on user_time (0.85 => 85%)
      *
-     * <code>double client_user_time = 6;</code>
+     * Generated from protobuf field <code>double client_user_time = 6;</code>
      */
     private $client_user_time = 0.0;
     /**
-     * <pre>
      * X% latency percentiles (in nanoseconds)
-     * </pre>
      *
-     * <code>double latency_50 = 7;</code>
+     * Generated from protobuf field <code>double latency_50 = 7;</code>
      */
     private $latency_50 = 0.0;
     /**
-     * <code>double latency_90 = 8;</code>
+     * Generated from protobuf field <code>double latency_90 = 8;</code>
      */
     private $latency_90 = 0.0;
     /**
-     * <code>double latency_95 = 9;</code>
+     * Generated from protobuf field <code>double latency_95 = 9;</code>
      */
     private $latency_95 = 0.0;
     /**
-     * <code>double latency_99 = 10;</code>
+     * Generated from protobuf field <code>double latency_99 = 10;</code>
      */
     private $latency_99 = 0.0;
     /**
-     * <code>double latency_999 = 11;</code>
+     * Generated from protobuf field <code>double latency_999 = 11;</code>
      */
     private $latency_999 = 0.0;
     /**
-     * <pre>
      * server cpu usage percentage
-     * </pre>
      *
-     * <code>double server_cpu_usage = 12;</code>
+     * Generated from protobuf field <code>double server_cpu_usage = 12;</code>
      */
     private $server_cpu_usage = 0.0;
     /**
-     * <pre>
      * Number of requests that succeeded/failed
-     * </pre>
      *
-     * <code>double successful_requests_per_second = 13;</code>
+     * Generated from protobuf field <code>double successful_requests_per_second = 13;</code>
      */
     private $successful_requests_per_second = 0.0;
     /**
-     * <code>double failed_requests_per_second = 14;</code>
+     * Generated from protobuf field <code>double failed_requests_per_second = 14;</code>
      */
     private $failed_requests_per_second = 0.0;
+    /**
+     * Number of polls called inside completion queue per request
+     *
+     * Generated from protobuf field <code>double client_polls_per_request = 15;</code>
+     */
+    private $client_polls_per_request = 0.0;
+    /**
+     * Generated from protobuf field <code>double server_polls_per_request = 16;</code>
+     */
+    private $server_polls_per_request = 0.0;
+    /**
+     * Queries per CPU-sec over all servers or clients
+     *
+     * Generated from protobuf field <code>double server_queries_per_cpu_sec = 17;</code>
+     */
+    private $server_queries_per_cpu_sec = 0.0;
+    /**
+     * Generated from protobuf field <code>double client_queries_per_cpu_sec = 18;</code>
+     */
+    private $client_queries_per_cpu_sec = 0.0;
 
     public function __construct() {
         \GPBMetadata\Src\Proto\Grpc\Testing\Control::initOnce();
@@ -117,11 +117,10 @@ class ScenarioResultSummary extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Total number of operations per second over all clients.
-     * </pre>
      *
-     * <code>double qps = 1;</code>
+     * Generated from protobuf field <code>double qps = 1;</code>
+     * @return float
      */
     public function getQps()
     {
@@ -129,24 +128,25 @@ class ScenarioResultSummary extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Total number of operations per second over all clients.
-     * </pre>
      *
-     * <code>double qps = 1;</code>
+     * Generated from protobuf field <code>double qps = 1;</code>
+     * @param float $var
+     * @return $this
      */
     public function setQps($var)
     {
         GPBUtil::checkDouble($var);
         $this->qps = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * QPS per one server core.
-     * </pre>
      *
-     * <code>double qps_per_server_core = 2;</code>
+     * Generated from protobuf field <code>double qps_per_server_core = 2;</code>
+     * @return float
      */
     public function getQpsPerServerCore()
     {
@@ -154,24 +154,25 @@ class ScenarioResultSummary extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * QPS per one server core.
-     * </pre>
      *
-     * <code>double qps_per_server_core = 2;</code>
+     * Generated from protobuf field <code>double qps_per_server_core = 2;</code>
+     * @param float $var
+     * @return $this
      */
     public function setQpsPerServerCore($var)
     {
         GPBUtil::checkDouble($var);
         $this->qps_per_server_core = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
-     * server load based on system_time (0.85 =&gt; 85%)
-     * </pre>
+     * server load based on system_time (0.85 => 85%)
      *
-     * <code>double server_system_time = 3;</code>
+     * Generated from protobuf field <code>double server_system_time = 3;</code>
+     * @return float
      */
     public function getServerSystemTime()
     {
@@ -179,24 +180,25 @@ class ScenarioResultSummary extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
-     * server load based on system_time (0.85 =&gt; 85%)
-     * </pre>
+     * server load based on system_time (0.85 => 85%)
      *
-     * <code>double server_system_time = 3;</code>
+     * Generated from protobuf field <code>double server_system_time = 3;</code>
+     * @param float $var
+     * @return $this
      */
     public function setServerSystemTime($var)
     {
         GPBUtil::checkDouble($var);
         $this->server_system_time = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
-     * server load based on user_time (0.85 =&gt; 85%)
-     * </pre>
+     * server load based on user_time (0.85 => 85%)
      *
-     * <code>double server_user_time = 4;</code>
+     * Generated from protobuf field <code>double server_user_time = 4;</code>
+     * @return float
      */
     public function getServerUserTime()
     {
@@ -204,24 +206,25 @@ class ScenarioResultSummary extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
-     * server load based on user_time (0.85 =&gt; 85%)
-     * </pre>
+     * server load based on user_time (0.85 => 85%)
      *
-     * <code>double server_user_time = 4;</code>
+     * Generated from protobuf field <code>double server_user_time = 4;</code>
+     * @param float $var
+     * @return $this
      */
     public function setServerUserTime($var)
     {
         GPBUtil::checkDouble($var);
         $this->server_user_time = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
-     * client load based on system_time (0.85 =&gt; 85%)
-     * </pre>
+     * client load based on system_time (0.85 => 85%)
      *
-     * <code>double client_system_time = 5;</code>
+     * Generated from protobuf field <code>double client_system_time = 5;</code>
+     * @return float
      */
     public function getClientSystemTime()
     {
@@ -229,24 +232,25 @@ class ScenarioResultSummary extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
-     * client load based on system_time (0.85 =&gt; 85%)
-     * </pre>
+     * client load based on system_time (0.85 => 85%)
      *
-     * <code>double client_system_time = 5;</code>
+     * Generated from protobuf field <code>double client_system_time = 5;</code>
+     * @param float $var
+     * @return $this
      */
     public function setClientSystemTime($var)
     {
         GPBUtil::checkDouble($var);
         $this->client_system_time = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
-     * client load based on user_time (0.85 =&gt; 85%)
-     * </pre>
+     * client load based on user_time (0.85 => 85%)
      *
-     * <code>double client_user_time = 6;</code>
+     * Generated from protobuf field <code>double client_user_time = 6;</code>
+     * @return float
      */
     public function getClientUserTime()
     {
@@ -254,24 +258,25 @@ class ScenarioResultSummary extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
-     * client load based on user_time (0.85 =&gt; 85%)
-     * </pre>
+     * client load based on user_time (0.85 => 85%)
      *
-     * <code>double client_user_time = 6;</code>
+     * Generated from protobuf field <code>double client_user_time = 6;</code>
+     * @param float $var
+     * @return $this
      */
     public function setClientUserTime($var)
     {
         GPBUtil::checkDouble($var);
         $this->client_user_time = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * X% latency percentiles (in nanoseconds)
-     * </pre>
      *
-     * <code>double latency_50 = 7;</code>
+     * Generated from protobuf field <code>double latency_50 = 7;</code>
+     * @return float
      */
     public function getLatency50()
     {
@@ -279,20 +284,23 @@ class ScenarioResultSummary extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * X% latency percentiles (in nanoseconds)
-     * </pre>
      *
-     * <code>double latency_50 = 7;</code>
+     * Generated from protobuf field <code>double latency_50 = 7;</code>
+     * @param float $var
+     * @return $this
      */
     public function setLatency50($var)
     {
         GPBUtil::checkDouble($var);
         $this->latency_50 = $var;
+
+        return $this;
     }
 
     /**
-     * <code>double latency_90 = 8;</code>
+     * Generated from protobuf field <code>double latency_90 = 8;</code>
+     * @return float
      */
     public function getLatency90()
     {
@@ -300,16 +308,21 @@ class ScenarioResultSummary extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>double latency_90 = 8;</code>
+     * Generated from protobuf field <code>double latency_90 = 8;</code>
+     * @param float $var
+     * @return $this
      */
     public function setLatency90($var)
     {
         GPBUtil::checkDouble($var);
         $this->latency_90 = $var;
+
+        return $this;
     }
 
     /**
-     * <code>double latency_95 = 9;</code>
+     * Generated from protobuf field <code>double latency_95 = 9;</code>
+     * @return float
      */
     public function getLatency95()
     {
@@ -317,16 +330,21 @@ class ScenarioResultSummary extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>double latency_95 = 9;</code>
+     * Generated from protobuf field <code>double latency_95 = 9;</code>
+     * @param float $var
+     * @return $this
      */
     public function setLatency95($var)
     {
         GPBUtil::checkDouble($var);
         $this->latency_95 = $var;
+
+        return $this;
     }
 
     /**
-     * <code>double latency_99 = 10;</code>
+     * Generated from protobuf field <code>double latency_99 = 10;</code>
+     * @return float
      */
     public function getLatency99()
     {
@@ -334,16 +352,21 @@ class ScenarioResultSummary extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>double latency_99 = 10;</code>
+     * Generated from protobuf field <code>double latency_99 = 10;</code>
+     * @param float $var
+     * @return $this
      */
     public function setLatency99($var)
     {
         GPBUtil::checkDouble($var);
         $this->latency_99 = $var;
+
+        return $this;
     }
 
     /**
-     * <code>double latency_999 = 11;</code>
+     * Generated from protobuf field <code>double latency_999 = 11;</code>
+     * @return float
      */
     public function getLatency999()
     {
@@ -351,20 +374,23 @@ class ScenarioResultSummary extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>double latency_999 = 11;</code>
+     * Generated from protobuf field <code>double latency_999 = 11;</code>
+     * @param float $var
+     * @return $this
      */
     public function setLatency999($var)
     {
         GPBUtil::checkDouble($var);
         $this->latency_999 = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * server cpu usage percentage
-     * </pre>
      *
-     * <code>double server_cpu_usage = 12;</code>
+     * Generated from protobuf field <code>double server_cpu_usage = 12;</code>
+     * @return float
      */
     public function getServerCpuUsage()
     {
@@ -372,24 +398,25 @@ class ScenarioResultSummary extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * server cpu usage percentage
-     * </pre>
      *
-     * <code>double server_cpu_usage = 12;</code>
+     * Generated from protobuf field <code>double server_cpu_usage = 12;</code>
+     * @param float $var
+     * @return $this
      */
     public function setServerCpuUsage($var)
     {
         GPBUtil::checkDouble($var);
         $this->server_cpu_usage = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Number of requests that succeeded/failed
-     * </pre>
      *
-     * <code>double successful_requests_per_second = 13;</code>
+     * Generated from protobuf field <code>double successful_requests_per_second = 13;</code>
+     * @return float
      */
     public function getSuccessfulRequestsPerSecond()
     {
@@ -397,20 +424,23 @@ class ScenarioResultSummary extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Number of requests that succeeded/failed
-     * </pre>
      *
-     * <code>double successful_requests_per_second = 13;</code>
+     * Generated from protobuf field <code>double successful_requests_per_second = 13;</code>
+     * @param float $var
+     * @return $this
      */
     public function setSuccessfulRequestsPerSecond($var)
     {
         GPBUtil::checkDouble($var);
         $this->successful_requests_per_second = $var;
+
+        return $this;
     }
 
     /**
-     * <code>double failed_requests_per_second = 14;</code>
+     * Generated from protobuf field <code>double failed_requests_per_second = 14;</code>
+     * @return float
      */
     public function getFailedRequestsPerSecond()
     {
@@ -418,12 +448,112 @@ class ScenarioResultSummary extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>double failed_requests_per_second = 14;</code>
+     * Generated from protobuf field <code>double failed_requests_per_second = 14;</code>
+     * @param float $var
+     * @return $this
      */
     public function setFailedRequestsPerSecond($var)
     {
         GPBUtil::checkDouble($var);
         $this->failed_requests_per_second = $var;
+
+        return $this;
+    }
+
+    /**
+     * Number of polls called inside completion queue per request
+     *
+     * Generated from protobuf field <code>double client_polls_per_request = 15;</code>
+     * @return float
+     */
+    public function getClientPollsPerRequest()
+    {
+        return $this->client_polls_per_request;
+    }
+
+    /**
+     * Number of polls called inside completion queue per request
+     *
+     * Generated from protobuf field <code>double client_polls_per_request = 15;</code>
+     * @param float $var
+     * @return $this
+     */
+    public function setClientPollsPerRequest($var)
+    {
+        GPBUtil::checkDouble($var);
+        $this->client_polls_per_request = $var;
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>double server_polls_per_request = 16;</code>
+     * @return float
+     */
+    public function getServerPollsPerRequest()
+    {
+        return $this->server_polls_per_request;
+    }
+
+    /**
+     * Generated from protobuf field <code>double server_polls_per_request = 16;</code>
+     * @param float $var
+     * @return $this
+     */
+    public function setServerPollsPerRequest($var)
+    {
+        GPBUtil::checkDouble($var);
+        $this->server_polls_per_request = $var;
+
+        return $this;
+    }
+
+    /**
+     * Queries per CPU-sec over all servers or clients
+     *
+     * Generated from protobuf field <code>double server_queries_per_cpu_sec = 17;</code>
+     * @return float
+     */
+    public function getServerQueriesPerCpuSec()
+    {
+        return $this->server_queries_per_cpu_sec;
+    }
+
+    /**
+     * Queries per CPU-sec over all servers or clients
+     *
+     * Generated from protobuf field <code>double server_queries_per_cpu_sec = 17;</code>
+     * @param float $var
+     * @return $this
+     */
+    public function setServerQueriesPerCpuSec($var)
+    {
+        GPBUtil::checkDouble($var);
+        $this->server_queries_per_cpu_sec = $var;
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>double client_queries_per_cpu_sec = 18;</code>
+     * @return float
+     */
+    public function getClientQueriesPerCpuSec()
+    {
+        return $this->client_queries_per_cpu_sec;
+    }
+
+    /**
+     * Generated from protobuf field <code>double client_queries_per_cpu_sec = 18;</code>
+     * @param float $var
+     * @return $this
+     */
+    public function setClientQueriesPerCpuSec($var)
+    {
+        GPBUtil::checkDouble($var);
+        $this->client_queries_per_cpu_sec = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/Scenarios.php b/src/php/tests/qps/generated_code/Grpc/Testing/Scenarios.php
index 278f555b760..2146b4776e2 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/Scenarios.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/Scenarios.php
@@ -9,16 +9,14 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * <pre>
  * A set of scenarios to be run with qps_json_driver
- * </pre>
  *
- * Protobuf type <code>grpc.testing.Scenarios</code>
+ * Generated from protobuf message <code>grpc.testing.Scenarios</code>
  */
 class Scenarios extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <code>repeated .grpc.testing.Scenario scenarios = 1;</code>
+     * Generated from protobuf field <code>repeated .grpc.testing.Scenario scenarios = 1;</code>
      */
     private $scenarios;
 
@@ -28,7 +26,8 @@ class Scenarios extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>repeated .grpc.testing.Scenario scenarios = 1;</code>
+     * Generated from protobuf field <code>repeated .grpc.testing.Scenario scenarios = 1;</code>
+     * @return \Google\Protobuf\Internal\RepeatedField
      */
     public function getScenarios()
     {
@@ -36,12 +35,16 @@ class Scenarios extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>repeated .grpc.testing.Scenario scenarios = 1;</code>
+     * Generated from protobuf field <code>repeated .grpc.testing.Scenario scenarios = 1;</code>
+     * @param \Grpc\Testing\Scenario[]|\Google\Protobuf\Internal\RepeatedField $var
+     * @return $this
      */
-    public function setScenarios(&$var)
+    public function setScenarios($var)
     {
-        GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::MESSAGE, \Grpc\Testing\Scenario::class);
-        $this->scenarios = $var;
+        $arr = GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::MESSAGE, \Grpc\Testing\Scenario::class);
+        $this->scenarios = $arr;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/SecurityParams.php b/src/php/tests/qps/generated_code/Grpc/Testing/SecurityParams.php
index 27a5b95cc94..8ce623a4bc1 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/SecurityParams.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/SecurityParams.php
@@ -9,22 +9,24 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * <pre>
  * presence of SecurityParams implies use of TLS
- * </pre>
  *
- * Protobuf type <code>grpc.testing.SecurityParams</code>
+ * Generated from protobuf message <code>grpc.testing.SecurityParams</code>
  */
 class SecurityParams extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <code>bool use_test_ca = 1;</code>
+     * Generated from protobuf field <code>bool use_test_ca = 1;</code>
      */
     private $use_test_ca = false;
     /**
-     * <code>string server_host_override = 2;</code>
+     * Generated from protobuf field <code>string server_host_override = 2;</code>
      */
     private $server_host_override = '';
+    /**
+     * Generated from protobuf field <code>string cred_type = 3;</code>
+     */
+    private $cred_type = '';
 
     public function __construct() {
         \GPBMetadata\Src\Proto\Grpc\Testing\Control::initOnce();
@@ -32,7 +34,8 @@ class SecurityParams extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>bool use_test_ca = 1;</code>
+     * Generated from protobuf field <code>bool use_test_ca = 1;</code>
+     * @return bool
      */
     public function getUseTestCa()
     {
@@ -40,16 +43,21 @@ class SecurityParams extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>bool use_test_ca = 1;</code>
+     * Generated from protobuf field <code>bool use_test_ca = 1;</code>
+     * @param bool $var
+     * @return $this
      */
     public function setUseTestCa($var)
     {
         GPBUtil::checkBool($var);
         $this->use_test_ca = $var;
+
+        return $this;
     }
 
     /**
-     * <code>string server_host_override = 2;</code>
+     * Generated from protobuf field <code>string server_host_override = 2;</code>
+     * @return string
      */
     public function getServerHostOverride()
     {
@@ -57,12 +65,38 @@ class SecurityParams extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>string server_host_override = 2;</code>
+     * Generated from protobuf field <code>string server_host_override = 2;</code>
+     * @param string $var
+     * @return $this
      */
     public function setServerHostOverride($var)
     {
         GPBUtil::checkString($var, True);
         $this->server_host_override = $var;
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>string cred_type = 3;</code>
+     * @return string
+     */
+    public function getCredType()
+    {
+        return $this->cred_type;
+    }
+
+    /**
+     * Generated from protobuf field <code>string cred_type = 3;</code>
+     * @param string $var
+     * @return $this
+     */
+    public function setCredType($var)
+    {
+        GPBUtil::checkString($var, True);
+        $this->cred_type = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ServerArgs.php b/src/php/tests/qps/generated_code/Grpc/Testing/ServerArgs.php
index 0d84b80124a..acf7e18b6da 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/ServerArgs.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ServerArgs.php
@@ -9,7 +9,7 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * Protobuf type <code>grpc.testing.ServerArgs</code>
+ * Generated from protobuf message <code>grpc.testing.ServerArgs</code>
  */
 class ServerArgs extends \Google\Protobuf\Internal\Message
 {
@@ -21,7 +21,8 @@ class ServerArgs extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>.grpc.testing.ServerConfig setup = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.ServerConfig setup = 1;</code>
+     * @return \Grpc\Testing\ServerConfig
      */
     public function getSetup()
     {
@@ -29,16 +30,21 @@ class ServerArgs extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>.grpc.testing.ServerConfig setup = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.ServerConfig setup = 1;</code>
+     * @param \Grpc\Testing\ServerConfig $var
+     * @return $this
      */
-    public function setSetup(&$var)
+    public function setSetup($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\ServerConfig::class);
         $this->writeOneof(1, $var);
+
+        return $this;
     }
 
     /**
-     * <code>.grpc.testing.Mark mark = 2;</code>
+     * Generated from protobuf field <code>.grpc.testing.Mark mark = 2;</code>
+     * @return \Grpc\Testing\Mark
      */
     public function getMark()
     {
@@ -46,14 +52,21 @@ class ServerArgs extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>.grpc.testing.Mark mark = 2;</code>
+     * Generated from protobuf field <code>.grpc.testing.Mark mark = 2;</code>
+     * @param \Grpc\Testing\Mark $var
+     * @return $this
      */
-    public function setMark(&$var)
+    public function setMark($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\Mark::class);
         $this->writeOneof(2, $var);
+
+        return $this;
     }
 
+    /**
+     * @return string
+     */
     public function getArgtype()
     {
         return $this->whichOneof("argtype");
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ServerConfig.php b/src/php/tests/qps/generated_code/Grpc/Testing/ServerConfig.php
index e2bcede48cb..8bd4c69566b 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/ServerConfig.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ServerConfig.php
@@ -9,77 +9,73 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * Protobuf type <code>grpc.testing.ServerConfig</code>
+ * Generated from protobuf message <code>grpc.testing.ServerConfig</code>
  */
 class ServerConfig extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <code>.grpc.testing.ServerType server_type = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.ServerType server_type = 1;</code>
      */
     private $server_type = 0;
     /**
-     * <code>.grpc.testing.SecurityParams security_params = 2;</code>
+     * Generated from protobuf field <code>.grpc.testing.SecurityParams security_params = 2;</code>
      */
     private $security_params = null;
     /**
-     * <pre>
      * Port on which to listen. Zero means pick unused port.
-     * </pre>
      *
-     * <code>int32 port = 4;</code>
+     * Generated from protobuf field <code>int32 port = 4;</code>
      */
     private $port = 0;
     /**
-     * <pre>
      * Only for async server. Number of threads used to serve the requests.
-     * </pre>
      *
-     * <code>int32 async_server_threads = 7;</code>
+     * Generated from protobuf field <code>int32 async_server_threads = 7;</code>
      */
     private $async_server_threads = 0;
     /**
-     * <pre>
      * Specify the number of cores to limit server to, if desired
-     * </pre>
      *
-     * <code>int32 core_limit = 8;</code>
+     * Generated from protobuf field <code>int32 core_limit = 8;</code>
      */
     private $core_limit = 0;
     /**
-     * <pre>
      * payload config, used in generic server.
      * Note this must NOT be used in proto (non-generic) servers. For proto servers,
      * 'response sizes' must be configured from the 'response_size' field of the
      * 'SimpleRequest' objects in RPC requests.
-     * </pre>
      *
-     * <code>.grpc.testing.PayloadConfig payload_config = 9;</code>
+     * Generated from protobuf field <code>.grpc.testing.PayloadConfig payload_config = 9;</code>
      */
     private $payload_config = null;
     /**
-     * <pre>
      * Specify the cores we should run the server on, if desired
-     * </pre>
      *
-     * <code>repeated int32 core_list = 10;</code>
+     * Generated from protobuf field <code>repeated int32 core_list = 10;</code>
      */
     private $core_list;
     /**
-     * <pre>
      * If we use an OTHER_SERVER client_type, this string gives more detail
-     * </pre>
      *
-     * <code>string other_server_api = 11;</code>
+     * Generated from protobuf field <code>string other_server_api = 11;</code>
      */
     private $other_server_api = '';
     /**
-     * <pre>
+     * Number of threads that share each completion queue
+     *
+     * Generated from protobuf field <code>int32 threads_per_cq = 12;</code>
+     */
+    private $threads_per_cq = 0;
+    /**
      * Buffer pool size (no buffer pool specified if unset)
-     * </pre>
      *
-     * <code>int32 resource_quota_size = 1001;</code>
+     * Generated from protobuf field <code>int32 resource_quota_size = 1001;</code>
      */
     private $resource_quota_size = 0;
+    /**
+     * Generated from protobuf field <code>repeated .grpc.testing.ChannelArg channel_args = 1002;</code>
+     */
+    private $channel_args;
 
     public function __construct() {
         \GPBMetadata\Src\Proto\Grpc\Testing\Control::initOnce();
@@ -87,7 +83,8 @@ class ServerConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>.grpc.testing.ServerType server_type = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.ServerType server_type = 1;</code>
+     * @return int
      */
     public function getServerType()
     {
@@ -95,16 +92,21 @@ class ServerConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>.grpc.testing.ServerType server_type = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.ServerType server_type = 1;</code>
+     * @param int $var
+     * @return $this
      */
     public function setServerType($var)
     {
         GPBUtil::checkEnum($var, \Grpc\Testing\ServerType::class);
         $this->server_type = $var;
+
+        return $this;
     }
 
     /**
-     * <code>.grpc.testing.SecurityParams security_params = 2;</code>
+     * Generated from protobuf field <code>.grpc.testing.SecurityParams security_params = 2;</code>
+     * @return \Grpc\Testing\SecurityParams
      */
     public function getSecurityParams()
     {
@@ -112,20 +114,23 @@ class ServerConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>.grpc.testing.SecurityParams security_params = 2;</code>
+     * Generated from protobuf field <code>.grpc.testing.SecurityParams security_params = 2;</code>
+     * @param \Grpc\Testing\SecurityParams $var
+     * @return $this
      */
-    public function setSecurityParams(&$var)
+    public function setSecurityParams($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\SecurityParams::class);
         $this->security_params = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Port on which to listen. Zero means pick unused port.
-     * </pre>
      *
-     * <code>int32 port = 4;</code>
+     * Generated from protobuf field <code>int32 port = 4;</code>
+     * @return int
      */
     public function getPort()
     {
@@ -133,24 +138,25 @@ class ServerConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Port on which to listen. Zero means pick unused port.
-     * </pre>
      *
-     * <code>int32 port = 4;</code>
+     * Generated from protobuf field <code>int32 port = 4;</code>
+     * @param int $var
+     * @return $this
      */
     public function setPort($var)
     {
         GPBUtil::checkInt32($var);
         $this->port = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Only for async server. Number of threads used to serve the requests.
-     * </pre>
      *
-     * <code>int32 async_server_threads = 7;</code>
+     * Generated from protobuf field <code>int32 async_server_threads = 7;</code>
+     * @return int
      */
     public function getAsyncServerThreads()
     {
@@ -158,24 +164,25 @@ class ServerConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Only for async server. Number of threads used to serve the requests.
-     * </pre>
      *
-     * <code>int32 async_server_threads = 7;</code>
+     * Generated from protobuf field <code>int32 async_server_threads = 7;</code>
+     * @param int $var
+     * @return $this
      */
     public function setAsyncServerThreads($var)
     {
         GPBUtil::checkInt32($var);
         $this->async_server_threads = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Specify the number of cores to limit server to, if desired
-     * </pre>
      *
-     * <code>int32 core_limit = 8;</code>
+     * Generated from protobuf field <code>int32 core_limit = 8;</code>
+     * @return int
      */
     public function getCoreLimit()
     {
@@ -183,27 +190,28 @@ class ServerConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Specify the number of cores to limit server to, if desired
-     * </pre>
      *
-     * <code>int32 core_limit = 8;</code>
+     * Generated from protobuf field <code>int32 core_limit = 8;</code>
+     * @param int $var
+     * @return $this
      */
     public function setCoreLimit($var)
     {
         GPBUtil::checkInt32($var);
         $this->core_limit = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * payload config, used in generic server.
      * Note this must NOT be used in proto (non-generic) servers. For proto servers,
      * 'response sizes' must be configured from the 'response_size' field of the
      * 'SimpleRequest' objects in RPC requests.
-     * </pre>
      *
-     * <code>.grpc.testing.PayloadConfig payload_config = 9;</code>
+     * Generated from protobuf field <code>.grpc.testing.PayloadConfig payload_config = 9;</code>
+     * @return \Grpc\Testing\PayloadConfig
      */
     public function getPayloadConfig()
     {
@@ -211,27 +219,28 @@ class ServerConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * payload config, used in generic server.
      * Note this must NOT be used in proto (non-generic) servers. For proto servers,
      * 'response sizes' must be configured from the 'response_size' field of the
      * 'SimpleRequest' objects in RPC requests.
-     * </pre>
      *
-     * <code>.grpc.testing.PayloadConfig payload_config = 9;</code>
+     * Generated from protobuf field <code>.grpc.testing.PayloadConfig payload_config = 9;</code>
+     * @param \Grpc\Testing\PayloadConfig $var
+     * @return $this
      */
-    public function setPayloadConfig(&$var)
+    public function setPayloadConfig($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\PayloadConfig::class);
         $this->payload_config = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Specify the cores we should run the server on, if desired
-     * </pre>
      *
-     * <code>repeated int32 core_list = 10;</code>
+     * Generated from protobuf field <code>repeated int32 core_list = 10;</code>
+     * @return \Google\Protobuf\Internal\RepeatedField
      */
     public function getCoreList()
     {
@@ -239,24 +248,25 @@ class ServerConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Specify the cores we should run the server on, if desired
-     * </pre>
      *
-     * <code>repeated int32 core_list = 10;</code>
+     * Generated from protobuf field <code>repeated int32 core_list = 10;</code>
+     * @param int[]|\Google\Protobuf\Internal\RepeatedField $var
+     * @return $this
      */
-    public function setCoreList(&$var)
+    public function setCoreList($var)
     {
-        GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::INT32);
-        $this->core_list = $var;
+        $arr = GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::INT32);
+        $this->core_list = $arr;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * If we use an OTHER_SERVER client_type, this string gives more detail
-     * </pre>
      *
-     * <code>string other_server_api = 11;</code>
+     * Generated from protobuf field <code>string other_server_api = 11;</code>
+     * @return string
      */
     public function getOtherServerApi()
     {
@@ -264,24 +274,51 @@ class ServerConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * If we use an OTHER_SERVER client_type, this string gives more detail
-     * </pre>
      *
-     * <code>string other_server_api = 11;</code>
+     * Generated from protobuf field <code>string other_server_api = 11;</code>
+     * @param string $var
+     * @return $this
      */
     public function setOtherServerApi($var)
     {
         GPBUtil::checkString($var, True);
         $this->other_server_api = $var;
+
+        return $this;
+    }
+
+    /**
+     * Number of threads that share each completion queue
+     *
+     * Generated from protobuf field <code>int32 threads_per_cq = 12;</code>
+     * @return int
+     */
+    public function getThreadsPerCq()
+    {
+        return $this->threads_per_cq;
+    }
+
+    /**
+     * Number of threads that share each completion queue
+     *
+     * Generated from protobuf field <code>int32 threads_per_cq = 12;</code>
+     * @param int $var
+     * @return $this
+     */
+    public function setThreadsPerCq($var)
+    {
+        GPBUtil::checkInt32($var);
+        $this->threads_per_cq = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Buffer pool size (no buffer pool specified if unset)
-     * </pre>
      *
-     * <code>int32 resource_quota_size = 1001;</code>
+     * Generated from protobuf field <code>int32 resource_quota_size = 1001;</code>
+     * @return int
      */
     public function getResourceQuotaSize()
     {
@@ -289,16 +326,40 @@ class ServerConfig extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Buffer pool size (no buffer pool specified if unset)
-     * </pre>
      *
-     * <code>int32 resource_quota_size = 1001;</code>
+     * Generated from protobuf field <code>int32 resource_quota_size = 1001;</code>
+     * @param int $var
+     * @return $this
      */
     public function setResourceQuotaSize($var)
     {
         GPBUtil::checkInt32($var);
         $this->resource_quota_size = $var;
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>repeated .grpc.testing.ChannelArg channel_args = 1002;</code>
+     * @return \Google\Protobuf\Internal\RepeatedField
+     */
+    public function getChannelArgs()
+    {
+        return $this->channel_args;
+    }
+
+    /**
+     * Generated from protobuf field <code>repeated .grpc.testing.ChannelArg channel_args = 1002;</code>
+     * @param \Grpc\Testing\ChannelArg[]|\Google\Protobuf\Internal\RepeatedField $var
+     * @return $this
+     */
+    public function setChannelArgs($var)
+    {
+        $arr = GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::MESSAGE, \Grpc\Testing\ChannelArg::class);
+        $this->channel_args = $arr;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ServerStats.php b/src/php/tests/qps/generated_code/Grpc/Testing/ServerStats.php
index 98b2af764c9..aea2cb0fce3 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/ServerStats.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ServerStats.php
@@ -9,51 +9,53 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * Protobuf type <code>grpc.testing.ServerStats</code>
+ * Generated from protobuf message <code>grpc.testing.ServerStats</code>
  */
 class ServerStats extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <pre>
      * wall clock time change in seconds since last reset
-     * </pre>
      *
-     * <code>double time_elapsed = 1;</code>
+     * Generated from protobuf field <code>double time_elapsed = 1;</code>
      */
     private $time_elapsed = 0.0;
     /**
-     * <pre>
      * change in user time (in seconds) used by the server since last reset
-     * </pre>
      *
-     * <code>double time_user = 2;</code>
+     * Generated from protobuf field <code>double time_user = 2;</code>
      */
     private $time_user = 0.0;
     /**
-     * <pre>
      * change in server time (in seconds) used by the server process and all
      * threads since last reset
-     * </pre>
      *
-     * <code>double time_system = 3;</code>
+     * Generated from protobuf field <code>double time_system = 3;</code>
      */
     private $time_system = 0.0;
     /**
-     * <pre>
      * change in total cpu time of the server (data from proc/stat)
-     * </pre>
      *
-     * <code>uint64 total_cpu_time = 4;</code>
+     * Generated from protobuf field <code>uint64 total_cpu_time = 4;</code>
      */
     private $total_cpu_time = 0;
     /**
-     * <pre>
      * change in idle time of the server (data from proc/stat)
-     * </pre>
      *
-     * <code>uint64 idle_cpu_time = 5;</code>
+     * Generated from protobuf field <code>uint64 idle_cpu_time = 5;</code>
      */
     private $idle_cpu_time = 0;
+    /**
+     * Number of polls called inside completion queue
+     *
+     * Generated from protobuf field <code>uint64 cq_poll_count = 6;</code>
+     */
+    private $cq_poll_count = 0;
+    /**
+     * Core library stats
+     *
+     * Generated from protobuf field <code>.grpc.core.Stats core_stats = 7;</code>
+     */
+    private $core_stats = null;
 
     public function __construct() {
         \GPBMetadata\Src\Proto\Grpc\Testing\Stats::initOnce();
@@ -61,11 +63,10 @@ class ServerStats extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * wall clock time change in seconds since last reset
-     * </pre>
      *
-     * <code>double time_elapsed = 1;</code>
+     * Generated from protobuf field <code>double time_elapsed = 1;</code>
+     * @return float
      */
     public function getTimeElapsed()
     {
@@ -73,24 +74,25 @@ class ServerStats extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * wall clock time change in seconds since last reset
-     * </pre>
      *
-     * <code>double time_elapsed = 1;</code>
+     * Generated from protobuf field <code>double time_elapsed = 1;</code>
+     * @param float $var
+     * @return $this
      */
     public function setTimeElapsed($var)
     {
         GPBUtil::checkDouble($var);
         $this->time_elapsed = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * change in user time (in seconds) used by the server since last reset
-     * </pre>
      *
-     * <code>double time_user = 2;</code>
+     * Generated from protobuf field <code>double time_user = 2;</code>
+     * @return float
      */
     public function getTimeUser()
     {
@@ -98,25 +100,26 @@ class ServerStats extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * change in user time (in seconds) used by the server since last reset
-     * </pre>
      *
-     * <code>double time_user = 2;</code>
+     * Generated from protobuf field <code>double time_user = 2;</code>
+     * @param float $var
+     * @return $this
      */
     public function setTimeUser($var)
     {
         GPBUtil::checkDouble($var);
         $this->time_user = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * change in server time (in seconds) used by the server process and all
      * threads since last reset
-     * </pre>
      *
-     * <code>double time_system = 3;</code>
+     * Generated from protobuf field <code>double time_system = 3;</code>
+     * @return float
      */
     public function getTimeSystem()
     {
@@ -124,25 +127,26 @@ class ServerStats extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * change in server time (in seconds) used by the server process and all
      * threads since last reset
-     * </pre>
      *
-     * <code>double time_system = 3;</code>
+     * Generated from protobuf field <code>double time_system = 3;</code>
+     * @param float $var
+     * @return $this
      */
     public function setTimeSystem($var)
     {
         GPBUtil::checkDouble($var);
         $this->time_system = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * change in total cpu time of the server (data from proc/stat)
-     * </pre>
      *
-     * <code>uint64 total_cpu_time = 4;</code>
+     * Generated from protobuf field <code>uint64 total_cpu_time = 4;</code>
+     * @return int|string
      */
     public function getTotalCpuTime()
     {
@@ -150,24 +154,25 @@ class ServerStats extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * change in total cpu time of the server (data from proc/stat)
-     * </pre>
      *
-     * <code>uint64 total_cpu_time = 4;</code>
+     * Generated from protobuf field <code>uint64 total_cpu_time = 4;</code>
+     * @param int|string $var
+     * @return $this
      */
     public function setTotalCpuTime($var)
     {
         GPBUtil::checkUint64($var);
         $this->total_cpu_time = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * change in idle time of the server (data from proc/stat)
-     * </pre>
      *
-     * <code>uint64 idle_cpu_time = 5;</code>
+     * Generated from protobuf field <code>uint64 idle_cpu_time = 5;</code>
+     * @return int|string
      */
     public function getIdleCpuTime()
     {
@@ -175,16 +180,70 @@ class ServerStats extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * change in idle time of the server (data from proc/stat)
-     * </pre>
      *
-     * <code>uint64 idle_cpu_time = 5;</code>
+     * Generated from protobuf field <code>uint64 idle_cpu_time = 5;</code>
+     * @param int|string $var
+     * @return $this
      */
     public function setIdleCpuTime($var)
     {
         GPBUtil::checkUint64($var);
         $this->idle_cpu_time = $var;
+
+        return $this;
+    }
+
+    /**
+     * Number of polls called inside completion queue
+     *
+     * Generated from protobuf field <code>uint64 cq_poll_count = 6;</code>
+     * @return int|string
+     */
+    public function getCqPollCount()
+    {
+        return $this->cq_poll_count;
+    }
+
+    /**
+     * Number of polls called inside completion queue
+     *
+     * Generated from protobuf field <code>uint64 cq_poll_count = 6;</code>
+     * @param int|string $var
+     * @return $this
+     */
+    public function setCqPollCount($var)
+    {
+        GPBUtil::checkUint64($var);
+        $this->cq_poll_count = $var;
+
+        return $this;
+    }
+
+    /**
+     * Core library stats
+     *
+     * Generated from protobuf field <code>.grpc.core.Stats core_stats = 7;</code>
+     * @return \Grpc\Core\Stats
+     */
+    public function getCoreStats()
+    {
+        return $this->core_stats;
+    }
+
+    /**
+     * Core library stats
+     *
+     * Generated from protobuf field <code>.grpc.core.Stats core_stats = 7;</code>
+     * @param \Grpc\Core\Stats $var
+     * @return $this
+     */
+    public function setCoreStats($var)
+    {
+        GPBUtil::checkMessage($var, \Grpc\Core\Stats::class);
+        $this->core_stats = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ServerStatus.php b/src/php/tests/qps/generated_code/Grpc/Testing/ServerStatus.php
index d293f03fbdf..04f2ca7c4ae 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/ServerStatus.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ServerStatus.php
@@ -9,28 +9,24 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * Protobuf type <code>grpc.testing.ServerStatus</code>
+ * Generated from protobuf message <code>grpc.testing.ServerStatus</code>
  */
 class ServerStatus extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <code>.grpc.testing.ServerStats stats = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.ServerStats stats = 1;</code>
      */
     private $stats = null;
     /**
-     * <pre>
      * the port bound by the server
-     * </pre>
      *
-     * <code>int32 port = 2;</code>
+     * Generated from protobuf field <code>int32 port = 2;</code>
      */
     private $port = 0;
     /**
-     * <pre>
      * Number of cores available to the server
-     * </pre>
      *
-     * <code>int32 cores = 3;</code>
+     * Generated from protobuf field <code>int32 cores = 3;</code>
      */
     private $cores = 0;
 
@@ -40,7 +36,8 @@ class ServerStatus extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>.grpc.testing.ServerStats stats = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.ServerStats stats = 1;</code>
+     * @return \Grpc\Testing\ServerStats
      */
     public function getStats()
     {
@@ -48,20 +45,23 @@ class ServerStatus extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>.grpc.testing.ServerStats stats = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.ServerStats stats = 1;</code>
+     * @param \Grpc\Testing\ServerStats $var
+     * @return $this
      */
-    public function setStats(&$var)
+    public function setStats($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\ServerStats::class);
         $this->stats = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * the port bound by the server
-     * </pre>
      *
-     * <code>int32 port = 2;</code>
+     * Generated from protobuf field <code>int32 port = 2;</code>
+     * @return int
      */
     public function getPort()
     {
@@ -69,24 +69,25 @@ class ServerStatus extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * the port bound by the server
-     * </pre>
      *
-     * <code>int32 port = 2;</code>
+     * Generated from protobuf field <code>int32 port = 2;</code>
+     * @param int $var
+     * @return $this
      */
     public function setPort($var)
     {
         GPBUtil::checkInt32($var);
         $this->port = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Number of cores available to the server
-     * </pre>
      *
-     * <code>int32 cores = 3;</code>
+     * Generated from protobuf field <code>int32 cores = 3;</code>
+     * @return int
      */
     public function getCores()
     {
@@ -94,16 +95,18 @@ class ServerStatus extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Number of cores available to the server
-     * </pre>
      *
-     * <code>int32 cores = 3;</code>
+     * Generated from protobuf field <code>int32 cores = 3;</code>
+     * @param int $var
+     * @return $this
      */
     public function setCores($var)
     {
         GPBUtil::checkInt32($var);
         $this->cores = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ServerType.php b/src/php/tests/qps/generated_code/Grpc/Testing/ServerType.php
index 605c83c3f76..4110e91c18a 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/ServerType.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ServerType.php
@@ -5,28 +5,26 @@
 namespace Grpc\Testing;
 
 /**
- * Protobuf enum <code>grpc.testing.ServerType</code>
+ * Protobuf enum <code>Grpc\Testing\ServerType</code>
  */
 class ServerType
 {
     /**
-     * <code>SYNC_SERVER = 0;</code>
+     * Generated from protobuf enum <code>SYNC_SERVER = 0;</code>
      */
     const SYNC_SERVER = 0;
     /**
-     * <code>ASYNC_SERVER = 1;</code>
+     * Generated from protobuf enum <code>ASYNC_SERVER = 1;</code>
      */
     const ASYNC_SERVER = 1;
     /**
-     * <code>ASYNC_GENERIC_SERVER = 2;</code>
+     * Generated from protobuf enum <code>ASYNC_GENERIC_SERVER = 2;</code>
      */
     const ASYNC_GENERIC_SERVER = 2;
     /**
-     * <pre>
      * used for some language-specific variants
-     * </pre>
      *
-     * <code>OTHER_SERVER = 3;</code>
+     * Generated from protobuf enum <code>OTHER_SERVER = 3;</code>
      */
     const OTHER_SERVER = 3;
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/SimpleProtoParams.php b/src/php/tests/qps/generated_code/Grpc/Testing/SimpleProtoParams.php
index 29834a3be71..507db598f03 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/SimpleProtoParams.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/SimpleProtoParams.php
@@ -9,16 +9,16 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * Protobuf type <code>grpc.testing.SimpleProtoParams</code>
+ * Generated from protobuf message <code>grpc.testing.SimpleProtoParams</code>
  */
 class SimpleProtoParams extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <code>int32 req_size = 1;</code>
+     * Generated from protobuf field <code>int32 req_size = 1;</code>
      */
     private $req_size = 0;
     /**
-     * <code>int32 resp_size = 2;</code>
+     * Generated from protobuf field <code>int32 resp_size = 2;</code>
      */
     private $resp_size = 0;
 
@@ -28,7 +28,8 @@ class SimpleProtoParams extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>int32 req_size = 1;</code>
+     * Generated from protobuf field <code>int32 req_size = 1;</code>
+     * @return int
      */
     public function getReqSize()
     {
@@ -36,16 +37,21 @@ class SimpleProtoParams extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>int32 req_size = 1;</code>
+     * Generated from protobuf field <code>int32 req_size = 1;</code>
+     * @param int $var
+     * @return $this
      */
     public function setReqSize($var)
     {
         GPBUtil::checkInt32($var);
         $this->req_size = $var;
+
+        return $this;
     }
 
     /**
-     * <code>int32 resp_size = 2;</code>
+     * Generated from protobuf field <code>int32 resp_size = 2;</code>
+     * @return int
      */
     public function getRespSize()
     {
@@ -53,12 +59,16 @@ class SimpleProtoParams extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <code>int32 resp_size = 2;</code>
+     * Generated from protobuf field <code>int32 resp_size = 2;</code>
+     * @param int $var
+     * @return $this
      */
     public function setRespSize($var)
     {
         GPBUtil::checkInt32($var);
         $this->resp_size = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/SimpleRequest.php b/src/php/tests/qps/generated_code/Grpc/Testing/SimpleRequest.php
index f84c95319f4..e0c2d2d94ce 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/SimpleRequest.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/SimpleRequest.php
@@ -9,81 +9,63 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * <pre>
  * Unary request.
- * </pre>
  *
- * Protobuf type <code>grpc.testing.SimpleRequest</code>
+ * Generated from protobuf message <code>grpc.testing.SimpleRequest</code>
  */
 class SimpleRequest extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <pre>
      * DEPRECATED, don't use. To be removed shortly.
      * Desired payload type in the response from the server.
      * If response_type is RANDOM, server randomly chooses one from other formats.
-     * </pre>
      *
-     * <code>.grpc.testing.PayloadType response_type = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.PayloadType response_type = 1;</code>
      */
     private $response_type = 0;
     /**
-     * <pre>
      * Desired payload size in the response from the server.
-     * </pre>
      *
-     * <code>int32 response_size = 2;</code>
+     * Generated from protobuf field <code>int32 response_size = 2;</code>
      */
     private $response_size = 0;
     /**
-     * <pre>
      * Optional input payload sent along with the request.
-     * </pre>
      *
-     * <code>.grpc.testing.Payload payload = 3;</code>
+     * Generated from protobuf field <code>.grpc.testing.Payload payload = 3;</code>
      */
     private $payload = null;
     /**
-     * <pre>
      * Whether SimpleResponse should include username.
-     * </pre>
      *
-     * <code>bool fill_username = 4;</code>
+     * Generated from protobuf field <code>bool fill_username = 4;</code>
      */
     private $fill_username = false;
     /**
-     * <pre>
      * Whether SimpleResponse should include OAuth scope.
-     * </pre>
      *
-     * <code>bool fill_oauth_scope = 5;</code>
+     * Generated from protobuf field <code>bool fill_oauth_scope = 5;</code>
      */
     private $fill_oauth_scope = false;
     /**
-     * <pre>
      * Whether to request the server to compress the response. This field is
      * "nullable" in order to interoperate seamlessly with clients not able to
      * implement the full compression tests by introspecting the call to verify
      * the response's compression status.
-     * </pre>
      *
-     * <code>.grpc.testing.BoolValue response_compressed = 6;</code>
+     * Generated from protobuf field <code>.grpc.testing.BoolValue response_compressed = 6;</code>
      */
     private $response_compressed = null;
     /**
-     * <pre>
      * Whether server should return a given status
-     * </pre>
      *
-     * <code>.grpc.testing.EchoStatus response_status = 7;</code>
+     * Generated from protobuf field <code>.grpc.testing.EchoStatus response_status = 7;</code>
      */
     private $response_status = null;
     /**
-     * <pre>
      * Whether the server should expect this request to be compressed.
-     * </pre>
      *
-     * <code>.grpc.testing.BoolValue expect_compressed = 8;</code>
+     * Generated from protobuf field <code>.grpc.testing.BoolValue expect_compressed = 8;</code>
      */
     private $expect_compressed = null;
 
@@ -93,13 +75,12 @@ class SimpleRequest extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * DEPRECATED, don't use. To be removed shortly.
      * Desired payload type in the response from the server.
      * If response_type is RANDOM, server randomly chooses one from other formats.
-     * </pre>
      *
-     * <code>.grpc.testing.PayloadType response_type = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.PayloadType response_type = 1;</code>
+     * @return int
      */
     public function getResponseType()
     {
@@ -107,26 +88,27 @@ class SimpleRequest extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * DEPRECATED, don't use. To be removed shortly.
      * Desired payload type in the response from the server.
      * If response_type is RANDOM, server randomly chooses one from other formats.
-     * </pre>
      *
-     * <code>.grpc.testing.PayloadType response_type = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.PayloadType response_type = 1;</code>
+     * @param int $var
+     * @return $this
      */
     public function setResponseType($var)
     {
         GPBUtil::checkEnum($var, \Grpc\Testing\PayloadType::class);
         $this->response_type = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Desired payload size in the response from the server.
-     * </pre>
      *
-     * <code>int32 response_size = 2;</code>
+     * Generated from protobuf field <code>int32 response_size = 2;</code>
+     * @return int
      */
     public function getResponseSize()
     {
@@ -134,24 +116,25 @@ class SimpleRequest extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Desired payload size in the response from the server.
-     * </pre>
      *
-     * <code>int32 response_size = 2;</code>
+     * Generated from protobuf field <code>int32 response_size = 2;</code>
+     * @param int $var
+     * @return $this
      */
     public function setResponseSize($var)
     {
         GPBUtil::checkInt32($var);
         $this->response_size = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Optional input payload sent along with the request.
-     * </pre>
      *
-     * <code>.grpc.testing.Payload payload = 3;</code>
+     * Generated from protobuf field <code>.grpc.testing.Payload payload = 3;</code>
+     * @return \Grpc\Testing\Payload
      */
     public function getPayload()
     {
@@ -159,24 +142,25 @@ class SimpleRequest extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Optional input payload sent along with the request.
-     * </pre>
      *
-     * <code>.grpc.testing.Payload payload = 3;</code>
+     * Generated from protobuf field <code>.grpc.testing.Payload payload = 3;</code>
+     * @param \Grpc\Testing\Payload $var
+     * @return $this
      */
-    public function setPayload(&$var)
+    public function setPayload($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\Payload::class);
         $this->payload = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Whether SimpleResponse should include username.
-     * </pre>
      *
-     * <code>bool fill_username = 4;</code>
+     * Generated from protobuf field <code>bool fill_username = 4;</code>
+     * @return bool
      */
     public function getFillUsername()
     {
@@ -184,24 +168,25 @@ class SimpleRequest extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Whether SimpleResponse should include username.
-     * </pre>
      *
-     * <code>bool fill_username = 4;</code>
+     * Generated from protobuf field <code>bool fill_username = 4;</code>
+     * @param bool $var
+     * @return $this
      */
     public function setFillUsername($var)
     {
         GPBUtil::checkBool($var);
         $this->fill_username = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Whether SimpleResponse should include OAuth scope.
-     * </pre>
      *
-     * <code>bool fill_oauth_scope = 5;</code>
+     * Generated from protobuf field <code>bool fill_oauth_scope = 5;</code>
+     * @return bool
      */
     public function getFillOauthScope()
     {
@@ -209,27 +194,28 @@ class SimpleRequest extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Whether SimpleResponse should include OAuth scope.
-     * </pre>
      *
-     * <code>bool fill_oauth_scope = 5;</code>
+     * Generated from protobuf field <code>bool fill_oauth_scope = 5;</code>
+     * @param bool $var
+     * @return $this
      */
     public function setFillOauthScope($var)
     {
         GPBUtil::checkBool($var);
         $this->fill_oauth_scope = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Whether to request the server to compress the response. This field is
      * "nullable" in order to interoperate seamlessly with clients not able to
      * implement the full compression tests by introspecting the call to verify
      * the response's compression status.
-     * </pre>
      *
-     * <code>.grpc.testing.BoolValue response_compressed = 6;</code>
+     * Generated from protobuf field <code>.grpc.testing.BoolValue response_compressed = 6;</code>
+     * @return \Grpc\Testing\BoolValue
      */
     public function getResponseCompressed()
     {
@@ -237,27 +223,28 @@ class SimpleRequest extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Whether to request the server to compress the response. This field is
      * "nullable" in order to interoperate seamlessly with clients not able to
      * implement the full compression tests by introspecting the call to verify
      * the response's compression status.
-     * </pre>
      *
-     * <code>.grpc.testing.BoolValue response_compressed = 6;</code>
+     * Generated from protobuf field <code>.grpc.testing.BoolValue response_compressed = 6;</code>
+     * @param \Grpc\Testing\BoolValue $var
+     * @return $this
      */
-    public function setResponseCompressed(&$var)
+    public function setResponseCompressed($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\BoolValue::class);
         $this->response_compressed = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Whether server should return a given status
-     * </pre>
      *
-     * <code>.grpc.testing.EchoStatus response_status = 7;</code>
+     * Generated from protobuf field <code>.grpc.testing.EchoStatus response_status = 7;</code>
+     * @return \Grpc\Testing\EchoStatus
      */
     public function getResponseStatus()
     {
@@ -265,24 +252,25 @@ class SimpleRequest extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Whether server should return a given status
-     * </pre>
      *
-     * <code>.grpc.testing.EchoStatus response_status = 7;</code>
+     * Generated from protobuf field <code>.grpc.testing.EchoStatus response_status = 7;</code>
+     * @param \Grpc\Testing\EchoStatus $var
+     * @return $this
      */
-    public function setResponseStatus(&$var)
+    public function setResponseStatus($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\EchoStatus::class);
         $this->response_status = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Whether the server should expect this request to be compressed.
-     * </pre>
      *
-     * <code>.grpc.testing.BoolValue expect_compressed = 8;</code>
+     * Generated from protobuf field <code>.grpc.testing.BoolValue expect_compressed = 8;</code>
+     * @return \Grpc\Testing\BoolValue
      */
     public function getExpectCompressed()
     {
@@ -290,16 +278,18 @@ class SimpleRequest extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Whether the server should expect this request to be compressed.
-     * </pre>
      *
-     * <code>.grpc.testing.BoolValue expect_compressed = 8;</code>
+     * Generated from protobuf field <code>.grpc.testing.BoolValue expect_compressed = 8;</code>
+     * @param \Grpc\Testing\BoolValue $var
+     * @return $this
      */
-    public function setExpectCompressed(&$var)
+    public function setExpectCompressed($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\BoolValue::class);
         $this->expect_compressed = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/SimpleResponse.php b/src/php/tests/qps/generated_code/Grpc/Testing/SimpleResponse.php
index ccc628ec4c0..d49f33746e2 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/SimpleResponse.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/SimpleResponse.php
@@ -9,37 +9,29 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * <pre>
  * Unary response, as configured by the request.
- * </pre>
  *
- * Protobuf type <code>grpc.testing.SimpleResponse</code>
+ * Generated from protobuf message <code>grpc.testing.SimpleResponse</code>
  */
 class SimpleResponse extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <pre>
      * Payload to increase message size.
-     * </pre>
      *
-     * <code>.grpc.testing.Payload payload = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.Payload payload = 1;</code>
      */
     private $payload = null;
     /**
-     * <pre>
      * The user the request came from, for verifying authentication was
      * successful when the client expected it.
-     * </pre>
      *
-     * <code>string username = 2;</code>
+     * Generated from protobuf field <code>string username = 2;</code>
      */
     private $username = '';
     /**
-     * <pre>
      * OAuth scope.
-     * </pre>
      *
-     * <code>string oauth_scope = 3;</code>
+     * Generated from protobuf field <code>string oauth_scope = 3;</code>
      */
     private $oauth_scope = '';
 
@@ -49,11 +41,10 @@ class SimpleResponse extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Payload to increase message size.
-     * </pre>
      *
-     * <code>.grpc.testing.Payload payload = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.Payload payload = 1;</code>
+     * @return \Grpc\Testing\Payload
      */
     public function getPayload()
     {
@@ -61,25 +52,26 @@ class SimpleResponse extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Payload to increase message size.
-     * </pre>
      *
-     * <code>.grpc.testing.Payload payload = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.Payload payload = 1;</code>
+     * @param \Grpc\Testing\Payload $var
+     * @return $this
      */
-    public function setPayload(&$var)
+    public function setPayload($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\Payload::class);
         $this->payload = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * The user the request came from, for verifying authentication was
      * successful when the client expected it.
-     * </pre>
      *
-     * <code>string username = 2;</code>
+     * Generated from protobuf field <code>string username = 2;</code>
+     * @return string
      */
     public function getUsername()
     {
@@ -87,25 +79,26 @@ class SimpleResponse extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * The user the request came from, for verifying authentication was
      * successful when the client expected it.
-     * </pre>
      *
-     * <code>string username = 2;</code>
+     * Generated from protobuf field <code>string username = 2;</code>
+     * @param string $var
+     * @return $this
      */
     public function setUsername($var)
     {
         GPBUtil::checkString($var, True);
         $this->username = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * OAuth scope.
-     * </pre>
      *
-     * <code>string oauth_scope = 3;</code>
+     * Generated from protobuf field <code>string oauth_scope = 3;</code>
+     * @return string
      */
     public function getOauthScope()
     {
@@ -113,16 +106,18 @@ class SimpleResponse extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * OAuth scope.
-     * </pre>
      *
-     * <code>string oauth_scope = 3;</code>
+     * Generated from protobuf field <code>string oauth_scope = 3;</code>
+     * @param string $var
+     * @return $this
      */
     public function setOauthScope($var)
     {
         GPBUtil::checkString($var, True);
         $this->oauth_scope = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/StreamingInputCallRequest.php b/src/php/tests/qps/generated_code/Grpc/Testing/StreamingInputCallRequest.php
index d7bbc707799..a7460af83a3 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/StreamingInputCallRequest.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/StreamingInputCallRequest.php
@@ -9,31 +9,25 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * <pre>
  * Client-streaming request.
- * </pre>
  *
- * Protobuf type <code>grpc.testing.StreamingInputCallRequest</code>
+ * Generated from protobuf message <code>grpc.testing.StreamingInputCallRequest</code>
  */
 class StreamingInputCallRequest extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <pre>
      * Optional input payload sent along with the request.
-     * </pre>
      *
-     * <code>.grpc.testing.Payload payload = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.Payload payload = 1;</code>
      */
     private $payload = null;
     /**
-     * <pre>
      * Whether the server should expect this request to be compressed. This field
      * is "nullable" in order to interoperate seamlessly with servers not able to
      * implement the full compression tests by introspecting the call to verify
      * the request's compression status.
-     * </pre>
      *
-     * <code>.grpc.testing.BoolValue expect_compressed = 2;</code>
+     * Generated from protobuf field <code>.grpc.testing.BoolValue expect_compressed = 2;</code>
      */
     private $expect_compressed = null;
 
@@ -43,11 +37,10 @@ class StreamingInputCallRequest extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Optional input payload sent along with the request.
-     * </pre>
      *
-     * <code>.grpc.testing.Payload payload = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.Payload payload = 1;</code>
+     * @return \Grpc\Testing\Payload
      */
     public function getPayload()
     {
@@ -55,27 +48,28 @@ class StreamingInputCallRequest extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Optional input payload sent along with the request.
-     * </pre>
      *
-     * <code>.grpc.testing.Payload payload = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.Payload payload = 1;</code>
+     * @param \Grpc\Testing\Payload $var
+     * @return $this
      */
-    public function setPayload(&$var)
+    public function setPayload($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\Payload::class);
         $this->payload = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Whether the server should expect this request to be compressed. This field
      * is "nullable" in order to interoperate seamlessly with servers not able to
      * implement the full compression tests by introspecting the call to verify
      * the request's compression status.
-     * </pre>
      *
-     * <code>.grpc.testing.BoolValue expect_compressed = 2;</code>
+     * Generated from protobuf field <code>.grpc.testing.BoolValue expect_compressed = 2;</code>
+     * @return \Grpc\Testing\BoolValue
      */
     public function getExpectCompressed()
     {
@@ -83,19 +77,21 @@ class StreamingInputCallRequest extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Whether the server should expect this request to be compressed. This field
      * is "nullable" in order to interoperate seamlessly with servers not able to
      * implement the full compression tests by introspecting the call to verify
      * the request's compression status.
-     * </pre>
      *
-     * <code>.grpc.testing.BoolValue expect_compressed = 2;</code>
+     * Generated from protobuf field <code>.grpc.testing.BoolValue expect_compressed = 2;</code>
+     * @param \Grpc\Testing\BoolValue $var
+     * @return $this
      */
-    public function setExpectCompressed(&$var)
+    public function setExpectCompressed($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\BoolValue::class);
         $this->expect_compressed = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/StreamingInputCallResponse.php b/src/php/tests/qps/generated_code/Grpc/Testing/StreamingInputCallResponse.php
index fdd1d0dbf8a..41f3893aa3f 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/StreamingInputCallResponse.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/StreamingInputCallResponse.php
@@ -9,20 +9,16 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * <pre>
  * Client-streaming response.
- * </pre>
  *
- * Protobuf type <code>grpc.testing.StreamingInputCallResponse</code>
+ * Generated from protobuf message <code>grpc.testing.StreamingInputCallResponse</code>
  */
 class StreamingInputCallResponse extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <pre>
      * Aggregated size of payloads received from the client.
-     * </pre>
      *
-     * <code>int32 aggregated_payload_size = 1;</code>
+     * Generated from protobuf field <code>int32 aggregated_payload_size = 1;</code>
      */
     private $aggregated_payload_size = 0;
 
@@ -32,11 +28,10 @@ class StreamingInputCallResponse extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Aggregated size of payloads received from the client.
-     * </pre>
      *
-     * <code>int32 aggregated_payload_size = 1;</code>
+     * Generated from protobuf field <code>int32 aggregated_payload_size = 1;</code>
+     * @return int
      */
     public function getAggregatedPayloadSize()
     {
@@ -44,16 +39,18 @@ class StreamingInputCallResponse extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Aggregated size of payloads received from the client.
-     * </pre>
      *
-     * <code>int32 aggregated_payload_size = 1;</code>
+     * Generated from protobuf field <code>int32 aggregated_payload_size = 1;</code>
+     * @param int $var
+     * @return $this
      */
     public function setAggregatedPayloadSize($var)
     {
         GPBUtil::checkInt32($var);
         $this->aggregated_payload_size = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/StreamingOutputCallRequest.php b/src/php/tests/qps/generated_code/Grpc/Testing/StreamingOutputCallRequest.php
index 2aab5fadad7..69d9cecffa7 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/StreamingOutputCallRequest.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/StreamingOutputCallRequest.php
@@ -9,48 +9,38 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * <pre>
  * Server-streaming request.
- * </pre>
  *
- * Protobuf type <code>grpc.testing.StreamingOutputCallRequest</code>
+ * Generated from protobuf message <code>grpc.testing.StreamingOutputCallRequest</code>
  */
 class StreamingOutputCallRequest extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <pre>
      * DEPRECATED, don't use. To be removed shortly.
      * Desired payload type in the response from the server.
      * If response_type is RANDOM, the payload from each response in the stream
      * might be of different types. This is to simulate a mixed type of payload
      * stream.
-     * </pre>
      *
-     * <code>.grpc.testing.PayloadType response_type = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.PayloadType response_type = 1;</code>
      */
     private $response_type = 0;
     /**
-     * <pre>
      * Configuration for each expected response message.
-     * </pre>
      *
-     * <code>repeated .grpc.testing.ResponseParameters response_parameters = 2;</code>
+     * Generated from protobuf field <code>repeated .grpc.testing.ResponseParameters response_parameters = 2;</code>
      */
     private $response_parameters;
     /**
-     * <pre>
      * Optional input payload sent along with the request.
-     * </pre>
      *
-     * <code>.grpc.testing.Payload payload = 3;</code>
+     * Generated from protobuf field <code>.grpc.testing.Payload payload = 3;</code>
      */
     private $payload = null;
     /**
-     * <pre>
      * Whether server should return a given status
-     * </pre>
      *
-     * <code>.grpc.testing.EchoStatus response_status = 7;</code>
+     * Generated from protobuf field <code>.grpc.testing.EchoStatus response_status = 7;</code>
      */
     private $response_status = null;
 
@@ -60,15 +50,14 @@ class StreamingOutputCallRequest extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * DEPRECATED, don't use. To be removed shortly.
      * Desired payload type in the response from the server.
      * If response_type is RANDOM, the payload from each response in the stream
      * might be of different types. This is to simulate a mixed type of payload
      * stream.
-     * </pre>
      *
-     * <code>.grpc.testing.PayloadType response_type = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.PayloadType response_type = 1;</code>
+     * @return int
      */
     public function getResponseType()
     {
@@ -76,28 +65,29 @@ class StreamingOutputCallRequest extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * DEPRECATED, don't use. To be removed shortly.
      * Desired payload type in the response from the server.
      * If response_type is RANDOM, the payload from each response in the stream
      * might be of different types. This is to simulate a mixed type of payload
      * stream.
-     * </pre>
      *
-     * <code>.grpc.testing.PayloadType response_type = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.PayloadType response_type = 1;</code>
+     * @param int $var
+     * @return $this
      */
     public function setResponseType($var)
     {
         GPBUtil::checkEnum($var, \Grpc\Testing\PayloadType::class);
         $this->response_type = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Configuration for each expected response message.
-     * </pre>
      *
-     * <code>repeated .grpc.testing.ResponseParameters response_parameters = 2;</code>
+     * Generated from protobuf field <code>repeated .grpc.testing.ResponseParameters response_parameters = 2;</code>
+     * @return \Google\Protobuf\Internal\RepeatedField
      */
     public function getResponseParameters()
     {
@@ -105,24 +95,25 @@ class StreamingOutputCallRequest extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Configuration for each expected response message.
-     * </pre>
      *
-     * <code>repeated .grpc.testing.ResponseParameters response_parameters = 2;</code>
+     * Generated from protobuf field <code>repeated .grpc.testing.ResponseParameters response_parameters = 2;</code>
+     * @param \Grpc\Testing\ResponseParameters[]|\Google\Protobuf\Internal\RepeatedField $var
+     * @return $this
      */
-    public function setResponseParameters(&$var)
+    public function setResponseParameters($var)
     {
-        GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::MESSAGE, \Grpc\Testing\ResponseParameters::class);
-        $this->response_parameters = $var;
+        $arr = GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::MESSAGE, \Grpc\Testing\ResponseParameters::class);
+        $this->response_parameters = $arr;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Optional input payload sent along with the request.
-     * </pre>
      *
-     * <code>.grpc.testing.Payload payload = 3;</code>
+     * Generated from protobuf field <code>.grpc.testing.Payload payload = 3;</code>
+     * @return \Grpc\Testing\Payload
      */
     public function getPayload()
     {
@@ -130,24 +121,25 @@ class StreamingOutputCallRequest extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Optional input payload sent along with the request.
-     * </pre>
      *
-     * <code>.grpc.testing.Payload payload = 3;</code>
+     * Generated from protobuf field <code>.grpc.testing.Payload payload = 3;</code>
+     * @param \Grpc\Testing\Payload $var
+     * @return $this
      */
-    public function setPayload(&$var)
+    public function setPayload($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\Payload::class);
         $this->payload = $var;
+
+        return $this;
     }
 
     /**
-     * <pre>
      * Whether server should return a given status
-     * </pre>
      *
-     * <code>.grpc.testing.EchoStatus response_status = 7;</code>
+     * Generated from protobuf field <code>.grpc.testing.EchoStatus response_status = 7;</code>
+     * @return \Grpc\Testing\EchoStatus
      */
     public function getResponseStatus()
     {
@@ -155,16 +147,18 @@ class StreamingOutputCallRequest extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Whether server should return a given status
-     * </pre>
      *
-     * <code>.grpc.testing.EchoStatus response_status = 7;</code>
+     * Generated from protobuf field <code>.grpc.testing.EchoStatus response_status = 7;</code>
+     * @param \Grpc\Testing\EchoStatus $var
+     * @return $this
      */
-    public function setResponseStatus(&$var)
+    public function setResponseStatus($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\EchoStatus::class);
         $this->response_status = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/StreamingOutputCallResponse.php b/src/php/tests/qps/generated_code/Grpc/Testing/StreamingOutputCallResponse.php
index c06c78c9d8f..52315bb4995 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/StreamingOutputCallResponse.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/StreamingOutputCallResponse.php
@@ -9,20 +9,16 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * <pre>
  * Server-streaming response, as configured by the request and parameters.
- * </pre>
  *
- * Protobuf type <code>grpc.testing.StreamingOutputCallResponse</code>
+ * Generated from protobuf message <code>grpc.testing.StreamingOutputCallResponse</code>
  */
 class StreamingOutputCallResponse extends \Google\Protobuf\Internal\Message
 {
     /**
-     * <pre>
      * Payload to increase response size.
-     * </pre>
      *
-     * <code>.grpc.testing.Payload payload = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.Payload payload = 1;</code>
      */
     private $payload = null;
 
@@ -32,11 +28,10 @@ class StreamingOutputCallResponse extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Payload to increase response size.
-     * </pre>
      *
-     * <code>.grpc.testing.Payload payload = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.Payload payload = 1;</code>
+     * @return \Grpc\Testing\Payload
      */
     public function getPayload()
     {
@@ -44,16 +39,18 @@ class StreamingOutputCallResponse extends \Google\Protobuf\Internal\Message
     }
 
     /**
-     * <pre>
      * Payload to increase response size.
-     * </pre>
      *
-     * <code>.grpc.testing.Payload payload = 1;</code>
+     * Generated from protobuf field <code>.grpc.testing.Payload payload = 1;</code>
+     * @param \Grpc\Testing\Payload $var
+     * @return $this
      */
-    public function setPayload(&$var)
+    public function setPayload($var)
     {
         GPBUtil::checkMessage($var, \Grpc\Testing\Payload::class);
         $this->payload = $var;
+
+        return $this;
     }
 
 }
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/Void.php b/src/php/tests/qps/generated_code/Grpc/Testing/Void.php
index 38c100845a0..623021d99b9 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/Void.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/Void.php
@@ -9,7 +9,7 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * Protobuf type <code>grpc.testing.Void</code>
+ * Generated from protobuf message <code>grpc.testing.Void</code>
  */
 class Void extends \Google\Protobuf\Internal\Message
 {
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/WorkerServiceClient.php b/src/php/tests/qps/generated_code/Grpc/Testing/WorkerServiceClient.php
index 959d839c80a..98c244ff9dc 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/WorkerServiceClient.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/WorkerServiceClient.php
@@ -18,17 +18,19 @@
 //
 // An integration test service that covers all the method signature permutations
 // of unary/streaming requests/responses.
-namespace Grpc\Testing {
+namespace Grpc\Testing;
 
-  class WorkerServiceClient extends \Grpc\BaseStub {
+/**
+ */
+class WorkerServiceClient extends \Grpc\BaseStub {
 
     /**
      * @param string $hostname hostname
      * @param array $opts channel options
-     * @param Grpc\Channel $channel (optional) re-use channel object
+     * @param \Grpc\Channel $channel (optional) re-use channel object
      */
     public function __construct($hostname, $opts, $channel = null) {
-      parent::__construct($hostname, $opts, $channel);
+        parent::__construct($hostname, $opts, $channel);
     }
 
     /**
@@ -42,9 +44,9 @@ namespace Grpc\Testing {
      * @param array $options call options
      */
     public function RunServer($metadata = [], $options = []) {
-      return $this->_bidiRequest('/grpc.testing.WorkerService/RunServer',
-      ['\Grpc\Testing\ServerStatus','decode'],
-      $metadata, $options);
+        return $this->_bidiRequest('/grpc.testing.WorkerService/RunServer',
+        ['\Grpc\Testing\ServerStatus','decode'],
+        $metadata, $options);
     }
 
     /**
@@ -58,9 +60,9 @@ namespace Grpc\Testing {
      * @param array $options call options
      */
     public function RunClient($metadata = [], $options = []) {
-      return $this->_bidiRequest('/grpc.testing.WorkerService/RunClient',
-      ['\Grpc\Testing\ClientStatus','decode'],
-      $metadata, $options);
+        return $this->_bidiRequest('/grpc.testing.WorkerService/RunClient',
+        ['\Grpc\Testing\ClientStatus','decode'],
+        $metadata, $options);
     }
 
     /**
@@ -71,10 +73,10 @@ namespace Grpc\Testing {
      */
     public function CoreCount(\Grpc\Testing\CoreRequest $argument,
       $metadata = [], $options = []) {
-      return $this->_simpleRequest('/grpc.testing.WorkerService/CoreCount',
-      $argument,
-      ['\Grpc\Testing\CoreResponse', 'decode'],
-      $metadata, $options);
+        return $this->_simpleRequest('/grpc.testing.WorkerService/CoreCount',
+        $argument,
+        ['\Grpc\Testing\CoreResponse', 'decode'],
+        $metadata, $options);
     }
 
     /**
@@ -85,12 +87,10 @@ namespace Grpc\Testing {
      */
     public function QuitWorker(\Grpc\Testing\Void $argument,
       $metadata = [], $options = []) {
-      return $this->_simpleRequest('/grpc.testing.WorkerService/QuitWorker',
-      $argument,
-      ['\Grpc\Testing\Void', 'decode'],
-      $metadata, $options);
+        return $this->_simpleRequest('/grpc.testing.WorkerService/QuitWorker',
+        $argument,
+        ['\Grpc\Testing\Void', 'decode'],
+        $metadata, $options);
     }
 
-  }
-
 }
diff --git a/src/php/tests/qps/histogram.php b/src/php/tests/qps/histogram.php
new file mode 100644
index 00000000000..c11a67c6186
--- /dev/null
+++ b/src/php/tests/qps/histogram.php
@@ -0,0 +1,93 @@
+<?php
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Histogram class for use in performance testing and measurement
+class Histogram {
+  private $resolution;
+  private $max_possible;
+  private $sum;
+  private $sum_of_squares;
+  private $multiplier;
+  private $count;
+  private $min_seen;
+  private $max_seen;
+  private $buckets;
+
+  private function bucket_for($value) {
+    return (int)(log($value) / log($this->multiplier));
+  }
+
+  public function __construct($resolution, $max_possible) {
+    $this->resolution = $resolution;
+    $this->max_possible = $max_possible;
+    $this->sum = 0;
+    $this->sum_of_squares = 0;
+    $this->multiplier = 1+$resolution;
+    $this->count = 0;
+    $this->min_seen = $max_possible;
+    $this->max_seen = 0;
+    $this->buckets = array_fill(0, $this->bucket_for($max_possible)+1, 0);
+  }
+
+  public function add($value) {
+    $this->sum += $value;
+    $this->sum_of_squares += $value * $value;
+    $this->count += 1;
+    if ($value < $this->min_seen) {
+      $this->min_seen = $value;
+    }
+    if ($value > $this->max_seen) {
+      $this->max_seen = $value;
+    }
+    $this->buckets[$this->bucket_for($value)] += 1;
+  }
+
+  public function minimum() {
+    return $this->min_seen;
+  }
+
+  public function maximum() {
+    return $this->max_seen;
+  }
+
+  public function sum() {
+    return $this->sum;
+  }
+
+  public function sum_of_squares() {
+    return $this->sum_of_squares;
+  }
+
+  public function count() {
+    return $this->count;
+  }
+
+  public function contents() {
+    return $this->buckets;
+  }
+
+  public function clean() {
+    $this->sum = 0;
+    $this->sum_of_squares = 0;
+    $this->count = 0;
+    $this->min_seen = $this->max_possible;
+    $this->max_seen = 0;
+    $this->buckets = array_fill(0, $this->bucket_for($this->max_possible)+1, 0);
+  }
+}
diff --git a/src/proto/grpc/testing/echo_messages.proto b/src/proto/grpc/testing/echo_messages.proto
index c5c5fdb3fc4..5396a2fd39a 100644
--- a/src/proto/grpc/testing/echo_messages.proto
+++ b/src/proto/grpc/testing/echo_messages.proto
@@ -45,6 +45,7 @@ message RequestParams {
   bool server_die = 12; // Server should not see a request with this set.
   string binary_error_details = 13;
   ErrorStatus expected_error = 14;
+  int32 server_sleep_us = 15; // Amount to sleep when invoking server
 }
 
 message EchoRequest {
diff --git a/src/proto/grpc/testing/proxy-service.proto b/src/proto/grpc/testing/proxy-service.proto
index 8d0a9498c02..deaabd13651 100644
--- a/src/proto/grpc/testing/proxy-service.proto
+++ b/src/proto/grpc/testing/proxy-service.proto
@@ -15,6 +15,7 @@
 syntax = "proto3";
 
 import "src/proto/grpc/testing/control.proto";
+import "src/proto/grpc/testing/stats.proto";
 
 package grpc.testing;
 
@@ -25,5 +26,6 @@ message ProxyStat {
 service ProxyClientService {
   rpc GetConfig(Void) returns (ClientConfig);
   rpc ReportTime(stream ProxyStat) returns (Void);
+  rpc ReportHist(stream HistogramData) returns (Void);
 }
 
diff --git a/src/python/grpcio/grpc_core_dependencies.py b/src/python/grpcio/grpc_core_dependencies.py
index 68e27530262..c5e4615cad4 100644
--- a/src/python/grpcio/grpc_core_dependencies.py
+++ b/src/python/grpcio/grpc_core_dependencies.py
@@ -21,7 +21,6 @@ CORE_SOURCE_FILES = [
   'src/core/lib/support/arena.cc',
   'src/core/lib/support/atm.cc',
   'src/core/lib/support/avl.cc',
-  'src/core/lib/support/backoff.cc',
   'src/core/lib/support/cmdline.cc',
   'src/core/lib/support/cpu_iphone.cc',
   'src/core/lib/support/cpu_linux.cc',
@@ -62,6 +61,7 @@ CORE_SOURCE_FILES = [
   'src/core/lib/support/tmpfile_windows.cc',
   'src/core/lib/support/wrap_memcpy.cc',
   'src/core/lib/surface/init.cc',
+  'src/core/lib/backoff/backoff.cc',
   'src/core/lib/channel/channel_args.cc',
   'src/core/lib/channel/channel_stack.cc',
   'src/core/lib/channel/channel_stack_builder.cc',
diff --git a/src/ruby/end2end/load_grpc_with_gc_stress_driver.rb b/src/ruby/end2end/load_grpc_with_gc_stress_driver.rb
new file mode 100755
index 00000000000..3668b95a052
--- /dev/null
+++ b/src/ruby/end2end/load_grpc_with_gc_stress_driver.rb
@@ -0,0 +1,32 @@
+#!/usr/bin/env ruby
+#
+# Copyright 2016 gRPC authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+this_dir = File.expand_path(File.dirname(__FILE__))
+protos_lib_dir = File.join(this_dir, 'lib')
+grpc_lib_dir = File.join(File.dirname(this_dir), 'lib')
+$LOAD_PATH.unshift(grpc_lib_dir) unless $LOAD_PATH.include?(grpc_lib_dir)
+$LOAD_PATH.unshift(protos_lib_dir) unless $LOAD_PATH.include?(protos_lib_dir)
+$LOAD_PATH.unshift(this_dir) unless $LOAD_PATH.include?(this_dir)
+
+GC.stress = 0x04
+
+require 'grpc'
+
+GRPC::Core::Channel.new('dummy_host', nil, :this_channel_is_insecure)
+GRPC::Core::Server.new({})
+GRPC::Core::ChannelCredentials.new
+GRPC::Core::CallCredentials.new(proc { |noop| noop })
+GRPC::Core::CompressionOptions.new
diff --git a/src/ruby/ext/grpc/rb_grpc.c b/src/ruby/ext/grpc/rb_grpc.c
index 933a3ac1525..b53f09edec4 100644
--- a/src/ruby/ext/grpc/rb_grpc.c
+++ b/src/ruby/ext/grpc/rb_grpc.c
@@ -315,8 +315,8 @@ void Init_grpc_c() {
     return;
   }
 
-  bg_thread_init_rb_mu = rb_mutex_new();
   rb_global_variable(&bg_thread_init_rb_mu);
+  bg_thread_init_rb_mu = rb_mutex_new();
 
   grpc_rb_mGRPC = rb_define_module("GRPC");
   grpc_rb_mGrpcCore = rb_define_module_under(grpc_rb_mGRPC, "Core");
diff --git a/src/ruby/qps/histogram.rb b/src/ruby/qps/histogram.rb
index 1a27e172180..e48fb842be4 100644
--- a/src/ruby/qps/histogram.rb
+++ b/src/ruby/qps/histogram.rb
@@ -16,6 +16,8 @@
 
 # Histogram class for use in performance testing and measurement
 
+require 'thread'
+
 class Histogram
   # Determine the bucket index for a given value
   # @param {number} value The value to check
@@ -27,6 +29,7 @@ class Histogram
   # @param {number} resolution The resolution of the histogram
   # @param {number} max_possible The maximum value for the histogram
   def initialize(resolution, max_possible)
+    @lock = Mutex.new
     @resolution=resolution
     @max_possible=max_possible
     @sum=0
@@ -70,4 +73,16 @@ class Histogram
   def contents
     @buckets
   end
+
+  def merge(hist)
+    @lock.synchronize do
+      @min_seen = hist.min_seen
+      @max_seen = hist.max_seen
+      @sum += hist.sum
+      @sum_of_squares += hist.sum_of_squares
+      @count += hist.count
+      received_bucket = hist.bucket.to_a
+      @buckets = @buckets.map.with_index{ |m,i| m + received_bucket[i].to_i }
+    end
+  end
 end
diff --git a/src/ruby/qps/proxy-worker.rb b/src/ruby/qps/proxy-worker.rb
index ae7006e7d60..fc5db50c1c8 100755
--- a/src/ruby/qps/proxy-worker.rb
+++ b/src/ruby/qps/proxy-worker.rb
@@ -41,32 +41,49 @@ class ProxyBenchmarkClientServiceImpl < Grpc::Testing::ProxyClientService::Servi
     @histmax = config.histogram_params.max_possible
     @histogram = Histogram.new(@histres, @histmax)
     @start_time = Time.now
-    # TODO(vjpai): Support multiple client channels by spawning off a PHP client per channel
-    if @use_c_ext
-      puts "Use protobuf c extension"
-      command = "php -d extension=" + File.expand_path(File.dirname(__FILE__)) + "/../../php/tests/qps/vendor/google/protobuf/php/ext/google/protobuf/modules/protobuf.so " + "-d extension=" + File.expand_path(File.dirname(__FILE__)) + "/../../php/ext/grpc/modules/grpc.so " + File.expand_path(File.dirname(__FILE__)) + "/../../php/tests/qps/client.php " + @mytarget
-    else
-      puts "Use protobuf php extension"
-      command = "php -d extension=" + File.expand_path(File.dirname(__FILE__)) + "/../../php/ext/grpc/modules/grpc.so " + File.expand_path(File.dirname(__FILE__)) + "/../../php/tests/qps/client.php " + @mytarget
-    end	
-    puts "Starting command: " + command
-    @php_pid = spawn(command)
+    @php_pid = Array.new(@config.client_channels)
+    (0..@config.client_channels-1).each do |chan|
+      Thread.new {
+        if @use_c_ext
+          puts "Use protobuf c extension"
+          command = "php -d extension=" + File.expand_path(File.dirname(__FILE__)) +
+            "/../../php/tests/qps/vendor/google/protobuf/php/ext/google/protobuf/modules/protobuf.so " +
+            "-d extension=" + File.expand_path(File.dirname(__FILE__)) + "/../../php/ext/grpc/modules/grpc.so " +
+            File.expand_path(File.dirname(__FILE__)) + "/../../php/tests/qps/client.php " + @mytarget + " #{chan%@config.server_targets.length}"
+        else
+          puts "Use protobuf php extension"
+          command = "php -d extension=" + File.expand_path(File.dirname(__FILE__)) + "/../../php/ext/grpc/modules/grpc.so " +
+            File.expand_path(File.dirname(__FILE__)) + "/../../php/tests/qps/client.php " + @mytarget + " #{chan%@config.server_targets.length}"
+        end
+        puts "[ruby proxy] Starting #{chan}th php-client command use c protobuf #{@use_c_ext}: " + command
+        @php_pid[chan] = spawn(command)
+        while true
+          sleep
+        end
+      }
+    end
   end
   def stop
-    Process.kill("TERM", @php_pid)
-    Process.wait(@php_pid)
+    (0..@config.client_channels-1).each do |chan|
+      Process.kill("TERM", @php_pid[chan])
+      Process.wait(@php_pid[chan])
+    end
   end
   def get_config(_args, _call)
-    puts "Answering get_config"
     @config
   end
   def report_time(call)
-    puts "Starting a time reporting stream"
     call.each_remote_read do |lat|
       @histogram.add((lat.latency)*1e9)
     end
     Grpc::Testing::Void.new
   end
+  def report_hist(call)
+    call.each_remote_read do |lat|
+      @histogram.merge(lat)
+    end
+    Grpc::Testing::Void.new
+  end
   def mark(reset)
     lat = Grpc::Testing::HistogramData.new(
       bucket: @histogram.contents,
@@ -135,7 +152,7 @@ def proxymain
     opts.on('--driver_port PORT', '<port>') do |v|
       options['driver_port'] = v
     end
-    opts.on("-c", "--[no-]c_proto_ext", "Use protobuf C-extention") do |c|
+    opts.on("-c", "--[no-]use_protobuf_c_extension", "Use protobuf C-extention") do |c|
       options[:c_ext] = c
     end
   end.parse!
@@ -143,7 +160,8 @@ def proxymain
   # Configure any errors with client or server child threads to surface
   Thread.abort_on_exception = true
 
-  s = GRPC::RpcServer.new
+  # Make sure proxy_server can handle the large number of calls in benchmarks
+  s = GRPC::RpcServer.new(pool_size: 1024)
   port = s.add_http2_port("0.0.0.0:" + options['driver_port'].to_s,
                           :this_port_is_insecure)
   bmc = ProxyBenchmarkClientServiceImpl.new(port, options[:c_ext])
diff --git a/src/ruby/qps/src/proto/grpc/testing/proxy-service_pb.rb b/src/ruby/qps/src/proto/grpc/testing/proxy-service_pb.rb
index d238198cca3..583b2ea6558 100644
--- a/src/ruby/qps/src/proto/grpc/testing/proxy-service_pb.rb
+++ b/src/ruby/qps/src/proto/grpc/testing/proxy-service_pb.rb
@@ -4,6 +4,7 @@
 require 'google/protobuf'
 
 require 'src/proto/grpc/testing/control_pb'
+require 'src/proto/grpc/testing/stats_pb'
 Google::Protobuf::DescriptorPool.generated_pool.build do
   add_message "grpc.testing.ProxyStat" do
     optional :latency, :double, 1
diff --git a/src/ruby/qps/src/proto/grpc/testing/proxy-service_services_pb.rb b/src/ruby/qps/src/proto/grpc/testing/proxy-service_services_pb.rb
index 484cf05f92f..e7bb59b8a09 100644
--- a/src/ruby/qps/src/proto/grpc/testing/proxy-service_services_pb.rb
+++ b/src/ruby/qps/src/proto/grpc/testing/proxy-service_services_pb.rb
@@ -32,6 +32,7 @@ module Grpc
 
         rpc :GetConfig, Void, ClientConfig
         rpc :ReportTime, stream(ProxyStat), Void
+        rpc :ReportHist, stream(HistogramData), Void
       end
 
       Stub = Service.rpc_stub_class
diff --git a/templates/gRPC-Core.podspec.template b/templates/gRPC-Core.podspec.template
index f3ac30c08d3..5657df85211 100644
--- a/templates/gRPC-Core.podspec.template
+++ b/templates/gRPC-Core.podspec.template
@@ -31,19 +31,11 @@
     return [f for f in out if not f.startswith("third_party/nanopb/")]
 
   def grpc_public_headers(libs):
-    excluded_files = ["include/grpc/support/atm_gcc_sync.h",
-                      "include/grpc/support/atm_windows.h",
-                      "include/grpc/support/sync_windows.h",
-                      "include/grpc/support/tls_gcc.h",
-                      "include/grpc/support/tls_msvc.h",
-                      "include/grpc/impl/codegen/atm_gcc_sync.h",
-                      "include/grpc/impl/codegen/atm_windows.h",
-                      "include/grpc/impl/codegen/sync_windows.h"]
     out = []
     for lib in libs:
       if lib.name in ("grpc", "gpr"):
         out += lib.get('public_headers', [])
-    return [f for f in out if not f in excluded_files]
+    return out
 
   def grpc_private_headers(libs):
     out = []
diff --git a/templates/gRPC.podspec.template b/templates/gRPC.podspec.template
index 5c92f9f9c42..4b360cfb4c4 100644
--- a/templates/gRPC.podspec.template
+++ b/templates/gRPC.podspec.template
@@ -65,10 +65,13 @@
     end
 
     s.subspec 'GID' do |ss|
+      ss.ios.deployment_target = '7.0'
+
       ss.header_mappings_dir = "#{src_dir}"
 
       ss.source_files = "#{src_dir}/GRPCCall+GID.{h,m}"
 
+      ss.dependency "#{s.name}/Main", version
       ss.dependency 'Google/SignIn'
     end
   end
diff --git a/templates/include/grpc/module.modulemap.template b/templates/include/grpc/module.modulemap.template
index 8edc4b56acd..e18bc3de50d 100644
--- a/templates/include/grpc/module.modulemap.template
+++ b/templates/include/grpc/module.modulemap.template
@@ -1,31 +1,57 @@
 %YAML 1.2
 --- |
   <%!
+  # TODO (mxyan): Make this list from build.yaml
+  textual_headers = ["include/grpc/support/atm_gcc_atomic.h",
+                     "include/grpc/support/atm_gcc_sync.h",
+                     "include/grpc/support/atm_windows.h",
+                     "include/grpc/support/sync_custom.h",
+                     "include/grpc/support/sync_posix.h",
+                     "include/grpc/support/sync_windows.h",
+                     "include/grpc/support/tls_gcc.h",
+                     "include/grpc/support/tls_msvc.h",
+                     "include/grpc/support/tls_pthread.h",
+                     "include/grpc/impl/codegen/atm_gcc_atomic.h",
+                     "include/grpc/impl/codegen/atm_gcc_sync.h",
+                     "include/grpc/impl/codegen/atm_windows.h",
+                     "include/grpc/impl/codegen/sync_custom.h",
+                     "include/grpc/impl/codegen/sync_posix.h",
+                     "include/grpc/impl/codegen/sync_windows.h"]
+
   def grpc_public_headers_no_dir(libs):
-    excluded_files = ["include/grpc/support/atm_gcc_sync.h",
-                      "include/grpc/support/atm_windows.h",
-                      "include/grpc/support/sync_windows.h",
-                      "include/grpc/support/tls_gcc.h",
-                      "include/grpc/support/tls_msvc.h",
-                      "include/grpc/impl/codegen/atm_gcc_sync.h",
-                      "include/grpc/impl/codegen/atm_windows.h",
-                      "include/grpc/impl/codegen/sync_windows.h"]
     out = []
     for lib in libs:
       if lib.name in ("grpc", "gpr"):
         out += lib.get('public_headers', [])
-    out = [f for f in out if f not in excluded_files]
+    out = [f for f in out if f not in textual_headers]
+    out = [hdr.split('/', 2)[2] for hdr in out]
+    return out
+
+  # Generate the list of platform-specific headers as textual headers so that
+  # they are not built when the module is built but only when they are named by
+  # an #include directive.
+  def grpc_public_textual_headers_no_dir(libs):
+    out = []
+    for lib in libs:
+      if lib.name in ("grpc", "gpr"):
+        out += lib.get('public_headers', [])
+    out = [f for f in out if f in textual_headers]
     out = [hdr.split('/', 2)[2] for hdr in out]
     return out
 
   def header_lines(files):
     return ('\n  ').join('header "%s"' % f for f in files)
+
+  def textual_header_lines(files):
+    return ('\n  ').join('textual header "%s"' % f for f in files)
   %>
   framework module grpc {
     umbrella header "grpc.h"
 
     ${header_lines(grpc_public_headers_no_dir(libs))}
 
+    ${textual_header_lines(grpc_public_textual_headers_no_dir(libs))}
+
     export *
     module * { export * }
   }
diff --git a/templates/tools/dockerfile/test/node_jessie_x64/Dockerfile.template b/templates/tools/dockerfile/test/node_jessie_x64/Dockerfile.template
index aa34a694fb0..af85a542358 100644
--- a/templates/tools/dockerfile/test/node_jessie_x64/Dockerfile.template
+++ b/templates/tools/dockerfile/test/node_jessie_x64/Dockerfile.template
@@ -32,5 +32,8 @@
   <%include file="../../python_deps.include"/>
   <%include file="../../node_deps.include"/>
   <%include file="../../run_tests_addons.include"/>
+  # Install Mako to generate files in grpc/grpc-node
+  RUN pip install Mako
+
   # Define the default command.
   CMD ["bash"]
diff --git a/templates/tools/run_tests/generated/tests.json.template b/templates/tools/run_tests/generated/tests.json.template
index 10ab2e445a4..0c9f0a14c47 100644
--- a/templates/tools/run_tests/generated/tests.json.template
+++ b/templates/tools/run_tests/generated/tests.json.template
@@ -13,7 +13,8 @@
            "exclude_iomgrs": tgt.get("exclude_iomgrs", []),
            "args": tgt.get("args", []),
            "flaky": tgt.flaky,
-           "cpu_cost": tgt.get("cpu_cost", 1.0)}
+           "cpu_cost": tgt.get("cpu_cost", 1.0),
+           "uses_polling": tgt.get("uses_polling", True)}
     timeout_seconds = tgt.get("timeout_seconds", None)
     if timeout_seconds:
       out['timeout_seconds'] = timeout_seconds
diff --git a/tools/internal_ci/linux/grpc_interop_tocloud.sh b/test/core/backoff/BUILD
old mode 100755
new mode 100644
similarity index 53%
rename from tools/internal_ci/linux/grpc_interop_tocloud.sh
rename to test/core/backoff/BUILD
index e3ba25af5df..4ae762007cb
--- a/tools/internal_ci/linux/grpc_interop_tocloud.sh
+++ b/test/core/backoff/BUILD
@@ -1,5 +1,4 @@
-#!/usr/bin/env bash
-# Copyright 2017 gRPC authors.
+# Copyright 2016 gRPC authors.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -13,14 +12,25 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-set -ex
+load("//bazel:grpc_build_system.bzl", "grpc_cc_library", "grpc_cc_test", "grpc_cc_binary")
 
-export LANG=en_US.UTF-8
+licenses(["notice"])  # Apache v2
 
-# Enter the gRPC repo root
-cd $(dirname $0)/../../..
+package(
+    features = [
+        "-layering_check",
+        "-parse_headers",
+    ],
+)
 
-source tools/internal_ci/helper_scripts/prepare_build_linux_rc
-source tools/internal_ci/helper_scripts/prepare_build_interop_rc
-
-tools/run_tests/run_interop_tests.py -l all -s all --use_docker --http2_interop --internal_ci -t -j 12 $@
+grpc_cc_test(
+    name = "backoff_test",
+    srcs = ["backoff_test.c"],
+    language = "C",
+    deps = [
+        "//:grpc",
+        "//test/core/util:grpc_test_util",
+        "//:gpr",
+        "//test/core/util:gpr_test_util",
+    ],
+)
diff --git a/test/core/backoff/backoff_test.c b/test/core/backoff/backoff_test.c
new file mode 100644
index 00000000000..a29cce6cc7b
--- /dev/null
+++ b/test/core/backoff/backoff_test.c
@@ -0,0 +1,150 @@
+/*
+ *
+ * Copyright 2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include "src/core/lib/backoff/backoff.h"
+
+#include <grpc/support/log.h>
+
+#include "test/core/util/test_config.h"
+
+static void test_constant_backoff(void) {
+  grpc_backoff backoff;
+  grpc_backoff_init(&backoff, 200 /* initial timeout */, 1.0 /* multiplier */,
+                    0.0 /* jitter */, 100 /* min timeout */,
+                    1000 /* max timeout */);
+
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  grpc_millis next = grpc_backoff_begin(&exec_ctx, &backoff);
+  GPR_ASSERT(next - grpc_exec_ctx_now(&exec_ctx) == 200);
+  for (int i = 0; i < 10000; i++) {
+    next = grpc_backoff_step(&exec_ctx, &backoff);
+    GPR_ASSERT(next - grpc_exec_ctx_now(&exec_ctx) == 200);
+    exec_ctx.now = next;
+  }
+  grpc_exec_ctx_finish(&exec_ctx);
+}
+
+static void test_min_connect(void) {
+  grpc_backoff backoff;
+  grpc_backoff_init(&backoff, 100 /* initial timeout */, 1.0 /* multiplier */,
+                    0.0 /* jitter */, 200 /* min timeout */,
+                    1000 /* max timeout */);
+
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  grpc_millis next = grpc_backoff_begin(&exec_ctx, &backoff);
+  GPR_ASSERT(next - grpc_exec_ctx_now(&exec_ctx) == 200);
+  grpc_exec_ctx_finish(&exec_ctx);
+}
+
+static void test_no_jitter_backoff(void) {
+  grpc_backoff backoff;
+  grpc_backoff_init(&backoff, 2 /* initial timeout */, 2.0 /* multiplier */,
+                    0.0 /* jitter */, 1 /* min timeout */,
+                    513 /* max timeout */);
+  // x_1 = 2
+  // x_n = 2**i + x_{i-1} ( = 2**(n+1) - 2 )
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  exec_ctx.now = 0;
+  exec_ctx.now_is_valid = true;
+  grpc_millis next = grpc_backoff_begin(&exec_ctx, &backoff);
+  GPR_ASSERT(next == 2);
+  exec_ctx.now = next;
+  next = grpc_backoff_step(&exec_ctx, &backoff);
+  GPR_ASSERT(next == 6);
+  exec_ctx.now = next;
+  next = grpc_backoff_step(&exec_ctx, &backoff);
+  GPR_ASSERT(next == 14);
+  exec_ctx.now = next;
+  next = grpc_backoff_step(&exec_ctx, &backoff);
+  GPR_ASSERT(next == 30);
+  exec_ctx.now = next;
+  next = grpc_backoff_step(&exec_ctx, &backoff);
+  GPR_ASSERT(next == 62);
+  exec_ctx.now = next;
+  next = grpc_backoff_step(&exec_ctx, &backoff);
+  GPR_ASSERT(next == 126);
+  exec_ctx.now = next;
+  next = grpc_backoff_step(&exec_ctx, &backoff);
+  GPR_ASSERT(next == 254);
+  exec_ctx.now = next;
+  next = grpc_backoff_step(&exec_ctx, &backoff);
+  GPR_ASSERT(next == 510);
+  exec_ctx.now = next;
+  next = grpc_backoff_step(&exec_ctx, &backoff);
+  GPR_ASSERT(next == 1022);
+  exec_ctx.now = next;
+  next = grpc_backoff_step(&exec_ctx, &backoff);
+  // Hit the maximum timeout. From this point onwards, retries will increase
+  // only by max timeout.
+  GPR_ASSERT(next == 1535);
+  exec_ctx.now = next;
+  next = grpc_backoff_step(&exec_ctx, &backoff);
+  GPR_ASSERT(next == 2048);
+  exec_ctx.now = next;
+  next = grpc_backoff_step(&exec_ctx, &backoff);
+  GPR_ASSERT(next == 2561);
+  grpc_exec_ctx_finish(&exec_ctx);
+}
+
+static void test_jitter_backoff(void) {
+  const int64_t initial_timeout = 500;
+  const double jitter = 0.1;
+  grpc_backoff backoff;
+  grpc_backoff_init(&backoff, (grpc_millis)initial_timeout,
+                    1.0 /* multiplier */, jitter, 100 /* min timeout */,
+                    1000 /* max timeout */);
+
+  backoff.rng_state = 0;  // force consistent PRNG
+
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  grpc_millis next = grpc_backoff_begin(&exec_ctx, &backoff);
+  GPR_ASSERT(next - grpc_exec_ctx_now(&exec_ctx) == 500);
+
+  int64_t expected_next_lower_bound =
+      (int64_t)((double)initial_timeout * (1 - jitter));
+  int64_t expected_next_upper_bound =
+      (int64_t)((double)initial_timeout * (1 + jitter));
+
+  for (int i = 0; i < 10000; i++) {
+    next = grpc_backoff_step(&exec_ctx, &backoff);
+
+    // next-now must be within (jitter*100)% of the previous timeout.
+    const int64_t timeout_millis = next - grpc_exec_ctx_now(&exec_ctx);
+    GPR_ASSERT(timeout_millis >= expected_next_lower_bound);
+    GPR_ASSERT(timeout_millis <= expected_next_upper_bound);
+
+    expected_next_lower_bound =
+        (int64_t)((double)timeout_millis * (1 - jitter));
+    expected_next_upper_bound =
+        (int64_t)((double)timeout_millis * (1 + jitter));
+    exec_ctx.now = next;
+  }
+  grpc_exec_ctx_finish(&exec_ctx);
+}
+
+int main(int argc, char **argv) {
+  grpc_test_init(argc, argv);
+  gpr_time_init();
+
+  test_constant_backoff();
+  test_min_connect();
+  test_no_jitter_backoff();
+  test_jitter_backoff();
+
+  return 0;
+}
diff --git a/test/core/bad_client/bad_client.c b/test/core/bad_client/bad_client.c
index fff0c793ed6..b7b28a9ac4e 100644
--- a/test/core/bad_client/bad_client.c
+++ b/test/core/bad_client/bad_client.c
@@ -84,13 +84,18 @@ void grpc_run_bad_client_test(
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_completion_queue *shutdown_cq;
 
-  hex = gpr_dump(client_payload, client_payload_length,
-                 GPR_DUMP_HEX | GPR_DUMP_ASCII);
+  if (client_payload_length < 4 * 1024) {
+    hex = gpr_dump(client_payload, client_payload_length,
+                   GPR_DUMP_HEX | GPR_DUMP_ASCII);
 
-  /* Add a debug log */
-  gpr_log(GPR_INFO, "TEST: %s", hex);
+    /* Add a debug log */
+    gpr_log(GPR_INFO, "TEST: %s", hex);
 
-  gpr_free(hex);
+    gpr_free(hex);
+  } else {
+    gpr_log(GPR_INFO, "TEST: (%" PRIdPTR " byte long string)",
+            client_payload_length);
+  }
 
   /* Init grpc */
   grpc_init();
diff --git a/test/core/bad_client/tests/window_overflow.c b/test/core/bad_client/tests/window_overflow.c
index 18c647ad8a7..e4b5f9711bd 100644
--- a/test/core/bad_client/tests/window_overflow.c
+++ b/test/core/bad_client/tests/window_overflow.c
@@ -69,7 +69,7 @@ int main(int argc, char **argv) {
 #define MAX_FRAME_SIZE 16384
 #define MESSAGES_PER_FRAME (MAX_FRAME_SIZE / 5)
 #define FRAME_SIZE (MESSAGES_PER_FRAME * 5)
-#define SEND_SIZE (100 * 1024)
+#define SEND_SIZE (6 * 1024 * 1024)
 #define NUM_FRAMES (SEND_SIZE / FRAME_SIZE + 1)
   grpc_test_init(argc, argv);
 
diff --git a/test/core/channel/channel_stack_test.c b/test/core/channel/channel_stack_test.c
index 7c3614b4a22..a07ef89ba82 100644
--- a/test/core/channel/channel_stack_test.c
+++ b/test/core/channel/channel_stack_test.c
@@ -125,7 +125,7 @@ static void test_create_channel_stack(void) {
       .context = NULL,
       .path = path,
       .start_time = gpr_now(GPR_CLOCK_MONOTONIC),
-      .deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC),
+      .deadline = GRPC_MILLIS_INF_FUTURE,
       .arena = NULL};
   grpc_error *error = grpc_call_stack_init(&exec_ctx, channel_stack, 1,
                                            free_call, call_stack, &args);
diff --git a/test/core/client_channel/resolvers/dns_resolver_connectivity_test.c b/test/core/client_channel/resolvers/dns_resolver_connectivity_test.c
index 364e1809633..4597285063e 100644
--- a/test/core/client_channel/resolvers/dns_resolver_connectivity_test.c
+++ b/test/core/client_channel/resolvers/dns_resolver_connectivity_test.c
@@ -106,7 +106,7 @@ static bool wait_loop(int deadline_seconds, gpr_event *ev) {
     deadline_seconds--;
 
     grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
-    grpc_timer_check(&exec_ctx, gpr_now(GPR_CLOCK_MONOTONIC), NULL);
+    grpc_timer_check(&exec_ctx, NULL);
     grpc_exec_ctx_finish(&exec_ctx);
   }
   return false;
diff --git a/test/core/end2end/fixtures/http_proxy_fixture.c b/test/core/end2end/fixtures/http_proxy_fixture.c
index a4cfc77bcb7..d29401fdc3a 100644
--- a/test/core/end2end/fixtures/http_proxy_fixture.c
+++ b/test/core/end2end/fixtures/http_proxy_fixture.c
@@ -412,8 +412,8 @@ static void on_read_request_done(grpc_exec_ctx* exec_ctx, void* arg,
   GPR_ASSERT(resolved_addresses->naddrs >= 1);
   // Connect to requested address.
   // The connection callback inherits our reference to conn.
-  const gpr_timespec deadline = gpr_time_add(
-      gpr_now(GPR_CLOCK_MONOTONIC), gpr_time_from_seconds(10, GPR_TIMESPAN));
+  const grpc_millis deadline =
+      grpc_exec_ctx_now(exec_ctx) + 10 * GPR_MS_PER_SEC;
   grpc_tcp_client_connect(exec_ctx, &conn->on_server_connect_done,
                           &conn->server_endpoint, conn->pollset_set, NULL,
                           &resolved_addresses->addrs[0], deadline);
@@ -469,14 +469,12 @@ static void thread_main(void* arg) {
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   do {
     gpr_ref(&proxy->users);
-    const gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
-    const gpr_timespec deadline =
-        gpr_time_add(now, gpr_time_from_seconds(1, GPR_TIMESPAN));
     grpc_pollset_worker* worker = NULL;
     gpr_mu_lock(proxy->mu);
     GRPC_LOG_IF_ERROR(
         "grpc_pollset_work",
-        grpc_pollset_work(&exec_ctx, proxy->pollset, &worker, now, deadline));
+        grpc_pollset_work(&exec_ctx, proxy->pollset, &worker,
+                          grpc_exec_ctx_now(&exec_ctx) + GPR_MS_PER_SEC));
     gpr_mu_unlock(proxy->mu);
     grpc_exec_ctx_flush(&exec_ctx);
   } while (!gpr_unref(&proxy->users));
diff --git a/test/core/end2end/fuzzers/api_fuzzer.c b/test/core/end2end/fuzzers/api_fuzzer.c
index 1228c9fe9ae..0a787bbf300 100644
--- a/test/core/end2end/fuzzers/api_fuzzer.c
+++ b/test/core/end2end/fuzzers/api_fuzzer.c
@@ -60,7 +60,9 @@ extern gpr_timespec (*gpr_now_impl)(gpr_clock_type clock_type);
 
 static gpr_timespec now_impl(gpr_clock_type clock_type) {
   GPR_ASSERT(clock_type != GPR_TIMESPAN);
-  return g_now;
+  gpr_timespec ts = g_now;
+  ts.clock_type = clock_type;
+  return ts;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -407,10 +409,8 @@ void my_resolve_address(grpc_exec_ctx *exec_ctx, const char *addr,
   r->addrs = addresses;
   r->lb_addrs = NULL;
   grpc_timer_init(
-      exec_ctx, &r->timer, gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC),
-                                        gpr_time_from_seconds(1, GPR_TIMESPAN)),
-      GRPC_CLOSURE_CREATE(finish_resolve, r, grpc_schedule_on_exec_ctx),
-      gpr_now(GPR_CLOCK_MONOTONIC));
+      exec_ctx, &r->timer, GPR_MS_PER_SEC + grpc_exec_ctx_now(exec_ctx),
+      GRPC_CLOSURE_CREATE(finish_resolve, r, grpc_schedule_on_exec_ctx));
 }
 
 grpc_ares_request *my_dns_lookup_ares(
@@ -424,10 +424,8 @@ grpc_ares_request *my_dns_lookup_ares(
   r->addrs = NULL;
   r->lb_addrs = lb_addrs;
   grpc_timer_init(
-      exec_ctx, &r->timer, gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC),
-                                        gpr_time_from_seconds(1, GPR_TIMESPAN)),
-      GRPC_CLOSURE_CREATE(finish_resolve, r, grpc_schedule_on_exec_ctx),
-      gpr_now(GPR_CLOCK_MONOTONIC));
+      exec_ctx, &r->timer, GPR_MS_PER_SEC + grpc_exec_ctx_now(exec_ctx),
+      GRPC_CLOSURE_CREATE(finish_resolve, r, grpc_schedule_on_exec_ctx));
   return NULL;
 }
 
@@ -487,10 +485,8 @@ static void sched_connect(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
   fc->ep = ep;
   fc->deadline = deadline;
   grpc_timer_init(
-      exec_ctx, &fc->timer, gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC),
-                                         gpr_time_from_millis(1, GPR_TIMESPAN)),
-      GRPC_CLOSURE_CREATE(do_connect, fc, grpc_schedule_on_exec_ctx),
-      gpr_now(GPR_CLOCK_MONOTONIC));
+      exec_ctx, &fc->timer, GPR_MS_PER_SEC + grpc_exec_ctx_now(exec_ctx),
+      GRPC_CLOSURE_CREATE(do_connect, fc, grpc_schedule_on_exec_ctx));
 }
 
 static void my_tcp_client_connect(grpc_exec_ctx *exec_ctx,
diff --git a/test/core/end2end/gen_build_yaml.py b/test/core/end2end/gen_build_yaml.py
index 33fd97f3bd0..f7f996d5c19 100755
--- a/test/core/end2end/gen_build_yaml.py
+++ b/test/core/end2end/gen_build_yaml.py
@@ -24,15 +24,15 @@ import hashlib
 
 FixtureOptions = collections.namedtuple(
     'FixtureOptions',
-    'fullstack includes_proxy dns_resolver name_resolution secure platforms ci_mac tracing exclude_configs exclude_iomgrs large_writes enables_compression supports_compression is_inproc is_http2 supports_proxy_auth')
+    'fullstack includes_proxy dns_resolver name_resolution secure platforms ci_mac tracing exclude_configs exclude_iomgrs large_writes enables_compression supports_compression is_inproc is_http2 supports_proxy_auth supports_write_buffering')
 default_unsecure_fixture_options = FixtureOptions(
-    True, False, True, True, False, ['windows', 'linux', 'mac', 'posix'], True, False, [], [], True, False, True, False, True, False)
+    True, False, True, True, False, ['windows', 'linux', 'mac', 'posix'], True, False, [], [], True, False, True, False, True, False, True)
 socketpair_unsecure_fixture_options = default_unsecure_fixture_options._replace(fullstack=False, dns_resolver=False)
 default_secure_fixture_options = default_unsecure_fixture_options._replace(secure=True)
 uds_fixture_options = default_unsecure_fixture_options._replace(dns_resolver=False, platforms=['linux', 'mac', 'posix'], exclude_iomgrs=['uv'])
 fd_unsecure_fixture_options = default_unsecure_fixture_options._replace(
     dns_resolver=False, fullstack=False, platforms=['linux', 'mac', 'posix'], exclude_iomgrs=['uv'])
-inproc_fixture_options = default_unsecure_fixture_options._replace(dns_resolver=False, fullstack=False, name_resolution=False, supports_compression=False, is_inproc=True, is_http2=False)
+inproc_fixture_options = default_unsecure_fixture_options._replace(dns_resolver=False, fullstack=False, name_resolution=False, supports_compression=False, is_inproc=True, is_http2=False, supports_write_buffering=False)
 
 # maps fixture name to whether it requires the security library
 END2END_FIXTURES = {
@@ -60,7 +60,6 @@ END2END_FIXTURES = {
     'h2_sockpair+trace': socketpair_unsecure_fixture_options._replace(
         ci_mac=False, tracing=True, large_writes=False, exclude_iomgrs=['uv']),
     'h2_ssl': default_secure_fixture_options,
-    'h2_ssl_cert': default_secure_fixture_options,
     'h2_ssl_proxy': default_secure_fixture_options._replace(
         includes_proxy=True, ci_mac=False, exclude_iomgrs=['uv']),
     'h2_uds': uds_fixture_options,
@@ -69,8 +68,8 @@ END2END_FIXTURES = {
 
 TestOptions = collections.namedtuple(
     'TestOptions',
-    'needs_fullstack needs_dns needs_names proxyable secure traceable cpu_cost exclude_iomgrs large_writes flaky allows_compression needs_compression exclude_inproc needs_http2 needs_proxy_auth')
-default_test_options = TestOptions(False, False, False, True, False, True, 1.0, [], False, False, True, False, False, False, False)
+    'needs_fullstack needs_dns needs_names proxyable secure traceable cpu_cost exclude_iomgrs large_writes flaky allows_compression needs_compression exclude_inproc needs_http2 needs_proxy_auth needs_write_buffering')
+default_test_options = TestOptions(False, False, False, True, False, True, 1.0, [], False, False, True, False, False, False, False, False)
 connectivity_test_options = default_test_options._replace(needs_fullstack=True)
 
 LOWCPU = 0.1
@@ -147,8 +146,10 @@ END2END_TESTS = {
     'streaming_error_response': default_test_options._replace(cpu_cost=LOWCPU),
     'trailing_metadata': default_test_options,
     'workaround_cronet_compression': default_test_options,
-    'write_buffering': default_test_options._replace(cpu_cost=LOWCPU),
-    'write_buffering_at_end': default_test_options._replace(cpu_cost=LOWCPU),
+    'write_buffering': default_test_options._replace(cpu_cost=LOWCPU,
+                                                     needs_write_buffering=True),
+    'write_buffering_at_end': default_test_options._replace(cpu_cost=LOWCPU,
+                                                     needs_write_buffering=True),
 }
 
 
@@ -186,6 +187,9 @@ def compatible(f, t):
   if END2END_TESTS[t].needs_proxy_auth:
     if not END2END_FIXTURES[f].supports_proxy_auth:
       return False
+  if END2END_TESTS[t].needs_write_buffering:
+    if not END2END_FIXTURES[f].supports_write_buffering:
+      return False
   return True
 
 
diff --git a/test/core/end2end/generate_tests.bzl b/test/core/end2end/generate_tests.bzl
index 9bbba26108c..89a95edfd7b 100755
--- a/test/core/end2end/generate_tests.bzl
+++ b/test/core/end2end/generate_tests.bzl
@@ -21,7 +21,8 @@ load("//bazel:grpc_build_system.bzl", "grpc_sh_test", "grpc_cc_binary", "grpc_cc
 def fixture_options(fullstack=True, includes_proxy=False, dns_resolver=True,
                     name_resolution=True, secure=True, tracing=False,
                     platforms=['windows', 'linux', 'mac', 'posix'],
-                    is_inproc=False, is_http2=True, supports_proxy_auth=False):
+                    is_inproc=False, is_http2=True, supports_proxy_auth=False,
+                    supports_write_buffering=True):
   return struct(
     fullstack=fullstack,
     includes_proxy=includes_proxy,
@@ -31,7 +32,8 @@ def fixture_options(fullstack=True, includes_proxy=False, dns_resolver=True,
     tracing=tracing,
     is_inproc=is_inproc,
     is_http2=is_http2,
-    supports_proxy_auth=supports_proxy_auth
+    supports_proxy_auth=supports_proxy_auth,
+    supports_write_buffering=supports_write_buffering
     #platforms=platforms
   )
 
@@ -56,20 +58,19 @@ END2END_FIXTURES = {
     'h2_sockpair+trace': fixture_options(fullstack=False, dns_resolver=False,
                                          tracing=True),
     'h2_ssl': fixture_options(secure=True),
-    'h2_ssl_cert': fixture_options(secure=True),
     'h2_ssl_proxy': fixture_options(includes_proxy=True, secure=True),
     'h2_uds': fixture_options(dns_resolver=False,
                               platforms=['linux', 'mac', 'posix']),
     'inproc': fixture_options(fullstack=False, dns_resolver=False,
                               name_resolution=False, is_inproc=True,
-                              is_http2=False),
+                              is_http2=False, supports_write_buffering=False),
 }
 
 
 def test_options(needs_fullstack=False, needs_dns=False, needs_names=False,
                  proxyable=True, secure=False, traceable=False,
                  exclude_inproc=False, needs_http2=False,
-                 needs_proxy_auth=False):
+                 needs_proxy_auth=False, needs_write_buffering=False):
   return struct(
     needs_fullstack=needs_fullstack,
     needs_dns=needs_dns,
@@ -79,7 +80,8 @@ def test_options(needs_fullstack=False, needs_dns=False, needs_names=False,
     traceable=traceable,
     exclude_inproc=exclude_inproc,
     needs_http2=needs_http2,
-    needs_proxy_auth=needs_proxy_auth
+    needs_proxy_auth=needs_proxy_auth,
+    needs_write_buffering=needs_write_buffering
   )
 
 
@@ -145,8 +147,8 @@ END2END_TESTS = {
     'authority_not_supported': test_options(),
     'filter_latency': test_options(),
     'workaround_cronet_compression': test_options(),
-    'write_buffering': test_options(),
-    'write_buffering_at_end': test_options(),
+    'write_buffering': test_options(needs_write_buffering=True),
+    'write_buffering_at_end': test_options(needs_write_buffering=True),
 }
 
 
@@ -175,6 +177,9 @@ def compatible(fopt, topt):
   if topt.needs_proxy_auth:
     if not fopt.supports_proxy_auth:
       return False
+  if topt.needs_write_buffering:
+    if not fopt.supports_write_buffering:
+      return False
   return True
 
 
diff --git a/test/core/end2end/fixtures/h2_ssl_cert.c b/test/core/end2end/h2_ssl_cert_test.cc
similarity index 88%
rename from test/core/end2end/fixtures/h2_ssl_cert.c
rename to test/core/end2end/h2_ssl_cert_test.cc
index 9b1ddadfe4c..6da5e8396ef 100644
--- a/test/core/end2end/fixtures/h2_ssl_cert.c
+++ b/test/core/end2end/h2_ssl_cert_test.cc
@@ -16,7 +16,9 @@
  *
  */
 
+extern "C" {
 #include "test/core/end2end/end2end_tests.h"
+}
 
 #include <stdio.h>
 #include <string.h>
@@ -25,6 +27,7 @@
 #include <grpc/support/host_port.h>
 #include <grpc/support/log.h>
 
+extern "C" {
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/security/credentials/credentials.h"
 #include "src/core/lib/support/env.h"
@@ -34,8 +37,12 @@
 #include "test/core/end2end/data/ssl_test_data.h"
 #include "test/core/util/port.h"
 #include "test/core/util/test_config.h"
+}
 
-extern void simple_request(grpc_end2end_test_config config);
+#include <gtest/gtest.h>
+
+namespace grpc {
+namespace testing {
 
 typedef struct fullstack_secure_fixture_data {
   char *localaddr;
@@ -46,7 +53,8 @@ static grpc_end2end_test_fixture chttp2_create_fixture_secure_fullstack(
   grpc_end2end_test_fixture f;
   int port = grpc_pick_unused_port_or_die();
   fullstack_secure_fixture_data *ffd =
-      gpr_malloc(sizeof(fullstack_secure_fixture_data));
+      static_cast<fullstack_secure_fixture_data *>(
+          gpr_malloc(sizeof(fullstack_secure_fixture_data)));
   memset(&f, 0, sizeof(f));
 
   gpr_join_host_port(&ffd->localaddr, "localhost", port);
@@ -69,7 +77,8 @@ static void process_auth_failure(void *state, grpc_auth_context *ctx,
 static void chttp2_init_client_secure_fullstack(
     grpc_end2end_test_fixture *f, grpc_channel_args *client_args,
     grpc_channel_credentials *creds) {
-  fullstack_secure_fixture_data *ffd = f->fixture_data;
+  fullstack_secure_fixture_data *ffd =
+      static_cast<fullstack_secure_fixture_data *>(f->fixture_data);
   f->client =
       grpc_secure_channel_create(creds, ffd->localaddr, client_args, NULL);
   GPR_ASSERT(f->client != NULL);
@@ -79,7 +88,8 @@ static void chttp2_init_client_secure_fullstack(
 static void chttp2_init_server_secure_fullstack(
     grpc_end2end_test_fixture *f, grpc_channel_args *server_args,
     grpc_server_credentials *server_creds) {
-  fullstack_secure_fixture_data *ffd = f->fixture_data;
+  fullstack_secure_fixture_data *ffd =
+      static_cast<fullstack_secure_fixture_data *>(f->fixture_data);
   if (f->server) {
     grpc_server_destroy(f->server);
   }
@@ -92,7 +102,8 @@ static void chttp2_init_server_secure_fullstack(
 }
 
 void chttp2_tear_down_secure_fullstack(grpc_end2end_test_fixture *f) {
-  fullstack_secure_fixture_data *ffd = f->fixture_data;
+  fullstack_secure_fixture_data *ffd =
+      static_cast<fullstack_secure_fixture_data *>(f->fixture_data);
   gpr_free(ffd->localaddr);
   gpr_free(ffd);
 }
@@ -166,9 +177,10 @@ typedef enum { NONE, SELF_SIGNED, SIGNED, BAD_CERT_PAIR } certtype;
     }                                                                        \
     ssl_creds =                                                              \
         grpc_ssl_credentials_create(test_root_cert, key_cert_pair, NULL);    \
-    grpc_arg ssl_name_override = {GRPC_ARG_STRING,                           \
-                                  GRPC_SSL_TARGET_NAME_OVERRIDE_ARG,         \
-                                  {"foo.test.google.fr"}};                   \
+    grpc_arg ssl_name_override = {                                           \
+        GRPC_ARG_STRING,                                                     \
+        const_cast<char *>(GRPC_SSL_TARGET_NAME_OVERRIDE_ARG),               \
+        {const_cast<char *>("foo.test.google.fr")}};                         \
     grpc_channel_args *new_client_args =                                     \
         grpc_channel_args_copy_and_add(client_args, &ssl_name_override, 1);  \
     chttp2_init_client_secure_fullstack(f, new_client_args, ssl_creds);      \
@@ -248,18 +260,6 @@ static grpc_end2end_test_config_wrapper configs[] = {
 
 static void *tag(intptr_t t) { return (void *)t; }
 
-static grpc_end2end_test_fixture begin_test(grpc_end2end_test_config config,
-                                            const char *test_name,
-                                            grpc_channel_args *client_args,
-                                            grpc_channel_args *server_args) {
-  grpc_end2end_test_fixture f;
-  gpr_log(GPR_INFO, "%s/%s", test_name, config.name);
-  f = config.create_fixture(client_args, server_args);
-  config.init_server(&f, server_args);
-  config.init_client(&f, client_args);
-  return f;
-}
-
 static gpr_timespec n_seconds_time(int n) {
   return grpc_timeout_seconds_to_deadline(n);
 }
@@ -319,7 +319,7 @@ static void simple_request_body(grpc_end2end_test_fixture f,
   op = ops;
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
-  op->flags = 0;
+  op->flags = GRPC_INITIAL_METADATA_WAIT_FOR_READY;
   op->reserved = NULL;
   op++;
   error = grpc_call_start_batch(c, ops, (size_t)(op - ops), tag(1), NULL);
@@ -332,15 +332,40 @@ static void simple_request_body(grpc_end2end_test_fixture f,
   cq_verifier_destroy(cqv);
 }
 
+class H2SslCertTest
+    : public ::testing::TestWithParam<grpc_end2end_test_config_wrapper> {
+ protected:
+  H2SslCertTest() {
+    gpr_log(GPR_INFO, "SSL_CERT_tests/%s", GetParam().config.name);
+  }
+  void SetUp() override {
+    fixture_ = GetParam().config.create_fixture(nullptr, nullptr);
+    GetParam().config.init_server(&fixture_, nullptr);
+    GetParam().config.init_client(&fixture_, nullptr);
+  }
+  void TearDown() override {
+    end_test(&fixture_);
+    GetParam().config.tear_down_data(&fixture_);
+  }
+
+  grpc_end2end_test_fixture fixture_;
+};
+
+TEST_P(H2SslCertTest, SimpleRequestBody) {
+  simple_request_body(fixture_, GetParam().result);
+}
+
+INSTANTIATE_TEST_CASE_P(H2SslCert, H2SslCertTest, ::testing::ValuesIn(configs));
+
+}  // namespace testing
+}  // namespace grpc
+
 int main(int argc, char **argv) {
-  size_t i;
   FILE *roots_file;
   size_t roots_size = strlen(test_root_cert);
   char *roots_filename;
 
   grpc_test_init(argc, argv);
-  grpc_end2end_tests_pre_init();
-
   /* Set the SSL roots env var. */
   roots_file =
       gpr_tmpfile("chttp2_simple_ssl_cert_fullstack_test", &roots_filename);
@@ -351,21 +376,13 @@ int main(int argc, char **argv) {
   gpr_setenv(GRPC_DEFAULT_SSL_ROOTS_FILE_PATH_ENV_VAR, roots_filename);
 
   grpc_init();
-
-  for (i = 0; i < sizeof(configs) / sizeof(*configs); i++) {
-    grpc_end2end_test_fixture f =
-        begin_test(configs[i].config, "SSL_CERT_tests", NULL, NULL);
-
-    simple_request_body(f, configs[i].result);
-    end_test(&f);
-    configs[i].config.tear_down_data(&f);
-  }
-
+  ::testing::InitGoogleTest(&argc, argv);
+  int ret = RUN_ALL_TESTS();
   grpc_shutdown();
 
   /* Cleanup. */
   remove(roots_filename);
   gpr_free(roots_filename);
 
-  return 0;
+  return ret;
 }
diff --git a/test/core/end2end/invalid_call_argument_test.c b/test/core/end2end/invalid_call_argument_test.c
index bf0d08adecf..e3fd5a8fbe1 100644
--- a/test/core/end2end/invalid_call_argument_test.c
+++ b/test/core/end2end/invalid_call_argument_test.c
@@ -92,7 +92,7 @@ static void prepare_test(int is_client) {
     op = g_state.ops;
     op->op = GRPC_OP_SEND_INITIAL_METADATA;
     op->data.send_initial_metadata.count = 0;
-    op->flags = 0;
+    op->flags = GRPC_INITIAL_METADATA_WAIT_FOR_READY;
     op->reserved = NULL;
     op++;
     GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(g_state.call, g_state.ops,
diff --git a/test/core/end2end/tests/bad_ping.c b/test/core/end2end/tests/bad_ping.c
index c97d11b3067..d442f124807 100644
--- a/test/core/end2end/tests/bad_ping.c
+++ b/test/core/end2end/tests/bad_ping.c
@@ -155,14 +155,16 @@ static void test_bad_ping(grpc_end2end_test_config config) {
   cq_verify(cqv);
 
   // Send too many pings to the server to trigger the punishment:
-  // The first ping is sent after data frames, it won't trigger a ping strike.
-  // Each of the following pings will trigger a ping strike, and we need at
-  // least (MAX_PING_STRIKES + 1) strikes to trigger the punishment. So
-  // (MAX_PING_STRIKES + 2) pings are needed here.
+  // Each ping will trigger a ping strike, and we need at least MAX_PING_STRIKES
+  // strikes to trigger the punishment. So (MAX_PING_STRIKES + 1) pings are
+  // needed here.
   int i;
-  for (i = 200; i < 202 + MAX_PING_STRIKES; i++) {
-    grpc_channel_ping(f.client, f.cq, tag(i), NULL);
-    CQ_EXPECT_COMPLETION(cqv, tag(i), 1);
+  for (i = 1; i <= MAX_PING_STRIKES + 1; i++) {
+    grpc_channel_ping(f.client, f.cq, tag(200 + i), NULL);
+    CQ_EXPECT_COMPLETION(cqv, tag(200 + i), 1);
+    if (i == MAX_PING_STRIKES + 1) {
+      CQ_EXPECT_COMPLETION(cqv, tag(1), 1);
+    }
     cq_verify(cqv);
   }
 
@@ -190,7 +192,6 @@ static void test_bad_ping(grpc_end2end_test_config config) {
   GPR_ASSERT(GRPC_CALL_OK == error);
 
   CQ_EXPECT_COMPLETION(cqv, tag(102), 1);
-  CQ_EXPECT_COMPLETION(cqv, tag(1), 1);
   cq_verify(cqv);
 
   grpc_server_shutdown_and_notify(f.server, f.cq, tag(0xdead));
diff --git a/test/core/end2end/tests/keepalive_timeout.c b/test/core/end2end/tests/keepalive_timeout.c
index 8d01f23c005..c4280149c7e 100644
--- a/test/core/end2end/tests/keepalive_timeout.c
+++ b/test/core/end2end/tests/keepalive_timeout.c
@@ -98,21 +98,21 @@ static void test_keepalive_timeout(grpc_end2end_test_config config) {
   grpc_byte_buffer *response_payload =
       grpc_raw_byte_buffer_create(&response_payload_slice, 1);
 
-  grpc_arg keepalive_args[] = {{.type = GRPC_ARG_INTEGER,
-                                .key = GRPC_ARG_KEEPALIVE_TIME_MS,
-                                .value.integer = 1500},
-                               {.type = GRPC_ARG_INTEGER,
-                                .key = GRPC_ARG_KEEPALIVE_TIMEOUT_MS,
-                                .value.integer = 0},
-                               {.type = GRPC_ARG_INTEGER,
-                                .key = GRPC_ARG_HTTP2_BDP_PROBE,
-                                .value.integer = 0}};
-
-  grpc_channel_args client_args = {.num_args = GPR_ARRAY_SIZE(keepalive_args),
-                                   .args = keepalive_args};
+  grpc_arg keepalive_arg_elems[] = {{.type = GRPC_ARG_INTEGER,
+                                     .key = GRPC_ARG_KEEPALIVE_TIME_MS,
+                                     .value.integer = 1500},
+                                    {.type = GRPC_ARG_INTEGER,
+                                     .key = GRPC_ARG_KEEPALIVE_TIMEOUT_MS,
+                                     .value.integer = 0},
+                                    {.type = GRPC_ARG_INTEGER,
+                                     .key = GRPC_ARG_HTTP2_BDP_PROBE,
+                                     .value.integer = 0}};
+  grpc_channel_args keepalive_args = {
+      .num_args = GPR_ARRAY_SIZE(keepalive_arg_elems),
+      .args = keepalive_arg_elems};
 
   grpc_end2end_test_fixture f =
-      begin_test(config, "keepalive_timeout", &client_args, NULL);
+      begin_test(config, "keepalive_timeout", &keepalive_args, NULL);
   cq_verifier *cqv = cq_verifier_create(f.cq);
   grpc_op ops[6];
   grpc_op *op;
diff --git a/test/core/end2end/tests/streaming_error_response.c b/test/core/end2end/tests/streaming_error_response.c
index 9d562b90906..8891b8674ce 100644
--- a/test/core/end2end/tests/streaming_error_response.c
+++ b/test/core/end2end/tests/streaming_error_response.c
@@ -183,7 +183,6 @@ static void test(grpc_end2end_test_config config, bool request_status_early) {
   GPR_ASSERT(GRPC_CALL_OK == error);
 
   CQ_EXPECT_COMPLETION(cqv, tag(103), 1);
-  cq_verify(cqv);
 
   if (!request_status_early) {
     memset(ops, 0, sizeof(ops));
diff --git a/test/core/http/httpcli_test.c b/test/core/http/httpcli_test.c
index 8a53903763d..cc1c16d695b 100644
--- a/test/core/http/httpcli_test.c
+++ b/test/core/http/httpcli_test.c
@@ -35,8 +35,9 @@ static grpc_httpcli_context g_context;
 static gpr_mu *g_mu;
 static grpc_polling_entity g_pops;
 
-static gpr_timespec n_seconds_time(int seconds) {
-  return grpc_timeout_seconds_to_deadline(seconds);
+static grpc_millis n_seconds_time(int seconds) {
+  return grpc_timespec_to_millis_round_up(
+      grpc_timeout_seconds_to_deadline(seconds));
 }
 
 static void on_finish(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
@@ -86,8 +87,7 @@ static void test_get(int port) {
     GPR_ASSERT(GRPC_LOG_IF_ERROR(
         "pollset_work",
         grpc_pollset_work(&exec_ctx, grpc_polling_entity_pollset(&g_pops),
-                          &worker, gpr_now(GPR_CLOCK_MONOTONIC),
-                          n_seconds_time(1))));
+                          &worker, n_seconds_time(1))));
     gpr_mu_unlock(g_mu);
     grpc_exec_ctx_finish(&exec_ctx);
     gpr_mu_lock(g_mu);
@@ -128,8 +128,7 @@ static void test_post(int port) {
     GPR_ASSERT(GRPC_LOG_IF_ERROR(
         "pollset_work",
         grpc_pollset_work(&exec_ctx, grpc_polling_entity_pollset(&g_pops),
-                          &worker, gpr_now(GPR_CLOCK_MONOTONIC),
-                          n_seconds_time(1))));
+                          &worker, n_seconds_time(1))));
     gpr_mu_unlock(g_mu);
     grpc_exec_ctx_finish(&exec_ctx);
     gpr_mu_lock(g_mu);
diff --git a/test/core/http/httpscli_test.c b/test/core/http/httpscli_test.c
index c7455bd8df3..f8a3cfdd764 100644
--- a/test/core/http/httpscli_test.c
+++ b/test/core/http/httpscli_test.c
@@ -35,8 +35,9 @@ static grpc_httpcli_context g_context;
 static gpr_mu *g_mu;
 static grpc_polling_entity g_pops;
 
-static gpr_timespec n_seconds_time(int seconds) {
-  return grpc_timeout_seconds_to_deadline(seconds);
+static grpc_millis n_seconds_time(int seconds) {
+  return grpc_timespec_to_millis_round_up(
+      grpc_timeout_seconds_to_deadline(seconds));
 }
 
 static void on_finish(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
@@ -87,8 +88,7 @@ static void test_get(int port) {
     GPR_ASSERT(GRPC_LOG_IF_ERROR(
         "pollset_work",
         grpc_pollset_work(&exec_ctx, grpc_polling_entity_pollset(&g_pops),
-                          &worker, gpr_now(GPR_CLOCK_MONOTONIC),
-                          n_seconds_time(1))));
+                          &worker, n_seconds_time(1))));
     gpr_mu_unlock(g_mu);
     grpc_exec_ctx_finish(&exec_ctx);
     gpr_mu_lock(g_mu);
@@ -130,8 +130,7 @@ static void test_post(int port) {
     GPR_ASSERT(GRPC_LOG_IF_ERROR(
         "pollset_work",
         grpc_pollset_work(&exec_ctx, grpc_polling_entity_pollset(&g_pops),
-                          &worker, gpr_now(GPR_CLOCK_MONOTONIC),
-                          n_seconds_time(1))));
+                          &worker, n_seconds_time(1))));
     gpr_mu_unlock(g_mu);
     grpc_exec_ctx_finish(&exec_ctx);
     gpr_mu_lock(g_mu);
diff --git a/test/core/iomgr/endpoint_tests.c b/test/core/iomgr/endpoint_tests.c
index f8570edde79..61e901f6455 100644
--- a/test/core/iomgr/endpoint_tests.c
+++ b/test/core/iomgr/endpoint_tests.c
@@ -176,10 +176,11 @@ static void read_and_write_test(grpc_endpoint_test_config config,
                                 size_t num_bytes, size_t write_size,
                                 size_t slice_size, bool shutdown) {
   struct read_and_write_test_state state;
-  gpr_timespec deadline = grpc_timeout_seconds_to_deadline(20);
   grpc_endpoint_test_fixture f =
       begin_test(config, "read_and_write_test", slice_size);
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  grpc_millis deadline =
+      grpc_timespec_to_millis_round_up(grpc_timeout_seconds_to_deadline(20));
   gpr_log(GPR_DEBUG, "num_bytes=%" PRIuPTR " write_size=%" PRIuPTR
                      " slice_size=%" PRIuPTR " shutdown=%d",
           num_bytes, write_size, slice_size, shutdown);
@@ -235,11 +236,10 @@ static void read_and_write_test(grpc_endpoint_test_config config,
   gpr_mu_lock(g_mu);
   while (!state.read_done || !state.write_done) {
     grpc_pollset_worker *worker = NULL;
-    GPR_ASSERT(gpr_time_cmp(gpr_now(GPR_CLOCK_MONOTONIC), deadline) < 0);
+    GPR_ASSERT(grpc_exec_ctx_now(&exec_ctx) < deadline);
     GPR_ASSERT(GRPC_LOG_IF_ERROR(
         "pollset_work",
-        grpc_pollset_work(&exec_ctx, g_pollset, &worker,
-                          gpr_now(GPR_CLOCK_MONOTONIC), deadline)));
+        grpc_pollset_work(&exec_ctx, g_pollset, &worker, deadline)));
   }
   gpr_mu_unlock(g_mu);
   grpc_exec_ctx_flush(&exec_ctx);
@@ -265,14 +265,14 @@ static void wait_for_fail_count(grpc_exec_ctx *exec_ctx, int *fail_count,
                                 int want_fail_count) {
   grpc_exec_ctx_flush(exec_ctx);
   gpr_mu_lock(g_mu);
-  gpr_timespec deadline = grpc_timeout_seconds_to_deadline(10);
-  while (gpr_time_cmp(gpr_now(deadline.clock_type), deadline) < 0 &&
+  grpc_millis deadline =
+      grpc_timespec_to_millis_round_up(grpc_timeout_seconds_to_deadline(10));
+  while (grpc_exec_ctx_now(exec_ctx) < deadline &&
          *fail_count < want_fail_count) {
     grpc_pollset_worker *worker = NULL;
     GPR_ASSERT(GRPC_LOG_IF_ERROR(
         "pollset_work",
-        grpc_pollset_work(exec_ctx, g_pollset, &worker,
-                          gpr_now(deadline.clock_type), deadline)));
+        grpc_pollset_work(exec_ctx, g_pollset, &worker, deadline)));
     gpr_mu_unlock(g_mu);
     grpc_exec_ctx_flush(exec_ctx);
     gpr_mu_lock(g_mu);
diff --git a/test/core/iomgr/ev_epollsig_linux_test.c b/test/core/iomgr/ev_epollsig_linux_test.c
index cca07bf0020..37aadacd497 100644
--- a/test/core/iomgr/ev_epollsig_linux_test.c
+++ b/test/core/iomgr/ev_epollsig_linux_test.c
@@ -238,10 +238,8 @@ static void test_threading_loop(void *arg) {
     grpc_pollset_worker *worker;
     gpr_mu_lock(shared->mu);
     GPR_ASSERT(GRPC_LOG_IF_ERROR(
-        "pollset_work",
-        grpc_pollset_work(&exec_ctx, shared->pollset, &worker,
-                          gpr_now(GPR_CLOCK_MONOTONIC),
-                          gpr_inf_future(GPR_CLOCK_MONOTONIC))));
+        "pollset_work", grpc_pollset_work(&exec_ctx, shared->pollset, &worker,
+                                          GRPC_MILLIS_INF_FUTURE)));
     gpr_mu_unlock(shared->mu);
     grpc_exec_ctx_finish(&exec_ctx);
   }
diff --git a/test/core/iomgr/fd_posix_test.c b/test/core/iomgr/fd_posix_test.c
index 881277a8d6a..1c62f34d3e6 100644
--- a/test/core/iomgr/fd_posix_test.c
+++ b/test/core/iomgr/fd_posix_test.c
@@ -252,10 +252,8 @@ static void server_wait_and_shutdown(server *sv) {
     grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
     grpc_pollset_worker *worker = NULL;
     GPR_ASSERT(GRPC_LOG_IF_ERROR(
-        "pollset_work",
-        grpc_pollset_work(&exec_ctx, g_pollset, &worker,
-                          gpr_now(GPR_CLOCK_MONOTONIC),
-                          gpr_inf_future(GPR_CLOCK_MONOTONIC))));
+        "pollset_work", grpc_pollset_work(&exec_ctx, g_pollset, &worker,
+                                          GRPC_MILLIS_INF_FUTURE)));
     gpr_mu_unlock(g_mu);
     grpc_exec_ctx_finish(&exec_ctx);
     gpr_mu_lock(g_mu);
@@ -371,10 +369,8 @@ static void client_wait_and_shutdown(client *cl) {
     grpc_pollset_worker *worker = NULL;
     grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
     GPR_ASSERT(GRPC_LOG_IF_ERROR(
-        "pollset_work",
-        grpc_pollset_work(&exec_ctx, g_pollset, &worker,
-                          gpr_now(GPR_CLOCK_MONOTONIC),
-                          gpr_inf_future(GPR_CLOCK_MONOTONIC))));
+        "pollset_work", grpc_pollset_work(&exec_ctx, g_pollset, &worker,
+                                          GRPC_MILLIS_INF_FUTURE)));
     gpr_mu_unlock(g_mu);
     grpc_exec_ctx_finish(&exec_ctx);
     gpr_mu_lock(g_mu);
@@ -477,10 +473,8 @@ static void test_grpc_fd_change(void) {
   while (a.cb_that_ran == NULL) {
     grpc_pollset_worker *worker = NULL;
     GPR_ASSERT(GRPC_LOG_IF_ERROR(
-        "pollset_work",
-        grpc_pollset_work(&exec_ctx, g_pollset, &worker,
-                          gpr_now(GPR_CLOCK_MONOTONIC),
-                          gpr_inf_future(GPR_CLOCK_MONOTONIC))));
+        "pollset_work", grpc_pollset_work(&exec_ctx, g_pollset, &worker,
+                                          GRPC_MILLIS_INF_FUTURE)));
     gpr_mu_unlock(g_mu);
     grpc_exec_ctx_finish(&exec_ctx);
     gpr_mu_lock(g_mu);
@@ -503,10 +497,8 @@ static void test_grpc_fd_change(void) {
   while (b.cb_that_ran == NULL) {
     grpc_pollset_worker *worker = NULL;
     GPR_ASSERT(GRPC_LOG_IF_ERROR(
-        "pollset_work",
-        grpc_pollset_work(&exec_ctx, g_pollset, &worker,
-                          gpr_now(GPR_CLOCK_MONOTONIC),
-                          gpr_inf_future(GPR_CLOCK_MONOTONIC))));
+        "pollset_work", grpc_pollset_work(&exec_ctx, g_pollset, &worker,
+                                          GRPC_MILLIS_INF_FUTURE)));
     gpr_mu_unlock(g_mu);
     grpc_exec_ctx_finish(&exec_ctx);
     gpr_mu_lock(g_mu);
diff --git a/test/core/iomgr/pollset_set_test.c b/test/core/iomgr/pollset_set_test.c
index 5750ac0f4b3..3dd4bc887c7 100644
--- a/test/core/iomgr/pollset_set_test.c
+++ b/test/core/iomgr/pollset_set_test.c
@@ -203,7 +203,7 @@ static void pollset_set_test_basic() {
    */
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_pollset_worker *worker;
-  gpr_timespec deadline;
+  grpc_millis deadline;
 
   test_fd tfds[10];
   test_pollset pollsets[3];
@@ -256,10 +256,10 @@ static void pollset_set_test_basic() {
     make_test_fds_readable(tfds, num_fds);
 
     gpr_mu_lock(pollsets[i].mu);
-    deadline = grpc_timeout_milliseconds_to_deadline(2);
+    deadline = grpc_timespec_to_millis_round_up(
+        grpc_timeout_milliseconds_to_deadline(2));
     GPR_ASSERT(GRPC_ERROR_NONE ==
-               grpc_pollset_work(&exec_ctx, pollsets[i].ps, &worker,
-                                 gpr_now(GPR_CLOCK_MONOTONIC), deadline));
+               grpc_pollset_work(&exec_ctx, pollsets[i].ps, &worker, deadline));
     gpr_mu_unlock(pollsets[i].mu);
 
     grpc_exec_ctx_flush(&exec_ctx);
@@ -308,7 +308,7 @@ void pollset_set_test_dup_fds() {
    */
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_pollset_worker *worker;
-  gpr_timespec deadline;
+  grpc_millis deadline;
 
   test_fd tfds[3];
   test_pollset pollset;
@@ -338,10 +338,10 @@ void pollset_set_test_dup_fds() {
   make_test_fds_readable(tfds, num_fds);
 
   gpr_mu_lock(pollset.mu);
-  deadline = grpc_timeout_milliseconds_to_deadline(2);
+  deadline = grpc_timespec_to_millis_round_up(
+      grpc_timeout_milliseconds_to_deadline(2));
   GPR_ASSERT(GRPC_ERROR_NONE ==
-             grpc_pollset_work(&exec_ctx, pollset.ps, &worker,
-                               gpr_now(GPR_CLOCK_MONOTONIC), deadline));
+             grpc_pollset_work(&exec_ctx, pollset.ps, &worker, deadline));
   gpr_mu_unlock(pollset.mu);
   grpc_exec_ctx_flush(&exec_ctx);
 
@@ -381,7 +381,7 @@ void pollset_set_test_empty_pollset() {
    */
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_pollset_worker *worker;
-  gpr_timespec deadline;
+  grpc_millis deadline;
 
   test_fd tfds[3];
   test_pollset pollsets[2];
@@ -407,10 +407,10 @@ void pollset_set_test_empty_pollset() {
   make_test_fds_readable(tfds, num_fds);
 
   gpr_mu_lock(pollsets[0].mu);
-  deadline = grpc_timeout_milliseconds_to_deadline(2);
+  deadline = grpc_timespec_to_millis_round_up(
+      grpc_timeout_milliseconds_to_deadline(2));
   GPR_ASSERT(GRPC_ERROR_NONE ==
-             grpc_pollset_work(&exec_ctx, pollsets[0].ps, &worker,
-                               gpr_now(GPR_CLOCK_MONOTONIC), deadline));
+             grpc_pollset_work(&exec_ctx, pollsets[0].ps, &worker, deadline));
   gpr_mu_unlock(pollsets[0].mu);
   grpc_exec_ctx_flush(&exec_ctx);
 
diff --git a/test/core/iomgr/resolve_address_posix_test.c b/test/core/iomgr/resolve_address_posix_test.c
index e4be99f03c7..cb9d6080fbb 100644
--- a/test/core/iomgr/resolve_address_posix_test.c
+++ b/test/core/iomgr/resolve_address_posix_test.c
@@ -72,35 +72,33 @@ void args_finish(grpc_exec_ctx *exec_ctx, args_struct *args) {
   gpr_free(args->pollset);
 }
 
-static gpr_timespec n_sec_deadline(int seconds) {
-  return gpr_time_add(gpr_now(GPR_CLOCK_REALTIME),
-                      gpr_time_from_seconds(seconds, GPR_TIMESPAN));
+static grpc_millis n_sec_deadline(int seconds) {
+  return grpc_timespec_to_millis_round_up(
+      grpc_timeout_seconds_to_deadline(seconds));
 }
 
 static void actually_poll(void *argsp) {
   args_struct *args = argsp;
-  gpr_timespec deadline = n_sec_deadline(10);
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  grpc_millis deadline = n_sec_deadline(10);
   while (true) {
     bool done = gpr_atm_acq_load(&args->done_atm) != 0;
     if (done) {
       break;
     }
-    gpr_timespec time_left =
-        gpr_time_sub(deadline, gpr_now(GPR_CLOCK_REALTIME));
-    gpr_log(GPR_DEBUG, "done=%d, time_left=%" PRId64 ".%09d", done,
-            time_left.tv_sec, time_left.tv_nsec);
-    GPR_ASSERT(gpr_time_cmp(time_left, gpr_time_0(GPR_TIMESPAN)) >= 0);
+    grpc_millis time_left = deadline - grpc_exec_ctx_now(&exec_ctx);
+    gpr_log(GPR_DEBUG, "done=%d, time_left=%" PRIdPTR, done, time_left);
+    GPR_ASSERT(time_left >= 0);
     grpc_pollset_worker *worker = NULL;
-    grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
     gpr_mu_lock(args->mu);
-    GRPC_LOG_IF_ERROR(
-        "pollset_work",
-        grpc_pollset_work(&exec_ctx, args->pollset, &worker,
-                          gpr_now(GPR_CLOCK_REALTIME), n_sec_deadline(1)));
+    GRPC_LOG_IF_ERROR("pollset_work",
+                      grpc_pollset_work(&exec_ctx, args->pollset, &worker,
+                                        n_sec_deadline(1)));
     gpr_mu_unlock(args->mu);
-    grpc_exec_ctx_finish(&exec_ctx);
+    grpc_exec_ctx_flush(&exec_ctx);
   }
   gpr_event_set(&args->ev, (void *)1);
+  grpc_exec_ctx_finish(&exec_ctx);
 }
 
 static void poll_pollset_until_request_done(args_struct *args) {
diff --git a/test/core/iomgr/resolve_address_test.c b/test/core/iomgr/resolve_address_test.c
index 1110c04b6e2..178bbbb95fd 100644
--- a/test/core/iomgr/resolve_address_test.c
+++ b/test/core/iomgr/resolve_address_test.c
@@ -68,34 +68,32 @@ void args_finish(grpc_exec_ctx *exec_ctx, args_struct *args) {
   gpr_free(args->pollset);
 }
 
-static gpr_timespec n_sec_deadline(int seconds) {
-  return gpr_time_add(gpr_now(GPR_CLOCK_REALTIME),
-                      gpr_time_from_seconds(seconds, GPR_TIMESPAN));
+static grpc_millis n_sec_deadline(int seconds) {
+  return grpc_timespec_to_millis_round_up(
+      grpc_timeout_seconds_to_deadline(seconds));
 }
 
 static void poll_pollset_until_request_done(args_struct *args) {
-  gpr_timespec deadline = n_sec_deadline(10);
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  grpc_millis deadline = n_sec_deadline(10);
   while (true) {
     bool done = gpr_atm_acq_load(&args->done_atm) != 0;
     if (done) {
       break;
     }
-    gpr_timespec time_left =
-        gpr_time_sub(deadline, gpr_now(GPR_CLOCK_REALTIME));
-    gpr_log(GPR_DEBUG, "done=%d, time_left=%" PRId64 ".%09d", done,
-            time_left.tv_sec, time_left.tv_nsec);
-    GPR_ASSERT(gpr_time_cmp(time_left, gpr_time_0(GPR_TIMESPAN)) >= 0);
+    grpc_millis time_left = deadline - grpc_exec_ctx_now(&exec_ctx);
+    gpr_log(GPR_DEBUG, "done=%d, time_left=%" PRIdPTR, done, time_left);
+    GPR_ASSERT(time_left >= 0);
     grpc_pollset_worker *worker = NULL;
-    grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
     gpr_mu_lock(args->mu);
-    GRPC_LOG_IF_ERROR(
-        "pollset_work",
-        grpc_pollset_work(&exec_ctx, args->pollset, &worker,
-                          gpr_now(GPR_CLOCK_REALTIME), n_sec_deadline(1)));
+    GRPC_LOG_IF_ERROR("pollset_work",
+                      grpc_pollset_work(&exec_ctx, args->pollset, &worker,
+                                        n_sec_deadline(1)));
     gpr_mu_unlock(args->mu);
-    grpc_exec_ctx_finish(&exec_ctx);
+    grpc_exec_ctx_flush(&exec_ctx);
   }
   gpr_event_set(&args->ev, (void *)1);
+  grpc_exec_ctx_finish(&exec_ctx);
 }
 
 static void must_succeed(grpc_exec_ctx *exec_ctx, void *argsp,
diff --git a/test/core/iomgr/tcp_client_posix_test.c b/test/core/iomgr/tcp_client_posix_test.c
index 1032da942b3..b8b76d1c426 100644
--- a/test/core/iomgr/tcp_client_posix_test.c
+++ b/test/core/iomgr/tcp_client_posix_test.c
@@ -46,8 +46,8 @@ static grpc_pollset *g_pollset;
 static int g_connections_complete = 0;
 static grpc_endpoint *g_connecting = NULL;
 
-static gpr_timespec test_deadline(void) {
-  return grpc_timeout_seconds_to_deadline(10);
+static grpc_millis test_deadline(void) {
+  return grpc_timespec_to_millis_round_up(grpc_timeout_seconds_to_deadline(10));
 }
 
 static void finish_connection() {
@@ -109,7 +109,7 @@ void test_succeeds(void) {
                          (socklen_t *)&resolved_addr.len) == 0);
   GRPC_CLOSURE_INIT(&done, must_succeed, NULL, grpc_schedule_on_exec_ctx);
   grpc_tcp_client_connect(&exec_ctx, &done, &g_connecting, g_pollset_set, NULL,
-                          &resolved_addr, gpr_inf_future(GPR_CLOCK_REALTIME));
+                          &resolved_addr, GRPC_MILLIS_INF_FUTURE);
 
   /* await the connection */
   do {
@@ -127,8 +127,8 @@ void test_succeeds(void) {
     GPR_ASSERT(GRPC_LOG_IF_ERROR(
         "pollset_work",
         grpc_pollset_work(&exec_ctx, g_pollset, &worker,
-                          gpr_now(GPR_CLOCK_MONOTONIC),
-                          grpc_timeout_seconds_to_deadline(5))));
+                          grpc_timespec_to_millis_round_up(
+                              grpc_timeout_seconds_to_deadline(5)))));
     gpr_mu_unlock(g_mu);
     grpc_exec_ctx_flush(&exec_ctx);
     gpr_mu_lock(g_mu);
@@ -159,25 +159,24 @@ void test_fails(void) {
   /* connect to a broken address */
   GRPC_CLOSURE_INIT(&done, must_fail, NULL, grpc_schedule_on_exec_ctx);
   grpc_tcp_client_connect(&exec_ctx, &done, &g_connecting, g_pollset_set, NULL,
-                          &resolved_addr, gpr_inf_future(GPR_CLOCK_REALTIME));
+                          &resolved_addr, GRPC_MILLIS_INF_FUTURE);
 
   gpr_mu_lock(g_mu);
 
   /* wait for the connection callback to finish */
   while (g_connections_complete == connections_complete_before) {
     grpc_pollset_worker *worker = NULL;
-    gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
-    gpr_timespec polling_deadline = test_deadline();
-    switch (grpc_timer_check(&exec_ctx, now, &polling_deadline)) {
+    grpc_millis polling_deadline = test_deadline();
+    switch (grpc_timer_check(&exec_ctx, &polling_deadline)) {
       case GRPC_TIMERS_FIRED:
         break;
       case GRPC_TIMERS_NOT_CHECKED:
-        polling_deadline = now;
+        polling_deadline = 0;
       /* fall through */
       case GRPC_TIMERS_CHECKED_AND_EMPTY:
         GPR_ASSERT(GRPC_LOG_IF_ERROR(
             "pollset_work", grpc_pollset_work(&exec_ctx, g_pollset, &worker,
-                                              now, polling_deadline)));
+                                              polling_deadline)));
         break;
     }
     gpr_mu_unlock(g_mu);
diff --git a/test/core/iomgr/tcp_client_uv_test.c b/test/core/iomgr/tcp_client_uv_test.c
index 0f1db4705bb..edfccbe8678 100644
--- a/test/core/iomgr/tcp_client_uv_test.c
+++ b/test/core/iomgr/tcp_client_uv_test.c
@@ -42,8 +42,8 @@ static grpc_pollset *g_pollset;
 static int g_connections_complete = 0;
 static grpc_endpoint *g_connecting = NULL;
 
-static gpr_timespec test_deadline(void) {
-  return grpc_timeout_seconds_to_deadline(10);
+static grpc_millis test_deadline(void) {
+  return grpc_timespec_to_millis_round_up(grpc_timeout_seconds_to_deadline(10));
 }
 
 static void finish_connection(grpc_exec_ctx *exec_ctx) {
@@ -110,7 +110,7 @@ void test_succeeds(void) {
                                 (int *)&resolved_addr.len) == 0);
   GRPC_CLOSURE_INIT(&done, must_succeed, NULL, grpc_schedule_on_exec_ctx);
   grpc_tcp_client_connect(&exec_ctx, &done, &g_connecting, NULL, NULL,
-                          &resolved_addr, gpr_inf_future(GPR_CLOCK_REALTIME));
+                          &resolved_addr, GRPC_MILLIS_INF_FUTURE);
 
   gpr_mu_lock(g_mu);
 
@@ -119,8 +119,8 @@ void test_succeeds(void) {
     GPR_ASSERT(GRPC_LOG_IF_ERROR(
         "pollset_work",
         grpc_pollset_work(&exec_ctx, g_pollset, &worker,
-                          gpr_now(GPR_CLOCK_MONOTONIC),
-                          grpc_timeout_seconds_to_deadline(5))));
+                          grpc_timespec_to_millis_round_up(
+                              grpc_timeout_seconds_to_deadline(5)))));
     gpr_mu_unlock(g_mu);
     grpc_exec_ctx_flush(&exec_ctx);
     gpr_mu_lock(g_mu);
@@ -154,7 +154,7 @@ void test_fails(void) {
   /* connect to a broken address */
   GRPC_CLOSURE_INIT(&done, must_fail, NULL, grpc_schedule_on_exec_ctx);
   grpc_tcp_client_connect(&exec_ctx, &done, &g_connecting, NULL, NULL,
-                          &resolved_addr, gpr_inf_future(GPR_CLOCK_REALTIME));
+                          &resolved_addr, GRPC_MILLIS_INF_FUTURE);
 
   gpr_mu_lock(g_mu);
 
@@ -162,17 +162,17 @@ void test_fails(void) {
   while (g_connections_complete == connections_complete_before) {
     grpc_pollset_worker *worker = NULL;
     gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
-    gpr_timespec polling_deadline = test_deadline();
-    switch (grpc_timer_check(&exec_ctx, now, &polling_deadline)) {
+    grpc_millis polling_deadline = test_deadline();
+    switch (grpc_timer_check(&exec_ctx, &polling_deadline)) {
       case GRPC_TIMERS_FIRED:
         break;
       case GRPC_TIMERS_NOT_CHECKED:
-        polling_deadline = now;
+        polling_deadline = grpc_timespec_to_millis_round_up(now);
       /* fall through */
       case GRPC_TIMERS_CHECKED_AND_EMPTY:
         GPR_ASSERT(GRPC_LOG_IF_ERROR(
             "pollset_work", grpc_pollset_work(&exec_ctx, g_pollset, &worker,
-                                              now, polling_deadline)));
+                                              polling_deadline)));
         break;
     }
     gpr_mu_unlock(g_mu);
diff --git a/test/core/iomgr/tcp_posix_test.c b/test/core/iomgr/tcp_posix_test.c
index cfb3cf897cb..6501160c6f4 100644
--- a/test/core/iomgr/tcp_posix_test.c
+++ b/test/core/iomgr/tcp_posix_test.c
@@ -162,7 +162,8 @@ static void read_test(size_t num_bytes, size_t slice_size) {
   grpc_endpoint *ep;
   struct read_socket_state state;
   size_t written_bytes;
-  gpr_timespec deadline = grpc_timeout_seconds_to_deadline(20);
+  grpc_millis deadline =
+      grpc_timespec_to_millis_round_up(grpc_timeout_seconds_to_deadline(20));
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
 
   gpr_log(GPR_INFO, "Read test of size %" PRIuPTR ", slice size %" PRIuPTR,
@@ -194,8 +195,7 @@ static void read_test(size_t num_bytes, size_t slice_size) {
     grpc_pollset_worker *worker = NULL;
     GPR_ASSERT(GRPC_LOG_IF_ERROR(
         "pollset_work",
-        grpc_pollset_work(&exec_ctx, g_pollset, &worker,
-                          gpr_now(GPR_CLOCK_MONOTONIC), deadline)));
+        grpc_pollset_work(&exec_ctx, g_pollset, &worker, deadline)));
     gpr_mu_unlock(g_mu);
     grpc_exec_ctx_finish(&exec_ctx);
     gpr_mu_lock(g_mu);
@@ -215,7 +215,8 @@ static void large_read_test(size_t slice_size) {
   grpc_endpoint *ep;
   struct read_socket_state state;
   ssize_t written_bytes;
-  gpr_timespec deadline = grpc_timeout_seconds_to_deadline(20);
+  grpc_millis deadline =
+      grpc_timespec_to_millis_round_up(grpc_timeout_seconds_to_deadline(20));
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
 
   gpr_log(GPR_INFO, "Start large read test, slice size %" PRIuPTR, slice_size);
@@ -246,8 +247,7 @@ static void large_read_test(size_t slice_size) {
     grpc_pollset_worker *worker = NULL;
     GPR_ASSERT(GRPC_LOG_IF_ERROR(
         "pollset_work",
-        grpc_pollset_work(&exec_ctx, g_pollset, &worker,
-                          gpr_now(GPR_CLOCK_MONOTONIC), deadline)));
+        grpc_pollset_work(&exec_ctx, g_pollset, &worker, deadline)));
     gpr_mu_unlock(g_mu);
     grpc_exec_ctx_finish(&exec_ctx);
     gpr_mu_lock(g_mu);
@@ -319,8 +319,8 @@ void drain_socket_blocking(int fd, size_t num_bytes, size_t read_size) {
     GPR_ASSERT(GRPC_LOG_IF_ERROR(
         "pollset_work",
         grpc_pollset_work(&exec_ctx, g_pollset, &worker,
-                          gpr_now(GPR_CLOCK_MONOTONIC),
-                          grpc_timeout_milliseconds_to_deadline(10))));
+                          grpc_timespec_to_millis_round_up(
+                              grpc_timeout_milliseconds_to_deadline(10)))));
     gpr_mu_unlock(g_mu);
     grpc_exec_ctx_finish(&exec_ctx);
     do {
@@ -353,7 +353,8 @@ static void write_test(size_t num_bytes, size_t slice_size) {
   uint8_t current_data = 0;
   grpc_slice_buffer outgoing;
   grpc_closure write_done_closure;
-  gpr_timespec deadline = grpc_timeout_seconds_to_deadline(20);
+  grpc_millis deadline =
+      grpc_timespec_to_millis_round_up(grpc_timeout_seconds_to_deadline(20));
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
 
   gpr_log(GPR_INFO,
@@ -390,8 +391,7 @@ static void write_test(size_t num_bytes, size_t slice_size) {
     }
     GPR_ASSERT(GRPC_LOG_IF_ERROR(
         "pollset_work",
-        grpc_pollset_work(&exec_ctx, g_pollset, &worker,
-                          gpr_now(GPR_CLOCK_MONOTONIC), deadline)));
+        grpc_pollset_work(&exec_ctx, g_pollset, &worker, deadline)));
     gpr_mu_unlock(g_mu);
     grpc_exec_ctx_finish(&exec_ctx);
     gpr_mu_lock(g_mu);
@@ -419,7 +419,8 @@ static void release_fd_test(size_t num_bytes, size_t slice_size) {
   struct read_socket_state state;
   size_t written_bytes;
   int fd;
-  gpr_timespec deadline = grpc_timeout_seconds_to_deadline(20);
+  grpc_millis deadline =
+      grpc_timespec_to_millis_round_up(grpc_timeout_seconds_to_deadline(20));
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_closure fd_released_cb;
   int fd_released_done = 0;
@@ -457,8 +458,7 @@ static void release_fd_test(size_t num_bytes, size_t slice_size) {
     grpc_pollset_worker *worker = NULL;
     GPR_ASSERT(GRPC_LOG_IF_ERROR(
         "pollset_work",
-        grpc_pollset_work(&exec_ctx, g_pollset, &worker,
-                          gpr_now(GPR_CLOCK_MONOTONIC), deadline)));
+        grpc_pollset_work(&exec_ctx, g_pollset, &worker, deadline)));
     gpr_log(GPR_DEBUG, "wakeup: read=%" PRIdPTR " target=%" PRIdPTR,
             state.read_bytes, state.target_read_bytes);
     gpr_mu_unlock(g_mu);
@@ -476,8 +476,7 @@ static void release_fd_test(size_t num_bytes, size_t slice_size) {
     grpc_pollset_worker *worker = NULL;
     GPR_ASSERT(GRPC_LOG_IF_ERROR(
         "pollset_work",
-        grpc_pollset_work(&exec_ctx, g_pollset, &worker,
-                          gpr_now(GPR_CLOCK_MONOTONIC), deadline)));
+        grpc_pollset_work(&exec_ctx, g_pollset, &worker, deadline)));
     gpr_log(GPR_DEBUG, "wakeup: fd_released_done=%d", fd_released_done);
   }
   gpr_mu_unlock(g_mu);
diff --git a/test/core/iomgr/tcp_server_posix_test.c b/test/core/iomgr/tcp_server_posix_test.c
index 4d84608376a..782dfb413a9 100644
--- a/test/core/iomgr/tcp_server_posix_test.c
+++ b/test/core/iomgr/tcp_server_posix_test.c
@@ -230,7 +230,8 @@ static void test_no_op_with_port_and_start(void) {
 
 static grpc_error *tcp_connect(grpc_exec_ctx *exec_ctx, const test_addr *remote,
                                on_connect_result *result) {
-  gpr_timespec deadline = grpc_timeout_seconds_to_deadline(10);
+  grpc_millis deadline =
+      grpc_timespec_to_millis_round_up(grpc_timeout_seconds_to_deadline(10));
   int clifd;
   int nconnects_before;
   const struct sockaddr *remote_addr =
@@ -253,11 +254,10 @@ static grpc_error *tcp_connect(grpc_exec_ctx *exec_ctx, const test_addr *remote,
   }
   gpr_log(GPR_DEBUG, "wait");
   while (g_nconnects == nconnects_before &&
-         gpr_time_cmp(deadline, gpr_now(deadline.clock_type)) > 0) {
+         deadline > grpc_exec_ctx_now(exec_ctx)) {
     grpc_pollset_worker *worker = NULL;
     grpc_error *err;
-    if ((err = grpc_pollset_work(exec_ctx, g_pollset, &worker,
-                                 gpr_now(GPR_CLOCK_MONOTONIC), deadline)) !=
+    if ((err = grpc_pollset_work(exec_ctx, g_pollset, &worker, deadline)) !=
         GRPC_ERROR_NONE) {
       gpr_mu_unlock(g_mu);
       close(clifd);
diff --git a/test/core/iomgr/tcp_server_uv_test.c b/test/core/iomgr/tcp_server_uv_test.c
index bd8ccb4f603..9fafd3177a9 100644
--- a/test/core/iomgr/tcp_server_uv_test.c
+++ b/test/core/iomgr/tcp_server_uv_test.c
@@ -207,7 +207,7 @@ static void tcp_connect(grpc_exec_ctx *exec_ctx, const struct sockaddr *remote,
     GPR_ASSERT(GRPC_LOG_IF_ERROR(
         "pollset_work",
         grpc_pollset_work(exec_ctx, g_pollset, &worker,
-                          gpr_now(GPR_CLOCK_MONOTONIC), deadline)));
+                          grpc_timespec_to_millis_round_up(deadline))));
     gpr_mu_unlock(g_mu);
     grpc_exec_ctx_finish(exec_ctx);
     gpr_mu_lock(g_mu);
@@ -246,7 +246,7 @@ static void test_connect(unsigned n) {
   GPR_ASSERT(GRPC_ERROR_NONE ==
              grpc_tcp_server_add_port(s, &resolved_addr, &svr_port));
   GPR_ASSERT(svr_port > 0);
-  GPR_ASSERT(uv_ip6_addr("::", svr_port, (struct sockaddr_in6 *)addr) == 0);
+  GPR_ASSERT((uv_ip6_addr("::", svr_port, (struct sockaddr_in6 *)addr)) == 0);
   /* Cannot use wildcard (port==0), because add_port() will try to reuse the
      same port as a previous add_port(). */
   svr1_port = grpc_pick_unused_port_or_die();
diff --git a/test/core/iomgr/timer_list_test.c b/test/core/iomgr/timer_list_test.c
index 5f8b01fdc46..c3d9f9d88d4 100644
--- a/test/core/iomgr/timer_list_test.c
+++ b/test/core/iomgr/timer_list_test.c
@@ -41,51 +41,45 @@ static void cb(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
 }
 
 static void add_test(void) {
-  gpr_timespec start = gpr_now(GPR_CLOCK_REALTIME);
   int i;
   grpc_timer timers[20];
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
 
   gpr_log(GPR_INFO, "add_test");
 
-  grpc_timer_list_init(start);
+  grpc_timer_list_init(&exec_ctx);
   grpc_timer_trace.value = 1;
   grpc_timer_check_trace.value = 1;
   memset(cb_called, 0, sizeof(cb_called));
 
+  grpc_millis start = grpc_exec_ctx_now(&exec_ctx);
+
   /* 10 ms timers.  will expire in the current epoch */
   for (i = 0; i < 10; i++) {
-    grpc_timer_init(
-        &exec_ctx, &timers[i],
-        gpr_time_add(start, gpr_time_from_millis(10, GPR_TIMESPAN)),
-        GRPC_CLOSURE_CREATE(cb, (void *)(intptr_t)i, grpc_schedule_on_exec_ctx),
-        start);
+    grpc_timer_init(&exec_ctx, &timers[i], start + 10,
+                    GRPC_CLOSURE_CREATE(cb, (void *)(intptr_t)i,
+                                        grpc_schedule_on_exec_ctx));
   }
 
   /* 1010 ms timers.  will expire in the next epoch */
   for (i = 10; i < 20; i++) {
-    grpc_timer_init(
-        &exec_ctx, &timers[i],
-        gpr_time_add(start, gpr_time_from_millis(1010, GPR_TIMESPAN)),
-        GRPC_CLOSURE_CREATE(cb, (void *)(intptr_t)i, grpc_schedule_on_exec_ctx),
-        start);
+    grpc_timer_init(&exec_ctx, &timers[i], start + 1010,
+                    GRPC_CLOSURE_CREATE(cb, (void *)(intptr_t)i,
+                                        grpc_schedule_on_exec_ctx));
   }
 
   /* collect timers.  Only the first batch should be ready. */
-  GPR_ASSERT(grpc_timer_check(
-                 &exec_ctx,
-                 gpr_time_add(start, gpr_time_from_millis(500, GPR_TIMESPAN)),
-                 NULL) == GRPC_TIMERS_FIRED);
+  exec_ctx.now = start + 500;
+  GPR_ASSERT(grpc_timer_check(&exec_ctx, NULL) == GRPC_TIMERS_FIRED);
   grpc_exec_ctx_finish(&exec_ctx);
   for (i = 0; i < 20; i++) {
     GPR_ASSERT(cb_called[i][1] == (i < 10));
     GPR_ASSERT(cb_called[i][0] == 0);
   }
 
-  GPR_ASSERT(grpc_timer_check(
-                 &exec_ctx,
-                 gpr_time_add(start, gpr_time_from_millis(600, GPR_TIMESPAN)),
-                 NULL) == GRPC_TIMERS_CHECKED_AND_EMPTY);
+  exec_ctx.now = start + 600;
+  GPR_ASSERT(grpc_timer_check(&exec_ctx, NULL) ==
+             GRPC_TIMERS_CHECKED_AND_EMPTY);
   grpc_exec_ctx_finish(&exec_ctx);
   for (i = 0; i < 30; i++) {
     GPR_ASSERT(cb_called[i][1] == (i < 10));
@@ -93,20 +87,17 @@ static void add_test(void) {
   }
 
   /* collect the rest of the timers */
-  GPR_ASSERT(grpc_timer_check(
-                 &exec_ctx,
-                 gpr_time_add(start, gpr_time_from_millis(1500, GPR_TIMESPAN)),
-                 NULL) == GRPC_TIMERS_FIRED);
+  exec_ctx.now = start + 1500;
+  GPR_ASSERT(grpc_timer_check(&exec_ctx, NULL) == GRPC_TIMERS_FIRED);
   grpc_exec_ctx_finish(&exec_ctx);
   for (i = 0; i < 30; i++) {
     GPR_ASSERT(cb_called[i][1] == (i < 20));
     GPR_ASSERT(cb_called[i][0] == 0);
   }
 
-  GPR_ASSERT(grpc_timer_check(
-                 &exec_ctx,
-                 gpr_time_add(start, gpr_time_from_millis(1600, GPR_TIMESPAN)),
-                 NULL) == GRPC_TIMERS_CHECKED_AND_EMPTY);
+  exec_ctx.now = start + 1600;
+  GPR_ASSERT(grpc_timer_check(&exec_ctx, NULL) ==
+             GRPC_TIMERS_CHECKED_AND_EMPTY);
   for (i = 0; i < 30; i++) {
     GPR_ASSERT(cb_called[i][1] == (i < 20));
     GPR_ASSERT(cb_called[i][0] == 0);
@@ -116,10 +107,6 @@ static void add_test(void) {
   grpc_exec_ctx_finish(&exec_ctx);
 }
 
-static gpr_timespec tfm(int m) {
-  return gpr_time_from_millis(m, GPR_CLOCK_REALTIME);
-}
-
 /* Cleaning up a list with pending timers. */
 void destruction_test(void) {
   grpc_timer timers[5];
@@ -127,32 +114,30 @@ void destruction_test(void) {
 
   gpr_log(GPR_INFO, "destruction_test");
 
-  grpc_timer_list_init(gpr_time_0(GPR_CLOCK_REALTIME));
+  exec_ctx.now_is_valid = true;
+  exec_ctx.now = 0;
+  grpc_timer_list_init(&exec_ctx);
   grpc_timer_trace.value = 1;
   grpc_timer_check_trace.value = 1;
   memset(cb_called, 0, sizeof(cb_called));
 
   grpc_timer_init(
-      &exec_ctx, &timers[0], tfm(100),
-      GRPC_CLOSURE_CREATE(cb, (void *)(intptr_t)0, grpc_schedule_on_exec_ctx),
-      gpr_time_0(GPR_CLOCK_REALTIME));
+      &exec_ctx, &timers[0], 100,
+      GRPC_CLOSURE_CREATE(cb, (void *)(intptr_t)0, grpc_schedule_on_exec_ctx));
   grpc_timer_init(
-      &exec_ctx, &timers[1], tfm(3),
-      GRPC_CLOSURE_CREATE(cb, (void *)(intptr_t)1, grpc_schedule_on_exec_ctx),
-      gpr_time_0(GPR_CLOCK_REALTIME));
+      &exec_ctx, &timers[1], 3,
+      GRPC_CLOSURE_CREATE(cb, (void *)(intptr_t)1, grpc_schedule_on_exec_ctx));
   grpc_timer_init(
-      &exec_ctx, &timers[2], tfm(100),
-      GRPC_CLOSURE_CREATE(cb, (void *)(intptr_t)2, grpc_schedule_on_exec_ctx),
-      gpr_time_0(GPR_CLOCK_REALTIME));
+      &exec_ctx, &timers[2], 100,
+      GRPC_CLOSURE_CREATE(cb, (void *)(intptr_t)2, grpc_schedule_on_exec_ctx));
   grpc_timer_init(
-      &exec_ctx, &timers[3], tfm(3),
-      GRPC_CLOSURE_CREATE(cb, (void *)(intptr_t)3, grpc_schedule_on_exec_ctx),
-      gpr_time_0(GPR_CLOCK_REALTIME));
+      &exec_ctx, &timers[3], 3,
+      GRPC_CLOSURE_CREATE(cb, (void *)(intptr_t)3, grpc_schedule_on_exec_ctx));
   grpc_timer_init(
-      &exec_ctx, &timers[4], tfm(1),
-      GRPC_CLOSURE_CREATE(cb, (void *)(intptr_t)4, grpc_schedule_on_exec_ctx),
-      gpr_time_0(GPR_CLOCK_REALTIME));
-  GPR_ASSERT(grpc_timer_check(&exec_ctx, tfm(2), NULL) == GRPC_TIMERS_FIRED);
+      &exec_ctx, &timers[4], 1,
+      GRPC_CLOSURE_CREATE(cb, (void *)(intptr_t)4, grpc_schedule_on_exec_ctx));
+  exec_ctx.now = 2;
+  GPR_ASSERT(grpc_timer_check(&exec_ctx, NULL) == GRPC_TIMERS_FIRED);
   grpc_exec_ctx_finish(&exec_ctx);
   GPR_ASSERT(1 == cb_called[4][1]);
   grpc_timer_cancel(&exec_ctx, &timers[0]);
diff --git a/test/core/iomgr/udp_server_test.c b/test/core/iomgr/udp_server_test.c
index 1d051bea62d..2e44d0abc8b 100644
--- a/test/core/iomgr/udp_server_test.c
+++ b/test/core/iomgr/udp_server_test.c
@@ -226,7 +226,7 @@ static void test_receive(int number_of_clients) {
   grpc_udp_server *s = grpc_udp_server_create(NULL);
   int i;
   int number_of_reads_before;
-  gpr_timespec deadline;
+  grpc_millis deadline;
   grpc_pollset *pollsets[1];
   LOG_TEST("test_receive");
   gpr_log(GPR_INFO, "clients=%d", number_of_clients);
@@ -252,7 +252,8 @@ static void test_receive(int number_of_clients) {
   gpr_mu_lock(g_mu);
 
   for (i = 0; i < number_of_clients; i++) {
-    deadline = grpc_timeout_seconds_to_deadline(10);
+    deadline =
+        grpc_timespec_to_millis_round_up(grpc_timeout_seconds_to_deadline(10));
 
     number_of_reads_before = g_number_of_reads;
     /* Create a socket, send a packet to the UDP server. */
@@ -262,14 +263,13 @@ static void test_receive(int number_of_clients) {
                        (socklen_t)resolved_addr.len) == 0);
     GPR_ASSERT(5 == write(clifd, "hello", 5));
     while (g_number_of_reads == number_of_reads_before &&
-           gpr_time_cmp(deadline, gpr_now(deadline.clock_type)) > 0) {
+           deadline > grpc_exec_ctx_now(&exec_ctx)) {
       grpc_pollset_worker *worker = NULL;
       GPR_ASSERT(GRPC_LOG_IF_ERROR(
           "pollset_work",
-          grpc_pollset_work(&exec_ctx, g_pollset, &worker,
-                            gpr_now(GPR_CLOCK_MONOTONIC), deadline)));
+          grpc_pollset_work(&exec_ctx, g_pollset, &worker, deadline)));
       gpr_mu_unlock(g_mu);
-      grpc_exec_ctx_finish(&exec_ctx);
+      grpc_exec_ctx_flush(&exec_ctx);
       gpr_mu_lock(g_mu);
     }
     GPR_ASSERT(g_number_of_reads == number_of_reads_before + 1);
diff --git a/test/core/security/credentials_test.c b/test/core/security/credentials_test.c
index 5ac58070c8c..34f310142c8 100644
--- a/test/core/security/credentials_test.c
+++ b/test/core/security/credentials_test.c
@@ -194,14 +194,13 @@ static void test_add_abunch_to_md_array(void) {
 static void test_oauth2_token_fetcher_creds_parsing_ok(void) {
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_mdelem token_md = GRPC_MDNULL;
-  gpr_timespec token_lifetime;
+  grpc_millis token_lifetime;
   grpc_httpcli_response response =
       http_response(200, valid_oauth2_json_response);
   GPR_ASSERT(grpc_oauth2_token_fetcher_credentials_parse_server_response(
                  &exec_ctx, &response, &token_md, &token_lifetime) ==
              GRPC_CREDENTIALS_OK);
-  GPR_ASSERT(token_lifetime.tv_sec == 3599);
-  GPR_ASSERT(token_lifetime.tv_nsec == 0);
+  GPR_ASSERT(token_lifetime == 3599 * GPR_MS_PER_SEC);
   GPR_ASSERT(grpc_slice_str_cmp(GRPC_MDKEY(token_md), "authorization") == 0);
   GPR_ASSERT(grpc_slice_str_cmp(GRPC_MDVALUE(token_md),
                                 "Bearer ya29.AHES6ZRN3-HlhAPya30GnW_bHSb_") ==
@@ -214,7 +213,7 @@ static void test_oauth2_token_fetcher_creds_parsing_ok(void) {
 static void test_oauth2_token_fetcher_creds_parsing_bad_http_status(void) {
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_mdelem token_md = GRPC_MDNULL;
-  gpr_timespec token_lifetime;
+  grpc_millis token_lifetime;
   grpc_httpcli_response response =
       http_response(401, valid_oauth2_json_response);
   GPR_ASSERT(grpc_oauth2_token_fetcher_credentials_parse_server_response(
@@ -227,7 +226,7 @@ static void test_oauth2_token_fetcher_creds_parsing_bad_http_status(void) {
 static void test_oauth2_token_fetcher_creds_parsing_empty_http_body(void) {
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_mdelem token_md = GRPC_MDNULL;
-  gpr_timespec token_lifetime;
+  grpc_millis token_lifetime;
   grpc_httpcli_response response = http_response(200, "");
   GPR_ASSERT(grpc_oauth2_token_fetcher_credentials_parse_server_response(
                  &exec_ctx, &response, &token_md, &token_lifetime) ==
@@ -239,7 +238,7 @@ static void test_oauth2_token_fetcher_creds_parsing_empty_http_body(void) {
 static void test_oauth2_token_fetcher_creds_parsing_invalid_json(void) {
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_mdelem token_md = GRPC_MDNULL;
-  gpr_timespec token_lifetime;
+  grpc_millis token_lifetime;
   grpc_httpcli_response response =
       http_response(200,
                     "{\"access_token\":\"ya29.AHES6ZRN3-HlhAPya30GnW_bHSb_\","
@@ -255,7 +254,7 @@ static void test_oauth2_token_fetcher_creds_parsing_invalid_json(void) {
 static void test_oauth2_token_fetcher_creds_parsing_missing_token(void) {
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_mdelem token_md = GRPC_MDNULL;
-  gpr_timespec token_lifetime;
+  grpc_millis token_lifetime;
   grpc_httpcli_response response = http_response(200,
                                                  "{"
                                                  " \"expires_in\":3599, "
@@ -270,7 +269,7 @@ static void test_oauth2_token_fetcher_creds_parsing_missing_token(void) {
 static void test_oauth2_token_fetcher_creds_parsing_missing_token_type(void) {
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_mdelem token_md = GRPC_MDNULL;
-  gpr_timespec token_lifetime;
+  grpc_millis token_lifetime;
   grpc_httpcli_response response =
       http_response(200,
                     "{\"access_token\":\"ya29.AHES6ZRN3-HlhAPya30GnW_bHSb_\","
@@ -287,7 +286,7 @@ static void test_oauth2_token_fetcher_creds_parsing_missing_token_lifetime(
     void) {
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_mdelem token_md = GRPC_MDNULL;
-  gpr_timespec token_lifetime;
+  grpc_millis token_lifetime;
   grpc_httpcli_response response =
       http_response(200,
                     "{\"access_token\":\"ya29.AHES6ZRN3-HlhAPya30GnW_bHSb_\","
@@ -555,7 +554,7 @@ static void validate_compute_engine_http_request(
 
 static int compute_engine_httpcli_get_success_override(
     grpc_exec_ctx *exec_ctx, const grpc_httpcli_request *request,
-    gpr_timespec deadline, grpc_closure *on_done,
+    grpc_millis deadline, grpc_closure *on_done,
     grpc_httpcli_response *response) {
   validate_compute_engine_http_request(request);
   *response = http_response(200, valid_oauth2_json_response);
@@ -565,7 +564,7 @@ static int compute_engine_httpcli_get_success_override(
 
 static int compute_engine_httpcli_get_failure_override(
     grpc_exec_ctx *exec_ctx, const grpc_httpcli_request *request,
-    gpr_timespec deadline, grpc_closure *on_done,
+    grpc_millis deadline, grpc_closure *on_done,
     grpc_httpcli_response *response) {
   validate_compute_engine_http_request(request);
   *response = http_response(403, "Not Authorized.");
@@ -575,7 +574,7 @@ static int compute_engine_httpcli_get_failure_override(
 
 static int httpcli_post_should_not_be_called(
     grpc_exec_ctx *exec_ctx, const grpc_httpcli_request *request,
-    const char *body_bytes, size_t body_size, gpr_timespec deadline,
+    const char *body_bytes, size_t body_size, grpc_millis deadline,
     grpc_closure *on_done, grpc_httpcli_response *response) {
   GPR_ASSERT("HTTP POST should not be called" == NULL);
   return 1;
@@ -583,7 +582,7 @@ static int httpcli_post_should_not_be_called(
 
 static int httpcli_get_should_not_be_called(grpc_exec_ctx *exec_ctx,
                                             const grpc_httpcli_request *request,
-                                            gpr_timespec deadline,
+                                            grpc_millis deadline,
                                             grpc_closure *on_done,
                                             grpc_httpcli_response *response) {
   GPR_ASSERT("HTTP GET should not be called" == NULL);
@@ -663,7 +662,7 @@ static void validate_refresh_token_http_request(
 
 static int refresh_token_httpcli_post_success(
     grpc_exec_ctx *exec_ctx, const grpc_httpcli_request *request,
-    const char *body, size_t body_size, gpr_timespec deadline,
+    const char *body, size_t body_size, grpc_millis deadline,
     grpc_closure *on_done, grpc_httpcli_response *response) {
   validate_refresh_token_http_request(request, body, body_size);
   *response = http_response(200, valid_oauth2_json_response);
@@ -673,7 +672,7 @@ static int refresh_token_httpcli_post_success(
 
 static int refresh_token_httpcli_post_failure(
     grpc_exec_ctx *exec_ctx, const grpc_httpcli_request *request,
-    const char *body, size_t body_size, gpr_timespec deadline,
+    const char *body, size_t body_size, grpc_millis deadline,
     grpc_closure *on_done, grpc_httpcli_response *response) {
   validate_refresh_token_http_request(request, body, body_size);
   *response = http_response(403, "Not Authorized.");
@@ -932,7 +931,7 @@ static void test_google_default_creds_refresh_token(void) {
 
 static int default_creds_gce_detection_httpcli_get_success_override(
     grpc_exec_ctx *exec_ctx, const grpc_httpcli_request *request,
-    gpr_timespec deadline, grpc_closure *on_done,
+    grpc_millis deadline, grpc_closure *on_done,
     grpc_httpcli_response *response) {
   *response = http_response(200, "");
   grpc_http_header *headers = gpr_malloc(sizeof(*headers) * 1);
@@ -996,7 +995,7 @@ static void test_google_default_creds_gce(void) {
 
 static int default_creds_gce_detection_httpcli_get_failure_override(
     grpc_exec_ctx *exec_ctx, const grpc_httpcli_request *request,
-    gpr_timespec deadline, grpc_closure *on_done,
+    grpc_millis deadline, grpc_closure *on_done,
     grpc_httpcli_response *response) {
   /* No magic header. */
   GPR_ASSERT(strcmp(request->http.path, "/") == 0);
diff --git a/test/core/security/jwt_verifier_test.c b/test/core/security/jwt_verifier_test.c
index 9b17fb516d0..a4bfe0130ee 100644
--- a/test/core/security/jwt_verifier_test.c
+++ b/test/core/security/jwt_verifier_test.c
@@ -324,7 +324,7 @@ static grpc_httpcli_response http_response(int status, char *body) {
 
 static int httpcli_post_should_not_be_called(
     grpc_exec_ctx *exec_ctx, const grpc_httpcli_request *request,
-    const char *body_bytes, size_t body_size, gpr_timespec deadline,
+    const char *body_bytes, size_t body_size, grpc_millis deadline,
     grpc_closure *on_done, grpc_httpcli_response *response) {
   GPR_ASSERT("HTTP POST should not be called" == NULL);
   return 1;
@@ -332,7 +332,7 @@ static int httpcli_post_should_not_be_called(
 
 static int httpcli_get_google_keys_for_email(
     grpc_exec_ctx *exec_ctx, const grpc_httpcli_request *request,
-    gpr_timespec deadline, grpc_closure *on_done,
+    grpc_millis deadline, grpc_closure *on_done,
     grpc_httpcli_response *response) {
   *response = http_response(200, good_google_email_keys());
   GPR_ASSERT(request->handshaker == &grpc_httpcli_ssl);
@@ -379,7 +379,7 @@ static void test_jwt_verifier_google_email_issuer_success(void) {
 
 static int httpcli_get_custom_keys_for_email(
     grpc_exec_ctx *exec_ctx, const grpc_httpcli_request *request,
-    gpr_timespec deadline, grpc_closure *on_done,
+    grpc_millis deadline, grpc_closure *on_done,
     grpc_httpcli_response *response) {
   *response = http_response(200, gpr_strdup(good_jwk_set));
   GPR_ASSERT(request->handshaker == &grpc_httpcli_ssl);
@@ -413,7 +413,7 @@ static void test_jwt_verifier_custom_email_issuer_success(void) {
 
 static int httpcli_get_jwk_set(grpc_exec_ctx *exec_ctx,
                                const grpc_httpcli_request *request,
-                               gpr_timespec deadline, grpc_closure *on_done,
+                               grpc_millis deadline, grpc_closure *on_done,
                                grpc_httpcli_response *response) {
   *response = http_response(200, gpr_strdup(good_jwk_set));
   GPR_ASSERT(request->handshaker == &grpc_httpcli_ssl);
@@ -425,7 +425,7 @@ static int httpcli_get_jwk_set(grpc_exec_ctx *exec_ctx,
 
 static int httpcli_get_openid_config(grpc_exec_ctx *exec_ctx,
                                      const grpc_httpcli_request *request,
-                                     gpr_timespec deadline,
+                                     grpc_millis deadline,
                                      grpc_closure *on_done,
                                      grpc_httpcli_response *response) {
   *response = http_response(200, gpr_strdup(good_openid_config));
@@ -471,7 +471,7 @@ static void on_verification_key_retrieval_error(grpc_exec_ctx *exec_ctx,
 
 static int httpcli_get_bad_json(grpc_exec_ctx *exec_ctx,
                                 const grpc_httpcli_request *request,
-                                gpr_timespec deadline, grpc_closure *on_done,
+                                grpc_millis deadline, grpc_closure *on_done,
                                 grpc_httpcli_response *response) {
   *response = http_response(200, gpr_strdup("{\"bad\": \"stuff\"}"));
   GPR_ASSERT(request->handshaker == &grpc_httpcli_ssl);
@@ -581,7 +581,7 @@ static void test_jwt_verifier_bad_signature(void) {
 
 static int httpcli_get_should_not_be_called(grpc_exec_ctx *exec_ctx,
                                             const grpc_httpcli_request *request,
-                                            gpr_timespec deadline,
+                                            grpc_millis deadline,
                                             grpc_closure *on_done,
                                             grpc_httpcli_response *response) {
   GPR_ASSERT(0);
diff --git a/test/core/security/oauth2_utils.c b/test/core/security/oauth2_utils.c
index d240403a293..73d6c5bc7dc 100644
--- a/test/core/security/oauth2_utils.c
+++ b/test/core/security/oauth2_utils.c
@@ -104,8 +104,7 @@ char *grpc_test_fetch_oauth2_token_with_credentials(
             "pollset_work",
             grpc_pollset_work(&exec_ctx,
                               grpc_polling_entity_pollset(&request.pops),
-                              &worker, gpr_now(GPR_CLOCK_MONOTONIC),
-                              gpr_inf_future(GPR_CLOCK_MONOTONIC)))) {
+                              &worker, GRPC_MILLIS_INF_FUTURE))) {
       request.is_done = true;
     }
   }
diff --git a/test/core/security/print_google_default_creds_token.c b/test/core/security/print_google_default_creds_token.c
index 3144717a853..29c38dfdf81 100644
--- a/test/core/security/print_google_default_creds_token.c
+++ b/test/core/security/print_google_default_creds_token.c
@@ -110,8 +110,7 @@ int main(int argc, char **argv) {
             "pollset_work",
             grpc_pollset_work(&exec_ctx,
                               grpc_polling_entity_pollset(&sync.pops), &worker,
-                              gpr_now(GPR_CLOCK_MONOTONIC),
-                              gpr_inf_future(GPR_CLOCK_MONOTONIC))))
+                              GRPC_MILLIS_INF_FUTURE)))
       sync.is_done = true;
     gpr_mu_unlock(sync.mu);
     grpc_exec_ctx_flush(&exec_ctx);
diff --git a/test/core/security/ssl_server_fuzzer.c b/test/core/security/ssl_server_fuzzer.c
index 9858b11c7c3..f9b754b8f21 100644
--- a/test/core/security/ssl_server_fuzzer.c
+++ b/test/core/security/ssl_server_fuzzer.c
@@ -84,8 +84,7 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
   grpc_security_status status =
       grpc_server_credentials_create_security_connector(&exec_ctx, creds, &sc);
   GPR_ASSERT(status == GRPC_SECURITY_OK);
-  gpr_timespec deadline = gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC),
-                                       gpr_time_from_seconds(1, GPR_TIMESPAN));
+  grpc_millis deadline = GPR_MS_PER_SEC + grpc_exec_ctx_now(&exec_ctx);
 
   struct handshake_state state;
   state.done_callback_called = false;
diff --git a/test/core/security/verify_jwt.c b/test/core/security/verify_jwt.c
index 5faa6352a87..cec6fb94b4e 100644
--- a/test/core/security/verify_jwt.c
+++ b/test/core/security/verify_jwt.c
@@ -102,11 +102,9 @@ int main(int argc, char **argv) {
   gpr_mu_lock(sync.mu);
   while (!sync.is_done) {
     grpc_pollset_worker *worker = NULL;
-    if (!GRPC_LOG_IF_ERROR(
-            "pollset_work",
-            grpc_pollset_work(&exec_ctx, sync.pollset, &worker,
-                              gpr_now(GPR_CLOCK_MONOTONIC),
-                              gpr_inf_future(GPR_CLOCK_MONOTONIC))))
+    if (!GRPC_LOG_IF_ERROR("pollset_work",
+                           grpc_pollset_work(&exec_ctx, sync.pollset, &worker,
+                                             GRPC_MILLIS_INF_FUTURE)))
       sync.is_done = true;
     gpr_mu_unlock(sync.mu);
     grpc_exec_ctx_flush(&exec_ctx);
diff --git a/test/core/slice/BUILD b/test/core/slice/BUILD
index f86a3a6082c..ad2308a4d69 100644
--- a/test/core/slice/BUILD
+++ b/test/core/slice/BUILD
@@ -20,11 +20,23 @@ licenses(["notice"])  # Apache v2
 
 load("//test/core/util:grpc_fuzzer.bzl", "grpc_fuzzer")
 
+grpc_fuzzer(
+    name = "percent_encode_fuzzer",
+    srcs = ["percent_encode_fuzzer.c"],
+    language = "C",
+    corpus = "percent_encode_corpus",
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//test/core/util:grpc_test_util",
+    ],
+)
+
 grpc_fuzzer(
     name = "percent_decode_fuzzer",
     srcs = ["percent_decode_fuzzer.c"],
     language = "C",
-    corpus = "response_corpus",
+    corpus = "percent_decode_corpus",
     deps = [
         "//:gpr",
         "//:grpc",
diff --git a/test/core/support/BUILD b/test/core/support/BUILD
index 096576e13c9..407c3eff7ba 100644
--- a/test/core/support/BUILD
+++ b/test/core/support/BUILD
@@ -38,16 +38,6 @@ grpc_cc_test(
     ],
 )
 
-grpc_cc_test(
-    name = "backoff_test",
-    srcs = ["backoff_test.c"],
-    language = "C",
-    deps = [
-        "//:gpr",
-        "//test/core/util:gpr_test_util",
-    ],
-)
-
 grpc_cc_test(
     name = "cmdline_test",
     srcs = ["cmdline_test.c"],
diff --git a/test/core/support/backoff_test.c b/test/core/support/backoff_test.c
deleted file mode 100644
index 23e3005af0a..00000000000
--- a/test/core/support/backoff_test.c
+++ /dev/null
@@ -1,143 +0,0 @@
-/*
- *
- * Copyright 2016 gRPC authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-#include "src/core/lib/support/backoff.h"
-
-#include <grpc/support/log.h>
-
-#include "test/core/util/test_config.h"
-
-static void test_constant_backoff(void) {
-  gpr_backoff backoff;
-  gpr_backoff_init(&backoff, 200 /* initial timeout */, 1.0 /* multiplier */,
-                   0.0 /* jitter */, 100 /* min timeout */,
-                   1000 /* max timeout */);
-
-  gpr_timespec now = gpr_time_0(GPR_TIMESPAN);
-  gpr_timespec next = gpr_backoff_begin(&backoff, now);
-  GPR_ASSERT(gpr_time_to_millis(gpr_time_sub(next, now)) == 200);
-  for (int i = 0; i < 10000; i++) {
-    next = gpr_backoff_step(&backoff, now);
-    GPR_ASSERT(gpr_time_to_millis(gpr_time_sub(next, now)) == 200);
-    now = next;
-  }
-}
-
-static void test_min_connect(void) {
-  gpr_backoff backoff;
-  gpr_backoff_init(&backoff, 100 /* initial timeout */, 1.0 /* multiplier */,
-                   0.0 /* jitter */, 200 /* min timeout */,
-                   1000 /* max timeout */);
-
-  gpr_timespec now = gpr_time_0(GPR_TIMESPAN);
-  gpr_timespec next = gpr_backoff_begin(&backoff, now);
-  GPR_ASSERT(gpr_time_to_millis(gpr_time_sub(next, now)) == 200);
-}
-
-static void test_no_jitter_backoff(void) {
-  gpr_backoff backoff;
-  gpr_backoff_init(&backoff, 2 /* initial timeout */, 2.0 /* multiplier */,
-                   0.0 /* jitter */, 1 /* min timeout */,
-                   513 /* max timeout */);
-  // x_1 = 2
-  // x_n = 2**i + x_{i-1} ( = 2**(n+1) - 2 )
-  gpr_timespec now = gpr_time_0(GPR_TIMESPAN);
-  gpr_timespec next = gpr_backoff_begin(&backoff, now);
-  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(2, GPR_TIMESPAN), next) == 0);
-  now = next;
-  next = gpr_backoff_step(&backoff, now);
-  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(6, GPR_TIMESPAN), next) == 0);
-  now = next;
-  next = gpr_backoff_step(&backoff, now);
-  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(14, GPR_TIMESPAN), next) == 0);
-  now = next;
-  next = gpr_backoff_step(&backoff, now);
-  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(30, GPR_TIMESPAN), next) == 0);
-  now = next;
-  next = gpr_backoff_step(&backoff, now);
-  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(62, GPR_TIMESPAN), next) == 0);
-  now = next;
-  next = gpr_backoff_step(&backoff, now);
-  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(126, GPR_TIMESPAN), next) == 0);
-  now = next;
-  next = gpr_backoff_step(&backoff, now);
-  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(254, GPR_TIMESPAN), next) == 0);
-  now = next;
-  next = gpr_backoff_step(&backoff, now);
-  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(510, GPR_TIMESPAN), next) == 0);
-  now = next;
-  next = gpr_backoff_step(&backoff, now);
-  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(1022, GPR_TIMESPAN), next) == 0);
-  now = next;
-  next = gpr_backoff_step(&backoff, now);
-  // Hit the maximum timeout. From this point onwards, retries will increase
-  // only by max timeout.
-  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(1535, GPR_TIMESPAN), next) == 0);
-  now = next;
-  next = gpr_backoff_step(&backoff, now);
-  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(2048, GPR_TIMESPAN), next) == 0);
-  now = next;
-  next = gpr_backoff_step(&backoff, now);
-  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(2561, GPR_TIMESPAN), next) == 0);
-}
-
-static void test_jitter_backoff(void) {
-  const int64_t initial_timeout = 500;
-  const double jitter = 0.1;
-  gpr_backoff backoff;
-  gpr_backoff_init(&backoff, initial_timeout, 1.0 /* multiplier */, jitter,
-                   100 /* min timeout */, 1000 /* max timeout */);
-
-  backoff.rng_state = 0;  // force consistent PRNG
-
-  gpr_timespec now = gpr_time_0(GPR_TIMESPAN);
-  gpr_timespec next = gpr_backoff_begin(&backoff, now);
-  GPR_ASSERT(gpr_time_to_millis(gpr_time_sub(next, now)) == 500);
-
-  int64_t expected_next_lower_bound =
-      (int64_t)((double)initial_timeout * (1 - jitter));
-  int64_t expected_next_upper_bound =
-      (int64_t)((double)initial_timeout * (1 + jitter));
-
-  for (int i = 0; i < 10000; i++) {
-    next = gpr_backoff_step(&backoff, now);
-
-    // next-now must be within (jitter*100)% of the previous timeout.
-    const int64_t timeout_millis = gpr_time_to_millis(gpr_time_sub(next, now));
-    GPR_ASSERT(timeout_millis >= expected_next_lower_bound);
-    GPR_ASSERT(timeout_millis <= expected_next_upper_bound);
-
-    expected_next_lower_bound =
-        (int64_t)((double)timeout_millis * (1 - jitter));
-    expected_next_upper_bound =
-        (int64_t)((double)timeout_millis * (1 + jitter));
-    now = next;
-  }
-}
-
-int main(int argc, char **argv) {
-  grpc_test_init(argc, argv);
-  gpr_time_init();
-
-  test_constant_backoff();
-  test_min_connect();
-  test_no_jitter_backoff();
-  test_jitter_backoff();
-
-  return 0;
-}
diff --git a/test/core/surface/concurrent_connectivity_test.c b/test/core/surface/concurrent_connectivity_test.c
index ec2cd8610bc..3595885ff6d 100644
--- a/test/core/surface/concurrent_connectivity_test.c
+++ b/test/core/surface/concurrent_connectivity_test.c
@@ -135,14 +135,12 @@ void bad_server_thread(void *vargs) {
 
   gpr_mu_lock(args->mu);
   while (gpr_atm_acq_load(&args->stop) == 0) {
-    gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
-    gpr_timespec deadline =
-        gpr_time_add(now, gpr_time_from_millis(100, GPR_TIMESPAN));
+    grpc_millis deadline = grpc_exec_ctx_now(&exec_ctx) + 100;
 
     grpc_pollset_worker *worker = NULL;
-    if (!GRPC_LOG_IF_ERROR("pollset_work",
-                           grpc_pollset_work(&exec_ctx, args->pollset, &worker,
-                                             now, deadline))) {
+    if (!GRPC_LOG_IF_ERROR(
+            "pollset_work",
+            grpc_pollset_work(&exec_ctx, args->pollset, &worker, deadline))) {
       gpr_atm_rel_store(&args->stop, 1);
     }
     gpr_mu_unlock(args->mu);
diff --git a/test/core/surface/init_test.c b/test/core/surface/init_test.c
index a9e80575af1..b835a2a8843 100644
--- a/test/core/surface/init_test.c
+++ b/test/core/surface/init_test.c
@@ -53,7 +53,7 @@ static void test_plugin() {
 }
 
 static void test_repeatedly() {
-  for (int i = 0; i < 100000; i++) {
+  for (int i = 0; i < 1000; i++) {
     grpc_init();
     grpc_shutdown();
   }
diff --git a/test/core/transport/bdp_estimator_test.c b/test/core/transport/bdp_estimator_test.c
index dda48f45b18..4912ad58872 100644
--- a/test/core/transport/bdp_estimator_test.c
+++ b/test/core/transport/bdp_estimator_test.c
@@ -24,9 +24,22 @@
 #include <grpc/support/string_util.h>
 #include <grpc/support/useful.h>
 #include <limits.h>
+#include "src/core/lib/iomgr/timer_manager.h"
 #include "src/core/lib/support/string.h"
 #include "test/core/util/test_config.h"
 
+extern gpr_timespec (*gpr_now_impl)(gpr_clock_type clock_type);
+
+static int g_clock = 0;
+
+static gpr_timespec fake_gpr_now(gpr_clock_type clock_type) {
+  return (gpr_timespec){
+      .tv_sec = g_clock, .tv_nsec = 0, .clock_type = clock_type,
+  };
+}
+
+static void inc_time(void) { g_clock += 30; }
+
 static void test_noop(void) {
   gpr_log(GPR_INFO, "test_noop");
   grpc_bdp_estimator est;
@@ -44,16 +57,19 @@ static void test_get_estimate_no_samples(void) {
 static void add_samples(grpc_bdp_estimator *estimator, int64_t *samples,
                         size_t n) {
   grpc_bdp_estimator_add_incoming_bytes(estimator, 1234567);
-  GPR_ASSERT(grpc_bdp_estimator_need_ping(estimator) == true);
+  inc_time();
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  GPR_ASSERT(grpc_bdp_estimator_need_ping(&exec_ctx, estimator) == true);
   grpc_bdp_estimator_schedule_ping(estimator);
   grpc_bdp_estimator_start_ping(estimator);
   for (size_t i = 0; i < n; i++) {
     grpc_bdp_estimator_add_incoming_bytes(estimator, samples[i]);
-    GPR_ASSERT(grpc_bdp_estimator_need_ping(estimator) == false);
+    GPR_ASSERT(grpc_bdp_estimator_need_ping(&exec_ctx, estimator) == false);
   }
   gpr_sleep_until(gpr_time_add(gpr_now(GPR_CLOCK_REALTIME),
                                gpr_time_from_millis(1, GPR_TIMESPAN)));
-  grpc_bdp_estimator_complete_ping(estimator);
+  grpc_bdp_estimator_complete_ping(&exec_ctx, estimator);
+  grpc_exec_ctx_finish(&exec_ctx);
 }
 
 static void add_sample(grpc_bdp_estimator *estimator, int64_t sample) {
@@ -130,7 +146,9 @@ static void test_get_estimate_random_values(size_t n) {
 
 int main(int argc, char **argv) {
   grpc_test_init(argc, argv);
+  gpr_now_impl = fake_gpr_now;
   grpc_init();
+  grpc_timer_manager_set_threading(false);
   test_noop();
   test_get_estimate_no_samples();
   test_get_estimate_1_sample();
diff --git a/test/core/transport/status_conversion_test.c b/test/core/transport/status_conversion_test.c
index 89558964c1c..de8fa4458a6 100644
--- a/test/core/transport/status_conversion_test.c
+++ b/test/core/transport/status_conversion_test.c
@@ -22,8 +22,13 @@
 
 #define GRPC_STATUS_TO_HTTP2_ERROR(a, b) \
   GPR_ASSERT(grpc_status_to_http2_error(a) == (b))
-#define HTTP2_ERROR_TO_GRPC_STATUS(a, deadline, b) \
-  GPR_ASSERT(grpc_http2_error_to_grpc_status(a, deadline) == (b))
+#define HTTP2_ERROR_TO_GRPC_STATUS(a, deadline, b)                           \
+  do {                                                                       \
+    grpc_exec_ctx my_exec_ctx = GRPC_EXEC_CTX_INIT;                          \
+    GPR_ASSERT(grpc_http2_error_to_grpc_status(&my_exec_ctx, a, deadline) == \
+               (b));                                                         \
+    grpc_exec_ctx_finish(&my_exec_ctx);                                      \
+  } while (0)
 #define GRPC_STATUS_TO_HTTP2_STATUS(a, b) \
   GPR_ASSERT(grpc_status_to_http2_status(a) == (b))
 #define HTTP2_STATUS_TO_GRPC_STATUS(a, b) \
@@ -79,7 +84,7 @@ int main(int argc, char **argv) {
   GRPC_STATUS_TO_HTTP2_STATUS(GRPC_STATUS_UNAVAILABLE, 200);
   GRPC_STATUS_TO_HTTP2_STATUS(GRPC_STATUS_DATA_LOSS, 200);
 
-  const gpr_timespec before_deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
+  const grpc_millis before_deadline = GRPC_MILLIS_INF_FUTURE;
   HTTP2_ERROR_TO_GRPC_STATUS(GRPC_HTTP2_NO_ERROR, before_deadline,
                              GRPC_STATUS_INTERNAL);
   HTTP2_ERROR_TO_GRPC_STATUS(GRPC_HTTP2_PROTOCOL_ERROR, before_deadline,
@@ -107,7 +112,7 @@ int main(int argc, char **argv) {
   HTTP2_ERROR_TO_GRPC_STATUS(GRPC_HTTP2_INADEQUATE_SECURITY, before_deadline,
                              GRPC_STATUS_PERMISSION_DENIED);
 
-  const gpr_timespec after_deadline = gpr_inf_past(GPR_CLOCK_MONOTONIC);
+  const grpc_millis after_deadline = 0;
   HTTP2_ERROR_TO_GRPC_STATUS(GRPC_HTTP2_NO_ERROR, after_deadline,
                              GRPC_STATUS_INTERNAL);
   HTTP2_ERROR_TO_GRPC_STATUS(GRPC_HTTP2_PROTOCOL_ERROR, after_deadline,
diff --git a/test/core/transport/timeout_encoding_test.c b/test/core/transport/timeout_encoding_test.c
index 6388ffbcec6..30357faed36 100644
--- a/test/core/transport/timeout_encoding_test.c
+++ b/test/core/transport/timeout_encoding_test.c
@@ -25,12 +25,13 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 #include <grpc/support/useful.h>
+#include "src/core/lib/support/murmur_hash.h"
 #include "src/core/lib/support/string.h"
 #include "test/core/util/test_config.h"
 
 #define LOG_TEST(x) gpr_log(GPR_INFO, "%s", x)
 
-static void assert_encodes_as(gpr_timespec ts, const char *s) {
+static void assert_encodes_as(grpc_millis ts, const char *s) {
   char buffer[GRPC_HTTP2_TIMEOUT_ENCODE_MIN_BUFSIZE];
   grpc_http2_encode_timeout(ts, buffer);
   gpr_log(GPR_INFO, "check '%s' == '%s'", buffer, s);
@@ -39,47 +40,43 @@ static void assert_encodes_as(gpr_timespec ts, const char *s) {
 
 void test_encoding(void) {
   LOG_TEST("test_encoding");
-  assert_encodes_as(gpr_time_from_micros(-1, GPR_TIMESPAN), "1n");
-  assert_encodes_as(gpr_time_from_seconds(-10, GPR_TIMESPAN), "1n");
-  assert_encodes_as(gpr_time_from_nanos(10, GPR_TIMESPAN), "10n");
-  assert_encodes_as(gpr_time_from_nanos(999999999, GPR_TIMESPAN), "1S");
-  assert_encodes_as(gpr_time_from_micros(1, GPR_TIMESPAN), "1u");
-  assert_encodes_as(gpr_time_from_micros(10, GPR_TIMESPAN), "10u");
-  assert_encodes_as(gpr_time_from_micros(100, GPR_TIMESPAN), "100u");
-  assert_encodes_as(gpr_time_from_micros(890, GPR_TIMESPAN), "890u");
-  assert_encodes_as(gpr_time_from_micros(900, GPR_TIMESPAN), "900u");
-  assert_encodes_as(gpr_time_from_micros(901, GPR_TIMESPAN), "901u");
-  assert_encodes_as(gpr_time_from_millis(1, GPR_TIMESPAN), "1m");
-  assert_encodes_as(gpr_time_from_millis(2, GPR_TIMESPAN), "2m");
-  assert_encodes_as(gpr_time_from_micros(10001, GPR_TIMESPAN), "10100u");
-  assert_encodes_as(gpr_time_from_micros(999999, GPR_TIMESPAN), "1S");
-  assert_encodes_as(gpr_time_from_millis(1000, GPR_TIMESPAN), "1S");
-  assert_encodes_as(gpr_time_from_millis(2000, GPR_TIMESPAN), "2S");
-  assert_encodes_as(gpr_time_from_millis(2500, GPR_TIMESPAN), "2500m");
-  assert_encodes_as(gpr_time_from_millis(59900, GPR_TIMESPAN), "59900m");
-  assert_encodes_as(gpr_time_from_seconds(50, GPR_TIMESPAN), "50S");
-  assert_encodes_as(gpr_time_from_seconds(59, GPR_TIMESPAN), "59S");
-  assert_encodes_as(gpr_time_from_seconds(60, GPR_TIMESPAN), "1M");
-  assert_encodes_as(gpr_time_from_seconds(80, GPR_TIMESPAN), "80S");
-  assert_encodes_as(gpr_time_from_seconds(90, GPR_TIMESPAN), "90S");
-  assert_encodes_as(gpr_time_from_minutes(2, GPR_TIMESPAN), "2M");
-  assert_encodes_as(gpr_time_from_minutes(20, GPR_TIMESPAN), "20M");
-  assert_encodes_as(gpr_time_from_hours(1, GPR_TIMESPAN), "1H");
-  assert_encodes_as(gpr_time_from_hours(10, GPR_TIMESPAN), "10H");
-  assert_encodes_as(gpr_time_from_seconds(1000000000, GPR_TIMESPAN),
-                    "1000000000S");
+  assert_encodes_as(-1, "1n");
+  assert_encodes_as(-10, "1n");
+  assert_encodes_as(1, "1m");
+  assert_encodes_as(10, "10m");
+  assert_encodes_as(100, "100m");
+  assert_encodes_as(890, "890m");
+  assert_encodes_as(900, "900m");
+  assert_encodes_as(901, "901m");
+  assert_encodes_as(1000, "1S");
+  assert_encodes_as(2000, "2S");
+  assert_encodes_as(2500, "2500m");
+  assert_encodes_as(59900, "59900m");
+  assert_encodes_as(50000, "50S");
+  assert_encodes_as(59000, "59S");
+  assert_encodes_as(60000, "1M");
+  assert_encodes_as(80000, "80S");
+  assert_encodes_as(90000, "90S");
+  assert_encodes_as(120000, "2M");
+  assert_encodes_as(20 * 60 * GPR_MS_PER_SEC, "20M");
+  assert_encodes_as(60 * 60 * GPR_MS_PER_SEC, "1H");
+  assert_encodes_as(10 * 60 * 60 * GPR_MS_PER_SEC, "10H");
 }
 
-static void assert_decodes_as(const char *buffer, gpr_timespec expected) {
-  gpr_timespec got;
-  gpr_log(GPR_INFO, "check decoding '%s'", buffer);
+static void assert_decodes_as(const char *buffer, grpc_millis expected) {
+  grpc_millis got;
+  uint32_t hash = gpr_murmur_hash3(buffer, strlen(buffer), 0);
+  gpr_log(GPR_INFO, "check decoding '%s' (hash=0x%x)", buffer, hash);
   GPR_ASSERT(1 == grpc_http2_decode_timeout(
                       grpc_slice_from_static_string(buffer), &got));
-  GPR_ASSERT(0 == gpr_time_cmp(got, expected));
+  if (got != expected) {
+    gpr_log(GPR_ERROR, "got:'%" PRIdPTR "' != expected:'%" PRIdPTR "'", got,
+            expected);
+    abort();
+  }
 }
 
-void decode_suite(char ext,
-                  gpr_timespec (*answer)(int64_t x, gpr_clock_type clock)) {
+void decode_suite(char ext, grpc_millis (*answer)(int64_t x)) {
   long test_vals[] = {1,       12,       123,       1234,     12345,   123456,
                       1234567, 12345678, 123456789, 98765432, 9876543, 987654,
                       98765,   9876,     987,       98,       9};
@@ -87,41 +84,57 @@ void decode_suite(char ext,
   char *input;
   for (i = 0; i < GPR_ARRAY_SIZE(test_vals); i++) {
     gpr_asprintf(&input, "%ld%c", test_vals[i], ext);
-    assert_decodes_as(input, answer(test_vals[i], GPR_TIMESPAN));
+    assert_decodes_as(input, answer(test_vals[i]));
     gpr_free(input);
 
     gpr_asprintf(&input, "   %ld%c", test_vals[i], ext);
-    assert_decodes_as(input, answer(test_vals[i], GPR_TIMESPAN));
+    assert_decodes_as(input, answer(test_vals[i]));
     gpr_free(input);
 
     gpr_asprintf(&input, "%ld %c", test_vals[i], ext);
-    assert_decodes_as(input, answer(test_vals[i], GPR_TIMESPAN));
+    assert_decodes_as(input, answer(test_vals[i]));
     gpr_free(input);
 
     gpr_asprintf(&input, "%ld %c  ", test_vals[i], ext);
-    assert_decodes_as(input, answer(test_vals[i], GPR_TIMESPAN));
+    assert_decodes_as(input, answer(test_vals[i]));
     gpr_free(input);
   }
 }
 
+static grpc_millis millis_from_nanos(int64_t x) {
+  return (grpc_millis)(x / GPR_NS_PER_MS + (x % GPR_NS_PER_MS != 0));
+}
+static grpc_millis millis_from_micros(int64_t x) {
+  return (grpc_millis)(x / GPR_US_PER_MS + (x % GPR_US_PER_MS != 0));
+}
+static grpc_millis millis_from_millis(int64_t x) { return (grpc_millis)x; }
+static grpc_millis millis_from_seconds(int64_t x) {
+  return (grpc_millis)(x * GPR_MS_PER_SEC);
+}
+static grpc_millis millis_from_minutes(int64_t x) {
+  return (grpc_millis)(x * 60 * GPR_MS_PER_SEC);
+}
+static grpc_millis millis_from_hours(int64_t x) {
+  return (grpc_millis)(x * 3600 * GPR_MS_PER_SEC);
+}
+
 void test_decoding(void) {
   LOG_TEST("test_decoding");
-  decode_suite('n', gpr_time_from_nanos);
-  decode_suite('u', gpr_time_from_micros);
-  decode_suite('m', gpr_time_from_millis);
-  decode_suite('S', gpr_time_from_seconds);
-  decode_suite('M', gpr_time_from_minutes);
-  decode_suite('H', gpr_time_from_hours);
-  assert_decodes_as("1000000000S",
-                    gpr_time_from_seconds(1000 * 1000 * 1000, GPR_TIMESPAN));
-  assert_decodes_as("1000000000000000000000u", gpr_inf_future(GPR_TIMESPAN));
-  assert_decodes_as("1000000001S", gpr_inf_future(GPR_TIMESPAN));
-  assert_decodes_as("2000000001S", gpr_inf_future(GPR_TIMESPAN));
-  assert_decodes_as("9999999999S", gpr_inf_future(GPR_TIMESPAN));
+  decode_suite('n', millis_from_nanos);
+  decode_suite('u', millis_from_micros);
+  decode_suite('m', millis_from_millis);
+  decode_suite('S', millis_from_seconds);
+  decode_suite('M', millis_from_minutes);
+  decode_suite('H', millis_from_hours);
+  assert_decodes_as("1000000000S", millis_from_seconds(1000 * 1000 * 1000));
+  assert_decodes_as("1000000000000000000000u", GRPC_MILLIS_INF_FUTURE);
+  assert_decodes_as("1000000001S", GRPC_MILLIS_INF_FUTURE);
+  assert_decodes_as("2000000001S", GRPC_MILLIS_INF_FUTURE);
+  assert_decodes_as("9999999999S", GRPC_MILLIS_INF_FUTURE);
 }
 
 static void assert_decoding_fails(const char *s) {
-  gpr_timespec x;
+  grpc_millis x;
   GPR_ASSERT(0 ==
              grpc_http2_decode_timeout(grpc_slice_from_static_string(s), &x));
 }
diff --git a/test/core/util/BUILD b/test/core/util/BUILD
index 10eefe159a8..abb50a0c996 100644
--- a/test/core/util/BUILD
+++ b/test/core/util/BUILD
@@ -89,12 +89,16 @@ grpc_cc_library(
 )
 
 grpc_cc_library(
-    name = "one_corpus_entry_fuzzer",
-    srcs = ["one_corpus_entry_fuzzer.c"],
+    name = "fuzzer_corpus_test",
+    srcs = ["fuzzer_corpus_test.cc"],
     deps = [
         ":gpr_test_util",
         "//:grpc",
     ],
+    external_deps = [
+        "gtest",
+        "gflags",
+    ],
 )
 
 sh_library(
diff --git a/test/core/util/fuzzer_corpus_test.cc b/test/core/util/fuzzer_corpus_test.cc
new file mode 100644
index 00000000000..a5e99a1bacd
--- /dev/null
+++ b/test/core/util/fuzzer_corpus_test.cc
@@ -0,0 +1,136 @@
+/*
+ *
+ * Copyright 2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include <stdbool.h>
+
+#include <dirent.h>
+#include <gflags/gflags.h>
+#include <grpc/support/log.h>
+#include <gtest/gtest.h>
+#include <stdio.h>
+#include <sys/types.h>
+
+#include "src/core/lib/iomgr/load_file.h"
+#include "test/core/util/test_config.h"
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size);
+extern "C" bool squelch;
+extern "C" bool leak_check;
+
+DEFINE_string(file, "", "Use this file as test data");
+DEFINE_string(directory, "", "Use this directory as test data");
+
+class FuzzerCorpusTest : public ::testing::TestWithParam<std::string> {};
+
+TEST_P(FuzzerCorpusTest, RunOneExample) {
+  gpr_log(GPR_DEBUG, "Example file: %s", GetParam().c_str());
+  grpc_slice buffer;
+  squelch = false;
+  leak_check = false;
+  GPR_ASSERT(GRPC_LOG_IF_ERROR("load_file",
+                               grpc_load_file(GetParam().c_str(), 0, &buffer)));
+  LLVMFuzzerTestOneInput(GRPC_SLICE_START_PTR(buffer),
+                         GRPC_SLICE_LENGTH(buffer));
+  grpc_slice_unref(buffer);
+}
+
+class ExampleGenerator
+    : public ::testing::internal::ParamGeneratorInterface<std::string> {
+ public:
+  virtual ::testing::internal::ParamIteratorInterface<std::string>* Begin()
+      const;
+  virtual ::testing::internal::ParamIteratorInterface<std::string>* End() const;
+
+ private:
+  void Materialize() const {
+    if (examples_.empty()) {
+      if (!FLAGS_file.empty()) examples_.push_back(FLAGS_file);
+      if (!FLAGS_directory.empty()) {
+        DIR* dp;
+        struct dirent* ep;
+        dp = opendir(FLAGS_directory.c_str());
+
+        if (dp != NULL) {
+          while ((ep = readdir(dp)) != nullptr) {
+            if (ep->d_type == DT_REG) {
+              examples_.push_back(FLAGS_directory + "/" + ep->d_name);
+            }
+          }
+
+          (void)closedir(dp);
+        } else {
+          perror("Couldn't open the directory");
+          abort();
+        }
+      }
+    }
+  }
+
+  mutable std::vector<std::string> examples_;
+};
+
+class ExampleIterator
+    : public ::testing::internal::ParamIteratorInterface<std::string> {
+ public:
+  ExampleIterator(const ExampleGenerator& base_,
+                  std::vector<std::string>::const_iterator begin)
+      : base_(base_), begin_(begin), current_(begin) {}
+
+  virtual const ExampleGenerator* BaseGenerator() const { return &base_; }
+
+  virtual void Advance() { current_++; }
+  virtual ExampleIterator* Clone() const { return new ExampleIterator(*this); }
+  virtual const std::string* Current() const { return &*current_; }
+
+  virtual bool Equals(const ParamIteratorInterface<std::string>& other) const {
+    return &base_ == other.BaseGenerator() &&
+           current_ == dynamic_cast<const ExampleIterator*>(&other)->current_;
+  }
+
+ private:
+  ExampleIterator(const ExampleIterator& other)
+      : base_(other.base_), begin_(other.begin_), current_(other.current_) {}
+
+  const ExampleGenerator& base_;
+  const std::vector<std::string>::const_iterator begin_;
+  std::vector<std::string>::const_iterator current_;
+};
+
+::testing::internal::ParamIteratorInterface<std::string>*
+ExampleGenerator::Begin() const {
+  Materialize();
+  return new ExampleIterator(*this, examples_.begin());
+}
+
+::testing::internal::ParamIteratorInterface<std::string>*
+ExampleGenerator::End() const {
+  Materialize();
+  return new ExampleIterator(*this, examples_.end());
+}
+
+INSTANTIATE_TEST_CASE_P(
+    CorpusExamples, FuzzerCorpusTest,
+    ::testing::internal::ParamGenerator<std::string>(new ExampleGenerator));
+
+int main(int argc, char** argv) {
+  grpc_test_init(argc, argv);
+  ::gflags::ParseCommandLineFlags(&argc, &argv, true);
+  ::testing::InitGoogleTest(&argc, argv);
+
+  return RUN_ALL_TESTS();
+}
diff --git a/test/core/util/grpc_fuzzer.bzl b/test/core/util/grpc_fuzzer.bzl
index 41f6cdc8ba6..55b6f1c1a5e 100644
--- a/test/core/util/grpc_fuzzer.bzl
+++ b/test/core/util/grpc_fuzzer.bzl
@@ -12,19 +12,17 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-load("//bazel:grpc_build_system.bzl", "grpc_cc_binary")
+load("//bazel:grpc_build_system.bzl", "grpc_cc_test")
 
 def grpc_fuzzer(name, corpus, srcs = [], deps = [], **kwargs):
-  grpc_cc_binary(
-    name = '%s/one_entry.bin' % name,
+  grpc_cc_test(
+    name = name,
     srcs = srcs,
-    deps = deps + ["//test/core/util:one_corpus_entry_fuzzer"],
+    deps = deps + ["//test/core/util:fuzzer_corpus_test"],
+    data = [corpus],
+    args = ['--directory', '$(location %s)' % corpus],
+    external_deps = [
+      'gtest',
+    ],
     **kwargs
   )
-  for entry in native.glob(['%s/*' % corpus]):
-    native.sh_test(
-      name = '%s/one_entry/%s' % (name, entry),
-      data = [':%s/one_entry.bin' % name, entry],
-      srcs = ['//test/core/util:fuzzer_one_entry_runner'],
-      args = ['$(location :%s/one_entry.bin)' % name, '$(location %s)' % entry]
-    )
diff --git a/test/core/util/port_server_client.c b/test/core/util/port_server_client.c
index ba4028dbeee..7b94ac4ada3 100644
--- a/test/core/util/port_server_client.c
+++ b/test/core/util/port_server_client.c
@@ -88,7 +88,7 @@ void grpc_free_port_using_server(int port) {
   grpc_resource_quota *resource_quota =
       grpc_resource_quota_create("port_server_client/free");
   grpc_httpcli_get(&exec_ctx, &context, &pr.pops, resource_quota, &req,
-                   grpc_timeout_seconds_to_deadline(30),
+                   grpc_exec_ctx_now(&exec_ctx) + 30 * GPR_MS_PER_SEC,
                    GRPC_CLOSURE_CREATE(freed_port_from_server, &pr,
                                        grpc_schedule_on_exec_ctx),
                    &rsp);
@@ -100,8 +100,8 @@ void grpc_free_port_using_server(int port) {
     if (!GRPC_LOG_IF_ERROR(
             "pollset_work",
             grpc_pollset_work(&exec_ctx, grpc_polling_entity_pollset(&pr.pops),
-                              &worker, gpr_now(GPR_CLOCK_MONOTONIC),
-                              grpc_timeout_seconds_to_deadline(1)))) {
+                              &worker,
+                              grpc_exec_ctx_now(&exec_ctx) + GPR_MS_PER_SEC))) {
       pr.done = 1;
     }
   }
@@ -173,7 +173,7 @@ static void got_port_from_server(grpc_exec_ctx *exec_ctx, void *arg,
     grpc_resource_quota *resource_quota =
         grpc_resource_quota_create("port_server_client/pick_retry");
     grpc_httpcli_get(exec_ctx, pr->ctx, &pr->pops, resource_quota, &req,
-                     grpc_timeout_seconds_to_deadline(10),
+                     grpc_exec_ctx_now(exec_ctx) + 30 * GPR_MS_PER_SEC,
                      GRPC_CLOSURE_CREATE(got_port_from_server, pr,
                                          grpc_schedule_on_exec_ctx),
                      &pr->response);
@@ -224,7 +224,7 @@ int grpc_pick_port_using_server(void) {
       grpc_resource_quota_create("port_server_client/pick");
   grpc_httpcli_get(
       &exec_ctx, &context, &pr.pops, resource_quota, &req,
-      grpc_timeout_seconds_to_deadline(30),
+      grpc_exec_ctx_now(&exec_ctx) + 30 * GPR_MS_PER_SEC,
       GRPC_CLOSURE_CREATE(got_port_from_server, &pr, grpc_schedule_on_exec_ctx),
       &pr.response);
   grpc_resource_quota_unref_internal(&exec_ctx, resource_quota);
@@ -235,8 +235,8 @@ int grpc_pick_port_using_server(void) {
     if (!GRPC_LOG_IF_ERROR(
             "pollset_work",
             grpc_pollset_work(&exec_ctx, grpc_polling_entity_pollset(&pr.pops),
-                              &worker, gpr_now(GPR_CLOCK_MONOTONIC),
-                              grpc_timeout_seconds_to_deadline(1)))) {
+                              &worker,
+                              grpc_exec_ctx_now(&exec_ctx) + GPR_MS_PER_SEC))) {
       pr.port = 0;
     }
   }
diff --git a/test/core/util/test_tcp_server.c b/test/core/util/test_tcp_server.c
index d3a1de8a3b1..611ecb330c1 100644
--- a/test/core/util/test_tcp_server.c
+++ b/test/core/util/test_tcp_server.c
@@ -31,6 +31,7 @@
 #include "src/core/lib/iomgr/resolve_address.h"
 #include "src/core/lib/iomgr/tcp_server.h"
 #include "test/core/util/port.h"
+#include "test/core/util/test_config.h"
 
 static void on_server_destroyed(grpc_exec_ctx *exec_ctx, void *data,
                                 grpc_error *error) {
@@ -78,14 +79,13 @@ void test_tcp_server_start(test_tcp_server *server, int port) {
 
 void test_tcp_server_poll(test_tcp_server *server, int seconds) {
   grpc_pollset_worker *worker = NULL;
-  gpr_timespec deadline =
-      gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC),
-                   gpr_time_from_seconds(seconds, GPR_TIMESPAN));
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  grpc_millis deadline = grpc_timespec_to_millis_round_up(
+      grpc_timeout_seconds_to_deadline(seconds));
   gpr_mu_lock(server->mu);
-  GRPC_LOG_IF_ERROR("pollset_work",
-                    grpc_pollset_work(&exec_ctx, server->pollset, &worker,
-                                      gpr_now(GPR_CLOCK_MONOTONIC), deadline));
+  GRPC_LOG_IF_ERROR(
+      "pollset_work",
+      grpc_pollset_work(&exec_ctx, server->pollset, &worker, deadline));
   gpr_mu_unlock(server->mu);
   grpc_exec_ctx_finish(&exec_ctx);
 }
diff --git a/test/cpp/common/alarm_cpp_test.cc b/test/cpp/common/alarm_cpp_test.cc
index 212972d25d7..7adc3102f41 100644
--- a/test/cpp/common/alarm_cpp_test.cc
+++ b/test/cpp/common/alarm_cpp_test.cc
@@ -142,7 +142,7 @@ TEST(AlarmTest, ZeroExpiry) {
   void* output_tag;
   bool ok;
   const CompletionQueue::NextStatus status = cq.AsyncNext(
-      (void**)&output_tag, &ok, grpc_timeout_seconds_to_deadline(0));
+      (void**)&output_tag, &ok, grpc_timeout_seconds_to_deadline(1));
 
   EXPECT_EQ(status, CompletionQueue::GOT_EVENT);
   EXPECT_TRUE(ok);
@@ -158,7 +158,7 @@ TEST(AlarmTest, NegativeExpiry) {
   void* output_tag;
   bool ok;
   const CompletionQueue::NextStatus status = cq.AsyncNext(
-      (void**)&output_tag, &ok, grpc_timeout_seconds_to_deadline(0));
+      (void**)&output_tag, &ok, grpc_timeout_seconds_to_deadline(1));
 
   EXPECT_EQ(status, CompletionQueue::GOT_EVENT);
   EXPECT_TRUE(ok);
diff --git a/test/cpp/end2end/async_end2end_test.cc b/test/cpp/end2end/async_end2end_test.cc
index 41090d161aa..2a33e8ae115 100644
--- a/test/cpp/end2end/async_end2end_test.cc
+++ b/test/cpp/end2end/async_end2end_test.cc
@@ -102,7 +102,23 @@ class Verifier {
   explicit Verifier(bool spin) : spin_(spin) {}
   // Expect sets the expected ok value for a specific tag
   Verifier& Expect(int i, bool expect_ok) {
-    expectations_[tag(i)] = expect_ok;
+    return ExpectUnless(i, expect_ok, false);
+  }
+  // ExpectUnless sets the expected ok value for a specific tag
+  // unless the tag was already marked seen (as a result of ExpectMaybe)
+  Verifier& ExpectUnless(int i, bool expect_ok, bool seen) {
+    if (!seen) {
+      expectations_[tag(i)] = expect_ok;
+    }
+    return *this;
+  }
+  // ExpectMaybe sets the expected ok value for a specific tag, but does not
+  // require it to appear
+  // If it does, sets *seen to true
+  Verifier& ExpectMaybe(int i, bool expect_ok, bool* seen) {
+    if (!*seen) {
+      maybe_expectations_[tag(i)] = MaybeExpect{expect_ok, seen};
+    }
     return *this;
   }
 
@@ -122,12 +138,7 @@ class Verifier {
     } else {
       EXPECT_TRUE(cq->Next(&got_tag, &ok));
     }
-    auto it = expectations_.find(got_tag);
-    EXPECT_TRUE(it != expectations_.end());
-    if (!ignore_ok) {
-      EXPECT_EQ(it->second, ok);
-    }
-    expectations_.erase(it);
+    GotTag(got_tag, ok, ignore_ok);
     return detag(got_tag);
   }
 
@@ -138,7 +149,7 @@ class Verifier {
   // This version of Verify allows optionally ignoring the
   // outcome of the expectation
   void Verify(CompletionQueue* cq, bool ignore_ok) {
-    GPR_ASSERT(!expectations_.empty());
+    GPR_ASSERT(!expectations_.empty() || !maybe_expectations_.empty());
     while (!expectations_.empty()) {
       Next(cq, ignore_ok);
     }
@@ -177,16 +188,43 @@ class Verifier {
           EXPECT_EQ(cq->AsyncNext(&got_tag, &ok, deadline),
                     CompletionQueue::GOT_EVENT);
         }
-        auto it = expectations_.find(got_tag);
-        EXPECT_TRUE(it != expectations_.end());
-        EXPECT_EQ(it->second, ok);
-        expectations_.erase(it);
+        GotTag(got_tag, ok, false);
       }
     }
   }
 
  private:
+  void GotTag(void* got_tag, bool ok, bool ignore_ok) {
+    auto it = expectations_.find(got_tag);
+    if (it != expectations_.end()) {
+      if (!ignore_ok) {
+        EXPECT_EQ(it->second, ok);
+      }
+      expectations_.erase(it);
+    } else {
+      auto it2 = maybe_expectations_.find(got_tag);
+      if (it2 != maybe_expectations_.end()) {
+        if (it2->second.seen != nullptr) {
+          EXPECT_FALSE(*it2->second.seen);
+          *it2->second.seen = true;
+        }
+        if (!ignore_ok) {
+          EXPECT_EQ(it2->second.ok, ok);
+        }
+      } else {
+        gpr_log(GPR_ERROR, "Unexpected tag: %p", tag);
+        abort();
+      }
+    }
+  }
+
+  struct MaybeExpect {
+    bool ok;
+    bool* seen;
+  };
+
   std::map<void*, bool> expectations_;
+  std::map<void*, MaybeExpect> maybe_expectations_;
   bool spin_;
 };
 
@@ -223,11 +261,8 @@ class TestScenario {
   bool disable_blocking;
   bool inproc;
   bool health_check_service;
-  // Although the below grpc::string's are logically const, we can't declare
-  // them const because of a limitation in the way old compilers (e.g., gcc-4.4)
-  // manage vector insertion using a copy constructor
-  grpc::string credentials_type;
-  grpc::string message_content;
+  const grpc::string credentials_type;
+  const grpc::string message_content;
 };
 
 static std::ostream& operator<<(std::ostream& out,
@@ -539,31 +574,19 @@ TEST_P(AsyncEnd2endTest, SimpleClientStreamingWithCoalescingApi) {
 
   cli_stream->Write(send_request, tag(3));
 
-  // 65536(64KB) is the default flow control window size. Should change this
-  // number when default flow control window size changes. For the write of
-  // send_request larger than the flow control window size, tag:3 will not come
-  // up until server read is initiated. For write of send_request smaller than
-  // the flow control window size, the request can take the free ride with
-  // initial metadata due to coalescing, thus write tag:3 will come up here.
-  if (GetParam().message_content.length() < 65536 || GetParam().inproc) {
-    Verifier(GetParam().disable_blocking)
-        .Expect(2, true)
-        .Expect(3, true)
-        .Verify(cq_.get());
-  } else {
-    Verifier(GetParam().disable_blocking).Expect(2, true).Verify(cq_.get());
-  }
+  bool seen3 = false;
+
+  Verifier(GetParam().disable_blocking)
+      .Expect(2, true)
+      .ExpectMaybe(3, true, &seen3)
+      .Verify(cq_.get());
 
   srv_stream.Read(&recv_request, tag(4));
 
-  if (GetParam().message_content.length() < 65536 || GetParam().inproc) {
-    Verifier(GetParam().disable_blocking).Expect(4, true).Verify(cq_.get());
-  } else {
-    Verifier(GetParam().disable_blocking)
-        .Expect(3, true)
-        .Expect(4, true)
-        .Verify(cq_.get());
-  }
+  Verifier(GetParam().disable_blocking)
+      .ExpectUnless(3, true, seen3)
+      .Expect(4, true)
+      .Verify(cq_.get());
 
   EXPECT_EQ(send_request.message(), recv_request.message());
 
@@ -834,31 +857,19 @@ TEST_P(AsyncEnd2endTest, SimpleBidiStreamingWithCoalescingApiWAF) {
 
   cli_stream->WriteLast(send_request, WriteOptions(), tag(3));
 
-  // 65536(64KB) is the default flow control window size. Should change this
-  // number when default flow control window size changes. For the write of
-  // send_request larger than the flow control window size, tag:3 will not come
-  // up until server read is initiated. For write of send_request smaller than
-  // the flow control window size, the request can take the free ride with
-  // initial metadata due to coalescing, thus write tag:3 will come up here.
-  if (GetParam().message_content.length() < 65536 || GetParam().inproc) {
-    Verifier(GetParam().disable_blocking)
-        .Expect(2, true)
-        .Expect(3, true)
-        .Verify(cq_.get());
-  } else {
-    Verifier(GetParam().disable_blocking).Expect(2, true).Verify(cq_.get());
-  }
+  bool seen3 = false;
+
+  Verifier(GetParam().disable_blocking)
+      .Expect(2, true)
+      .ExpectMaybe(3, true, &seen3)
+      .Verify(cq_.get());
 
   srv_stream.Read(&recv_request, tag(4));
 
-  if (GetParam().message_content.length() < 65536 || GetParam().inproc) {
-    Verifier(GetParam().disable_blocking).Expect(4, true).Verify(cq_.get());
-  } else {
-    Verifier(GetParam().disable_blocking)
-        .Expect(3, true)
-        .Expect(4, true)
-        .Verify(cq_.get());
-  }
+  Verifier(GetParam().disable_blocking)
+      .ExpectUnless(3, true, seen3)
+      .Expect(4, true)
+      .Verify(cq_.get());
   EXPECT_EQ(send_request.message(), recv_request.message());
 
   srv_stream.Read(&recv_request, tag(5));
@@ -902,31 +913,19 @@ TEST_P(AsyncEnd2endTest, SimpleBidiStreamingWithCoalescingApiWL) {
 
   cli_stream->WriteLast(send_request, WriteOptions(), tag(3));
 
-  // 65536(64KB) is the default flow control window size. Should change this
-  // number when default flow control window size changes. For the write of
-  // send_request larger than the flow control window size, tag:3 will not come
-  // up until server read is initiated. For write of send_request smaller than
-  // the flow control window size, the request can take the free ride with
-  // initial metadata due to coalescing, thus write tag:3 will come up here.
-  if (GetParam().message_content.length() < 65536 || GetParam().inproc) {
-    Verifier(GetParam().disable_blocking)
-        .Expect(2, true)
-        .Expect(3, true)
-        .Verify(cq_.get());
-  } else {
-    Verifier(GetParam().disable_blocking).Expect(2, true).Verify(cq_.get());
-  }
+  bool seen3 = false;
+
+  Verifier(GetParam().disable_blocking)
+      .Expect(2, true)
+      .ExpectMaybe(3, true, &seen3)
+      .Verify(cq_.get());
 
   srv_stream.Read(&recv_request, tag(4));
 
-  if (GetParam().message_content.length() < 65536 || GetParam().inproc) {
-    Verifier(GetParam().disable_blocking).Expect(4, true).Verify(cq_.get());
-  } else {
-    Verifier(GetParam().disable_blocking)
-        .Expect(3, true)
-        .Expect(4, true)
-        .Verify(cq_.get());
-  }
+  Verifier(GetParam().disable_blocking)
+      .ExpectUnless(3, true, seen3)
+      .Expect(4, true)
+      .Verify(cq_.get());
   EXPECT_EQ(send_request.message(), recv_request.message());
 
   srv_stream.Read(&recv_request, tag(5));
@@ -1305,7 +1304,6 @@ class AsyncEnd2endServerTryCancelTest : public AsyncEnd2endTest {
       ServerTryCancelRequestPhase server_try_cancel) {
     ResetStub();
 
-    EchoRequest send_request;
     EchoRequest recv_request;
     EchoResponse send_response;
     EchoResponse recv_response;
@@ -1316,31 +1314,24 @@ class AsyncEnd2endServerTryCancelTest : public AsyncEnd2endTest {
     ServerAsyncReader<EchoResponse, EchoRequest> srv_stream(&srv_ctx);
 
     // Initiate the 'RequestStream' call on client
+    CompletionQueue cli_cq;
+
     std::unique_ptr<ClientAsyncWriter<EchoRequest>> cli_stream(
-        stub_->AsyncRequestStream(&cli_ctx, &recv_response, cq_.get(), tag(1)));
-    Verifier(GetParam().disable_blocking).Expect(1, true).Verify(cq_.get());
+        stub_->AsyncRequestStream(&cli_ctx, &recv_response, &cli_cq, tag(1)));
 
     // On the server, request to be notified of 'RequestStream' calls
     // and receive the 'RequestStream' call just made by the client
     srv_ctx.AsyncNotifyWhenDone(tag(11));
     service_->RequestRequestStream(&srv_ctx, &srv_stream, cq_.get(), cq_.get(),
                                    tag(2));
+    std::thread t1([this, &cli_cq] {
+      Verifier(GetParam().disable_blocking).Expect(1, true).Verify(&cli_cq);
+    });
     Verifier(GetParam().disable_blocking).Expect(2, true).Verify(cq_.get());
-
-    // Client sends 3 messages (tags 3, 4 and 5)
-    for (int tag_idx = 3; tag_idx <= 5; tag_idx++) {
-      send_request.set_message("Ping " + grpc::to_string(tag_idx));
-      cli_stream->Write(send_request, tag(tag_idx));
-      Verifier(GetParam().disable_blocking)
-          .Expect(tag_idx, true)
-          .Verify(cq_.get());
-    }
-    cli_stream->WritesDone(tag(6));
-    Verifier(GetParam().disable_blocking).Expect(6, true).Verify(cq_.get());
+    t1.join();
 
     bool expected_server_cq_result = true;
-    bool ignore_cq_result = false;
-    bool want_done_tag = false;
+    bool expected_client_cq_result = true;
 
     if (server_try_cancel == CANCEL_BEFORE_PROCESSING) {
       srv_ctx.TryCancel();
@@ -1348,10 +1339,36 @@ class AsyncEnd2endServerTryCancelTest : public AsyncEnd2endTest {
       EXPECT_TRUE(srv_ctx.IsCancelled());
 
       // Since cancellation is done before server reads any results, we know
-      // for sure that all cq results will return false from this point forward
+      // for sure that all server cq results will return false from this
+      // point forward
       expected_server_cq_result = false;
+      expected_client_cq_result = false;
     }
 
+    bool ignore_client_cq_result =
+        (server_try_cancel == CANCEL_DURING_PROCESSING) ||
+        (server_try_cancel == CANCEL_BEFORE_PROCESSING);
+
+    std::thread cli_thread([&cli_cq, &cli_stream, &expected_client_cq_result,
+                            &ignore_client_cq_result, this] {
+      EchoRequest send_request;
+      // Client sends 3 messages (tags 3, 4 and 5)
+      for (int tag_idx = 3; tag_idx <= 5; tag_idx++) {
+        send_request.set_message("Ping " + grpc::to_string(tag_idx));
+        cli_stream->Write(send_request, tag(tag_idx));
+        Verifier(GetParam().disable_blocking)
+            .Expect(tag_idx, expected_client_cq_result)
+            .Verify(&cli_cq, ignore_client_cq_result);
+      }
+      cli_stream->WritesDone(tag(6));
+      // Ignore ok on WritesDone since cancel can affect it
+      Verifier(GetParam().disable_blocking)
+          .Expect(6, expected_client_cq_result)
+          .Verify(&cli_cq, ignore_client_cq_result);
+    });
+
+    bool ignore_cq_result = false;
+    bool want_done_tag = false;
     std::thread* server_try_cancel_thd = nullptr;
 
     auto verif = Verifier(GetParam().disable_blocking);
@@ -1388,6 +1405,8 @@ class AsyncEnd2endServerTryCancelTest : public AsyncEnd2endTest {
       }
     }
 
+    cli_thread.join();
+
     if (server_try_cancel_thd != nullptr) {
       server_try_cancel_thd->join();
       delete server_try_cancel_thd;
@@ -1416,9 +1435,15 @@ class AsyncEnd2endServerTryCancelTest : public AsyncEnd2endTest {
 
     // Client will see the cancellation
     cli_stream->Finish(&recv_status, tag(10));
-    Verifier(GetParam().disable_blocking).Expect(10, true).Verify(cq_.get());
+    Verifier(GetParam().disable_blocking).Expect(10, true).Verify(&cli_cq);
     EXPECT_FALSE(recv_status.ok());
     EXPECT_EQ(::grpc::StatusCode::CANCELLED, recv_status.error_code());
+
+    cli_cq.Shutdown();
+    void* dummy_tag;
+    bool dummy_ok;
+    while (cli_cq.Next(&dummy_tag, &dummy_ok)) {
+    }
   }
 
   // Helper for testing server-streaming RPCs which are cancelled on the server.
@@ -1440,7 +1465,6 @@ class AsyncEnd2endServerTryCancelTest : public AsyncEnd2endTest {
     EchoRequest send_request;
     EchoRequest recv_request;
     EchoResponse send_response;
-    EchoResponse recv_response;
     Status recv_status;
     ClientContext cli_ctx;
     ServerContext srv_ctx;
@@ -1448,20 +1472,29 @@ class AsyncEnd2endServerTryCancelTest : public AsyncEnd2endTest {
 
     send_request.set_message("Ping");
     // Initiate the 'ResponseStream' call on the client
+    CompletionQueue cli_cq;
     std::unique_ptr<ClientAsyncReader<EchoResponse>> cli_stream(
-        stub_->AsyncResponseStream(&cli_ctx, send_request, cq_.get(), tag(1)));
-    Verifier(GetParam().disable_blocking).Expect(1, true).Verify(cq_.get());
+        stub_->AsyncResponseStream(&cli_ctx, send_request, &cli_cq, tag(1)));
     // On the server, request to be notified of 'ResponseStream' calls and
     // receive the call just made by the client
     srv_ctx.AsyncNotifyWhenDone(tag(11));
     service_->RequestResponseStream(&srv_ctx, &recv_request, &srv_stream,
                                     cq_.get(), cq_.get(), tag(2));
+
+    std::thread t1([this, &cli_cq] {
+      Verifier(GetParam().disable_blocking).Expect(1, true).Verify(&cli_cq);
+    });
     Verifier(GetParam().disable_blocking).Expect(2, true).Verify(cq_.get());
+    t1.join();
+
     EXPECT_EQ(send_request.message(), recv_request.message());
 
     bool expected_cq_result = true;
     bool ignore_cq_result = false;
     bool want_done_tag = false;
+    bool expected_client_cq_result = true;
+    bool ignore_client_cq_result =
+        (server_try_cancel != CANCEL_BEFORE_PROCESSING);
 
     if (server_try_cancel == CANCEL_BEFORE_PROCESSING) {
       srv_ctx.TryCancel();
@@ -1471,8 +1504,21 @@ class AsyncEnd2endServerTryCancelTest : public AsyncEnd2endTest {
       // We know for sure that all cq results will be false from this point
       // since the server cancelled the RPC
       expected_cq_result = false;
+      expected_client_cq_result = false;
     }
 
+    std::thread cli_thread([&cli_cq, &cli_stream, &expected_client_cq_result,
+                            &ignore_client_cq_result, this] {
+      // Client attempts to read the three messages from the server
+      for (int tag_idx = 6; tag_idx <= 8; tag_idx++) {
+        EchoResponse recv_response;
+        cli_stream->Read(&recv_response, tag(tag_idx));
+        Verifier(GetParam().disable_blocking)
+            .Expect(tag_idx, expected_client_cq_result)
+            .Verify(&cli_cq, ignore_client_cq_result);
+      }
+    });
+
     std::thread* server_try_cancel_thd = nullptr;
 
     auto verif = Verifier(GetParam().disable_blocking);
@@ -1520,10 +1566,6 @@ class AsyncEnd2endServerTryCancelTest : public AsyncEnd2endTest {
       srv_ctx.TryCancel();
       want_done_tag = true;
       verif.Expect(11, true);
-
-      // Client reads may fail bacause it is notified that the stream is
-      // cancelled.
-      ignore_cq_result = true;
     }
 
     if (want_done_tag) {
@@ -1532,13 +1574,7 @@ class AsyncEnd2endServerTryCancelTest : public AsyncEnd2endTest {
       want_done_tag = false;
     }
 
-    // Client attemts to read the three messages from the server
-    for (int tag_idx = 6; tag_idx <= 8; tag_idx++) {
-      cli_stream->Read(&recv_response, tag(tag_idx));
-      Verifier(GetParam().disable_blocking)
-          .Expect(tag_idx, expected_cq_result)
-          .Verify(cq_.get(), ignore_cq_result);
-    }
+    cli_thread.join();
 
     // The RPC has been cancelled at this point for sure (i.e irrespective of
     // the value of `server_try_cancel` is). So, from this point forward, we
@@ -1550,9 +1586,15 @@ class AsyncEnd2endServerTryCancelTest : public AsyncEnd2endTest {
 
     // Client will see the cancellation
     cli_stream->Finish(&recv_status, tag(10));
-    Verifier(GetParam().disable_blocking).Expect(10, true).Verify(cq_.get());
+    Verifier(GetParam().disable_blocking).Expect(10, true).Verify(&cli_cq);
     EXPECT_FALSE(recv_status.ok());
     EXPECT_EQ(::grpc::StatusCode::CANCELLED, recv_status.error_code());
+
+    cli_cq.Shutdown();
+    void* dummy_tag;
+    bool dummy_ok;
+    while (cli_cq.Next(&dummy_tag, &dummy_ok)) {
+    }
   }
 
   // Helper for testing bidirectinal-streaming RPCs which are cancelled on the
@@ -1585,38 +1627,52 @@ class AsyncEnd2endServerTryCancelTest : public AsyncEnd2endTest {
     // Initiate the call from the client side
     std::unique_ptr<ClientAsyncReaderWriter<EchoRequest, EchoResponse>>
         cli_stream(stub_->AsyncBidiStream(&cli_ctx, cq_.get(), tag(1)));
-    Verifier(GetParam().disable_blocking).Expect(1, true).Verify(cq_.get());
 
     // On the server, request to be notified of the 'BidiStream' call and
     // receive the call just made by the client
     srv_ctx.AsyncNotifyWhenDone(tag(11));
     service_->RequestBidiStream(&srv_ctx, &srv_stream, cq_.get(), cq_.get(),
                                 tag(2));
-    Verifier(GetParam().disable_blocking).Expect(2, true).Verify(cq_.get());
+    Verifier(GetParam().disable_blocking)
+        .Expect(1, true)
+        .Expect(2, true)
+        .Verify(cq_.get());
+
+    auto verif = Verifier(GetParam().disable_blocking);
 
     // Client sends the first and the only message
     send_request.set_message("Ping");
     cli_stream->Write(send_request, tag(3));
-    Verifier(GetParam().disable_blocking).Expect(3, true).Verify(cq_.get());
+    verif.Expect(3, true);
 
     bool expected_cq_result = true;
     bool ignore_cq_result = false;
     bool want_done_tag = false;
 
+    int got_tag, got_tag2;
+    bool tag_3_done = false;
+
     if (server_try_cancel == CANCEL_BEFORE_PROCESSING) {
       srv_ctx.TryCancel();
-      Verifier(GetParam().disable_blocking).Expect(11, true).Verify(cq_.get());
-      EXPECT_TRUE(srv_ctx.IsCancelled());
-
-      // We know for sure that all cq results will be false from this point
-      // since the server cancelled the RPC
+      verif.Expect(11, true);
+      // We know for sure that all server cq results will be false from
+      // this point since the server cancelled the RPC. However, we can't
+      // say for sure about the client
       expected_cq_result = false;
+      ignore_cq_result = true;
+
+      do {
+        got_tag = verif.Next(cq_.get(), ignore_cq_result);
+        GPR_ASSERT(((got_tag == 3) && !tag_3_done) || (got_tag == 11));
+        if (got_tag == 3) {
+          tag_3_done = true;
+        }
+      } while (got_tag != 11);
+      EXPECT_TRUE(srv_ctx.IsCancelled());
     }
 
     std::thread* server_try_cancel_thd = nullptr;
 
-    auto verif = Verifier(GetParam().disable_blocking);
-
     if (server_try_cancel == CANCEL_DURING_PROCESSING) {
       server_try_cancel_thd =
           new std::thread(&ServerContext::TryCancel, &srv_ctx);
@@ -1631,39 +1687,42 @@ class AsyncEnd2endServerTryCancelTest : public AsyncEnd2endTest {
       verif.Expect(11, true);
     }
 
-    int got_tag;
     srv_stream.Read(&recv_request, tag(4));
     verif.Expect(4, expected_cq_result);
-    got_tag = verif.Next(cq_.get(), ignore_cq_result);
-    GPR_ASSERT((got_tag == 4) || (got_tag == 11 && want_done_tag));
-    if (got_tag == 11) {
+    got_tag = tag_3_done ? 3 : verif.Next(cq_.get(), ignore_cq_result);
+    got_tag2 = verif.Next(cq_.get(), ignore_cq_result);
+    GPR_ASSERT((got_tag == 3) || (got_tag == 4) ||
+               (got_tag == 11 && want_done_tag));
+    GPR_ASSERT((got_tag2 == 3) || (got_tag2 == 4) ||
+               (got_tag2 == 11 && want_done_tag));
+    // If we get 3 and 4, we don't need to wait for 11, but if
+    // we get 11, we should also clear 3 and 4
+    if (got_tag + got_tag2 != 7) {
       EXPECT_TRUE(srv_ctx.IsCancelled());
       want_done_tag = false;
-      // Now get the other entry that we were waiting on
-      EXPECT_EQ(verif.Next(cq_.get(), ignore_cq_result), 4);
+      got_tag = verif.Next(cq_.get(), ignore_cq_result);
+      GPR_ASSERT((got_tag == 3) || (got_tag == 4));
     }
 
     send_response.set_message("Pong");
     srv_stream.Write(send_response, tag(5));
     verif.Expect(5, expected_cq_result);
-    got_tag = verif.Next(cq_.get(), ignore_cq_result);
-    GPR_ASSERT((got_tag == 5) || (got_tag == 11 && want_done_tag));
-    if (got_tag == 11) {
-      EXPECT_TRUE(srv_ctx.IsCancelled());
-      want_done_tag = false;
-      // Now get the other entry that we were waiting on
-      EXPECT_EQ(verif.Next(cq_.get(), ignore_cq_result), 5);
-    }
 
     cli_stream->Read(&recv_response, tag(6));
     verif.Expect(6, expected_cq_result);
     got_tag = verif.Next(cq_.get(), ignore_cq_result);
-    GPR_ASSERT((got_tag == 6) || (got_tag == 11 && want_done_tag));
-    if (got_tag == 11) {
+    got_tag2 = verif.Next(cq_.get(), ignore_cq_result);
+    GPR_ASSERT((got_tag == 5) || (got_tag == 6) ||
+               (got_tag == 11 && want_done_tag));
+    GPR_ASSERT((got_tag2 == 5) || (got_tag2 == 6) ||
+               (got_tag2 == 11 && want_done_tag));
+    // If we get 5 and 6, we don't need to wait for 11, but if
+    // we get 11, we should also clear 5 and 6
+    if (got_tag + got_tag2 != 11) {
       EXPECT_TRUE(srv_ctx.IsCancelled());
       want_done_tag = false;
-      // Now get the other entry that we were waiting on
-      EXPECT_EQ(verif.Next(cq_.get(), ignore_cq_result), 6);
+      got_tag = verif.Next(cq_.get(), ignore_cq_result);
+      GPR_ASSERT((got_tag == 5) || (got_tag == 6));
     }
 
     // This is expected to succeed in all cases
@@ -1788,7 +1847,7 @@ std::vector<TestScenario> CreateTestScenarios(bool test_disable_blocking,
   GPR_ASSERT(!credentials_types.empty());
 
   messages.push_back("Hello");
-  for (int sz = 1; sz < test_big_limit; sz *= 2) {
+  for (int sz = 1; sz <= test_big_limit; sz *= 32) {
     grpc::string big_msg;
     for (int i = 0; i < sz * 1024; i++) {
       char c = 'a' + (i % 26);
diff --git a/test/cpp/end2end/end2end_test.cc b/test/cpp/end2end/end2end_test.cc
index 5dae5b014bd..c5178526f8f 100644
--- a/test/cpp/end2end/end2end_test.cc
+++ b/test/cpp/end2end/end2end_test.cc
@@ -198,10 +198,7 @@ class TestScenario {
   void Log() const;
   bool use_proxy;
   bool inproc;
-  // Although the below grpc::string is logically const, we can't declare
-  // them const because of a limitation in the way old compilers (e.g., gcc-4.4)
-  // manage vector insertion using a copy constructor
-  grpc::string credentials_type;
+  const grpc::string credentials_type;
 };
 
 static std::ostream& operator<<(std::ostream& out,
@@ -1283,6 +1280,8 @@ TEST_P(ProxyEnd2endTest, RpcDeadlineExpires) {
   EchoResponse response;
   request.set_message("Hello");
   request.mutable_param()->set_skip_cancelled_check(true);
+  // Let server sleep for 2 ms first to guarantee expiry
+  request.mutable_param()->set_server_sleep_us(2 * 1000);
 
   ClientContext context;
   std::chrono::system_clock::time_point deadline =
@@ -1410,6 +1409,10 @@ TEST_P(ProxyEnd2endTest, HugeResponse) {
 }
 
 TEST_P(ProxyEnd2endTest, Peer) {
+  // Peer is not meaningful for inproc
+  if (GetParam().inproc) {
+    return;
+  }
   ResetStub();
   EchoRequest request;
   EchoResponse response;
@@ -1778,11 +1781,10 @@ std::vector<TestScenario> CreateTestScenarios(bool use_proxy,
     credentials_types.push_back(kInsecureCredentialsType);
   }
   GPR_ASSERT(!credentials_types.empty());
-  for (auto it = credentials_types.begin(); it != credentials_types.end();
-       ++it) {
-    scenarios.emplace_back(false, false, *it);
+  for (const auto& cred : credentials_types) {
+    scenarios.emplace_back(false, false, cred);
     if (use_proxy) {
-      scenarios.emplace_back(true, false, *it);
+      scenarios.emplace_back(true, false, cred);
     }
   }
   if (test_inproc && insec_ok()) {
@@ -1801,7 +1803,7 @@ INSTANTIATE_TEST_CASE_P(End2endServerTryCancel, End2endServerTryCancelTest,
 
 INSTANTIATE_TEST_CASE_P(ProxyEnd2end, ProxyEnd2endTest,
                         ::testing::ValuesIn(CreateTestScenarios(true, true,
-                                                                true, false)));
+                                                                true, true)));
 
 INSTANTIATE_TEST_CASE_P(SecureEnd2end, SecureEnd2endTest,
                         ::testing::ValuesIn(CreateTestScenarios(false, false,
diff --git a/test/cpp/end2end/generic_end2end_test.cc b/test/cpp/end2end/generic_end2end_test.cc
index 33b35108d22..94501823023 100644
--- a/test/cpp/end2end/generic_end2end_test.cc
+++ b/test/cpp/end2end/generic_end2end_test.cc
@@ -145,7 +145,7 @@ class GenericEnd2endTest : public ::testing::Test {
 
       if (check_deadline) {
         EXPECT_TRUE(gpr_time_similar(deadline, srv_ctx.raw_deadline(),
-                                     gpr_time_from_millis(100, GPR_TIMESPAN)));
+                                     gpr_time_from_millis(1000, GPR_TIMESPAN)));
       }
 
       ByteBuffer recv_buffer;
diff --git a/test/cpp/end2end/test_service_impl.cc b/test/cpp/end2end/test_service_impl.cc
index 4fa98c24f57..e4f7c08f252 100644
--- a/test/cpp/end2end/test_service_impl.cc
+++ b/test/cpp/end2end/test_service_impl.cc
@@ -73,6 +73,14 @@ void CheckServerAuthContext(
 
 Status TestServiceImpl::Echo(ServerContext* context, const EchoRequest* request,
                              EchoResponse* response) {
+  // A bit of sleep to make sure that short deadline tests fail
+  if (request->has_param() && request->param().server_sleep_us() > 0) {
+    gpr_sleep_until(
+        gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC),
+                     gpr_time_from_micros(request->param().server_sleep_us(),
+                                          GPR_TIMESPAN)));
+  }
+
   if (request->has_param() && request->param().server_die()) {
     gpr_log(GPR_ERROR, "The request should not reach application handler.");
     GPR_ASSERT(0);
diff --git a/test/cpp/interop/stress_test.cc b/test/cpp/interop/stress_test.cc
index 9cc5a8168b3..c6d3600be85 100644
--- a/test/cpp/interop/stress_test.cc
+++ b/test/cpp/interop/stress_test.cc
@@ -257,6 +257,7 @@ int main(int argc, char** argv) {
   gpr_log(GPR_INFO, "Starting test(s)..");
 
   std::vector<std::thread> test_threads;
+  std::vector<std::unique_ptr<StressTestInteropClient>> clients;
 
   // Create and start the test threads.
   // Note that:
@@ -282,9 +283,9 @@ int main(int argc, char** argv) {
       // Create stub(s) for each channel
       for (int stub_idx = 0; stub_idx < FLAGS_num_stubs_per_channel;
            stub_idx++) {
-        StressTestInteropClient* client = new StressTestInteropClient(
+        clients.emplace_back(new StressTestInteropClient(
             ++thread_idx, *it, channel, test_selector, FLAGS_test_duration_secs,
-            FLAGS_sleep_duration_ms, FLAGS_do_not_abort_on_transient_failures);
+            FLAGS_sleep_duration_ms, FLAGS_do_not_abort_on_transient_failures));
 
         bool is_already_created = false;
         // QpsGauge name
@@ -293,7 +294,7 @@ int main(int argc, char** argv) {
                       server_idx, channel_idx, stub_idx);
 
         test_threads.emplace_back(std::thread(
-            &StressTestInteropClient::MainLoop, client,
+            &StressTestInteropClient::MainLoop, clients.back().get(),
             metrics_service.CreateQpsGauge(buffer, &is_already_created)));
 
         // The QpsGauge should not have been already created
diff --git a/test/cpp/microbenchmarks/bm_call_create.cc b/test/cpp/microbenchmarks/bm_call_create.cc
index cadc9b2a114..cf9a42e8c60 100644
--- a/test/cpp/microbenchmarks/bm_call_create.cc
+++ b/test/cpp/microbenchmarks/bm_call_create.cc
@@ -554,7 +554,7 @@ static void BM_IsolatedFilter(benchmark::State &state) {
   grpc_exec_ctx_flush(&exec_ctx);
   grpc_call_stack *call_stack = static_cast<grpc_call_stack *>(
       gpr_zalloc(channel_stack->call_stack_size));
-  gpr_timespec deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
+  grpc_millis deadline = GRPC_MILLIS_INF_FUTURE;
   gpr_timespec start_time = gpr_now(GPR_CLOCK_MONOTONIC);
   grpc_slice method = grpc_slice_from_static_string("/foo/bar");
   grpc_call_final_info final_info;
diff --git a/test/cpp/microbenchmarks/bm_chttp2_transport.cc b/test/cpp/microbenchmarks/bm_chttp2_transport.cc
index 070034fe336..6f9dee78224 100644
--- a/test/cpp/microbenchmarks/bm_chttp2_transport.cc
+++ b/test/cpp/microbenchmarks/bm_chttp2_transport.cc
@@ -321,7 +321,7 @@ static void BM_StreamCreateSendInitialMetadataDestroy(benchmark::State &state) {
 
   grpc_metadata_batch b;
   grpc_metadata_batch_init(&b);
-  b.deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
+  b.deadline = GRPC_MILLIS_INF_FUTURE;
   std::vector<grpc_mdelem> elems = Metadata::GetElems(f.exec_ctx());
   std::vector<grpc_linked_mdelem> storage(elems.size());
   for (size_t i = 0; i < elems.size(); i++) {
@@ -410,7 +410,7 @@ static void BM_TransportStreamSend(benchmark::State &state) {
 
   grpc_metadata_batch b;
   grpc_metadata_batch_init(&b);
-  b.deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
+  b.deadline = GRPC_MILLIS_INF_FUTURE;
   std::vector<grpc_mdelem> elems =
       RepresentativeClientInitialMetadata::GetElems(f.exec_ctx());
   std::vector<grpc_linked_mdelem> storage(elems.size());
@@ -542,7 +542,7 @@ static void BM_TransportStreamRecv(benchmark::State &state) {
   grpc_metadata_batch_init(&b);
   grpc_metadata_batch b_recv;
   grpc_metadata_batch_init(&b_recv);
-  b.deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
+  b.deadline = GRPC_MILLIS_INF_FUTURE;
   std::vector<grpc_mdelem> elems =
       RepresentativeClientInitialMetadata::GetElems(f.exec_ctx());
   std::vector<grpc_linked_mdelem> storage(elems.size());
diff --git a/test/cpp/microbenchmarks/bm_cq_multiple_threads.cc b/test/cpp/microbenchmarks/bm_cq_multiple_threads.cc
index 5c9405f583d..57a69acf01e 100644
--- a/test/cpp/microbenchmarks/bm_cq_multiple_threads.cc
+++ b/test/cpp/microbenchmarks/bm_cq_multiple_threads.cc
@@ -73,9 +73,9 @@ static void cq_done_cb(grpc_exec_ctx* exec_ctx, void* done_arg,
 /* Queues a completion tag if deadline is > 0.
  * Does nothing if deadline is 0 (i.e gpr_time_0(GPR_CLOCK_MONOTONIC)) */
 static grpc_error* pollset_work(grpc_exec_ctx* exec_ctx, grpc_pollset* ps,
-                                grpc_pollset_worker** worker, gpr_timespec now,
-                                gpr_timespec deadline) {
-  if (gpr_time_cmp(deadline, gpr_time_0(GPR_CLOCK_MONOTONIC)) == 0) {
+                                grpc_pollset_worker** worker,
+                                grpc_millis deadline) {
+  if (deadline == 0) {
     gpr_log(GPR_DEBUG, "no-op");
     return GRPC_ERROR_NONE;
   }
diff --git a/test/cpp/microbenchmarks/bm_error.cc b/test/cpp/microbenchmarks/bm_error.cc
index bd5f02e172e..56b80dfcf6d 100644
--- a/test/cpp/microbenchmarks/bm_error.cc
+++ b/test/cpp/microbenchmarks/bm_error.cc
@@ -159,39 +159,39 @@ BENCHMARK(BM_ErrorGetPresentInt);
 // Fixtures for tests: generate different kinds of errors
 class ErrorNone {
  public:
-  gpr_timespec deadline() const { return deadline_; }
+  grpc_millis deadline() const { return deadline_; }
   grpc_error* error() const { return GRPC_ERROR_NONE; }
 
  private:
-  const gpr_timespec deadline_ = gpr_inf_future(GPR_CLOCK_MONOTONIC);
+  const grpc_millis deadline_ = GRPC_MILLIS_INF_FUTURE;
 };
 
 class ErrorCancelled {
  public:
-  gpr_timespec deadline() const { return deadline_; }
+  grpc_millis deadline() const { return deadline_; }
   grpc_error* error() const { return GRPC_ERROR_CANCELLED; }
 
  private:
-  const gpr_timespec deadline_ = gpr_inf_future(GPR_CLOCK_MONOTONIC);
+  const grpc_millis deadline_ = GRPC_MILLIS_INF_FUTURE;
 };
 
 class SimpleError {
  public:
-  gpr_timespec deadline() const { return deadline_; }
+  grpc_millis deadline() const { return deadline_; }
   grpc_error* error() const { return error_.get(); }
 
  private:
-  const gpr_timespec deadline_ = gpr_inf_future(GPR_CLOCK_MONOTONIC);
+  const grpc_millis deadline_ = GRPC_MILLIS_INF_FUTURE;
   ErrorPtr error_{GRPC_ERROR_CREATE_FROM_STATIC_STRING("Error")};
 };
 
 class ErrorWithGrpcStatus {
  public:
-  gpr_timespec deadline() const { return deadline_; }
+  grpc_millis deadline() const { return deadline_; }
   grpc_error* error() const { return error_.get(); }
 
  private:
-  const gpr_timespec deadline_ = gpr_inf_future(GPR_CLOCK_MONOTONIC);
+  const grpc_millis deadline_ = GRPC_MILLIS_INF_FUTURE;
   ErrorPtr error_{grpc_error_set_int(
       GRPC_ERROR_CREATE_FROM_STATIC_STRING("Error"), GRPC_ERROR_INT_GRPC_STATUS,
       GRPC_STATUS_UNIMPLEMENTED)};
@@ -199,11 +199,11 @@ class ErrorWithGrpcStatus {
 
 class ErrorWithHttpError {
  public:
-  gpr_timespec deadline() const { return deadline_; }
+  grpc_millis deadline() const { return deadline_; }
   grpc_error* error() const { return error_.get(); }
 
  private:
-  const gpr_timespec deadline_ = gpr_inf_future(GPR_CLOCK_MONOTONIC);
+  const grpc_millis deadline_ = GRPC_MILLIS_INF_FUTURE;
   ErrorPtr error_{grpc_error_set_int(
       GRPC_ERROR_CREATE_FROM_STATIC_STRING("Error"), GRPC_ERROR_INT_HTTP2_ERROR,
       GRPC_HTTP2_COMPRESSION_ERROR)};
@@ -211,11 +211,11 @@ class ErrorWithHttpError {
 
 class ErrorWithNestedGrpcStatus {
  public:
-  gpr_timespec deadline() const { return deadline_; }
+  grpc_millis deadline() const { return deadline_; }
   grpc_error* error() const { return error_.get(); }
 
  private:
-  const gpr_timespec deadline_ = gpr_inf_future(GPR_CLOCK_MONOTONIC);
+  const grpc_millis deadline_ = GRPC_MILLIS_INF_FUTURE;
   ErrorPtr nested_error_{grpc_error_set_int(
       GRPC_ERROR_CREATE_FROM_STATIC_STRING("Error"), GRPC_ERROR_INT_GRPC_STATUS,
       GRPC_STATUS_UNIMPLEMENTED)};
@@ -248,12 +248,14 @@ template <class Fixture>
 static void BM_ErrorGetStatus(benchmark::State& state) {
   TrackCounters track_counters;
   Fixture fixture;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   while (state.KeepRunning()) {
     grpc_status_code status;
     grpc_slice slice;
-    grpc_error_get_status(fixture.error(), fixture.deadline(), &status, &slice,
-                          NULL);
+    grpc_error_get_status(&exec_ctx, fixture.error(), fixture.deadline(),
+                          &status, &slice, NULL);
   }
+  grpc_exec_ctx_finish(&exec_ctx);
   track_counters.Finish(state);
 }
 
@@ -261,11 +263,13 @@ template <class Fixture>
 static void BM_ErrorGetStatusCode(benchmark::State& state) {
   TrackCounters track_counters;
   Fixture fixture;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   while (state.KeepRunning()) {
     grpc_status_code status;
-    grpc_error_get_status(fixture.error(), fixture.deadline(), &status, NULL,
-                          NULL);
+    grpc_error_get_status(&exec_ctx, fixture.error(), fixture.deadline(),
+                          &status, NULL, NULL);
   }
+  grpc_exec_ctx_finish(&exec_ctx);
   track_counters.Finish(state);
 }
 
@@ -273,11 +277,13 @@ template <class Fixture>
 static void BM_ErrorHttpError(benchmark::State& state) {
   TrackCounters track_counters;
   Fixture fixture;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   while (state.KeepRunning()) {
     grpc_http2_error_code error;
-    grpc_error_get_status(fixture.error(), fixture.deadline(), NULL, NULL,
-                          &error);
+    grpc_error_get_status(&exec_ctx, fixture.error(), fixture.deadline(), NULL,
+                          NULL, &error);
   }
+  grpc_exec_ctx_finish(&exec_ctx);
   track_counters.Finish(state);
 }
 
diff --git a/test/cpp/microbenchmarks/bm_fullstack_trickle.cc b/test/cpp/microbenchmarks/bm_fullstack_trickle.cc
index 2656566a50b..adb5e6657f2 100644
--- a/test/cpp/microbenchmarks/bm_fullstack_trickle.cc
+++ b/test/cpp/microbenchmarks/bm_fullstack_trickle.cc
@@ -29,6 +29,7 @@
 extern "C" {
 #include "src/core/ext/transport/chttp2/transport/chttp2_transport.h"
 #include "src/core/ext/transport/chttp2/transport/internal.h"
+#include "src/core/lib/iomgr/timer_manager.h"
 #include "test/core/util/trickle_endpoint.h"
 }
 
@@ -45,6 +46,22 @@ DEFINE_int32(warmup_max_time_seconds, 10,
 namespace grpc {
 namespace testing {
 
+gpr_atm g_now_us = 0;
+
+static gpr_timespec fake_now(gpr_clock_type clock_type) {
+  gpr_timespec t;
+  gpr_atm now = gpr_atm_no_barrier_load(&g_now_us);
+  t.tv_sec = now / GPR_US_PER_SEC;
+  t.tv_nsec = (now % GPR_US_PER_SEC) * GPR_NS_PER_US;
+  t.clock_type = clock_type;
+  return t;
+}
+
+static void inc_time() {
+  gpr_atm_no_barrier_fetch_add(&g_now_us, 100);
+  grpc_timer_manager_tick();
+}
+
 static void* tag(intptr_t x) { return reinterpret_cast<void*>(x); }
 
 template <class A0>
@@ -158,6 +175,7 @@ class TrickledCHTTP2 : public EndpointPairFixture {
 
   void Step(bool update_stats) {
     grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+    inc_time();
     size_t client_backlog =
         grpc_trickle_endpoint_trickle(&exec_ctx, endpoint_pair_.client);
     size_t server_backlog =
@@ -212,9 +230,8 @@ static void TrickleCQNext(TrickledCHTTP2* fixture, void** t, bool* ok,
                           int64_t iteration) {
   while (true) {
     fixture->Log(iteration);
-    switch (fixture->cq()->AsyncNext(
-        t, ok, gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC),
-                            gpr_time_from_micros(100, GPR_TIMESPAN)))) {
+    switch (
+        fixture->cq()->AsyncNext(t, ok, gpr_inf_past(GPR_CLOCK_MONOTONIC))) {
       case CompletionQueue::TIMEOUT:
         fixture->Step(iteration != -1);
         break;
@@ -289,9 +306,15 @@ static void BM_PumpStreamServerToClient_Trickle(benchmark::State& state) {
       inner_loop(false);
     }
     response_rw.Finish(Status::OK, tag(1));
-    need_tags = (1 << 0) | (1 << 1);
+    grpc::Status status;
+    request_rw->Finish(&status, tag(2));
+    need_tags = (1 << 0) | (1 << 1) | (1 << 2);
     while (need_tags) {
       TrickleCQNext(fixture.get(), &t, &ok, -1);
+      if (t == tag(0) && ok) {
+        request_rw->Read(&recv_response, tag(0));
+        continue;
+      }
       int i = (int)(intptr_t)t;
       GPR_ASSERT(need_tags & (1 << i));
       need_tags &= ~(1 << i);
@@ -419,8 +442,12 @@ BENCHMARK(BM_PumpUnbalancedUnary_Trickle)->Apply(UnaryTrickleArgs);
 }
 }
 
+extern "C" gpr_timespec (*gpr_now_impl)(gpr_clock_type clock_type);
+
 int main(int argc, char** argv) {
   ::benchmark::Initialize(&argc, argv);
   ::grpc::testing::InitTest(&argc, &argv, false);
+  grpc_timer_manager_set_threading(false);
+  gpr_now_impl = ::grpc::testing::fake_now;
   ::benchmark::RunSpecifiedBenchmarks();
 }
diff --git a/test/cpp/microbenchmarks/bm_pollset.cc b/test/cpp/microbenchmarks/bm_pollset.cc
index 1fc1f2f83b1..eab1e894802 100644
--- a/test/cpp/microbenchmarks/bm_pollset.cc
+++ b/test/cpp/microbenchmarks/bm_pollset.cc
@@ -117,11 +117,9 @@ static void BM_PollEmptyPollset(benchmark::State& state) {
   gpr_mu* mu;
   grpc_pollset_init(ps, &mu);
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
-  gpr_timespec now = gpr_time_0(GPR_CLOCK_MONOTONIC);
-  gpr_timespec deadline = gpr_inf_past(GPR_CLOCK_MONOTONIC);
   gpr_mu_lock(mu);
   while (state.KeepRunning()) {
-    GRPC_ERROR_UNREF(grpc_pollset_work(&exec_ctx, ps, NULL, now, deadline));
+    GRPC_ERROR_UNREF(grpc_pollset_work(&exec_ctx, ps, NULL, 0));
   }
   grpc_closure shutdown_ps_closure;
   GRPC_CLOSURE_INIT(&shutdown_ps_closure, shutdown_ps, ps,
@@ -223,8 +221,6 @@ static void BM_SingleThreadPollOneFd(benchmark::State& state) {
   gpr_mu* mu;
   grpc_pollset_init(ps, &mu);
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
-  gpr_timespec now = gpr_time_0(GPR_CLOCK_MONOTONIC);
-  gpr_timespec deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
   grpc_wakeup_fd wakeup_fd;
   GRPC_ERROR_UNREF(grpc_wakeup_fd_init(&wakeup_fd));
   grpc_fd* wakeup = grpc_fd_create(wakeup_fd.read_fd, "wakeup_read");
@@ -245,7 +241,8 @@ static void BM_SingleThreadPollOneFd(benchmark::State& state) {
   grpc_fd_notify_on_read(&exec_ctx, wakeup, continue_closure);
   gpr_mu_lock(mu);
   while (!done) {
-    GRPC_ERROR_UNREF(grpc_pollset_work(&exec_ctx, ps, NULL, now, deadline));
+    GRPC_ERROR_UNREF(
+        grpc_pollset_work(&exec_ctx, ps, NULL, GRPC_MILLIS_INF_FUTURE));
   }
   grpc_fd_orphan(&exec_ctx, wakeup, NULL, NULL, false /* already_closed */,
                  "done");
diff --git a/test/cpp/microbenchmarks/fullstack_fixtures.h b/test/cpp/microbenchmarks/fullstack_fixtures.h
index ecd28c3f8ac..a7f85045052 100644
--- a/test/cpp/microbenchmarks/fullstack_fixtures.h
+++ b/test/cpp/microbenchmarks/fullstack_fixtures.h
@@ -85,7 +85,7 @@ class FullstackFixture : public BaseFixture {
   }
 
   virtual ~FullstackFixture() {
-    server_->Shutdown();
+    server_->Shutdown(gpr_inf_past(GPR_CLOCK_MONOTONIC));
     cq_->Shutdown();
     void* tag;
     bool ok;
@@ -212,7 +212,7 @@ class EndpointPairFixture : public BaseFixture {
   }
 
   virtual ~EndpointPairFixture() {
-    server_->Shutdown();
+    server_->Shutdown(gpr_inf_past(GPR_CLOCK_MONOTONIC));
     cq_->Shutdown();
     void* tag;
     bool ok;
diff --git a/test/cpp/naming/resolver_component_test.cc b/test/cpp/naming/resolver_component_test.cc
index cc851ca9d5a..7d0371bea4c 100644
--- a/test/cpp/naming/resolver_component_test.cc
+++ b/test/cpp/naming/resolver_component_test.cc
@@ -199,10 +199,10 @@ void PollPollsetUntilRequestDone(ArgsStruct *args) {
     grpc_pollset_worker *worker = NULL;
     grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
     gpr_mu_lock(args->mu);
-    GRPC_LOG_IF_ERROR(
-        "pollset_work",
-        grpc_pollset_work(&exec_ctx, args->pollset, &worker,
-                          gpr_now(GPR_CLOCK_REALTIME), NSecondDeadline(1)));
+    GRPC_LOG_IF_ERROR("pollset_work",
+                      grpc_pollset_work(&exec_ctx, args->pollset, &worker,
+                                        grpc_timespec_to_millis_round_up(
+                                            NSecondDeadline(1))));
     gpr_mu_unlock(args->mu);
     grpc_exec_ctx_finish(&exec_ctx);
   }
diff --git a/test/cpp/qps/client.h b/test/cpp/qps/client.h
index 7fbaf63492e..abf755b3935 100644
--- a/test/cpp/qps/client.h
+++ b/test/cpp/qps/client.h
@@ -226,6 +226,7 @@ class Client {
   }
 
   virtual void DestroyMultithreading() = 0;
+  virtual void InitThreadFunc(size_t thread_idx) = 0;
   virtual bool ThreadFunc(HistogramEntry* histogram, size_t thread_idx) = 0;
 
   void SetupLoadTest(const ClientConfig& config, size_t num_threads) {
@@ -299,13 +300,18 @@ class Client {
     Thread& operator=(const Thread&);
 
     void ThreadFunc() {
+      int wait_loop = 0;
       while (!gpr_event_wait(
           &client_->start_requests_,
           gpr_time_add(gpr_now(GPR_CLOCK_REALTIME),
-                       gpr_time_from_seconds(1, GPR_TIMESPAN)))) {
-        gpr_log(GPR_INFO, "Waiting for benchmark to start");
+                       gpr_time_from_seconds(20, GPR_TIMESPAN)))) {
+        gpr_log(GPR_INFO, "%" PRIdPTR ": Waiting for benchmark to start (%d)",
+                idx_, wait_loop);
+        wait_loop++;
       }
 
+      client_->InitThreadFunc(idx_);
+
       for (;;) {
         // run the loop body
         HistogramEntry entry;
@@ -380,6 +386,13 @@ class ClientImpl : public Client {
           config.server_targets(i % config.server_targets_size()), config,
           create_stub_, i);
     }
+    std::vector<std::unique_ptr<std::thread>> connecting_threads;
+    for (auto& c : channels_) {
+      connecting_threads.emplace_back(c.WaitForReady());
+    }
+    for (auto& t : connecting_threads) {
+      t->join();
+    }
 
     ClientRequestCreator<RequestType> create_req(&request_,
                                                  config.payload_config());
@@ -414,14 +427,19 @@ class ClientImpl : public Client {
           !config.security_params().use_test_ca(),
           std::shared_ptr<CallCredentials>(), args);
       gpr_log(GPR_INFO, "Connecting to %s", target.c_str());
-      GPR_ASSERT(channel_->WaitForConnected(
-          gpr_time_add(gpr_now(GPR_CLOCK_REALTIME),
-                       gpr_time_from_seconds(300, GPR_TIMESPAN))));
       stub_ = create_stub(channel_);
     }
     Channel* get_channel() { return channel_.get(); }
     StubType* get_stub() { return stub_.get(); }
 
+    std::unique_ptr<std::thread> WaitForReady() {
+      return std::unique_ptr<std::thread>(new std::thread([this]() {
+        GPR_ASSERT(channel_->WaitForConnected(
+            gpr_time_add(gpr_now(GPR_CLOCK_REALTIME),
+                         gpr_time_from_seconds(10, GPR_TIMESPAN))));
+      }));
+    }
+
    private:
     void set_channel_args(const ClientConfig& config, ChannelArguments* args) {
       for (auto channel_arg : config.channel_args()) {
diff --git a/test/cpp/qps/client_async.cc b/test/cpp/qps/client_async.cc
index f5807da81e3..9ed4e0b3552 100644
--- a/test/cpp/qps/client_async.cc
+++ b/test/cpp/qps/client_async.cc
@@ -236,6 +236,7 @@ class AsyncClient : public ClientImpl<StubType, RequestType> {
     this->EndThreads();  // this needed for resolution
   }
 
+  void InitThreadFunc(size_t thread_idx) override final {}
   bool ThreadFunc(HistogramEntry* entry, size_t thread_idx) override final {
     void* got_tag;
     bool ok;
diff --git a/test/cpp/qps/client_sync.cc b/test/cpp/qps/client_sync.cc
index 5d212f1acc0..94554a46b20 100644
--- a/test/cpp/qps/client_sync.cc
+++ b/test/cpp/qps/client_sync.cc
@@ -103,6 +103,8 @@ class SynchronousUnaryClient final : public SynchronousClient {
   }
   ~SynchronousUnaryClient() {}
 
+  void InitThreadFunc(size_t thread_idx) override {}
+
   bool ThreadFunc(HistogramEntry* entry, size_t thread_idx) override {
     if (!WaitToIssue(thread_idx)) {
       return true;
@@ -174,13 +176,7 @@ class SynchronousStreamingPingPongClient final
           grpc::ClientReaderWriter<SimpleRequest, SimpleResponse>> {
  public:
   SynchronousStreamingPingPongClient(const ClientConfig& config)
-      : SynchronousStreamingClient(config) {
-    for (size_t thread_idx = 0; thread_idx < num_threads_; thread_idx++) {
-      auto* stub = channels_[thread_idx % channels_.size()].get_stub();
-      stream_[thread_idx] = stub->StreamingCall(&context_[thread_idx]);
-      messages_issued_[thread_idx] = 0;
-    }
-  }
+      : SynchronousStreamingClient(config) {}
   ~SynchronousStreamingPingPongClient() {
     std::vector<std::thread> cleanup_threads;
     for (size_t i = 0; i < num_threads_; i++) {
@@ -196,6 +192,12 @@ class SynchronousStreamingPingPongClient final
     }
   }
 
+  void InitThreadFunc(size_t thread_idx) override {
+    auto* stub = channels_[thread_idx % channels_.size()].get_stub();
+    stream_[thread_idx] = stub->StreamingCall(&context_[thread_idx]);
+    messages_issued_[thread_idx] = 0;
+  }
+
   bool ThreadFunc(HistogramEntry* entry, size_t thread_idx) override {
     if (!WaitToIssue(thread_idx)) {
       return true;
@@ -228,14 +230,7 @@ class SynchronousStreamingFromClientClient final
     : public SynchronousStreamingClient<grpc::ClientWriter<SimpleRequest>> {
  public:
   SynchronousStreamingFromClientClient(const ClientConfig& config)
-      : SynchronousStreamingClient(config), last_issue_(num_threads_) {
-    for (size_t thread_idx = 0; thread_idx < num_threads_; thread_idx++) {
-      auto* stub = channels_[thread_idx % channels_.size()].get_stub();
-      stream_[thread_idx] = stub->StreamingFromClient(&context_[thread_idx],
-                                                      &responses_[thread_idx]);
-      last_issue_[thread_idx] = UsageTimer::Now();
-    }
-  }
+      : SynchronousStreamingClient(config), last_issue_(num_threads_) {}
   ~SynchronousStreamingFromClientClient() {
     std::vector<std::thread> cleanup_threads;
     for (size_t i = 0; i < num_threads_; i++) {
@@ -251,6 +246,13 @@ class SynchronousStreamingFromClientClient final
     }
   }
 
+  void InitThreadFunc(size_t thread_idx) override {
+    auto* stub = channels_[thread_idx % channels_.size()].get_stub();
+    stream_[thread_idx] = stub->StreamingFromClient(&context_[thread_idx],
+                                                    &responses_[thread_idx]);
+    last_issue_[thread_idx] = UsageTimer::Now();
+  }
+
   bool ThreadFunc(HistogramEntry* entry, size_t thread_idx) override {
     // Figure out how to make histogram sensible if this is rate-paced
     if (!WaitToIssue(thread_idx)) {
@@ -279,13 +281,12 @@ class SynchronousStreamingFromServerClient final
     : public SynchronousStreamingClient<grpc::ClientReader<SimpleResponse>> {
  public:
   SynchronousStreamingFromServerClient(const ClientConfig& config)
-      : SynchronousStreamingClient(config), last_recv_(num_threads_) {
-    for (size_t thread_idx = 0; thread_idx < num_threads_; thread_idx++) {
-      auto* stub = channels_[thread_idx % channels_.size()].get_stub();
-      stream_[thread_idx] =
-          stub->StreamingFromServer(&context_[thread_idx], request_);
-      last_recv_[thread_idx] = UsageTimer::Now();
-    }
+      : SynchronousStreamingClient(config), last_recv_(num_threads_) {}
+  void InitThreadFunc(size_t thread_idx) override {
+    auto* stub = channels_[thread_idx % channels_.size()].get_stub();
+    stream_[thread_idx] =
+        stub->StreamingFromServer(&context_[thread_idx], request_);
+    last_recv_[thread_idx] = UsageTimer::Now();
   }
   bool ThreadFunc(HistogramEntry* entry, size_t thread_idx) override {
     GPR_TIMER_SCOPE("SynchronousStreamingFromServerClient::ThreadFunc", 0);
@@ -311,12 +312,7 @@ class SynchronousStreamingBothWaysClient final
           grpc::ClientReaderWriter<SimpleRequest, SimpleResponse>> {
  public:
   SynchronousStreamingBothWaysClient(const ClientConfig& config)
-      : SynchronousStreamingClient(config) {
-    for (size_t thread_idx = 0; thread_idx < num_threads_; thread_idx++) {
-      auto* stub = channels_[thread_idx % channels_.size()].get_stub();
-      stream_[thread_idx] = stub->StreamingBothWays(&context_[thread_idx]);
-    }
-  }
+      : SynchronousStreamingClient(config) {}
   ~SynchronousStreamingBothWaysClient() {
     std::vector<std::thread> cleanup_threads;
     for (size_t i = 0; i < num_threads_; i++) {
@@ -332,6 +328,10 @@ class SynchronousStreamingBothWaysClient final
     }
   }
 
+  void InitThreadFunc(size_t thread_idx) override {
+    auto* stub = channels_[thread_idx % channels_.size()].get_stub();
+    stream_[thread_idx] = stub->StreamingBothWays(&context_[thread_idx]);
+  }
   bool ThreadFunc(HistogramEntry* entry, size_t thread_idx) override {
     // TODO (vjpai): Do this
     return true;
diff --git a/tools/debug/core/chttp2_ref_leak.py b/tools/debug/core/chttp2_ref_leak.py
new file mode 100755
index 00000000000..d693dd9e540
--- /dev/null
+++ b/tools/debug/core/chttp2_ref_leak.py
@@ -0,0 +1,42 @@
+#!/usr/bin/env python2.7
+# Copyright 2017 gRPC authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Reads stdin to find chttp2_refcount log lines, and prints reference leaks
+# to stdout
+
+import collections
+import sys
+import re
+
+def new_obj():
+  return ['destroy']
+
+outstanding = collections.defaultdict(new_obj)
+
+# Sample log line:
+# chttp2:unref:0x629000005200 2->1 destroy [src/core/ext/transport/chttp2/transport/chttp2_transport.c:599]
+
+for line in sys.stdin:
+  m = re.search(r'chttp2:(  ref|unref):0x([a-fA-F0-9]+) [^ ]+ ([^[]+) \[(.*)\]', line)
+  if m:
+    if m.group(1) == '  ref':
+      outstanding[m.group(2)].append(m.group(3))
+    else:
+      outstanding[m.group(2)].remove(m.group(3))
+
+for obj, remaining in outstanding.items():
+  if remaining:
+    print 'LEAKED: %s %r' % (obj, remaining)
+
diff --git a/tools/dockerfile/test/node_jessie_x64/Dockerfile b/tools/dockerfile/test/node_jessie_x64/Dockerfile
index 4f18dbae794..d0e5af64cc1 100644
--- a/tools/dockerfile/test/node_jessie_x64/Dockerfile
+++ b/tools/dockerfile/test/node_jessie_x64/Dockerfile
@@ -102,5 +102,8 @@ RUN ln -s /usr/bin/ccache /usr/local/bin/clang++
 
 RUN mkdir /var/local/jenkins
 
+# Install Mako to generate files in grpc/grpc-node
+RUN pip install Mako
+
 # Define the default command.
 CMD ["bash"]
diff --git a/tools/doxygen/Doxyfile.c++.internal b/tools/doxygen/Doxyfile.c++.internal
index 584dd0af57b..0f7e8cd3a8d 100644
--- a/tools/doxygen/Doxyfile.c++.internal
+++ b/tools/doxygen/Doxyfile.c++.internal
@@ -933,6 +933,7 @@ include/grpc/support/tls_pthread.h \
 include/grpc/support/useful.h \
 include/grpc/support/workaround_list.h \
 src/core/ext/transport/inproc/inproc_transport.h \
+src/core/lib/backoff/backoff.h \
 src/core/lib/channel/channel_args.h \
 src/core/lib/channel/channel_stack.h \
 src/core/lib/channel/channel_stack_builder.h \
@@ -952,6 +953,7 @@ src/core/lib/debug/trace.h \
 src/core/lib/http/format_request.h \
 src/core/lib/http/httpcli.h \
 src/core/lib/http/parser.h \
+src/core/lib/iomgr/block_annotate.h \
 src/core/lib/iomgr/call_combiner.h \
 src/core/lib/iomgr/closure.h \
 src/core/lib/iomgr/combiner.h \
@@ -1028,8 +1030,6 @@ src/core/lib/support/arena.h \
 src/core/lib/support/atomic.h \
 src/core/lib/support/atomic_with_atm.h \
 src/core/lib/support/atomic_with_std.h \
-src/core/lib/support/backoff.h \
-src/core/lib/support/block_annotate.h \
 src/core/lib/support/env.h \
 src/core/lib/support/memory.h \
 src/core/lib/support/mpscq.h \
diff --git a/tools/doxygen/Doxyfile.core b/tools/doxygen/Doxyfile.core
index b8514fe3114..c8fd2ee48b2 100644
--- a/tools/doxygen/Doxyfile.core
+++ b/tools/doxygen/Doxyfile.core
@@ -772,6 +772,7 @@ doc/connection-backoff-interop-test-description.md \
 doc/connection-backoff.md \
 doc/connectivity-semantics-and-api.md \
 doc/core/grpc-error.md \
+doc/core/moving-to-c++.md \
 doc/core/pending_api_cleanups.md \
 doc/cpp-style-guide.md \
 doc/environment_variables.md \
diff --git a/tools/doxygen/Doxyfile.core.internal b/tools/doxygen/Doxyfile.core.internal
index dc6df1decdc..8c221ac4cb0 100644
--- a/tools/doxygen/Doxyfile.core.internal
+++ b/tools/doxygen/Doxyfile.core.internal
@@ -772,6 +772,7 @@ doc/connection-backoff-interop-test-description.md \
 doc/connection-backoff.md \
 doc/connectivity-semantics-and-api.md \
 doc/core/grpc-error.md \
+doc/core/moving-to-c++.md \
 doc/core/pending_api_cleanups.md \
 doc/cpp-style-guide.md \
 doc/environment_variables.md \
@@ -1058,6 +1059,8 @@ src/core/ext/transport/inproc/inproc_plugin.cc \
 src/core/ext/transport/inproc/inproc_transport.cc \
 src/core/ext/transport/inproc/inproc_transport.h \
 src/core/lib/README.md \
+src/core/lib/backoff/backoff.cc \
+src/core/lib/backoff/backoff.h \
 src/core/lib/channel/README.md \
 src/core/lib/channel/channel_args.cc \
 src/core/lib/channel/channel_args.h \
@@ -1098,6 +1101,7 @@ src/core/lib/http/httpcli_security_connector.cc \
 src/core/lib/http/parser.cc \
 src/core/lib/http/parser.h \
 src/core/lib/iomgr/README.md \
+src/core/lib/iomgr/block_annotate.h \
 src/core/lib/iomgr/call_combiner.cc \
 src/core/lib/iomgr/call_combiner.h \
 src/core/lib/iomgr/closure.cc \
@@ -1303,9 +1307,6 @@ src/core/lib/support/atomic.h \
 src/core/lib/support/atomic_with_atm.h \
 src/core/lib/support/atomic_with_std.h \
 src/core/lib/support/avl.cc \
-src/core/lib/support/backoff.cc \
-src/core/lib/support/backoff.h \
-src/core/lib/support/block_annotate.h \
 src/core/lib/support/cmdline.cc \
 src/core/lib/support/cpu_iphone.cc \
 src/core/lib/support/cpu_linux.cc \
diff --git a/tools/internal_ci/helper_scripts/prepare_build_linux_rc b/tools/internal_ci/helper_scripts/prepare_build_linux_rc
index 2ade8dac51f..ea2a17f2bcf 100644
--- a/tools/internal_ci/helper_scripts/prepare_build_linux_rc
+++ b/tools/internal_ci/helper_scripts/prepare_build_linux_rc
@@ -32,11 +32,4 @@ PYTHONWARNINGS=ignore XDG_CACHE_HOME=/tmp/xdg-cache-home sudo -E pip install cov
 # Download Docker images from DockerHub
 export DOCKERHUB_ORGANIZATION=grpctesting
 
-# If this is a PR using RUN_TESTS_FLAGS var, then add flags to filter tests
-if [ -n "$KOKORO_GITHUB_PULL_REQUEST_NUMBER" ] && [ -n "$RUN_TESTS_FLAGS" ]; then
-  sudo apt-get install -y jq
-  ghprbTargetBranch=$(curl -s https://api.github.com/repos/grpc/grpc/pulls/$KOKORO_GITHUB_PULL_REQUEST_NUMBER | jq -r .base.ref)
-  export RUN_TESTS_FLAGS="$RUN_TESTS_FLAGS --filter_pr_tests --base_branch origin/$ghprbTargetBranch"	
-fi
-
 git submodule update --init
diff --git a/tools/internal_ci/helper_scripts/prepare_build_macos_rc b/tools/internal_ci/helper_scripts/prepare_build_macos_rc
index dd98a12c65a..8f2056096dc 100644
--- a/tools/internal_ci/helper_scripts/prepare_build_macos_rc
+++ b/tools/internal_ci/helper_scripts/prepare_build_macos_rc
@@ -40,11 +40,12 @@ pip install google-api-python-client --user python
 export GOOGLE_APPLICATION_CREDENTIALS=${KOKORO_GFILE_DIR}/GrpcTesting-d0eeee2db331.json
 
 # If this is a PR using RUN_TESTS_FLAGS var, then add flags to filter tests
-if [ -n "$KOKORO_GITHUB_PULL_REQUEST_NUMBER" ] && [ -n "$RUN_TESTS_FLAGS" ]; then
-  brew install jq
-  ghprbTargetBranch=$(curl -s https://api.github.com/repos/grpc/grpc/pulls/$KOKORO_GITHUB_PULL_REQUEST_NUMBER | jq -r .base.ref)
-  export RUN_TESTS_FLAGS="$RUN_TESTS_FLAGS --filter_pr_tests --base_branch origin/$ghprbTargetBranch"
-fi
+# TODO(matt-kwong): enable after fixing brew issue
+# if [ -n "$KOKORO_GITHUB_PULL_REQUEST_NUMBER" ] && [ -n "$RUN_TESTS_FLAGS" ]; then
+#   brew install jq
+#   ghprbTargetBranch=$(curl -s https://api.github.com/repos/grpc/grpc/pulls/$KOKORO_GITHUB_PULL_REQUEST_NUMBER | jq -r .base.ref)
+#   export RUN_TESTS_FLAGS="$RUN_TESTS_FLAGS --filter_pr_tests --base_branch origin/$ghprbTargetBranch"
+# fi
 
 set +ex  # rvm script is very verbose and exits with errorcode
 source $HOME/.rvm/scripts/rvm
@@ -60,7 +61,7 @@ pod repo update  # needed by python
 
 # python
 pip install virtualenv --user python
-pip install -U six tox setuptools twisted pyyaml --user python
+pip install -U Mako six tox setuptools twisted pyyaml --user python
 export PYTHONPATH=/Library/Python/3.4/site-packages
 
 # set xcode version for Obj-C tests
diff --git a/tools/internal_ci/linux/grpc_interop_tocloud.cfg b/tools/internal_ci/linux/grpc_interop_tocloud.cfg
index 2803616007a..13aec15770b 100644
--- a/tools/internal_ci/linux/grpc_interop_tocloud.cfg
+++ b/tools/internal_ci/linux/grpc_interop_tocloud.cfg
@@ -15,8 +15,7 @@
 # Config file for the internal CI (in protobuf text format)
 
 # Location of the continuous shell script in repository.
-build_file: "grpc/tools/internal_ci/linux/grpc_interop_tocloud.sh"
-# grpc_interop tests can take 6+ hours to complete.
+build_file: "grpc/tools/internal_ci/linux/grpc_run_interop_tests.sh"
 timeout_mins: 60
 action {
   define_artifacts {
@@ -24,3 +23,8 @@ action {
     regex: "github/grpc/reports/**"
   }
 }
+
+env_vars {
+  key: "RUN_TESTS_FLAGS"
+  value: "-l all -s all --use_docker --http2_interop --internal_ci -t -j 12 --bq_result_table interop_results"
+}
diff --git a/tools/internal_ci/linux/grpc_interop_toprod.cfg b/tools/internal_ci/linux/grpc_interop_toprod.cfg
index 903480a3d18..8d025c4f60d 100644
--- a/tools/internal_ci/linux/grpc_interop_toprod.cfg
+++ b/tools/internal_ci/linux/grpc_interop_toprod.cfg
@@ -15,8 +15,7 @@
 # Config file for the internal CI (in protobuf text format)
 
 # Location of the continuous shell script in repository.
-build_file: "grpc/tools/internal_ci/linux/grpc_interop_toprod.sh"
-# grpc_interop tests can take 6+ hours to complete.
+build_file: "grpc/tools/internal_ci/linux/grpc_run_interop_tests.sh"
 timeout_mins: 60
 action {
   define_artifacts {
@@ -25,3 +24,7 @@ action {
   }
 }
 
+env_vars {
+  key: "RUN_TESTS_FLAGS"
+  value: "-l all --cloud_to_prod --cloud_to_prod_auth --prod_servers default gateway_v4 --use_docker --internal_ci -t -j 12 --bq_result_table interop_results"
+}
diff --git a/tools/internal_ci/linux/grpc_interop_toprod.sh b/tools/internal_ci/linux/grpc_interop_toprod.sh
deleted file mode 100755
index 3d06185406a..00000000000
--- a/tools/internal_ci/linux/grpc_interop_toprod.sh
+++ /dev/null
@@ -1,32 +0,0 @@
-#!/usr/bin/env bash
-# Copyright 2017 gRPC authors.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-set -ex
-
-export LANG=en_US.UTF-8
-
-# Enter the gRPC repo root
-cd $(dirname $0)/../../..
-
-source tools/internal_ci/helper_scripts/prepare_build_linux_rc
-source tools/internal_ci/helper_scripts/prepare_build_interop_rc
-
-tools/run_tests/run_interop_tests.py \
-    -l all \
-    --cloud_to_prod \
-    --cloud_to_prod_auth \
-    --prod_servers default gateway_v4 \
-    --use_docker --internal_ci -t -j 12 $@
-
diff --git a/tools/internal_ci/linux/grpc_interop_badserver_java.sh b/tools/internal_ci/linux/grpc_run_interop_tests.sh
similarity index 88%
rename from tools/internal_ci/linux/grpc_interop_badserver_java.sh
rename to tools/internal_ci/linux/grpc_run_interop_tests.sh
index d25845ca507..1f4eda2d529 100755
--- a/tools/internal_ci/linux/grpc_interop_badserver_java.sh
+++ b/tools/internal_ci/linux/grpc_run_interop_tests.sh
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/bin/bash
 # Copyright 2017 gRPC authors.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -23,5 +23,4 @@ cd $(dirname $0)/../../..
 source tools/internal_ci/helper_scripts/prepare_build_linux_rc
 source tools/internal_ci/helper_scripts/prepare_build_interop_rc
 
-tools/run_tests/run_interop_tests.py -l java --use_docker --http2_server_interop
-
+tools/run_tests/run_interop_tests.py $RUN_TESTS_FLAGS
diff --git a/tools/internal_ci/linux/grpc_run_tests_matrix.sh b/tools/internal_ci/linux/grpc_run_tests_matrix.sh
index bd1430b7415..1018708f967 100755
--- a/tools/internal_ci/linux/grpc_run_tests_matrix.sh
+++ b/tools/internal_ci/linux/grpc_run_tests_matrix.sh
@@ -20,6 +20,13 @@ cd $(dirname $0)/../../..
 
 source tools/internal_ci/helper_scripts/prepare_build_linux_rc
 
+# If this is a PR using RUN_TESTS_FLAGS var, then add flags to filter tests
+if [ -n "$KOKORO_GITHUB_PULL_REQUEST_NUMBER" ] && [ -n "$RUN_TESTS_FLAGS" ]; then
+  sudo apt-get install -y jq
+  ghprbTargetBranch=$(curl -s https://api.github.com/repos/grpc/grpc/pulls/$KOKORO_GITHUB_PULL_REQUEST_NUMBER | jq -r .base.ref)
+  export RUN_TESTS_FLAGS="$RUN_TESTS_FLAGS --filter_pr_tests --base_branch origin/$ghprbTargetBranch"
+fi
+
 tools/run_tests/run_tests_matrix.py $RUN_TESTS_FLAGS || FAILED="true"
 
 # Reveal leftover processes that might be left behind by the build
diff --git a/tools/internal_ci/linux/grpc_interop_badserver_java.cfg b/tools/internal_ci/linux/pull_request/grpc_interop_tocloud.cfg
similarity index 76%
rename from tools/internal_ci/linux/grpc_interop_badserver_java.cfg
rename to tools/internal_ci/linux/pull_request/grpc_interop_tocloud.cfg
index dc2114273ea..cb18e8e8682 100644
--- a/tools/internal_ci/linux/grpc_interop_badserver_java.cfg
+++ b/tools/internal_ci/linux/pull_request/grpc_interop_tocloud.cfg
@@ -15,12 +15,16 @@
 # Config file for the internal CI (in protobuf text format)
 
 # Location of the continuous shell script in repository.
-build_file: "grpc/tools/internal_ci/linux/grpc_interop_badserver_java.sh"
-# grpc_interop tests can take 6+ hours to complete.
-timeout_mins: 480
+build_file: "grpc/tools/internal_ci/linux/grpc_run_interop_tests.sh"
+timeout_mins: 60
 action {
   define_artifacts {
-    regex: "**/report.xml"
+    regex: "**/sponge_log.xml"
     regex: "github/grpc/reports/**"
   }
 }
+
+env_vars {
+  key: "RUN_TESTS_FLAGS"
+  value: "-l all -s all --use_docker --http2_interop --internal_ci -t -j 12"
+}
diff --git a/tools/internal_ci/linux/grpc_interop_badserver_python.cfg b/tools/internal_ci/linux/pull_request/grpc_interop_toprod.cfg
similarity index 72%
rename from tools/internal_ci/linux/grpc_interop_badserver_python.cfg
rename to tools/internal_ci/linux/pull_request/grpc_interop_toprod.cfg
index ec738fcf74a..e141d9f6486 100644
--- a/tools/internal_ci/linux/grpc_interop_badserver_python.cfg
+++ b/tools/internal_ci/linux/pull_request/grpc_interop_toprod.cfg
@@ -15,12 +15,16 @@
 # Config file for the internal CI (in protobuf text format)
 
 # Location of the continuous shell script in repository.
-build_file: "grpc/tools/internal_ci/linux/grpc_interop_badserver_python.sh"
-# grpc_interop tests can take 6+ hours to complete.
-timeout_mins: 480
+build_file: "grpc/tools/internal_ci/linux/grpc_run_interop_tests.sh"
+timeout_mins: 60
 action {
   define_artifacts {
-    regex: "**/report.xml"
+    regex: "**/sponge_log.xml"
     regex: "github/grpc/reports/**"
   }
 }
+
+env_vars {
+  key: "RUN_TESTS_FLAGS"
+  value: "-l all --allow_flakes --cloud_to_prod --cloud_to_prod_auth --prod_servers default gateway_v4 --use_docker --internal_ci -t -j 12"
+}
diff --git a/tools/interop_matrix/README.md b/tools/interop_matrix/README.md
index c2f354399f0..c0e9a33c5e4 100644
--- a/tools/interop_matrix/README.md
+++ b/tools/interop_matrix/README.md
@@ -47,7 +47,7 @@ For more details on each step, refer to sections below.
 
 ## Instructions for running test cases against GCR images
 - Run `tools/interop_matrix/run_interop_matrix_tests.py`.  Useful options:
-  - `--release` specifies a git release tag.  Defaults to `--release=master`.  Make sure the GCR images with the tag have been created using `create_matrix_images.py` above.
+  - `--release` specifies a git release tag.  Defaults to `--release=all`.  Make sure the GCR images with the tag have been created using `create_matrix_images.py` above.
   - `--language` specifies a language.  Defaults to `--language=all`.
   For example, To test all languages for all gRPC releases across all runtimes, do `tools/interop_matrix/run_interop_matrix_test.py --release=all`.
 - The output for all the test cases is recorded in a junit style xml file (default to 'report.xml').
diff --git a/tools/interop_matrix/create_testcases.sh b/tools/interop_matrix/create_testcases.sh
index d06fb34ff9a..3d34b2ef25a 100755
--- a/tools/interop_matrix/create_testcases.sh
+++ b/tools/interop_matrix/create_testcases.sh
@@ -31,9 +31,12 @@ TESTCASES_DIR=${GRPC_ROOT}/tools/interop_matrix/testcases
 
 echo "Create '$LANG' test cases for gRPC release '${RELEASE:=master}'"
 
+echo $client_lang
 # Invoke run_interop_test in manual mode.
+# TODO(adelez): Add cloud_gateways when we figure out how to skip them if not 
+# running in GCE.
 ${GRPC_ROOT}/tools/run_tests/run_interop_tests.py -l $LANG --use_docker \
-  --cloud_to_prod --manual_run
+  --cloud_to_prod --prod_servers default gateway_v4 --manual_run
 
 # Clean up
 function cleanup {
@@ -52,11 +55,18 @@ function cleanup {
   [ -e "$CMDS_SH" ] && rm $CMDS_SH
 }
 trap cleanup EXIT
+# TODO(adelez): add test auth tests but do not run if not testing on GCE.
 # Running the testcases as sanity unless we are asked to skip.
 [ -z "$SKIP_TEST" ] && (echo "Running test cases: $CMDS_SH"; sh $CMDS_SH)
 
+# Convert c++ to cxx. 
+if [$LANG == "c++" ]; then
+client_lang="cxx"
+else
+client_lang=$LANG
+fi
 mkdir -p $TESTCASES_DIR
-testcase=$TESTCASES_DIR/${LANG}__$RELEASE
+testcase=$TESTCASES_DIR/${client_lang}__$RELEASE
 if [ -e $testcase ]; then
   echo "Updating: $testcase"
   diff $testcase $CMDS_SH || true
diff --git a/tools/interop_matrix/run_interop_matrix_tests.py b/tools/interop_matrix/run_interop_matrix_tests.py
index 4315c8277df..48c918d25d4 100755
--- a/tools/interop_matrix/run_interop_matrix_tests.py
+++ b/tools/interop_matrix/run_interop_matrix_tests.py
@@ -48,9 +48,8 @@ argp.add_argument('-j', '--jobs', default=multiprocessing.cpu_count(), type=int)
 argp.add_argument('--gcr_path',
                   default='gcr.io/grpc-testing',
                   help='Path of docker images in Google Container Registry')
-
 argp.add_argument('--release',
-                  default='master',
+                  default='all',
                   choices=['all', 'master'] + _RELEASES,
                   help='Release tags to test.  When testing all '
                   'releases defined in client_matrix.py, use "all".')
@@ -69,6 +68,13 @@ argp.add_argument('--report_file',
                   default='report.xml',
                   help='The result file to create.')
 
+argp.add_argument('--allow_flakes',
+                  default=False,
+                  action='store_const',
+                  const=True,
+                  help=('Allow flaky tests to show as passing (re-runs failed '
+                        'tests up to five times)'))
+
 args = argp.parse_args()
 
 
@@ -94,14 +100,15 @@ def find_all_images_for_lang(lang):
   for runtime in client_matrix.LANG_RUNTIME_MATRIX[lang]:
     image_path = '%s/grpc_interop_%s' % (args.gcr_path, runtime)
     output = subprocess.check_output(['gcloud', 'beta', 'container', 'images',
-                                        'list-tags', '--format=json', image_path])
+                                      'list-tags', '--format=json', image_path])
     docker_image_list = json.loads(output)
     # All images should have a single tag or no tag.
+    # TODO(adelez): Remove tagless images.
     tags = [i['tags'][0] for i in docker_image_list if i['tags']]
     jobset.message('START', 'Found images for %s: %s' % (image_path, tags),
                    do_newline=True)
     skipped = len(docker_image_list) - len(tags)
-    jobset.message('START', 'Skipped images (no-tag/unknown-tag): %d' % skipped,
+    jobset.message('SKIPPED', 'Skipped images (no-tag/unknown-tag): %d' % skipped,
                    do_newline=True)
     # Filter tags based on the releases.
     images[runtime] = [(tag,'%s:%s' % (image_path,tag)) for tag in tags if
@@ -130,7 +137,8 @@ def find_test_cases(lang, release):
           spec = jobset.JobSpec(cmdline=line,
                                 shortname=shortname,
                                 timeout_seconds=_TEST_TIMEOUT,
-                                shell=True)
+                                shell=True,
+                                flake_retries=5 if args.allow_flakes else 0)
           job_spec_list.append(spec)
       jobset.message('START',
                      'Loaded %s tests from %s' % (len(job_spec_list), testcases),
@@ -148,6 +156,7 @@ def run_tests_for_lang(lang, runtime, images):
 
   images is a list of (<release-tag>, <image-full-path>) tuple.
   """
+  total_num_failures = 0
   for image_tuple in images:
     release, image = image_tuple
     jobset.message('START', 'Testing %s' % image, do_newline=True)
@@ -161,6 +170,7 @@ def run_tests_for_lang(lang, runtime, images):
                                          maxjobs=args.jobs)
     if num_failures:
       jobset.message('FAILED', 'Some tests failed', do_newline=True)
+      total_num_failures += num_failures
     else:
       jobset.message('SUCCESS', 'All tests passed', do_newline=True)
 
@@ -170,6 +180,9 @@ def run_tests_for_lang(lang, runtime, images):
         'grpc_interop_matrix',
         '%s__%s %s'%(lang,runtime,release),
         str(uuid.uuid4()))
+  
+  return total_num_failures
+
 
 _docker_images_cleanup = []
 def cleanup():
@@ -180,9 +193,14 @@ def cleanup():
 atexit.register(cleanup)
 
 languages = args.language if args.language != ['all'] else _LANGUAGES
+total_num_failures = 0
 for lang in languages:
   docker_images = find_all_images_for_lang(lang)
   for runtime in sorted(docker_images.keys()):
-    run_tests_for_lang(lang, runtime, docker_images[runtime])
+    total_num_failures += run_tests_for_lang(lang, runtime, docker_images[runtime])
 
 report_utils.create_xml_report_file(_xml_report_tree, args.report_file)
+
+if total_num_failures:
+  sys.exit(1)
+sys.exit(0)
diff --git a/tools/interop_matrix/testcases/cxx__master b/tools/interop_matrix/testcases/cxx__master
index ccd28595301..e0fed53f088 100755
--- a/tools/interop_matrix/testcases/cxx__master
+++ b/tools/interop_matrix/testcases/cxx__master
@@ -1,5 +1,5 @@
 #!/bin/bash
-echo "Testing ${docker_image:=grpc_interop_cxx:1423f288-ac00-4f3a-9885-771258eecae3}"
+echo "Testing ${docker_image:=grpc_interop_cxx:78de6f80-524d-4bc9-bfb2-f00c24ceafed}"
 docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "bins/opt/interop_client --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=large_unary"
 docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "bins/opt/interop_client --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=empty_unary"
 docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "bins/opt/interop_client --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=ping_pong"
@@ -9,3 +9,12 @@ docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c
 docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "bins/opt/interop_client --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=cancel_after_begin"
 docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "bins/opt/interop_client --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=cancel_after_first_response"
 docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "bins/opt/interop_client --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=timeout_on_sleeping_server"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "bins/opt/interop_client --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=large_unary"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "bins/opt/interop_client --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=empty_unary"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "bins/opt/interop_client --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=ping_pong"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "bins/opt/interop_client --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=empty_stream"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "bins/opt/interop_client --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=client_streaming"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "bins/opt/interop_client --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=server_streaming"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "bins/opt/interop_client --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=cancel_after_begin"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "bins/opt/interop_client --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=cancel_after_first_response"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "bins/opt/interop_client --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=timeout_on_sleeping_server"
diff --git a/tools/interop_matrix/testcases/go__master b/tools/interop_matrix/testcases/go__master
index 2624c7f92c5..33b25d6a16b 100755
--- a/tools/interop_matrix/testcases/go__master
+++ b/tools/interop_matrix/testcases/go__master
@@ -1,5 +1,5 @@
 #!/bin/bash
-echo "Testing ${docker_image:=grpc_interop_go:41fffd01-a6c8-41b6-8136-c0aaa1ec2437}"
+echo "Testing ${docker_image:=grpc_interop_go:dd8fbf3a-4964-4387-9997-5dadeea09835}"
 docker run -i --rm=true -w /go/src/google.golang.org/grpc/interop/client --net=host $docker_image bash -c "go run client.go --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=large_unary"
 docker run -i --rm=true -w /go/src/google.golang.org/grpc/interop/client --net=host $docker_image bash -c "go run client.go --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=empty_unary"
 docker run -i --rm=true -w /go/src/google.golang.org/grpc/interop/client --net=host $docker_image bash -c "go run client.go --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=ping_pong"
@@ -9,3 +9,12 @@ docker run -i --rm=true -w /go/src/google.golang.org/grpc/interop/client --net=h
 docker run -i --rm=true -w /go/src/google.golang.org/grpc/interop/client --net=host $docker_image bash -c "go run client.go --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=cancel_after_begin"
 docker run -i --rm=true -w /go/src/google.golang.org/grpc/interop/client --net=host $docker_image bash -c "go run client.go --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=cancel_after_first_response"
 docker run -i --rm=true -w /go/src/google.golang.org/grpc/interop/client --net=host $docker_image bash -c "go run client.go --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=timeout_on_sleeping_server"
+docker run -i --rm=true -w /go/src/google.golang.org/grpc/interop/client --net=host $docker_image bash -c "go run client.go --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=large_unary"
+docker run -i --rm=true -w /go/src/google.golang.org/grpc/interop/client --net=host $docker_image bash -c "go run client.go --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=empty_unary"
+docker run -i --rm=true -w /go/src/google.golang.org/grpc/interop/client --net=host $docker_image bash -c "go run client.go --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=ping_pong"
+docker run -i --rm=true -w /go/src/google.golang.org/grpc/interop/client --net=host $docker_image bash -c "go run client.go --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=empty_stream"
+docker run -i --rm=true -w /go/src/google.golang.org/grpc/interop/client --net=host $docker_image bash -c "go run client.go --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=client_streaming"
+docker run -i --rm=true -w /go/src/google.golang.org/grpc/interop/client --net=host $docker_image bash -c "go run client.go --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=server_streaming"
+docker run -i --rm=true -w /go/src/google.golang.org/grpc/interop/client --net=host $docker_image bash -c "go run client.go --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=cancel_after_begin"
+docker run -i --rm=true -w /go/src/google.golang.org/grpc/interop/client --net=host $docker_image bash -c "go run client.go --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=cancel_after_first_response"
+docker run -i --rm=true -w /go/src/google.golang.org/grpc/interop/client --net=host $docker_image bash -c "go run client.go --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=timeout_on_sleeping_server"
diff --git a/tools/interop_matrix/testcases/java__master b/tools/interop_matrix/testcases/java__master
index cf431646e9a..dbd87279a6d 100755
--- a/tools/interop_matrix/testcases/java__master
+++ b/tools/interop_matrix/testcases/java__master
@@ -1,5 +1,5 @@
 #!/bin/bash
-echo "Testing ${docker_image:=grpc_interop_java:ea528843-be34-4ff3-a136-e4609424e061}"
+echo "Testing ${docker_image:=grpc_interop_java:a764b50c-1788-4387-9b9e-5cfa93927006}"
 docker run -i --rm=true -w /var/local/git/grpc/../grpc-java --net=host $docker_image bash -c "./run-test-client.sh --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=large_unary"
 docker run -i --rm=true -w /var/local/git/grpc/../grpc-java --net=host $docker_image bash -c "./run-test-client.sh --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=empty_unary"
 docker run -i --rm=true -w /var/local/git/grpc/../grpc-java --net=host $docker_image bash -c "./run-test-client.sh --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=ping_pong"
@@ -9,3 +9,12 @@ docker run -i --rm=true -w /var/local/git/grpc/../grpc-java --net=host $docker_i
 docker run -i --rm=true -w /var/local/git/grpc/../grpc-java --net=host $docker_image bash -c "./run-test-client.sh --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=cancel_after_begin"
 docker run -i --rm=true -w /var/local/git/grpc/../grpc-java --net=host $docker_image bash -c "./run-test-client.sh --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=cancel_after_first_response"
 docker run -i --rm=true -w /var/local/git/grpc/../grpc-java --net=host $docker_image bash -c "./run-test-client.sh --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=timeout_on_sleeping_server"
+docker run -i --rm=true -w /var/local/git/grpc/../grpc-java --net=host $docker_image bash -c "./run-test-client.sh --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=large_unary"
+docker run -i --rm=true -w /var/local/git/grpc/../grpc-java --net=host $docker_image bash -c "./run-test-client.sh --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=empty_unary"
+docker run -i --rm=true -w /var/local/git/grpc/../grpc-java --net=host $docker_image bash -c "./run-test-client.sh --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=ping_pong"
+docker run -i --rm=true -w /var/local/git/grpc/../grpc-java --net=host $docker_image bash -c "./run-test-client.sh --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=empty_stream"
+docker run -i --rm=true -w /var/local/git/grpc/../grpc-java --net=host $docker_image bash -c "./run-test-client.sh --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=client_streaming"
+docker run -i --rm=true -w /var/local/git/grpc/../grpc-java --net=host $docker_image bash -c "./run-test-client.sh --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=server_streaming"
+docker run -i --rm=true -w /var/local/git/grpc/../grpc-java --net=host $docker_image bash -c "./run-test-client.sh --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=cancel_after_begin"
+docker run -i --rm=true -w /var/local/git/grpc/../grpc-java --net=host $docker_image bash -c "./run-test-client.sh --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=cancel_after_first_response"
+docker run -i --rm=true -w /var/local/git/grpc/../grpc-java --net=host $docker_image bash -c "./run-test-client.sh --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=timeout_on_sleeping_server"
diff --git a/tools/jenkins/run_full_performance.sh b/tools/jenkins/run_full_performance.sh
index 9598fd77349..195cc68003d 100755
--- a/tools/jenkins/run_full_performance.sh
+++ b/tools/jenkins/run_full_performance.sh
@@ -21,7 +21,7 @@ cd $(dirname $0)/../..
 
 # run 8core client vs 8core server
 tools/run_tests/run_performance_tests.py \
-    -l c++ csharp node ruby java python go node_express php_protobuf_php php_protobuf_c \
+    -l c++ csharp node ruby java python go node_express php7 php7_protobuf_c \
     --netperf \
     --category scalable \
     --bq_result_table performance_test.performance_experiment \
diff --git a/tools/run_tests/generated/sources_and_headers.json b/tools/run_tests/generated/sources_and_headers.json
index 6c2a0cf4166..073a3fef4ca 100644
--- a/tools/run_tests/generated/sources_and_headers.json
+++ b/tools/run_tests/generated/sources_and_headers.json
@@ -99,6 +99,23 @@
     "third_party": false, 
     "type": "target"
   }, 
+  {
+    "deps": [
+      "gpr", 
+      "gpr_test_util", 
+      "grpc", 
+      "grpc_test_util"
+    ], 
+    "headers": [], 
+    "is_filegroup": false, 
+    "language": "c", 
+    "name": "backoff_test", 
+    "src": [
+      "test/core/backoff/backoff_test.c"
+    ], 
+    "third_party": false, 
+    "type": "target"
+  }, 
   {
     "deps": [
       "gpr", 
@@ -726,21 +743,6 @@
     "third_party": false, 
     "type": "target"
   }, 
-  {
-    "deps": [
-      "gpr", 
-      "gpr_test_util"
-    ], 
-    "headers": [], 
-    "is_filegroup": false, 
-    "language": "c", 
-    "name": "gpr_backoff_test", 
-    "src": [
-      "test/core/support/backoff_test.c"
-    ], 
-    "third_party": false, 
-    "type": "target"
-  }, 
   {
     "deps": [
       "gpr", 
@@ -3487,6 +3489,28 @@
     "third_party": false, 
     "type": "target"
   }, 
+  {
+    "deps": [
+      "gpr", 
+      "gpr_test_util", 
+      "grpc", 
+      "grpc++", 
+      "grpc++_test", 
+      "grpc_test_util"
+    ], 
+    "headers": [
+      "test/core/end2end/end2end_tests.h"
+    ], 
+    "is_filegroup": false, 
+    "language": "c++", 
+    "name": "h2_ssl_cert_test", 
+    "src": [
+      "test/core/end2end/end2end_tests.h", 
+      "test/core/end2end/h2_ssl_cert_test.cc"
+    ], 
+    "third_party": false, 
+    "type": "target"
+  }, 
   {
     "deps": [
       "gpr", 
@@ -5285,24 +5309,6 @@
     "third_party": false, 
     "type": "target"
   }, 
-  {
-    "deps": [
-      "end2end_tests", 
-      "gpr", 
-      "gpr_test_util", 
-      "grpc", 
-      "grpc_test_util"
-    ], 
-    "headers": [], 
-    "is_filegroup": false, 
-    "language": "c", 
-    "name": "h2_ssl_cert_test", 
-    "src": [
-      "test/core/end2end/fixtures/h2_ssl_cert.c"
-    ], 
-    "third_party": false, 
-    "type": "target"
-  }, 
   {
     "deps": [
       "end2end_tests", 
@@ -7773,7 +7779,6 @@
       "src/core/lib/support/arena.cc", 
       "src/core/lib/support/atm.cc", 
       "src/core/lib/support/avl.cc", 
-      "src/core/lib/support/backoff.cc", 
       "src/core/lib/support/cmdline.cc", 
       "src/core/lib/support/cpu_iphone.cc", 
       "src/core/lib/support/cpu_linux.cc", 
@@ -7854,8 +7859,6 @@
       "src/core/lib/support/atomic.h", 
       "src/core/lib/support/atomic_with_atm.h", 
       "src/core/lib/support/atomic_with_std.h", 
-      "src/core/lib/support/backoff.h", 
-      "src/core/lib/support/block_annotate.h", 
       "src/core/lib/support/env.h", 
       "src/core/lib/support/memory.h", 
       "src/core/lib/support/mpscq.h", 
@@ -7903,8 +7906,6 @@
       "src/core/lib/support/atomic.h", 
       "src/core/lib/support/atomic_with_atm.h", 
       "src/core/lib/support/atomic_with_std.h", 
-      "src/core/lib/support/backoff.h", 
-      "src/core/lib/support/block_annotate.h", 
       "src/core/lib/support/env.h", 
       "src/core/lib/support/memory.h", 
       "src/core/lib/support/mpscq.h", 
@@ -7997,6 +7998,7 @@
     "language": "c", 
     "name": "grpc_base", 
     "src": [
+      "src/core/lib/backoff/backoff.cc", 
       "src/core/lib/channel/channel_args.cc", 
       "src/core/lib/channel/channel_stack.cc", 
       "src/core/lib/channel/channel_stack_builder.cc", 
@@ -8150,6 +8152,7 @@
       "include/grpc/slice_buffer.h", 
       "include/grpc/status.h", 
       "include/grpc/support/workaround_list.h", 
+      "src/core/lib/backoff/backoff.h", 
       "src/core/lib/channel/channel_args.h", 
       "src/core/lib/channel/channel_stack.h", 
       "src/core/lib/channel/channel_stack_builder.h", 
@@ -8168,6 +8171,7 @@
       "src/core/lib/http/format_request.h", 
       "src/core/lib/http/httpcli.h", 
       "src/core/lib/http/parser.h", 
+      "src/core/lib/iomgr/block_annotate.h", 
       "src/core/lib/iomgr/call_combiner.h", 
       "src/core/lib/iomgr/closure.h", 
       "src/core/lib/iomgr/combiner.h", 
@@ -8283,6 +8287,7 @@
       "include/grpc/slice_buffer.h", 
       "include/grpc/status.h", 
       "include/grpc/support/workaround_list.h", 
+      "src/core/lib/backoff/backoff.h", 
       "src/core/lib/channel/channel_args.h", 
       "src/core/lib/channel/channel_stack.h", 
       "src/core/lib/channel/channel_stack_builder.h", 
@@ -8301,6 +8306,7 @@
       "src/core/lib/http/format_request.h", 
       "src/core/lib/http/httpcli.h", 
       "src/core/lib/http/parser.h", 
+      "src/core/lib/iomgr/block_annotate.h", 
       "src/core/lib/iomgr/call_combiner.h", 
       "src/core/lib/iomgr/closure.h", 
       "src/core/lib/iomgr/combiner.h", 
diff --git a/tools/run_tests/generated/tests.json b/tools/run_tests/generated/tests.json
index 1fefb52f07d..a1644dfa097 100644
--- a/tools/run_tests/generated/tests.json
+++ b/tools/run_tests/generated/tests.json
@@ -21,7 +21,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -43,7 +44,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -65,7 +67,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -87,7 +90,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -109,7 +113,31 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
+  }, 
+  {
+    "args": [], 
+    "ci_platforms": [
+      "linux", 
+      "mac", 
+      "posix", 
+      "windows"
+    ], 
+    "cpu_cost": 1.0, 
+    "exclude_configs": [], 
+    "exclude_iomgrs": [], 
+    "flaky": false, 
+    "gtest": false, 
+    "language": "c", 
+    "name": "backoff_test", 
+    "platforms": [
+      "linux", 
+      "mac", 
+      "posix", 
+      "windows"
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -133,7 +161,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -155,7 +184,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -177,7 +207,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -199,7 +230,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -221,7 +253,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -243,7 +276,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -265,7 +299,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -287,7 +322,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -309,7 +345,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -331,7 +368,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -353,7 +391,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -375,7 +414,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -397,7 +437,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -419,7 +460,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -441,7 +483,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -465,7 +508,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -487,7 +531,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -511,7 +556,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -533,7 +579,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -555,7 +602,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -579,7 +627,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -601,7 +650,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -619,7 +669,8 @@
     "name": "ev_epollsig_linux_test", 
     "platforms": [
       "linux"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -641,7 +692,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -661,7 +713,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -683,7 +736,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -705,7 +759,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -725,7 +780,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -745,7 +801,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -767,7 +824,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -789,29 +847,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
-  }, 
-  {
-    "args": [], 
-    "ci_platforms": [
-      "linux", 
-      "mac", 
-      "posix", 
-      "windows"
     ], 
-    "cpu_cost": 1.0, 
-    "exclude_configs": [], 
-    "exclude_iomgrs": [], 
-    "flaky": false, 
-    "gtest": false, 
-    "language": "c", 
-    "name": "gpr_backoff_test", 
-    "platforms": [
-      "linux", 
-      "mac", 
-      "posix", 
-      "windows"
-    ]
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -833,7 +870,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -855,7 +893,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -877,7 +916,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -899,7 +939,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -921,7 +962,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -943,7 +985,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -965,7 +1008,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": false
   }, 
   {
     "args": [], 
@@ -987,7 +1031,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1009,7 +1054,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1031,7 +1077,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1053,7 +1100,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1075,7 +1123,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1097,7 +1146,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1119,7 +1169,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1141,7 +1192,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1163,7 +1215,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1185,7 +1238,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1207,7 +1261,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1229,7 +1284,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1251,7 +1307,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1273,7 +1330,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1295,7 +1353,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1319,7 +1378,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1341,7 +1401,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1363,7 +1424,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1383,7 +1445,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1405,7 +1468,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1427,7 +1491,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1445,7 +1510,8 @@
     "name": "handshake_client", 
     "platforms": [
       "linux"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1463,7 +1529,8 @@
     "name": "handshake_server", 
     "platforms": [
       "linux"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1485,7 +1552,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1507,7 +1575,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1529,7 +1598,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1551,7 +1621,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1571,7 +1642,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1587,7 +1659,8 @@
     "name": "httpscli_test", 
     "platforms": [
       "linux"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1609,7 +1682,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1631,7 +1705,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1653,7 +1728,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1675,7 +1751,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1697,7 +1774,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1719,7 +1797,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1741,7 +1820,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1761,7 +1841,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1783,7 +1864,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1805,7 +1887,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1827,7 +1910,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1849,7 +1933,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1871,7 +1956,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1893,7 +1979,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1917,7 +2004,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1939,7 +2027,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1961,7 +2050,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -1979,7 +2069,8 @@
     "name": "pollset_set_test", 
     "platforms": [
       "linux"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2001,7 +2092,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2023,7 +2115,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2045,7 +2138,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2067,7 +2161,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2091,7 +2186,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2115,7 +2211,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2137,7 +2234,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2159,7 +2257,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2181,7 +2280,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2203,7 +2303,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2225,7 +2326,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2247,7 +2349,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2269,7 +2372,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2291,7 +2395,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2313,7 +2418,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2333,7 +2439,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2355,7 +2462,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2377,7 +2485,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2399,7 +2508,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2421,7 +2531,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2445,7 +2556,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2467,7 +2579,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2489,7 +2602,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2513,7 +2627,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2535,7 +2650,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2557,7 +2673,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2581,7 +2698,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2605,7 +2723,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2627,7 +2746,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2649,7 +2769,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2671,7 +2792,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2691,7 +2813,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2713,7 +2836,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2735,7 +2859,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2757,7 +2882,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2779,7 +2905,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2801,7 +2928,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [], 
@@ -2823,7 +2951,8 @@
       "mac", 
       "posix", 
       "windows"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [
@@ -2845,7 +2974,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [
@@ -2867,7 +2997,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [
@@ -2889,7 +3020,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [
@@ -2911,7 +3043,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [
@@ -2933,7 +3066,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [
@@ -2955,7 +3089,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [
@@ -2977,7 +3112,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "uses_polling": true
   }, 
   {
     "args": [
@@ -2999,7 +3135,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
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@@ -27723,7 +26609,7 @@
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@@ -30793,260 +29679,7 @@
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-    "exclude_iomgrs": [], 
-    "flaky": false, 
-    "language": "c", 
-    "name": "inproc_test", 
-    "platforms": [
-      "windows", 
-      "linux", 
-      "mac", 
-      "posix"
-    ]
-  }, 
-  {
-    "args": [
-      "request_with_flags"
-    ], 
-    "ci_platforms": [
-      "windows", 
-      "linux", 
-      "mac", 
-      "posix"
-    ], 
-    "cpu_cost": 0.1, 
-    "exclude_configs": [], 
-    "exclude_iomgrs": [], 
-    "flaky": false, 
-    "language": "c", 
-    "name": "inproc_test", 
-    "platforms": [
-      "windows", 
-      "linux", 
-      "mac", 
-      "posix"
-    ]
-  }, 
-  {
-    "args": [
-      "request_with_payload"
-    ], 
-    "ci_platforms": [
-      "windows", 
-      "linux", 
-      "mac", 
-      "posix"
-    ], 
-    "cpu_cost": 0.1, 
-    "exclude_configs": [], 
-    "exclude_iomgrs": [], 
-    "flaky": false, 
-    "language": "c", 
-    "name": "inproc_test", 
-    "platforms": [
-      "windows", 
-      "linux", 
-      "mac", 
-      "posix"
-    ]
-  }, 
-  {
-    "args": [
-      "resource_quota_server"
-    ], 
-    "ci_platforms": [
-      "windows", 
-      "linux", 
-      "mac", 
-      "posix"
-    ], 
-    "cpu_cost": 1.0, 
-    "exclude_configs": [], 
-    "exclude_iomgrs": [], 
-    "flaky": false, 
-    "language": "c", 
-    "name": "inproc_test", 
-    "platforms": [
-      "windows", 
-      "linux", 
-      "mac", 
-      "posix"
-    ]
-  }, 
-  {
-    "args": [
-      "server_finishes_request"
-    ], 
-    "ci_platforms": [
-      "windows", 
-      "linux", 
-      "mac", 
-      "posix"
-    ], 
-    "cpu_cost": 0.1, 
-    "exclude_configs": [], 
-    "exclude_iomgrs": [], 
-    "flaky": false, 
-    "language": "c", 
-    "name": "inproc_test", 
-    "platforms": [
-      "windows", 
-      "linux", 
-      "mac", 
-      "posix"
-    ]
-  }, 
-  {
-    "args": [
-      "shutdown_finishes_calls"
-    ], 
-    "ci_platforms": [
-      "windows", 
-      "linux", 
-      "mac", 
-      "posix"
-    ], 
-    "cpu_cost": 0.1, 
-    "exclude_configs": [], 
-    "exclude_iomgrs": [], 
-    "flaky": false, 
-    "language": "c", 
-    "name": "inproc_test", 
-    "platforms": [
-      "windows", 
-      "linux", 
-      "mac", 
-      "posix"
-    ]
-  }, 
-  {
-    "args": [
-      "shutdown_finishes_tags"
-    ], 
-    "ci_platforms": [
-      "windows", 
-      "linux", 
-      "mac", 
-      "posix"
-    ], 
-    "cpu_cost": 0.1, 
-    "exclude_configs": [], 
-    "exclude_iomgrs": [], 
-    "flaky": false, 
-    "language": "c", 
-    "name": "inproc_test", 
-    "platforms": [
-      "windows", 
-      "linux", 
-      "mac", 
-      "posix"
-    ]
-  }, 
-  {
-    "args": [
-      "simple_cacheable_request"
-    ], 
-    "ci_platforms": [
-      "windows", 
-      "linux", 
-      "mac", 
-      "posix"
-    ], 
-    "cpu_cost": 0.1, 
-    "exclude_configs": [], 
-    "exclude_iomgrs": [], 
-    "flaky": false, 
-    "language": "c", 
-    "name": "inproc_test", 
-    "platforms": [
-      "windows", 
-      "linux", 
-      "mac", 
-      "posix"
-    ]
-  }, 
-  {
-    "args": [
-      "simple_metadata"
-    ], 
-    "ci_platforms": [
-      "windows", 
-      "linux", 
-      "mac", 
-      "posix"
-    ], 
-    "cpu_cost": 1.0, 
-    "exclude_configs": [], 
-    "exclude_iomgrs": [], 
-    "flaky": false, 
-    "language": "c", 
-    "name": "inproc_test", 
-    "platforms": [
-      "windows", 
-      "linux", 
-      "mac", 
-      "posix"
-    ]
-  }, 
-  {
-    "args": [
-      "simple_request"
-    ], 
-    "ci_platforms": [
-      "windows", 
-      "linux", 
-      "mac", 
-      "posix"
-    ], 
-    "cpu_cost": 1.0, 
-    "exclude_configs": [], 
-    "exclude_iomgrs": [], 
-    "flaky": false, 
-    "language": "c", 
-    "name": "inproc_test", 
-    "platforms": [
-      "windows", 
-      "linux", 
-      "mac", 
-      "posix"
-    ]
-  }, 
-  {
-    "args": [
-      "streaming_error_response"
-    ], 
-    "ci_platforms": [
-      "windows", 
-      "linux", 
-      "mac", 
-      "posix"
-    ], 
-    "cpu_cost": 0.1, 
-    "exclude_configs": [], 
-    "exclude_iomgrs": [], 
-    "flaky": false, 
-    "language": "c", 
-    "name": "inproc_test", 
-    "platforms": [
-      "windows", 
-      "linux", 
-      "mac", 
-      "posix"
-    ]
-  }, 
-  {
-    "args": [
-      "trailing_metadata"
+      "registered_call"
     ], 
     "ci_platforms": [
       "windows", 
@@ -31069,7 +29702,53 @@
   }, 
   {
     "args": [
-      "workaround_cronet_compression"
+      "request_with_flags"
+    ], 
+    "ci_platforms": [
+      "windows", 
+      "linux", 
+      "mac", 
+      "posix"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [], 
+    "exclude_iomgrs": [], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "inproc_test", 
+    "platforms": [
+      "windows", 
+      "linux", 
+      "mac", 
+      "posix"
+    ]
+  }, 
+  {
+    "args": [
+      "request_with_payload"
+    ], 
+    "ci_platforms": [
+      "windows", 
+      "linux", 
+      "mac", 
+      "posix"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [], 
+    "exclude_iomgrs": [], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "inproc_test", 
+    "platforms": [
+      "windows", 
+      "linux", 
+      "mac", 
+      "posix"
+    ]
+  }, 
+  {
+    "args": [
+      "resource_quota_server"
     ], 
     "ci_platforms": [
       "windows", 
@@ -31092,7 +29771,7 @@
   }, 
   {
     "args": [
-      "write_buffering"
+      "server_finishes_request"
     ], 
     "ci_platforms": [
       "windows", 
@@ -31115,7 +29794,7 @@
   }, 
   {
     "args": [
-      "write_buffering_at_end"
+      "shutdown_finishes_calls"
     ], 
     "ci_platforms": [
       "windows", 
@@ -31136,6 +29815,167 @@
       "posix"
     ]
   }, 
+  {
+    "args": [
+      "shutdown_finishes_tags"
+    ], 
+    "ci_platforms": [
+      "windows", 
+      "linux", 
+      "mac", 
+      "posix"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [], 
+    "exclude_iomgrs": [], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "inproc_test", 
+    "platforms": [
+      "windows", 
+      "linux", 
+      "mac", 
+      "posix"
+    ]
+  }, 
+  {
+    "args": [
+      "simple_cacheable_request"
+    ], 
+    "ci_platforms": [
+      "windows", 
+      "linux", 
+      "mac", 
+      "posix"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [], 
+    "exclude_iomgrs": [], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "inproc_test", 
+    "platforms": [
+      "windows", 
+      "linux", 
+      "mac", 
+      "posix"
+    ]
+  }, 
+  {
+    "args": [
+      "simple_metadata"
+    ], 
+    "ci_platforms": [
+      "windows", 
+      "linux", 
+      "mac", 
+      "posix"
+    ], 
+    "cpu_cost": 1.0, 
+    "exclude_configs": [], 
+    "exclude_iomgrs": [], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "inproc_test", 
+    "platforms": [
+      "windows", 
+      "linux", 
+      "mac", 
+      "posix"
+    ]
+  }, 
+  {
+    "args": [
+      "simple_request"
+    ], 
+    "ci_platforms": [
+      "windows", 
+      "linux", 
+      "mac", 
+      "posix"
+    ], 
+    "cpu_cost": 1.0, 
+    "exclude_configs": [], 
+    "exclude_iomgrs": [], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "inproc_test", 
+    "platforms": [
+      "windows", 
+      "linux", 
+      "mac", 
+      "posix"
+    ]
+  }, 
+  {
+    "args": [
+      "streaming_error_response"
+    ], 
+    "ci_platforms": [
+      "windows", 
+      "linux", 
+      "mac", 
+      "posix"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [], 
+    "exclude_iomgrs": [], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "inproc_test", 
+    "platforms": [
+      "windows", 
+      "linux", 
+      "mac", 
+      "posix"
+    ]
+  }, 
+  {
+    "args": [
+      "trailing_metadata"
+    ], 
+    "ci_platforms": [
+      "windows", 
+      "linux", 
+      "mac", 
+      "posix"
+    ], 
+    "cpu_cost": 1.0, 
+    "exclude_configs": [], 
+    "exclude_iomgrs": [], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "inproc_test", 
+    "platforms": [
+      "windows", 
+      "linux", 
+      "mac", 
+      "posix"
+    ]
+  }, 
+  {
+    "args": [
+      "workaround_cronet_compression"
+    ], 
+    "ci_platforms": [
+      "windows", 
+      "linux", 
+      "mac", 
+      "posix"
+    ], 
+    "cpu_cost": 1.0, 
+    "exclude_configs": [], 
+    "exclude_iomgrs": [], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "inproc_test", 
+    "platforms": [
+      "windows", 
+      "linux", 
+      "mac", 
+      "posix"
+    ]
+  }, 
   {
     "args": [
       "authority_not_supported"
@@ -49473,52 +48313,6 @@
       "posix"
     ]
   }, 
-  {
-    "args": [
-      "write_buffering"
-    ], 
-    "ci_platforms": [
-      "windows", 
-      "linux", 
-      "mac", 
-      "posix"
-    ], 
-    "cpu_cost": 0.1, 
-    "exclude_configs": [], 
-    "exclude_iomgrs": [], 
-    "flaky": false, 
-    "language": "c", 
-    "name": "inproc_nosec_test", 
-    "platforms": [
-      "windows", 
-      "linux", 
-      "mac", 
-      "posix"
-    ]
-  }, 
-  {
-    "args": [
-      "write_buffering_at_end"
-    ], 
-    "ci_platforms": [
-      "windows", 
-      "linux", 
-      "mac", 
-      "posix"
-    ], 
-    "cpu_cost": 0.1, 
-    "exclude_configs": [], 
-    "exclude_iomgrs": [], 
-    "flaky": false, 
-    "language": "c", 
-    "name": "inproc_nosec_test", 
-    "platforms": [
-      "windows", 
-      "linux", 
-      "mac", 
-      "posix"
-    ]
-  }, 
   {
     "args": [
       "--scenarios_json", 
diff --git a/tools/run_tests/helper_scripts/run_ruby_end2end_tests.sh b/tools/run_tests/helper_scripts/run_ruby_end2end_tests.sh
index 7914b0e29a0..5cfab14fee5 100755
--- a/tools/run_tests/helper_scripts/run_ruby_end2end_tests.sh
+++ b/tools/run_tests/helper_scripts/run_ruby_end2end_tests.sh
@@ -27,4 +27,5 @@ ruby src/ruby/end2end/killed_client_thread_driver.rb || EXIT_CODE=1
 ruby src/ruby/end2end/forking_client_driver.rb || EXIT_CODE=1
 ruby src/ruby/end2end/grpc_class_init_driver.rb || EXIT_CODE=1
 ruby src/ruby/end2end/multiple_killed_watching_threads_driver.rb || EXIT_CODE=1
+ruby src/ruby/end2end/load_grpc_with_gc_stress_driver.rb || EXIT_CODE=1
 exit $EXIT_CODE
diff --git a/tools/run_tests/performance/build_performance.sh b/tools/run_tests/performance/build_performance.sh
index e46d4e00403..e7d8db8e3ea 100755
--- a/tools/run_tests/performance/build_performance.sh
+++ b/tools/run_tests/performance/build_performance.sh
@@ -31,6 +31,7 @@ then
   make CONFIG=${CONFIG} EMBED_OPENSSL=true EMBED_ZLIB=true qps_worker qps_json_driver -j8
 fi
 
+PHP_ALREADY_BUILT=""
 for language in $@
 do
   case "$language" in
@@ -43,6 +44,14 @@ do
   "go")
     tools/run_tests/performance/build_performance_go.sh
     ;;
+  "php7"|"php7_protobuf_c")
+    if [ -n "$PHP_ALREADY_BUILT" ]; then
+      echo "Skipping PHP build as already built by $PHP_ALREADY_BUILT"
+    else
+      PHP_ALREADY_BUILT=$language
+      tools/run_tests/performance/build_performance_php7.sh
+    fi
+    ;;
   "csharp")
     python tools/run_tests/run_tests.py -l $language -c $CONFIG --build_only -j 8 --compiler coreclr
     ;;
diff --git a/tools/internal_ci/linux/grpc_interop_badserver_python.sh b/tools/run_tests/performance/build_performance_php7.sh
similarity index 66%
rename from tools/internal_ci/linux/grpc_interop_badserver_python.sh
rename to tools/run_tests/performance/build_performance_php7.sh
index c2bd4e79ac1..141c9fd1c81 100755
--- a/tools/internal_ci/linux/grpc_interop_badserver_python.sh
+++ b/tools/run_tests/performance/build_performance_php7.sh
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/bin/bash
 # Copyright 2017 gRPC authors.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -15,13 +15,16 @@
 
 set -ex
 
-export LANG=en_US.UTF-8
-
-# Enter the gRPC repo root
 cd $(dirname $0)/../../..
+CONFIG=${CONFIG:-opt}
+python tools/run_tests/run_tests.py -l php7 -c $CONFIG --build_only -j 8
 
-source tools/internal_ci/helper_scripts/prepare_build_linux_rc
-source tools/internal_ci/helper_scripts/prepare_build_interop_rc
-
-tools/run_tests/run_interop_tests.py -l python --use_docker --http2_server_interop
+# Set up all dependences needed for PHP QPS test
+cd src/php/tests/qps
+composer install
+# Install protobuf C-extension for php
+cd vendor/google/protobuf/php/ext/google/protobuf
+phpize
+./configure
+make
 
diff --git a/tools/run_tests/performance/massage_qps_stats.py b/tools/run_tests/performance/massage_qps_stats.py
index 9b9355308a3..ebbfe6c26cd 100644
--- a/tools/run_tests/performance/massage_qps_stats.py
+++ b/tools/run_tests/performance/massage_qps_stats.py
@@ -74,6 +74,7 @@ def massage_qps_stats(scenario_result):
     stats["core_http2_initiate_write_due_to_transport_flow_control_unstalled"] = massage_qps_stats_helpers.counter(core_stats, "http2_initiate_write_due_to_transport_flow_control_unstalled")
     stats["core_http2_initiate_write_due_to_ping_response"] = massage_qps_stats_helpers.counter(core_stats, "http2_initiate_write_due_to_ping_response")
     stats["core_http2_initiate_write_due_to_force_rst_stream"] = massage_qps_stats_helpers.counter(core_stats, "http2_initiate_write_due_to_force_rst_stream")
+    stats["core_http2_spurious_writes_begun"] = massage_qps_stats_helpers.counter(core_stats, "http2_spurious_writes_begun")
     stats["core_hpack_recv_indexed"] = massage_qps_stats_helpers.counter(core_stats, "hpack_recv_indexed")
     stats["core_hpack_recv_lithdr_incidx"] = massage_qps_stats_helpers.counter(core_stats, "hpack_recv_lithdr_incidx")
     stats["core_hpack_recv_lithdr_incidx_v"] = massage_qps_stats_helpers.counter(core_stats, "hpack_recv_lithdr_incidx_v")
diff --git a/tools/run_tests/performance/run_worker_php.sh b/tools/run_tests/performance/run_worker_php.sh
index e524d5286d0..8c7ceef2ff7 100755
--- a/tools/run_tests/performance/run_worker_php.sh
+++ b/tools/run_tests/performance/run_worker_php.sh
@@ -17,17 +17,7 @@ source ~/.rvm/scripts/rvm
 set -ex
 
 cd $(dirname $0)/../../..
-repo=$(pwd)
-# First set up all dependences needed for PHP QPS test
-cd $repo
-cd src/php/tests/qps
-composer install
-# Install protobuf C-extension for php
-cd vendor/google/protobuf/php/ext/google/protobuf
-phpize
-./configure
-make
+
 # The proxy worker for PHP is implemented in Ruby
-cd $repo
 ruby src/ruby/qps/proxy-worker.rb $@
 
diff --git a/tools/run_tests/performance/scenario_config.py b/tools/run_tests/performance/scenario_config.py
index 5019358ab3e..8f01eb4b2aa 100644
--- a/tools/run_tests/performance/scenario_config.py
+++ b/tools/run_tests/performance/scenario_config.py
@@ -800,39 +800,54 @@ class RubyLanguage:
     return 'ruby'
 
 
-class PhpLanguage:
+class Php7Language:
 
-  def __init__(self, use_protobuf_c_extension=False):
+  def __init__(self, php7_protobuf_c=False):
     pass
-    self.use_protobuf_c_extension=use_protobuf_c_extension
+    self.php7_protobuf_c=php7_protobuf_c
     self.safename = str(self)
 
   def worker_cmdline(self):
-    if self.use_protobuf_c_extension:
-        return ['tools/run_tests/performance/run_worker_php.sh -c']
+    if self.php7_protobuf_c:
+        return ['tools/run_tests/performance/run_worker_php.sh --use_protobuf_c_extension']
     return ['tools/run_tests/performance/run_worker_php.sh']
 
   def worker_port_offset(self):
+    if self.php7_protobuf_c:
+        return 900
     return 800
 
   def scenarios(self):
-    php_extension_mode='php_protobuf_php_extension'
-    if self.use_protobuf_c_extension:
-        php_extension_mode='php_protobuf_c_extension'
+    php7_extension_mode='php7_protobuf_php_extension'
+    if self.php7_protobuf_c:
+        php7_extension_mode='php7_protobuf_c_extension'
     
     yield _ping_pong_scenario(
-        '%s_to_cpp_protobuf_sync_unary_ping_pong' % php_extension_mode, 
+        '%s_to_cpp_protobuf_sync_unary_ping_pong' % php7_extension_mode,
         rpc_type='UNARY', client_type='SYNC_CLIENT', server_type='SYNC_SERVER',
         server_language='c++', async_server_threads=1)
 
     yield _ping_pong_scenario(
-        '%s_to_cpp_protobuf_sync_streaming_ping_pong' % php_extension_mode, 
+        '%s_to_cpp_protobuf_sync_streaming_ping_pong' % php7_extension_mode,
         rpc_type='STREAMING', client_type='SYNC_CLIENT', server_type='SYNC_SERVER',
         server_language='c++', async_server_threads=1)
 
-  def __str__(self):
-    return 'php'
+    # TODO(ddyihai): Investigate why when async_server_threads=1/CPU usage 340%, the QPS performs
+    # better than async_server_threads=0/CPU usage 490%.
+    yield _ping_pong_scenario(
+        '%s_to_cpp_protobuf_sync_unary_qps_unconstrained' % php7_extension_mode,
+        rpc_type='UNARY', client_type='SYNC_CLIENT', server_type='ASYNC_SERVER',
+        server_language='c++', outstanding=1, async_server_threads=1, unconstrained_client='sync')
 
+    yield _ping_pong_scenario(
+        '%s_to_cpp_protobuf_sync_streaming_qps_unconstrained' % php7_extension_mode,
+        rpc_type='STREAMING', client_type='SYNC_CLIENT', server_type='ASYNC_SERVER',
+        server_language='c++', outstanding=1, async_server_threads=1, unconstrained_client='sync')
+
+  def __str__(self):
+    if self.php7_protobuf_c:
+        return 'php7_protobuf_c'
+    return 'php7'
 
 class JavaLanguage:
 
@@ -1031,8 +1046,8 @@ LANGUAGES = {
     'node' : NodeLanguage(),
     'node_express': NodeExpressLanguage(),
     'ruby' : RubyLanguage(),
-    'php_protobuf_php' : PhpLanguage(),
-    'php_protobuf_c' : PhpLanguage(use_protobuf_c_extension=True),
+    'php7' : Php7Language(),
+    'php7_protobuf_c' : Php7Language(php7_protobuf_c=True),
     'java' : JavaLanguage(),
     'python' : PythonLanguage(),
     'go' : GoLanguage(),
diff --git a/tools/run_tests/performance/scenario_result_schema.json b/tools/run_tests/performance/scenario_result_schema.json
index 2f0fd916d4f..169221d18c5 100644
--- a/tools/run_tests/performance/scenario_result_schema.json
+++ b/tools/run_tests/performance/scenario_result_schema.json
@@ -380,6 +380,11 @@
         "name": "core_http2_initiate_write_due_to_force_rst_stream", 
         "type": "INTEGER"
       }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_spurious_writes_begun", 
+        "type": "INTEGER"
+      }, 
       {
         "mode": "NULLABLE", 
         "name": "core_hpack_recv_indexed", 
@@ -1172,6 +1177,11 @@
         "name": "core_http2_initiate_write_due_to_force_rst_stream", 
         "type": "INTEGER"
       }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_spurious_writes_begun", 
+        "type": "INTEGER"
+      }, 
       {
         "mode": "NULLABLE", 
         "name": "core_hpack_recv_indexed", 
diff --git a/tools/run_tests/python_utils/jobset.py b/tools/run_tests/python_utils/jobset.py
index 82a3bc14352..658b814d81f 100755
--- a/tools/run_tests/python_utils/jobset.py
+++ b/tools/run_tests/python_utils/jobset.py
@@ -306,8 +306,8 @@ class Job(object):
         else:
           self._state = _FAILURE
           if not self._suppress_failure_message:
-            message('FAILED', '%s [ret=%d, pid=%d]' % (
-                self._spec.shortname, self._process.returncode, self._process.pid),
+            message('FAILED', '%s [ret=%d, pid=%d, time=%.1fsec]' % (
+                self._spec.shortname, self._process.returncode, self._process.pid, elapsed),
                 stdout(), do_newline=True)
           self.result.state = 'FAILED'
           self.result.num_failures += 1
@@ -326,7 +326,7 @@ class Job(object):
             self.result.cpu_estimated = float('%.01f' % self._spec.cpu_cost)
             measurement = '; cpu_cost=%.01f; estimated=%.01f' % (self.result.cpu_measured, self.result.cpu_estimated)
         if not self._quiet_success:
-          message('PASSED', '%s [time=%.1fsec; retries=%d:%d%s]' % (
+          message('PASSED', '%s [time=%.1fsec, retries=%d:%d%s]' % (
               self._spec.shortname, elapsed, self._retries, self._timeout_retries, measurement),
               stdout() if self._spec.verbose_success else None,
               do_newline=self._newline_on_success or self._travis)
@@ -334,6 +334,8 @@ class Job(object):
     elif (self._state == _RUNNING and
           self._spec.timeout_seconds is not None and
           time.time() - self._start > self._spec.timeout_seconds):
+      elapsed = time.time() - self._start
+      self.result.elapsed_time = elapsed
       if self._timeout_retries < self._spec.timeout_retries:
         message('TIMEOUT_FLAKE', '%s [pid=%d]' % (self._spec.shortname, self._process.pid), stdout(), do_newline=True)
         self._timeout_retries += 1
@@ -344,7 +346,7 @@ class Job(object):
         self._process.terminate()
         self.start()
       else:
-        message('TIMEOUT', '%s [pid=%d]' % (self._spec.shortname, self._process.pid), stdout(), do_newline=True)
+        message('TIMEOUT', '%s [pid=%d, time=%.1fsec]' % (self._spec.shortname, self._process.pid, elapsed), stdout(), do_newline=True)
         self.kill()
         self.result.state = 'TIMEOUT'
         self.result.num_failures += 1
@@ -410,7 +412,7 @@ class Jobset(object):
       if current_cpu_cost + spec.cpu_cost <= self._maxjobs:
         if len(self._running) < self._maxjobs_cpu_agnostic:
           break
-      self.reap()
+      self.reap(spec.shortname, spec.cpu_cost)
     if self.cancelled(): return False
     job = Job(spec,
               self._newline_on_success,
@@ -422,7 +424,7 @@ class Jobset(object):
       self.resultset[job.GetSpec().shortname] = []
     return True
 
-  def reap(self):
+  def reap(self, waiting_for=None, waiting_for_cost=None):
     """Collect the dead jobs."""
     while self._running:
       dead = set()
@@ -450,8 +452,12 @@ class Jobset(object):
           sofar = now - self._start_time
           remaining = sofar / self._completed * (self._remaining + len(self._running))
           rstr = 'ETA %.1f sec; %s' % (remaining, rstr)
-        message('WAITING', '%s%d jobs running, %d complete, %d failed' % (
-            rstr, len(self._running), self._completed, self._failures))
+        if waiting_for is not None:
+          wstr = ' next: %s @ %.2f cpu' % (waiting_for, waiting_for_cost)
+        else:
+          wstr = ''
+        message('WAITING', '%s%d jobs running, %d complete, %d failed (load %.2f)%s' % (
+            rstr, len(self._running), self._completed, self._failures, self.cpu_cost(), wstr))
       if platform_string() == 'windows':
         time.sleep(0.1)
       else:
diff --git a/tools/run_tests/python_utils/upload_test_results.py b/tools/run_tests/python_utils/upload_test_results.py
index 580e7f7d810..ea97bc0aec1 100644
--- a/tools/run_tests/python_utils/upload_test_results.py
+++ b/tools/run_tests/python_utils/upload_test_results.py
@@ -51,6 +51,19 @@ _RESULTS_SCHEMA = [
   ('cpu_measured', 'FLOAT', 'Actual CPU usage of test'),
   ('return_code', 'INTEGER', 'Exit code of test'),
 ]
+_INTEROP_RESULTS_SCHEMA = [
+  ('job_name', 'STRING', 'Name of Jenkins/Kokoro job'),
+  ('build_id', 'INTEGER', 'Build ID of Jenkins/Kokoro job'),
+  ('build_url', 'STRING', 'URL of Jenkins/Kokoro job'),
+  ('test_name', 'STRING', 'Unique test name combining client, server, and test_name'),
+  ('suite', 'STRING', 'Test suite: cloud_to_cloud, cloud_to_prod, or cloud_to_prod_auth'),
+  ('client', 'STRING', 'Client language'),
+  ('server', 'STRING', 'Server host name'),
+  ('test_case', 'STRING', 'Name of test case'),
+  ('result', 'STRING', 'Test result: PASSED, TIMEOUT, FAILED, or SKIPPED'),
+  ('timestamp', 'TIMESTAMP', 'Timestamp of test run'),
+  ('elapsed_time', 'FLOAT', 'How long test took to run'),
+]
 
 
 def _get_build_metadata(test_results):
@@ -102,6 +115,53 @@ def upload_results_to_bq(resultset, bq_table, args, platform):
       test_results['timestamp'] = time.strftime('%Y-%m-%d %H:%M:%S')
 
       row = big_query_utils.make_row(str(uuid.uuid4()), test_results)
-      if not big_query_utils.insert_rows(bq, _PROJECT_ID, _DATASET_ID, bq_table, [row]):
-        print('Error uploading result to bigquery.')
-        sys.exit(1)
+
+      # TODO(jtattermusch): rows are inserted one by one, very inefficient
+      max_retries = 3
+      for attempt in range(max_retries):
+        if big_query_utils.insert_rows(bq, _PROJECT_ID, _DATASET_ID, bq_table, [row]):
+          break
+        else:
+          if attempt < max_retries - 1:
+            print('Error uploading result to bigquery, will retry.')
+          else:
+            print('Error uploading result to bigquery, all attempts failed.')
+            sys.exit(1)
+
+
+def upload_interop_results_to_bq(resultset, bq_table, args):
+  """Upload interop test results to a BQ table.
+
+  Args:
+      resultset: dictionary generated by jobset.run
+      bq_table: string name of table to create/upload results to in BQ
+      args: args in run_interop_tests.py, generated by argparse
+  """
+  bq = big_query_utils.create_big_query()
+  big_query_utils.create_partitioned_table(bq, _PROJECT_ID, _DATASET_ID, bq_table, _INTEROP_RESULTS_SCHEMA, _DESCRIPTION,
+                                           partition_type=_PARTITION_TYPE, expiration_ms= _EXPIRATION_MS)
+
+  for shortname, results in six.iteritems(resultset):
+    for result in results:
+      test_results = {}
+      _get_build_metadata(test_results)
+      test_results['elapsed_time'] = '%.2f' % result.elapsed_time
+      test_results['result'] = result.state
+      test_results['test_name'] = shortname
+      test_results['suite'] = shortname.split(':')[0]
+      test_results['client'] = shortname.split(':')[1]
+      test_results['server'] = shortname.split(':')[2]
+      test_results['test_case'] = shortname.split(':')[3]
+      test_results['timestamp'] = time.strftime('%Y-%m-%d %H:%M:%S')
+      row = big_query_utils.make_row(str(uuid.uuid4()), test_results)
+      # TODO(jtattermusch): rows are inserted one by one, very inefficient
+      max_retries = 3
+      for attempt in range(max_retries):
+        if big_query_utils.insert_rows(bq, _PROJECT_ID, _DATASET_ID, bq_table, [row]):
+          break
+        else:
+          if attempt < max_retries - 1:
+            print('Error uploading result to bigquery, will retry.')
+          else:
+            print('Error uploading result to bigquery, all attempts failed.')
+            sys.exit(1)
diff --git a/tools/run_tests/run_interop_tests.py b/tools/run_tests/run_interop_tests.py
index 1537641aee9..192f8e76eb4 100755
--- a/tools/run_tests/run_interop_tests.py
+++ b/tools/run_tests/run_interop_tests.py
@@ -35,6 +35,11 @@ import traceback
 import python_utils.dockerjob as dockerjob
 import python_utils.jobset as jobset
 import python_utils.report_utils as report_utils
+# It's ok to not import because this is only necessary to upload results to BQ.
+try:
+  from python_utils.upload_test_results import upload_interop_results_to_bq
+except ImportError as e:
+  print(e)
 
 # Docker doesn't clean up after itself, so we do it on exit.
 atexit.register(lambda: subprocess.call(['stty', 'echo']))
@@ -956,6 +961,11 @@ argp.add_argument('--internal_ci',
                   const=True,
                   help=('Put reports into subdirectories to improve '
                         'presentation of results by Internal CI.'))
+argp.add_argument('--bq_result_table',
+                  default='',
+                  type=str,
+                  nargs='?',
+                  help='Upload test results to a specified BQ table.')
 args = argp.parse_args()
 
 servers = set(s for s in itertools.chain.from_iterable(_SERVERS
@@ -1205,6 +1215,8 @@ try:
   num_failures, resultset = jobset.run(jobs, newline_on_success=True,
                                        maxjobs=args.jobs,
                                        skip_jobs=args.manual_run)
+  if args.bq_result_table and resultset:
+    upload_interop_results_to_bq(resultset, args.bq_result_table, args)
   if num_failures:
     jobset.message('FAILED', 'Some tests failed', do_newline=True)
   else:
diff --git a/tools/run_tests/run_tests.py b/tools/run_tests/run_tests.py
index 1c416798277..ea21c81875d 100755
--- a/tools/run_tests/run_tests.py
+++ b/tools/run_tests/run_tests.py
@@ -286,7 +286,7 @@ class CLanguage(object):
         continue
       polling_strategies = (_POLLING_STRATEGIES.get(self.platform, ['all'])
                             if target.get('uses_polling', True)
-                            else ['all'])
+                            else ['none'])
       if self.args.iomgr_platform == 'uv':
         polling_strategies = ['all']
       for polling_strategy in polling_strategies:
@@ -1551,8 +1551,11 @@ class BuildAndRunError(object):
 
 
 def _has_epollexclusive():
+  binary = 'bins/%s/check_epollexclusive' % args.config
+  if not os.path.exists(binary):
+    return False
   try:
-    subprocess.check_call('bins/%s/check_epollexclusive' % args.config)
+    subprocess.check_call(binary)
     return True
   except subprocess.CalledProcessError, e:
     return False