Merge branch 'master' of https://github.com/grpc/grpc into channelz-subchannels

.github/CODEOWNERS

@@ -3,7 +3,7 @@
 # repository as the source of truth for module ownership.
 /**/OWNERS @markdroth @nicolasnoble @a11r
 /bazel/** @nicolasnoble @dgquintas @a11r @vjpai
-/cmake/** @jtattermusch @nicolasnoble @matt-kwong
+/cmake/** @jtattermusch @nicolasnoble @mehrdada
 /src/core/ext/filters/client_channel/** @markdroth @dgquintas @AspirinSJL
-/tools/dockerfile/** @jtattermusch @matt-kwong @nicolasnoble
-/tools/run_tests/performance/** @ncteisen @matt-kwong @jtattermusch
+/tools/dockerfile/** @jtattermusch @mehrdada @nicolasnoble
+/tools/run_tests/performance/** @ncteisen @apolcyn @jtattermusch

.github/mergeable.yml

@@ -1,6 +1,14 @@
 mergeable:
   pull_requests:
     label:
-      must_include:
-        regex: "release notes: yes|release notes: no"
-        message: "Add release notes yes/no label. For yes, add lang label"
+      or:
+        - and:
+          - must_include:
+              regex: 'release notes: yes'
+              message: 'Please include release note: yes'
+          - must_include:
+              regex: '^lang\/'
+              message: 'Please include a language label'
+        - must_include:
+            regex: 'release notes: no'
+            message: 'Please include release note: no'

BUILD

@@ -1499,6 +1499,8 @@ grpc_cc_library(
         "src/core/lib/security/credentials/plugin/plugin_credentials.cc",
         "src/core/lib/security/credentials/ssl/ssl_credentials.cc",
         "src/core/lib/security/security_connector/alts_security_connector.cc",
+        "src/core/lib/security/security_connector/load_system_roots_fallback.cc",
+        "src/core/lib/security/security_connector/load_system_roots_linux.cc",
         "src/core/lib/security/security_connector/local_security_connector.cc",
         "src/core/lib/security/security_connector/security_connector.cc",
         "src/core/lib/security/transport/client_auth_filter.cc",
@@ -1527,6 +1529,8 @@ grpc_cc_library(
         "src/core/lib/security/credentials/plugin/plugin_credentials.h",
         "src/core/lib/security/credentials/ssl/ssl_credentials.h",
         "src/core/lib/security/security_connector/alts_security_connector.h",
+        "src/core/lib/security/security_connector/load_system_roots.h",
+        "src/core/lib/security/security_connector/load_system_roots_linux.h",
         "src/core/lib/security/security_connector/local_security_connector.h",
         "src/core/lib/security/security_connector/security_connector.h",
         "src/core/lib/security/transport/auth_filters.h",

CMakeLists.txt

@@ -100,6 +100,8 @@ if (MSVC)
   add_definitions(-D_WIN32_WINNT=0x600 -D_SCL_SECURE_NO_WARNINGS -D_CRT_SECURE_NO_WARNINGS -D_WINSOCK_DEPRECATED_NO_WARNINGS)
   # needed to compile protobuf
   add_definitions(/wd4065 /wd4506)
+  # TODO(jtattermusch): revisit warnings that were silenced as part of upgrade to protobuf3.6.0
+  add_definitions(/wd4200 /wd4291 /wd4244)
   # TODO(jtattermusch): revisit C4267 occurrences throughout the code
   add_definitions(/wd4267)
   # TODO(jtattermusch): needed to build boringssl with VS2017, revisit later
@@ -579,6 +581,7 @@ add_dependencies(buildtests_cxx generic_end2end_test)
 add_dependencies(buildtests_cxx golden_file_test)
 add_dependencies(buildtests_cxx grpc_alts_credentials_options_test)
 add_dependencies(buildtests_cxx grpc_cli)
+add_dependencies(buildtests_cxx grpc_linux_system_roots_test)
 add_dependencies(buildtests_cxx grpc_tool_test)
 add_dependencies(buildtests_cxx grpclb_api_test)
 add_dependencies(buildtests_cxx grpclb_end2end_test)
@@ -660,12 +663,8 @@ add_dependencies(buildtests_cxx transport_security_common_api_test)
 if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
 add_dependencies(buildtests_cxx writes_per_rpc_test)
 endif()
-if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
 add_dependencies(buildtests_cxx resolver_component_test_unsecure)
-endif()
-if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
 add_dependencies(buildtests_cxx resolver_component_test)
-endif()
 if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
 add_dependencies(buildtests_cxx resolver_component_tests_runner_invoker_unsecure)
 endif()
@@ -674,9 +673,7 @@ add_dependencies(buildtests_cxx resolver_component_tests_runner_invoker)
 endif()
 add_dependencies(buildtests_cxx address_sorting_test_unsecure)
 add_dependencies(buildtests_cxx address_sorting_test)
-if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
 add_dependencies(buildtests_cxx cancel_ares_query_test)
-endif()
 
 add_custom_target(buildtests
   DEPENDS buildtests_c buildtests_cxx)
@@ -1133,6 +1130,8 @@ add_library(grpc
   src/core/lib/security/credentials/plugin/plugin_credentials.cc
   src/core/lib/security/credentials/ssl/ssl_credentials.cc
   src/core/lib/security/security_connector/alts_security_connector.cc
+  src/core/lib/security/security_connector/load_system_roots_fallback.cc
+  src/core/lib/security/security_connector/load_system_roots_linux.cc
   src/core/lib/security/security_connector/local_security_connector.cc
   src/core/lib/security/security_connector/security_connector.cc
   src/core/lib/security/transport/client_auth_filter.cc
@@ -1563,6 +1562,8 @@ add_library(grpc_cronet
   src/core/lib/security/credentials/plugin/plugin_credentials.cc
   src/core/lib/security/credentials/ssl/ssl_credentials.cc
   src/core/lib/security/security_connector/alts_security_connector.cc
+  src/core/lib/security/security_connector/load_system_roots_fallback.cc
+  src/core/lib/security/security_connector/load_system_roots_linux.cc
   src/core/lib/security/security_connector/local_security_connector.cc
   src/core/lib/security/security_connector/security_connector.cc
   src/core/lib/security/transport/client_auth_filter.cc
@@ -12150,6 +12151,44 @@ if (gRPC_INSTALL)
 endif()
 
 endif (gRPC_BUILD_CODEGEN)
+if (gRPC_BUILD_TESTS)
+
+add_executable(grpc_linux_system_roots_test
+  test/core/security/linux_system_roots_test.cc
+  third_party/googletest/googletest/src/gtest-all.cc
+  third_party/googletest/googlemock/src/gmock-all.cc
+)
+
+
+target_include_directories(grpc_linux_system_roots_test
+  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}
+  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/include
+  PRIVATE ${_gRPC_SSL_INCLUDE_DIR}
+  PRIVATE ${_gRPC_PROTOBUF_INCLUDE_DIR}
+  PRIVATE ${_gRPC_ZLIB_INCLUDE_DIR}
+  PRIVATE ${_gRPC_BENCHMARK_INCLUDE_DIR}
+  PRIVATE ${_gRPC_CARES_INCLUDE_DIR}
+  PRIVATE ${_gRPC_GFLAGS_INCLUDE_DIR}
+  PRIVATE ${_gRPC_ADDRESS_SORTING_INCLUDE_DIR}
+  PRIVATE ${_gRPC_NANOPB_INCLUDE_DIR}
+  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(grpc_linux_system_roots_test
+  ${_gRPC_PROTOBUF_LIBRARIES}
+  ${_gRPC_ALLTARGETS_LIBRARIES}
+  grpc_test_util
+  grpc
+  gpr_test_util
+  gpr
+  ${_gRPC_GFLAGS_LIBRARIES}
+)
+
+endif (gRPC_BUILD_TESTS)
 if (gRPC_BUILD_CODEGEN)
 
 add_executable(grpc_node_plugin
@@ -16211,7 +16250,6 @@ target_link_libraries(inproc_nosec_test
 
 endif (gRPC_BUILD_TESTS)
 if (gRPC_BUILD_TESTS)
-if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
 
 add_executable(resolver_component_test_unsecure
   test/cpp/naming/resolver_component_test.cc
@@ -16251,10 +16289,8 @@ target_link_libraries(resolver_component_test_unsecure
   ${_gRPC_GFLAGS_LIBRARIES}
 )
 
-endif()
 endif (gRPC_BUILD_TESTS)
 if (gRPC_BUILD_TESTS)
-if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
 
 add_executable(resolver_component_test
   test/cpp/naming/resolver_component_test.cc
@@ -16294,7 +16330,6 @@ target_link_libraries(resolver_component_test
   ${_gRPC_GFLAGS_LIBRARIES}
 )
 
-endif()
 endif (gRPC_BUILD_TESTS)
 if (gRPC_BUILD_TESTS)
 if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
@@ -16465,7 +16500,6 @@ target_link_libraries(address_sorting_test
 
 endif (gRPC_BUILD_TESTS)
 if (gRPC_BUILD_TESTS)
-if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
 
 add_executable(cancel_ares_query_test
   test/cpp/naming/cancel_ares_query_test.cc
@@ -16505,7 +16539,6 @@ target_link_libraries(cancel_ares_query_test
   ${_gRPC_GFLAGS_LIBRARIES}
 )
 
-endif()
 endif (gRPC_BUILD_TESTS)
 if (gRPC_BUILD_TESTS)
 

Makefile

@@ -1170,6 +1170,7 @@ grpc_alts_credentials_options_test: $(BINDIR)/$(CONFIG)/grpc_alts_credentials_op
 grpc_cli: $(BINDIR)/$(CONFIG)/grpc_cli
 grpc_cpp_plugin: $(BINDIR)/$(CONFIG)/grpc_cpp_plugin
 grpc_csharp_plugin: $(BINDIR)/$(CONFIG)/grpc_csharp_plugin
+grpc_linux_system_roots_test: $(BINDIR)/$(CONFIG)/grpc_linux_system_roots_test
 grpc_node_plugin: $(BINDIR)/$(CONFIG)/grpc_node_plugin
 grpc_objective_c_plugin: $(BINDIR)/$(CONFIG)/grpc_objective_c_plugin
 grpc_php_plugin: $(BINDIR)/$(CONFIG)/grpc_php_plugin
@@ -1670,6 +1671,7 @@ buildtests_cxx: privatelibs_cxx \
   $(BINDIR)/$(CONFIG)/golden_file_test \
   $(BINDIR)/$(CONFIG)/grpc_alts_credentials_options_test \
   $(BINDIR)/$(CONFIG)/grpc_cli \
+  $(BINDIR)/$(CONFIG)/grpc_linux_system_roots_test \
   $(BINDIR)/$(CONFIG)/grpc_tool_test \
   $(BINDIR)/$(CONFIG)/grpclb_api_test \
   $(BINDIR)/$(CONFIG)/grpclb_end2end_test \
@@ -1849,6 +1851,7 @@ buildtests_cxx: privatelibs_cxx \
   $(BINDIR)/$(CONFIG)/golden_file_test \
   $(BINDIR)/$(CONFIG)/grpc_alts_credentials_options_test \
   $(BINDIR)/$(CONFIG)/grpc_cli \
+  $(BINDIR)/$(CONFIG)/grpc_linux_system_roots_test \
   $(BINDIR)/$(CONFIG)/grpc_tool_test \
   $(BINDIR)/$(CONFIG)/grpclb_api_test \
   $(BINDIR)/$(CONFIG)/grpclb_end2end_test \
@@ -2316,6 +2319,8 @@ test_cxx: buildtests_cxx
 	$(Q) $(BINDIR)/$(CONFIG)/golden_file_test || ( echo test golden_file_test failed ; exit 1 )
 	$(E) "[RUN]     Testing grpc_alts_credentials_options_test"
 	$(Q) $(BINDIR)/$(CONFIG)/grpc_alts_credentials_options_test || ( echo test grpc_alts_credentials_options_test failed ; exit 1 )
+	$(E) "[RUN]     Testing grpc_linux_system_roots_test"
+	$(Q) $(BINDIR)/$(CONFIG)/grpc_linux_system_roots_test || ( echo test grpc_linux_system_roots_test failed ; exit 1 )
 	$(E) "[RUN]     Testing grpc_tool_test"
 	$(Q) $(BINDIR)/$(CONFIG)/grpc_tool_test || ( echo test grpc_tool_test failed ; exit 1 )
 	$(E) "[RUN]     Testing grpclb_api_test"
@@ -3608,6 +3613,8 @@ LIBGRPC_SRC = \
     src/core/lib/security/credentials/plugin/plugin_credentials.cc \
     src/core/lib/security/credentials/ssl/ssl_credentials.cc \
     src/core/lib/security/security_connector/alts_security_connector.cc \
+    src/core/lib/security/security_connector/load_system_roots_fallback.cc \
+    src/core/lib/security/security_connector/load_system_roots_linux.cc \
     src/core/lib/security/security_connector/local_security_connector.cc \
     src/core/lib/security/security_connector/security_connector.cc \
     src/core/lib/security/transport/client_auth_filter.cc \
@@ -4037,6 +4044,8 @@ LIBGRPC_CRONET_SRC = \
     src/core/lib/security/credentials/plugin/plugin_credentials.cc \
     src/core/lib/security/credentials/ssl/ssl_credentials.cc \
     src/core/lib/security/security_connector/alts_security_connector.cc \
+    src/core/lib/security/security_connector/load_system_roots_fallback.cc \
+    src/core/lib/security/security_connector/load_system_roots_linux.cc \
     src/core/lib/security/security_connector/local_security_connector.cc \
     src/core/lib/security/security_connector/security_connector.cc \
     src/core/lib/security/transport/client_auth_filter.cc \
@@ -17907,6 +17916,49 @@ ifneq ($(NO_DEPS),true)
 endif
 
 
+GRPC_LINUX_SYSTEM_ROOTS_TEST_SRC = \
+    test/core/security/linux_system_roots_test.cc \
+
+GRPC_LINUX_SYSTEM_ROOTS_TEST_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(GRPC_LINUX_SYSTEM_ROOTS_TEST_SRC))))
+ifeq ($(NO_SECURE),true)
+
+# You can't build secure targets if you don't have OpenSSL.
+
+$(BINDIR)/$(CONFIG)/grpc_linux_system_roots_test: openssl_dep_error
+
+else
+
+
+
+
+ifeq ($(NO_PROTOBUF),true)
+
+# You can't build the protoc plugins or protobuf-enabled targets if you don't have protobuf 3.5.0+.
+
+$(BINDIR)/$(CONFIG)/grpc_linux_system_roots_test: protobuf_dep_error
+
+else
+
+$(BINDIR)/$(CONFIG)/grpc_linux_system_roots_test: $(PROTOBUF_DEP) $(GRPC_LINUX_SYSTEM_ROOTS_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) $(LDXX) $(LDFLAGS) $(GRPC_LINUX_SYSTEM_ROOTS_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgrpc_test_util.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)/grpc_linux_system_roots_test
+
+endif
+
+endif
+
+$(OBJDIR)/$(CONFIG)/test/core/security/linux_system_roots_test.o:  $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a
+
+deps_grpc_linux_system_roots_test: $(GRPC_LINUX_SYSTEM_ROOTS_TEST_OBJS:.o=.dep)
+
+ifneq ($(NO_SECURE),true)
+ifneq ($(NO_DEPS),true)
+-include $(GRPC_LINUX_SYSTEM_ROOTS_TEST_OBJS:.o=.dep)
+endif
+endif
+
+
 GRPC_NODE_PLUGIN_SRC = \
     src/compiler/node_plugin.cc \
 
@@ -24651,6 +24703,8 @@ src/core/lib/security/credentials/oauth2/oauth2_credentials.cc: $(OPENSSL_DEP)
 src/core/lib/security/credentials/plugin/plugin_credentials.cc: $(OPENSSL_DEP)
 src/core/lib/security/credentials/ssl/ssl_credentials.cc: $(OPENSSL_DEP)
 src/core/lib/security/security_connector/alts_security_connector.cc: $(OPENSSL_DEP)
+src/core/lib/security/security_connector/load_system_roots_fallback.cc: $(OPENSSL_DEP)
+src/core/lib/security/security_connector/load_system_roots_linux.cc: $(OPENSSL_DEP)
 src/core/lib/security/security_connector/local_security_connector.cc: $(OPENSSL_DEP)
 src/core/lib/security/security_connector/security_connector.cc: $(OPENSSL_DEP)
 src/core/lib/security/transport/client_auth_filter.cc: $(OPENSSL_DEP)

bazel/grpc_deps.bzl

@@ -116,9 +116,9 @@ def grpc_deps():
     if "com_google_protobuf" not in native.existing_rules():
         native.http_archive(
             name = "com_google_protobuf",
-            strip_prefix = "protobuf-b5fbb742af122b565925987e65c08957739976a7",
-            url = "https://github.com/google/protobuf/archive/b5fbb742af122b565925987e65c08957739976a7.tar.gz",
-            )
+            strip_prefix = "protobuf-48cb18e5c419ddd23d9badcfe4e9df7bde1979b2",
+            url = "https://github.com/google/protobuf/archive/48cb18e5c419ddd23d9badcfe4e9df7bde1979b2.tar.gz",
+        )
 
     if "com_github_nanopb_nanopb" not in native.existing_rules():
         native.new_http_archive(

build.yaml

@@ -792,6 +792,8 @@ filegroups:
   - src/core/lib/security/credentials/plugin/plugin_credentials.h
   - src/core/lib/security/credentials/ssl/ssl_credentials.h
   - src/core/lib/security/security_connector/alts_security_connector.h
+  - src/core/lib/security/security_connector/load_system_roots.h
+  - src/core/lib/security/security_connector/load_system_roots_linux.h
   - src/core/lib/security/security_connector/local_security_connector.h
   - src/core/lib/security/security_connector/security_connector.h
   - src/core/lib/security/transport/auth_filters.h
@@ -819,6 +821,8 @@ filegroups:
   - src/core/lib/security/credentials/plugin/plugin_credentials.cc
   - src/core/lib/security/credentials/ssl/ssl_credentials.cc
   - src/core/lib/security/security_connector/alts_security_connector.cc
+  - src/core/lib/security/security_connector/load_system_roots_fallback.cc
+  - src/core/lib/security/security_connector/load_system_roots_linux.cc
   - src/core/lib/security/security_connector/local_security_connector.cc
   - src/core/lib/security/security_connector/security_connector.cc
   - src/core/lib/security/transport/client_auth_filter.cc
@@ -4698,6 +4702,17 @@ targets:
   secure: false
   vs_config_type: Application
   vs_project_guid: '{3C813052-A49A-4662-B90A-1ADBEC7EE453}'
+- name: grpc_linux_system_roots_test
+  gtest: true
+  build: test
+  language: c++
+  src:
+  - test/core/security/linux_system_roots_test.cc
+  deps:
+  - grpc_test_util
+  - grpc
+  - gpr_test_util
+  - gpr
 - name: grpc_node_plugin
   build: protoc
   language: c++

cmake/OWNERS

@@ -1,4 +1,4 @@
 set noparent
 @jtattermusch
 @nicolasnoble
-@matt-kwong
+@mehrdada

config.m4

@@ -280,6 +280,8 @@ if test "$PHP_GRPC" != "no"; then
     src/core/lib/security/credentials/plugin/plugin_credentials.cc \
     src/core/lib/security/credentials/ssl/ssl_credentials.cc \
     src/core/lib/security/security_connector/alts_security_connector.cc \
+    src/core/lib/security/security_connector/load_system_roots_fallback.cc \
+    src/core/lib/security/security_connector/load_system_roots_linux.cc \
     src/core/lib/security/security_connector/local_security_connector.cc \
     src/core/lib/security/security_connector/security_connector.cc \
     src/core/lib/security/transport/client_auth_filter.cc \

config.w32

@@ -255,6 +255,8 @@ if (PHP_GRPC != "no") {
     "src\\core\\lib\\security\\credentials\\plugin\\plugin_credentials.cc " +
     "src\\core\\lib\\security\\credentials\\ssl\\ssl_credentials.cc " +
     "src\\core\\lib\\security\\security_connector\\alts_security_connector.cc " +
+    "src\\core\\lib\\security\\security_connector\\load_system_roots_fallback.cc " +
+    "src\\core\\lib\\security\\security_connector\\load_system_roots_linux.cc " +
     "src\\core\\lib\\security\\security_connector\\local_security_connector.cc " +
     "src\\core\\lib\\security\\security_connector\\security_connector.cc " +
     "src\\core\\lib\\security\\transport\\client_auth_filter.cc " +

doc/csharp/server_reflection.md

@@ -30,7 +30,8 @@ server.Start();
 ```
 
 After starting the server, you can verify that the server reflection
-is working properly by using the `grpc_cli` command line tool:
+is working properly by using the [`grpc_cli` command line
+tool](https://github.com/grpc/grpc/blob/master/doc/command_line_tool.md):
 
  ```sh
   $ grpc_cli ls localhost:50051

doc/python/server_reflection.md

@@ -0,0 +1,61 @@
+# gRPC Python Server Reflection
+
+This document shows how to use gRPC Server Reflection in gRPC Python.
+Please see [C++ Server Reflection Tutorial](../server_reflection_tutorial.md)
+for general information and more examples how to use server reflection.
+
+## Enable server reflection in Python servers
+
+gRPC Python Server Reflection is an add-on library.
+To use it, first install the [grpcio-reflection](https://pypi.org/project/grpcio-reflection/)
+PyPI package into your project.
+
+Note that with Python you need to manually register the service
+descriptors with the reflection service implementation when creating a server
+(this isn't necessary with e.g. C++ or Java)
+```python
+# add the following import statement to use server reflection
+from grpc_reflection.v1alpha import reflection
+# ...
+def serve():
+    server = grpc.server(futures.ThreadPoolExecutor(max_workers=10))
+    helloworld_pb2_grpc.add_GreeterServicer_to_server(Greeter(), server)
+    # the reflection service will be aware of "Greeter" and "ServerReflection" services.
+    SERVICE_NAMES = (
+        helloworld_pb2.DESCRIPTOR.services_by_name['Greeter'].full_name,
+        reflection.SERVICE_NAME,
+    )
+    reflection.enable_server_reflection(SERVICE_NAMES, server)
+    server.add_insecure_port('[::]:50051')
+    server.start()
+```
+
+Please see
+[greeter_server_with_reflection.py](https://github.com/grpc/grpc/blob/master/examples/python/helloworld/greeter_server_with_reflection.py)
+in the examples directory for the full example, which extends the gRPC [Python
+`Greeter` example](https://github.com/grpc/tree/master/examples/python/helloworld) on a
+reflection-enabled server.
+
+After starting the server, you can verify that the server reflection
+is working properly by using the [`grpc_cli` command line
+tool](https://github.com/grpc/grpc/blob/master/doc/command_line_tool.md):
+
+ ```sh
+  $ grpc_cli ls localhost:50051
+  ```
+
+  output:
+  ```sh
+  grpc.reflection.v1alpha.ServerReflection
+  helloworld.Greeter
+  ```
+
+  For more examples and instructions how to use the `grpc_cli` tool,
+  please refer to the [`grpc_cli` documentation](../command_line_tool.md)
+  and the [C++ Server Reflection Tutorial](../server_reflection_tutorial.md).
+
+## Additional Resources
+
+The [Server Reflection Protocol](../server-reflection.md) provides detailed
+information about how the server reflection works and describes the server reflection
+protocol in detail.

doc/server-reflection.md

@@ -191,6 +191,6 @@ each language:
 - [Go](https://github.com/grpc/grpc-go/blob/master/Documentation/server-reflection-tutorial.md#enable-server-reflection)
 - [C++](https://grpc.io/grpc/cpp/md_doc_server_reflection_tutorial.html)
 - [C#](https://github.com/grpc/grpc/blob/master/doc/csharp/server_reflection.md)
-- Python: (tutorial not yet written)
+- [Python](https://github.com/grpc/grpc/blob/master/doc/python/server_reflection.md)
 - Ruby: not yet implemented [#2567](https://github.com/grpc/grpc/issues/2567)
 - Node: not yet implemented [#2568](https://github.com/grpc/grpc/issues/2568)

doc/ssl-performance.md

@@ -0,0 +1,36 @@
+# SSL in gRPC and performance
+
+The SSL requirement of gRPC isn't necessarily making it easy to integrate. The HTTP/2 protocol requires ALPN support, which is a fairly new handshake protocol only supported by recent implementations.
+
+As a result, we've tried hard to provide a smooth experience to our users when compiling and distributing gRPC, but this may come at performance costs due to this. More specifically, we will sometime build the SSL library by disabling assembly code
+(by setting the `OPENSSL_NO_ASM` option), which can impact performance by an order of magnitude when processing encrypted streams.
+
+## gRPC C++: Building from Source
+
+Build system | Condition | Platform | Uses assembly optimizations
+---|---|---|--
+Makefile | with OpenSSL 1.0.2 development files | all | :heavy_check_mark:
+Makefile | all other cases | all | :x:
+Bazel | | Linux | :heavy_check_mark:
+Bazel | | MacOS | :heavy_check_mark:
+Bazel | | Windows | :x:
+CMake | boringssl from submodule (default) | all | :x:
+CMake | pre-installed OpenSSL 1.0.2+ (`gRPC_SSL_PROVIDER=package`) | all | :heavy_check_mark:
+
+## Other Languages: Binary/Source Packages
+
+In addition, we are shipping packages for language implementations. These packages are source packages, but also have pre-built binaries being distributed. Building packages from source may give a different result in some cases.
+
+Language | From source | Platform | Uses assembly optimizations
+---|---|---|---
+C#      | n/a | all | :x:
+Node.JS | n/a | Linux | :heavy_check_mark:
+Node.JS | n/a | MacOS | :heavy_check_mark:
+Node.JS | n/a | Windows | :x:
+Electron | n/a | all | :heavy_check_mark:
+ObjC | Yes | iOS | :x:
+PHP | Yes | all | Same as the `Makefile` case from above
+PHP | No | all | :x:
+Python | n/a | all | :x:
+Ruby | No | all | :x:
+

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+# SHA256 Fingerprint: 2c:ab:ea:fe:37:d0:6c:a2:2a:ba:73:91:c0:03:3d:25:98:29:52:c4:53:64:73:49:76:3a:3a:b5:ad:6c:cf:69
+-----BEGIN CERTIFICATE-----
+MIIFgzCCA2ugAwIBAgIORea7A4Mzw4VlSOb/RVEwDQYJKoZIhvcNAQEMBQAwTDEg
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+5hpxbqCo8YLoRT5s1gLXCmeDBVrJpBA=
+-----END CERTIFICATE-----

examples/csharp/HelloworldXamarin/README.md

@@ -8,27 +8,29 @@ The example depends on experimental Grpc.Core nuget package that hasn't
 been officially released and is only available via the [daily builds](https://packages.grpc.io/)
 source.
 
+HINT: To download the package, please manually download the latest `.nupkg` packages from "Daily Builds" in [packages.grpc.io](https://packages.grpc.io/) into a local directory. Then add a nuget source that points to that directory (That can be [done in Visual Studio](https://docs.microsoft.com/en-us/nuget/tools/package-manager-ui#package-sources) or Visual Studio for Mac via "Configure nuget sources"). After that, nuget will also explore that directory when looking for packages.
+
 BACKGROUND
 -------------
-The example project supports Xamarin.Android and Xamarin.iOS
+The example project supports `Xamarin.Android` and `Xamarin.iOS`.
 
 For this sample, we've already generated the server and client stubs from [helloworld.proto][].
 
 PREREQUISITES
 -------------
 
-- The latest version Xamarin Studio or Visual Studio 2017 with Xamarin support installed.
+- The latest version Visual Studio 2017 or Visual Studio for Mac with Xamarin support installed.
 
 BUILD
 -------
 
-- Open the `HelloworldXamarin.sln` in Visual Studio (or Xamarin Studio)
+- Open the `HelloworldXamarin.sln` in Visual Studio (or Visual Studio for Mac)
 - Build the solution (Build -> Build All)
 
 Try it!
 -------
 
-You can deploy the example apps directly through Xamarin Studio IDE.
+You can deploy the example apps directly through Visual Studio IDE.
 Deployments can target both Android and iOS (both support physical device
 deployment as well as simulator).
 

examples/python/helloworld/greeter_server_with_reflection.py

@@ -0,0 +1,52 @@
+# Copyright 2018 The 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.
+"""The reflection-enabled version of gRPC helloworld.Greeter server."""
+
+from concurrent import futures
+import time
+
+import grpc
+from grpc_reflection.v1alpha import reflection
+
+import helloworld_pb2
+import helloworld_pb2_grpc
+
+_ONE_DAY_IN_SECONDS = 60 * 60 * 24
+
+
+class Greeter(helloworld_pb2_grpc.GreeterServicer):
+
+    def SayHello(self, request, context):
+        return helloworld_pb2.HelloReply(message='Hello, %s!' % request.name)
+
+
+def serve():
+    server = grpc.server(futures.ThreadPoolExecutor(max_workers=10))
+    helloworld_pb2_grpc.add_GreeterServicer_to_server(Greeter(), server)
+    SERVICE_NAMES = (
+        helloworld_pb2.DESCRIPTOR.services_by_name['Greeter'].full_name,
+        reflection.SERVICE_NAME,
+    )
+    reflection.enable_server_reflection(SERVICE_NAMES, server)
+    server.add_insecure_port('[::]:50051')
+    server.start()
+    try:
+        while True:
+            time.sleep(_ONE_DAY_IN_SECONDS)
+    except KeyboardInterrupt:
+        server.stop(0)
+
+
+if __name__ == '__main__':
+    serve()

examples/python/multiplex/helloworld_pb2.py

@@ -21,7 +21,6 @@ DESCRIPTOR = _descriptor.FileDescriptor(
   syntax='proto3',
   serialized_pb=_b('\n\x10helloworld.proto\x12\nhelloworld\"\x1c\n\x0cHelloRequest\x12\x0c\n\x04name\x18\x01 \x01(\t\"\x1d\n\nHelloReply\x12\x0f\n\x07message\x18\x01 \x01(\t2I\n\x07Greeter\x12>\n\x08SayHello\x12\x18.helloworld.HelloRequest\x1a\x16.helloworld.HelloReply\"\x00\x42\x36\n\x1bio.grpc.examples.helloworldB\x0fHelloWorldProtoP\x01\xa2\x02\x03HLWb\x06proto3')
 )
-_sym_db.RegisterFileDescriptor(DESCRIPTOR)
 
 
 
@@ -89,6 +88,7 @@ _HELLOREPLY = _descriptor.Descriptor(
 
 DESCRIPTOR.message_types_by_name['HelloRequest'] = _HELLOREQUEST
 DESCRIPTOR.message_types_by_name['HelloReply'] = _HELLOREPLY
+_sym_db.RegisterFileDescriptor(DESCRIPTOR)
 
 HelloRequest = _reflection.GeneratedProtocolMessageType('HelloRequest', (_message.Message,), dict(
   DESCRIPTOR = _HELLOREQUEST,
@@ -107,123 +107,28 @@ _sym_db.RegisterMessage(HelloReply)
 
 DESCRIPTOR.has_options = True
 DESCRIPTOR._options = _descriptor._ParseOptions(descriptor_pb2.FileOptions(), _b('\n\033io.grpc.examples.helloworldB\017HelloWorldProtoP\001\242\002\003HLW'))
-try:
-  # THESE ELEMENTS WILL BE DEPRECATED.
-  # Please use the generated *_pb2_grpc.py files instead.
-  import grpc
-  from grpc.framework.common import cardinality
-  from grpc.framework.interfaces.face import utilities as face_utilities
-  from grpc.beta import implementations as beta_implementations
-  from grpc.beta import interfaces as beta_interfaces
-
-
-  class GreeterStub(object):
-    """The greeting service definition.
-    """
-
-    def __init__(self, channel):
-      """Constructor.
-
-      Args:
-        channel: A grpc.Channel.
-      """
-      self.SayHello = channel.unary_unary(
-          '/helloworld.Greeter/SayHello',
-          request_serializer=HelloRequest.SerializeToString,
-          response_deserializer=HelloReply.FromString,
-          )
-
-
-  class GreeterServicer(object):
-    """The greeting service definition.
-    """
-
-    def SayHello(self, request, context):
-      """Sends a greeting
-      """
-      context.set_code(grpc.StatusCode.UNIMPLEMENTED)
-      context.set_details('Method not implemented!')
-      raise NotImplementedError('Method not implemented!')
-
-
-  def add_GreeterServicer_to_server(servicer, server):
-    rpc_method_handlers = {
-        'SayHello': grpc.unary_unary_rpc_method_handler(
-            servicer.SayHello,
-            request_deserializer=HelloRequest.FromString,
-            response_serializer=HelloReply.SerializeToString,
-        ),
-    }
-    generic_handler = grpc.method_handlers_generic_handler(
-        'helloworld.Greeter', rpc_method_handlers)
-    server.add_generic_rpc_handlers((generic_handler,))
-
-
-  class BetaGreeterServicer(object):
-    """The Beta API is deprecated for 0.15.0 and later.
-
-    It is recommended to use the GA API (classes and functions in this
-    file not marked beta) for all further purposes. This class was generated
-    only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0."""
-    """The greeting service definition.
-    """
-    def SayHello(self, request, context):
-      """Sends a greeting
-      """
-      context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)
-
-
-  class BetaGreeterStub(object):
-    """The Beta API is deprecated for 0.15.0 and later.
-
-    It is recommended to use the GA API (classes and functions in this
-    file not marked beta) for all further purposes. This class was generated
-    only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0."""
-    """The greeting service definition.
-    """
-    def SayHello(self, request, timeout, metadata=None, with_call=False, protocol_options=None):
-      """Sends a greeting
-      """
-      raise NotImplementedError()
-    SayHello.future = None
-
-
-  def beta_create_Greeter_server(servicer, pool=None, pool_size=None, default_timeout=None, maximum_timeout=None):
-    """The Beta API is deprecated for 0.15.0 and later.
-
-    It is recommended to use the GA API (classes and functions in this
-    file not marked beta) for all further purposes. This function was
-    generated only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0"""
-    request_deserializers = {
-      ('helloworld.Greeter', 'SayHello'): HelloRequest.FromString,
-    }
-    response_serializers = {
-      ('helloworld.Greeter', 'SayHello'): HelloReply.SerializeToString,
-    }
-    method_implementations = {
-      ('helloworld.Greeter', 'SayHello'): face_utilities.unary_unary_inline(servicer.SayHello),
-    }
-    server_options = beta_implementations.server_options(request_deserializers=request_deserializers, response_serializers=response_serializers, thread_pool=pool, thread_pool_size=pool_size, default_timeout=default_timeout, maximum_timeout=maximum_timeout)
-    return beta_implementations.server(method_implementations, options=server_options)
-
-
-  def beta_create_Greeter_stub(channel, host=None, metadata_transformer=None, pool=None, pool_size=None):
-    """The Beta API is deprecated for 0.15.0 and later.
-
-    It is recommended to use the GA API (classes and functions in this
-    file not marked beta) for all further purposes. This function was
-    generated only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0"""
-    request_serializers = {
-      ('helloworld.Greeter', 'SayHello'): HelloRequest.SerializeToString,
-    }
-    response_deserializers = {
-      ('helloworld.Greeter', 'SayHello'): HelloReply.FromString,
-    }
-    cardinalities = {
-      'SayHello': cardinality.Cardinality.UNARY_UNARY,
-    }
-    stub_options = beta_implementations.stub_options(host=host, metadata_transformer=metadata_transformer, request_serializers=request_serializers, response_deserializers=response_deserializers, thread_pool=pool, thread_pool_size=pool_size)
-    return beta_implementations.dynamic_stub(channel, 'helloworld.Greeter', cardinalities, options=stub_options)
-except ImportError:
-  pass
+
+_GREETER = _descriptor.ServiceDescriptor(
+  name='Greeter',
+  full_name='helloworld.Greeter',
+  file=DESCRIPTOR,
+  index=0,
+  options=None,
+  serialized_start=93,
+  serialized_end=166,
+  methods=[
+  _descriptor.MethodDescriptor(
+    name='SayHello',
+    full_name='helloworld.Greeter.SayHello',
+    index=0,
+    containing_service=None,
+    input_type=_HELLOREQUEST,
+    output_type=_HELLOREPLY,
+    options=None,
+  ),
+])
+_sym_db.RegisterServiceDescriptor(_GREETER)
+
+DESCRIPTOR.services_by_name['Greeter'] = _GREETER
+
 # @@protoc_insertion_point(module_scope)

examples/python/multiplex/helloworld_pb2_grpc.py

@@ -1,6 +1,5 @@
+# Generated by the gRPC Python protocol compiler plugin. DO NOT EDIT!
 import grpc
-from grpc.framework.common import cardinality
-from grpc.framework.interfaces.face import utilities as face_utilities
 
 import helloworld_pb2 as helloworld__pb2
 

examples/python/multiplex/route_guide_pb2.py

@@ -21,7 +21,6 @@ DESCRIPTOR = _descriptor.FileDescriptor(
   syntax='proto3',
   serialized_pb=_b('\n\x11route_guide.proto\x12\nrouteguide\",\n\x05Point\x12\x10\n\x08latitude\x18\x01 \x01(\x05\x12\x11\n\tlongitude\x18\x02 \x01(\x05\"I\n\tRectangle\x12\x1d\n\x02lo\x18\x01 \x01(\x0b\x32\x11.routeguide.Point\x12\x1d\n\x02hi\x18\x02 \x01(\x0b\x32\x11.routeguide.Point\"<\n\x07\x46\x65\x61ture\x12\x0c\n\x04name\x18\x01 \x01(\t\x12#\n\x08location\x18\x02 \x01(\x0b\x32\x11.routeguide.Point\"A\n\tRouteNote\x12#\n\x08location\x18\x01 \x01(\x0b\x32\x11.routeguide.Point\x12\x0f\n\x07message\x18\x02 \x01(\t\"b\n\x0cRouteSummary\x12\x13\n\x0bpoint_count\x18\x01 \x01(\x05\x12\x15\n\rfeature_count\x18\x02 \x01(\x05\x12\x10\n\x08\x64istance\x18\x03 \x01(\x05\x12\x14\n\x0c\x65lapsed_time\x18\x04 \x01(\x05\x32\x85\x02\n\nRouteGuide\x12\x36\n\nGetFeature\x12\x11.routeguide.Point\x1a\x13.routeguide.Feature\"\x00\x12>\n\x0cListFeatures\x12\x15.routeguide.Rectangle\x1a\x13.routeguide.Feature\"\x00\x30\x01\x12>\n\x0bRecordRoute\x12\x11.routeguide.Point\x1a\x18.routeguide.RouteSummary\"\x00(\x01\x12?\n\tRouteChat\x12\x15.routeguide.RouteNote\x1a\x15.routeguide.RouteNote\"\x00(\x01\x30\x01\x42\x36\n\x1bio.grpc.examples.routeguideB\x0fRouteGuideProtoP\x01\xa2\x02\x03RTGb\x06proto3')
 )
-_sym_db.RegisterFileDescriptor(DESCRIPTOR)
 
 
 
@@ -238,6 +237,7 @@ DESCRIPTOR.message_types_by_name['Rectangle'] = _RECTANGLE
 DESCRIPTOR.message_types_by_name['Feature'] = _FEATURE
 DESCRIPTOR.message_types_by_name['RouteNote'] = _ROUTENOTE
 DESCRIPTOR.message_types_by_name['RouteSummary'] = _ROUTESUMMARY
+_sym_db.RegisterFileDescriptor(DESCRIPTOR)
 
 Point = _reflection.GeneratedProtocolMessageType('Point', (_message.Message,), dict(
   DESCRIPTOR = _POINT,
@@ -277,265 +277,55 @@ _sym_db.RegisterMessage(RouteSummary)
 
 DESCRIPTOR.has_options = True
 DESCRIPTOR._options = _descriptor._ParseOptions(descriptor_pb2.FileOptions(), _b('\n\033io.grpc.examples.routeguideB\017RouteGuideProtoP\001\242\002\003RTG'))
-try:
-  # THESE ELEMENTS WILL BE DEPRECATED.
-  # Please use the generated *_pb2_grpc.py files instead.
-  import grpc
-  from grpc.framework.common import cardinality
-  from grpc.framework.interfaces.face import utilities as face_utilities
-  from grpc.beta import implementations as beta_implementations
-  from grpc.beta import interfaces as beta_interfaces
-
-
-  class RouteGuideStub(object):
-    """Interface exported by the server.
-    """
-
-    def __init__(self, channel):
-      """Constructor.
-
-      Args:
-        channel: A grpc.Channel.
-      """
-      self.GetFeature = channel.unary_unary(
-          '/routeguide.RouteGuide/GetFeature',
-          request_serializer=Point.SerializeToString,
-          response_deserializer=Feature.FromString,
-          )
-      self.ListFeatures = channel.unary_stream(
-          '/routeguide.RouteGuide/ListFeatures',
-          request_serializer=Rectangle.SerializeToString,
-          response_deserializer=Feature.FromString,
-          )
-      self.RecordRoute = channel.stream_unary(
-          '/routeguide.RouteGuide/RecordRoute',
-          request_serializer=Point.SerializeToString,
-          response_deserializer=RouteSummary.FromString,
-          )
-      self.RouteChat = channel.stream_stream(
-          '/routeguide.RouteGuide/RouteChat',
-          request_serializer=RouteNote.SerializeToString,
-          response_deserializer=RouteNote.FromString,
-          )
-
-
-  class RouteGuideServicer(object):
-    """Interface exported by the server.
-    """
-
-    def GetFeature(self, request, context):
-      """A simple RPC.
-
-      Obtains the feature at a given position.
-
-      A feature with an empty name is returned if there's no feature at the given
-      position.
-      """
-      context.set_code(grpc.StatusCode.UNIMPLEMENTED)
-      context.set_details('Method not implemented!')
-      raise NotImplementedError('Method not implemented!')
-
-    def ListFeatures(self, request, context):
-      """A server-to-client streaming RPC.
-
-      Obtains the Features available within the given Rectangle.  Results are
-      streamed rather than returned at once (e.g. in a response message with a
-      repeated field), as the rectangle may cover a large area and contain a
-      huge number of features.
-      """
-      context.set_code(grpc.StatusCode.UNIMPLEMENTED)
-      context.set_details('Method not implemented!')
-      raise NotImplementedError('Method not implemented!')
-
-    def RecordRoute(self, request_iterator, context):
-      """A client-to-server streaming RPC.
-
-      Accepts a stream of Points on a route being traversed, returning a
-      RouteSummary when traversal is completed.
-      """
-      context.set_code(grpc.StatusCode.UNIMPLEMENTED)
-      context.set_details('Method not implemented!')
-      raise NotImplementedError('Method not implemented!')
-
-    def RouteChat(self, request_iterator, context):
-      """A Bidirectional streaming RPC.
-
-      Accepts a stream of RouteNotes sent while a route is being traversed,
-      while receiving other RouteNotes (e.g. from other users).
-      """
-      context.set_code(grpc.StatusCode.UNIMPLEMENTED)
-      context.set_details('Method not implemented!')
-      raise NotImplementedError('Method not implemented!')
-
-
-  def add_RouteGuideServicer_to_server(servicer, server):
-    rpc_method_handlers = {
-        'GetFeature': grpc.unary_unary_rpc_method_handler(
-            servicer.GetFeature,
-            request_deserializer=Point.FromString,
-            response_serializer=Feature.SerializeToString,
-        ),
-        'ListFeatures': grpc.unary_stream_rpc_method_handler(
-            servicer.ListFeatures,
-            request_deserializer=Rectangle.FromString,
-            response_serializer=Feature.SerializeToString,
-        ),
-        'RecordRoute': grpc.stream_unary_rpc_method_handler(
-            servicer.RecordRoute,
-            request_deserializer=Point.FromString,
-            response_serializer=RouteSummary.SerializeToString,
-        ),
-        'RouteChat': grpc.stream_stream_rpc_method_handler(
-            servicer.RouteChat,
-            request_deserializer=RouteNote.FromString,
-            response_serializer=RouteNote.SerializeToString,
-        ),
-    }
-    generic_handler = grpc.method_handlers_generic_handler(
-        'routeguide.RouteGuide', rpc_method_handlers)
-    server.add_generic_rpc_handlers((generic_handler,))
-
-
-  class BetaRouteGuideServicer(object):
-    """The Beta API is deprecated for 0.15.0 and later.
 
-    It is recommended to use the GA API (classes and functions in this
-    file not marked beta) for all further purposes. This class was generated
-    only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0."""
-    """Interface exported by the server.
-    """
-    def GetFeature(self, request, context):
-      """A simple RPC.
-
-      Obtains the feature at a given position.
-
-      A feature with an empty name is returned if there's no feature at the given
-      position.
-      """
-      context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)
-    def ListFeatures(self, request, context):
-      """A server-to-client streaming RPC.
-
-      Obtains the Features available within the given Rectangle.  Results are
-      streamed rather than returned at once (e.g. in a response message with a
-      repeated field), as the rectangle may cover a large area and contain a
-      huge number of features.
-      """
-      context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)
-    def RecordRoute(self, request_iterator, context):
-      """A client-to-server streaming RPC.
-
-      Accepts a stream of Points on a route being traversed, returning a
-      RouteSummary when traversal is completed.
-      """
-      context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)
-    def RouteChat(self, request_iterator, context):
-      """A Bidirectional streaming RPC.
-
-      Accepts a stream of RouteNotes sent while a route is being traversed,
-      while receiving other RouteNotes (e.g. from other users).
-      """
-      context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)
-
-
-  class BetaRouteGuideStub(object):
-    """The Beta API is deprecated for 0.15.0 and later.
-
-    It is recommended to use the GA API (classes and functions in this
-    file not marked beta) for all further purposes. This class was generated
-    only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0."""
-    """Interface exported by the server.
-    """
-    def GetFeature(self, request, timeout, metadata=None, with_call=False, protocol_options=None):
-      """A simple RPC.
-
-      Obtains the feature at a given position.
-
-      A feature with an empty name is returned if there's no feature at the given
-      position.
-      """
-      raise NotImplementedError()
-    GetFeature.future = None
-    def ListFeatures(self, request, timeout, metadata=None, with_call=False, protocol_options=None):
-      """A server-to-client streaming RPC.
-
-      Obtains the Features available within the given Rectangle.  Results are
-      streamed rather than returned at once (e.g. in a response message with a
-      repeated field), as the rectangle may cover a large area and contain a
-      huge number of features.
-      """
-      raise NotImplementedError()
-    def RecordRoute(self, request_iterator, timeout, metadata=None, with_call=False, protocol_options=None):
-      """A client-to-server streaming RPC.
-
-      Accepts a stream of Points on a route being traversed, returning a
-      RouteSummary when traversal is completed.
-      """
-      raise NotImplementedError()
-    RecordRoute.future = None
-    def RouteChat(self, request_iterator, timeout, metadata=None, with_call=False, protocol_options=None):
-      """A Bidirectional streaming RPC.
-
-      Accepts a stream of RouteNotes sent while a route is being traversed,
-      while receiving other RouteNotes (e.g. from other users).
-      """
-      raise NotImplementedError()
-
-
-  def beta_create_RouteGuide_server(servicer, pool=None, pool_size=None, default_timeout=None, maximum_timeout=None):
-    """The Beta API is deprecated for 0.15.0 and later.
-
-    It is recommended to use the GA API (classes and functions in this
-    file not marked beta) for all further purposes. This function was
-    generated only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0"""
-    request_deserializers = {
-      ('routeguide.RouteGuide', 'GetFeature'): Point.FromString,
-      ('routeguide.RouteGuide', 'ListFeatures'): Rectangle.FromString,
-      ('routeguide.RouteGuide', 'RecordRoute'): Point.FromString,
-      ('routeguide.RouteGuide', 'RouteChat'): RouteNote.FromString,
-    }
-    response_serializers = {
-      ('routeguide.RouteGuide', 'GetFeature'): Feature.SerializeToString,
-      ('routeguide.RouteGuide', 'ListFeatures'): Feature.SerializeToString,
-      ('routeguide.RouteGuide', 'RecordRoute'): RouteSummary.SerializeToString,
-      ('routeguide.RouteGuide', 'RouteChat'): RouteNote.SerializeToString,
-    }
-    method_implementations = {
-      ('routeguide.RouteGuide', 'GetFeature'): face_utilities.unary_unary_inline(servicer.GetFeature),
-      ('routeguide.RouteGuide', 'ListFeatures'): face_utilities.unary_stream_inline(servicer.ListFeatures),
-      ('routeguide.RouteGuide', 'RecordRoute'): face_utilities.stream_unary_inline(servicer.RecordRoute),
-      ('routeguide.RouteGuide', 'RouteChat'): face_utilities.stream_stream_inline(servicer.RouteChat),
-    }
-    server_options = beta_implementations.server_options(request_deserializers=request_deserializers, response_serializers=response_serializers, thread_pool=pool, thread_pool_size=pool_size, default_timeout=default_timeout, maximum_timeout=maximum_timeout)
-    return beta_implementations.server(method_implementations, options=server_options)
-
-
-  def beta_create_RouteGuide_stub(channel, host=None, metadata_transformer=None, pool=None, pool_size=None):
-    """The Beta API is deprecated for 0.15.0 and later.
+_ROUTEGUIDE = _descriptor.ServiceDescriptor(
+  name='RouteGuide',
+  full_name='routeguide.RouteGuide',
+  file=DESCRIPTOR,
+  index=0,
+  options=None,
+  serialized_start=384,
+  serialized_end=645,
+  methods=[
+  _descriptor.MethodDescriptor(
+    name='GetFeature',
+    full_name='routeguide.RouteGuide.GetFeature',
+    index=0,
+    containing_service=None,
+    input_type=_POINT,
+    output_type=_FEATURE,
+    options=None,
+  ),
+  _descriptor.MethodDescriptor(
+    name='ListFeatures',
+    full_name='routeguide.RouteGuide.ListFeatures',
+    index=1,
+    containing_service=None,
+    input_type=_RECTANGLE,
+    output_type=_FEATURE,
+    options=None,
+  ),
+  _descriptor.MethodDescriptor(
+    name='RecordRoute',
+    full_name='routeguide.RouteGuide.RecordRoute',
+    index=2,
+    containing_service=None,
+    input_type=_POINT,
+    output_type=_ROUTESUMMARY,
+    options=None,
+  ),
+  _descriptor.MethodDescriptor(
+    name='RouteChat',
+    full_name='routeguide.RouteGuide.RouteChat',
+    index=3,
+    containing_service=None,
+    input_type=_ROUTENOTE,
+    output_type=_ROUTENOTE,
+    options=None,
+  ),
+])
+_sym_db.RegisterServiceDescriptor(_ROUTEGUIDE)
+
+DESCRIPTOR.services_by_name['RouteGuide'] = _ROUTEGUIDE
 
-    It is recommended to use the GA API (classes and functions in this
-    file not marked beta) for all further purposes. This function was
-    generated only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0"""
-    request_serializers = {
-      ('routeguide.RouteGuide', 'GetFeature'): Point.SerializeToString,
-      ('routeguide.RouteGuide', 'ListFeatures'): Rectangle.SerializeToString,
-      ('routeguide.RouteGuide', 'RecordRoute'): Point.SerializeToString,
-      ('routeguide.RouteGuide', 'RouteChat'): RouteNote.SerializeToString,
-    }
-    response_deserializers = {
-      ('routeguide.RouteGuide', 'GetFeature'): Feature.FromString,
-      ('routeguide.RouteGuide', 'ListFeatures'): Feature.FromString,
-      ('routeguide.RouteGuide', 'RecordRoute'): RouteSummary.FromString,
-      ('routeguide.RouteGuide', 'RouteChat'): RouteNote.FromString,
-    }
-    cardinalities = {
-      'GetFeature': cardinality.Cardinality.UNARY_UNARY,
-      'ListFeatures': cardinality.Cardinality.UNARY_STREAM,
-      'RecordRoute': cardinality.Cardinality.STREAM_UNARY,
-      'RouteChat': cardinality.Cardinality.STREAM_STREAM,
-    }
-    stub_options = beta_implementations.stub_options(host=host, metadata_transformer=metadata_transformer, request_serializers=request_serializers, response_deserializers=response_deserializers, thread_pool=pool, thread_pool_size=pool_size)
-    return beta_implementations.dynamic_stub(channel, 'routeguide.RouteGuide', cardinalities, options=stub_options)
-except ImportError:
-  pass
 # @@protoc_insertion_point(module_scope)

examples/python/multiplex/route_guide_pb2_grpc.py

@@ -1,6 +1,5 @@
+# Generated by the gRPC Python protocol compiler plugin. DO NOT EDIT!
 import grpc
-from grpc.framework.common import cardinality
-from grpc.framework.interfaces.face import utilities as face_utilities
 
 import route_guide_pb2 as route__guide__pb2
 

gRPC-C++.podspec

@@ -278,6 +278,8 @@ Pod::Spec.new do |s|
                       'src/core/lib/security/credentials/plugin/plugin_credentials.h',
                       'src/core/lib/security/credentials/ssl/ssl_credentials.h',
                       'src/core/lib/security/security_connector/alts_security_connector.h',
+                      'src/core/lib/security/security_connector/load_system_roots.h',
+                      'src/core/lib/security/security_connector/load_system_roots_linux.h',
                       'src/core/lib/security/security_connector/local_security_connector.h',
                       'src/core/lib/security/security_connector/security_connector.h',
                       'src/core/lib/security/transport/auth_filters.h',

gRPC-Core.podspec

@@ -289,6 +289,8 @@ Pod::Spec.new do |s|
                       'src/core/lib/security/credentials/plugin/plugin_credentials.h',
                       'src/core/lib/security/credentials/ssl/ssl_credentials.h',
                       'src/core/lib/security/security_connector/alts_security_connector.h',
+                      'src/core/lib/security/security_connector/load_system_roots.h',
+                      'src/core/lib/security/security_connector/load_system_roots_linux.h',
                       'src/core/lib/security/security_connector/local_security_connector.h',
                       'src/core/lib/security/security_connector/security_connector.h',
                       'src/core/lib/security/transport/auth_filters.h',
@@ -705,6 +707,8 @@ Pod::Spec.new do |s|
                       'src/core/lib/security/credentials/plugin/plugin_credentials.cc',
                       'src/core/lib/security/credentials/ssl/ssl_credentials.cc',
                       'src/core/lib/security/security_connector/alts_security_connector.cc',
+                      'src/core/lib/security/security_connector/load_system_roots_fallback.cc',
+                      'src/core/lib/security/security_connector/load_system_roots_linux.cc',
                       'src/core/lib/security/security_connector/local_security_connector.cc',
                       'src/core/lib/security/security_connector/security_connector.cc',
                       'src/core/lib/security/transport/client_auth_filter.cc',
@@ -882,6 +886,8 @@ Pod::Spec.new do |s|
                               'src/core/lib/security/credentials/plugin/plugin_credentials.h',
                               'src/core/lib/security/credentials/ssl/ssl_credentials.h',
                               'src/core/lib/security/security_connector/alts_security_connector.h',
+                              'src/core/lib/security/security_connector/load_system_roots.h',
+                              'src/core/lib/security/security_connector/load_system_roots_linux.h',
                               'src/core/lib/security/security_connector/local_security_connector.h',
                               'src/core/lib/security/security_connector/security_connector.h',
                               'src/core/lib/security/transport/auth_filters.h',

grpc.def

@@ -42,6 +42,7 @@ EXPORTS
     grpc_census_call_get_context
     grpc_channel_get_target
     grpc_channel_get_info
+    grpc_channel_reset_connect_backoff
     grpc_insecure_channel_create
     grpc_lame_client_channel_create
     grpc_channel_destroy

grpc.gemspec

@@ -222,6 +222,8 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/lib/security/credentials/plugin/plugin_credentials.h )
   s.files += %w( src/core/lib/security/credentials/ssl/ssl_credentials.h )
   s.files += %w( src/core/lib/security/security_connector/alts_security_connector.h )
+  s.files += %w( src/core/lib/security/security_connector/load_system_roots.h )
+  s.files += %w( src/core/lib/security/security_connector/load_system_roots_linux.h )
   s.files += %w( src/core/lib/security/security_connector/local_security_connector.h )
   s.files += %w( src/core/lib/security/security_connector/security_connector.h )
   s.files += %w( src/core/lib/security/transport/auth_filters.h )
@@ -642,6 +644,8 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/lib/security/credentials/plugin/plugin_credentials.cc )
   s.files += %w( src/core/lib/security/credentials/ssl/ssl_credentials.cc )
   s.files += %w( src/core/lib/security/security_connector/alts_security_connector.cc )
+  s.files += %w( src/core/lib/security/security_connector/load_system_roots_fallback.cc )
+  s.files += %w( src/core/lib/security/security_connector/load_system_roots_linux.cc )
   s.files += %w( src/core/lib/security/security_connector/local_security_connector.cc )
   s.files += %w( src/core/lib/security/security_connector/security_connector.cc )
   s.files += %w( src/core/lib/security/transport/client_auth_filter.cc )

grpc.gyp

@@ -472,6 +472,8 @@
         'src/core/lib/security/credentials/plugin/plugin_credentials.cc',
         'src/core/lib/security/credentials/ssl/ssl_credentials.cc',
         'src/core/lib/security/security_connector/alts_security_connector.cc',
+        'src/core/lib/security/security_connector/load_system_roots_fallback.cc',
+        'src/core/lib/security/security_connector/load_system_roots_linux.cc',
         'src/core/lib/security/security_connector/local_security_connector.cc',
         'src/core/lib/security/security_connector/security_connector.cc',
         'src/core/lib/security/transport/client_auth_filter.cc',

include/grpc/grpc.h

@@ -274,6 +274,11 @@ GRPCAPI char* grpc_channel_get_target(grpc_channel* channel);
 GRPCAPI void grpc_channel_get_info(grpc_channel* channel,
                                    const grpc_channel_info* channel_info);
 
+/** EXPERIMENTAL.  Resets the channel's connect backoff.
+    TODO(roth): When we see whether this proves useful, either promote
+    to non-experimental or remove it. */
+GRPCAPI void grpc_channel_reset_connect_backoff(grpc_channel* channel);
+
 /** Create a client channel to 'target'. Additional channel level configuration
     MAY be provided by grpc_channel_args, though the expectation is that most
     clients will want to simply pass NULL. The user data in 'args' need only

include/grpcpp/channel.h

@@ -30,6 +30,14 @@
 struct grpc_channel;
 
 namespace grpc {
+
+namespace experimental {
+/// Resets the channel's connection backoff.
+/// TODO(roth): Once we see whether this proves useful, either create a gRFC
+/// and change this to be a method of the Channel class, or remove it.
+void ChannelResetConnectionBackoff(Channel* channel);
+}  // namespace experimental
+
 /// Channels represent a connection to an endpoint. Created by \a CreateChannel.
 class Channel final : public ChannelInterface,
                       public internal::CallHook,
@@ -52,6 +60,7 @@ class Channel final : public ChannelInterface,
  private:
   template <class InputMessage, class OutputMessage>
   friend class internal::BlockingUnaryCallImpl;
+  friend void experimental::ChannelResetConnectionBackoff(Channel* channel);
   friend std::shared_ptr<Channel> CreateChannelInternal(
       const grpc::string& host, grpc_channel* c_channel);
   Channel(const grpc::string& host, grpc_channel* c_channel);

include/grpcpp/impl/codegen/async_generic_service.h

@@ -52,12 +52,12 @@ class GenericServerContext final : public ServerContext {
 //   ServerBuilder builder;
 //   auto cq = builder.AddCompletionQueue();
 //   AsyncGenericService generic_service;
-//   builder.RegisterAsyncGeneicService(&generic_service);
+//   builder.RegisterAsyncGenericService(&generic_service);
 //   auto server = builder.BuildAndStart();
 //
 //   // request a new call
 //   GenericServerContext context;
-//   GenericAsyncReaderWriter stream;
+//   GenericServerAsyncReaderWriter stream;
 //   generic_service.RequestCall(&context, &stream, cq.get(), cq.get(), tag);
 //
 // When tag is retrieved from cq->Next(), context.method() can be used to look

package.xml

@@ -227,6 +227,8 @@
     <file baseinstalldir="/" name="src/core/lib/security/credentials/plugin/plugin_credentials.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/security/credentials/ssl/ssl_credentials.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/security/security_connector/alts_security_connector.h" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/security/security_connector/load_system_roots.h" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/security/security_connector/load_system_roots_linux.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/security/security_connector/local_security_connector.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/security/security_connector/security_connector.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/security/transport/auth_filters.h" role="src" />
@@ -647,6 +649,8 @@
     <file baseinstalldir="/" name="src/core/lib/security/credentials/plugin/plugin_credentials.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/security/credentials/ssl/ssl_credentials.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/security/security_connector/alts_security_connector.cc" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/security/security_connector/load_system_roots_fallback.cc" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/security/security_connector/load_system_roots_linux.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/security/security_connector/local_security_connector.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/security/security_connector/security_connector.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/security/transport/client_auth_filter.cc" role="src" />

src/core/ext/filters/client_channel/client_channel.cc

@@ -622,6 +622,17 @@ static void start_transport_op_locked(void* arg, grpc_error* error_ignored) {
     }
     GRPC_ERROR_UNREF(op->disconnect_with_error);
   }
+
+  if (op->reset_connect_backoff) {
+    if (chand->resolver != nullptr) {
+      chand->resolver->ResetBackoffLocked();
+      chand->resolver->RequestReresolutionLocked();
+    }
+    if (chand->lb_policy != nullptr) {
+      chand->lb_policy->ResetBackoffLocked();
+    }
+  }
+
   GRPC_CHANNEL_STACK_UNREF(chand->owning_stack, "start_transport_op");
 
   GRPC_CLOSURE_SCHED(op->on_consumed, GRPC_ERROR_NONE);

src/core/ext/filters/client_channel/client_channel_plugin.cc

@@ -56,7 +56,7 @@ void grpc_client_channel_init(void) {
   grpc_register_http_proxy_mapper();
   grpc_subchannel_index_init();
   grpc_channel_init_register_stage(
-      GRPC_CLIENT_CHANNEL, GRPC_CHANNEL_INIT_BUILTIN_PRIORITY, append_filter,
+      GRPC_CLIENT_CHANNEL, GRPC_CHANNEL_INIT_PRIORITY_MAX, append_filter,
       (void*)&grpc_client_channel_filter);
   grpc_http_connect_register_handshaker_factory();
 }

src/core/ext/filters/client_channel/lb_policy.h

@@ -144,7 +144,10 @@ class LoadBalancingPolicy
   /// consider whether this method is still needed.
   virtual void ExitIdleLocked() GRPC_ABSTRACT;
 
-  /// populates child_subchannels and child_channels with the uuids of this
+  /// Resets connection backoff.
+  virtual void ResetBackoffLocked() GRPC_ABSTRACT;
+
+  /// Populates child_subchannels and child_channels with the uuids of this
   /// LB policy's referenced children. This is not invoked from the
   /// client_channel's combiner. The implementation is responsible for
   /// providing its own synchronization.

src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc

@@ -134,6 +134,7 @@ class GrpcLb : public LoadBalancingPolicy {
       grpc_error** connectivity_error) override;
   void HandOffPendingPicksLocked(LoadBalancingPolicy* new_policy) override;
   void ExitIdleLocked() override;
+  void ResetBackoffLocked() override;
   void FillChildRefsForChannelz(ChildRefsList* child_subchannels,
                                 ChildRefsList* child_channels) override;
 
@@ -1214,6 +1215,15 @@ void GrpcLb::ExitIdleLocked() {
   }
 }
 
+void GrpcLb::ResetBackoffLocked() {
+  if (lb_channel_ != nullptr) {
+    grpc_channel_reset_connect_backoff(lb_channel_);
+  }
+  if (rr_policy_ != nullptr) {
+    rr_policy_->ResetBackoffLocked();
+  }
+}
+
 bool GrpcLb::PickLocked(PickState* pick, grpc_error** error) {
   PendingPick* pp = PendingPickCreate(pick);
   bool pick_done = false;
@@ -1880,7 +1890,7 @@ void grpc_lb_policy_grpclb_init() {
           grpc_core::UniquePtr<grpc_core::LoadBalancingPolicyFactory>(
               grpc_core::New<grpc_core::GrpcLbFactory>()));
   grpc_channel_init_register_stage(GRPC_CLIENT_SUBCHANNEL,
-                                   GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
+                                   GRPC_CHANNEL_INIT_PRIORITY_LOW,
                                    maybe_add_client_load_reporting_filter,
                                    (void*)&grpc_client_load_reporting_filter);
 }

src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc

@@ -57,6 +57,7 @@ class PickFirst : public LoadBalancingPolicy {
       grpc_error** connectivity_error) override;
   void HandOffPendingPicksLocked(LoadBalancingPolicy* new_policy) override;
   void ExitIdleLocked() override;
+  void ResetBackoffLocked() override;
   void FillChildRefsForChannelz(ChildRefsList* child_subchannels,
                                 ChildRefsList* ignored) override;
 
@@ -259,6 +260,13 @@ void PickFirst::ExitIdleLocked() {
   }
 }
 
+void PickFirst::ResetBackoffLocked() {
+  subchannel_list_->ResetBackoffLocked();
+  if (latest_pending_subchannel_list_ != nullptr) {
+    latest_pending_subchannel_list_->ResetBackoffLocked();
+  }
+}
+
 bool PickFirst::PickLocked(PickState* pick, grpc_error** error) {
   // If we have a selected subchannel already, return synchronously.
   if (selected_ != nullptr) {

src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc

@@ -68,6 +68,7 @@ class RoundRobin : public LoadBalancingPolicy {
       grpc_error** connectivity_error) override;
   void HandOffPendingPicksLocked(LoadBalancingPolicy* new_policy) override;
   void ExitIdleLocked() override;
+  void ResetBackoffLocked() override;
   void FillChildRefsForChannelz(ChildRefsList* child_subchannels,
                                 ChildRefsList* ignored) override;
 
@@ -333,6 +334,13 @@ void RoundRobin::ExitIdleLocked() {
   }
 }
 
+void RoundRobin::ResetBackoffLocked() {
+  subchannel_list_->ResetBackoffLocked();
+  if (latest_pending_subchannel_list_ != nullptr) {
+    latest_pending_subchannel_list_->ResetBackoffLocked();
+  }
+}
+
 bool RoundRobin::DoPickLocked(PickState* pick) {
   const size_t next_ready_index =
       subchannel_list_->GetNextReadySubchannelIndexLocked();

src/core/ext/filters/client_channel/lb_policy/subchannel_list.h

@@ -107,6 +107,11 @@ class SubchannelData {
   // being unreffed.
   virtual void UnrefSubchannelLocked(const char* reason);
 
+  // Resets the connection backoff.
+  // TODO(roth): This method should go away when we move the backoff
+  // code out of the subchannel and into the LB policies.
+  void ResetBackoffLocked();
+
   // Starts watching the connectivity state of the subchannel.
   // ProcessConnectivityChangeLocked() will be called when the
   // connectivity state changes.
@@ -206,6 +211,11 @@ class SubchannelList
   LoadBalancingPolicy* policy() const { return policy_; }
   TraceFlag* tracer() const { return tracer_; }
 
+  // Resets connection backoff of all subchannels.
+  // TODO(roth): We will probably need to rethink this as part of moving
+  // the backoff code out of subchannels and into LB policies.
+  void ResetBackoffLocked();
+
   // Note: Caller must ensure that this is invoked inside of the combiner.
   void Orphan() override {
     ShutdownLocked();
@@ -298,6 +308,14 @@ void SubchannelData<SubchannelListType, SubchannelDataType>::
   }
 }
 
+template <typename SubchannelListType, typename SubchannelDataType>
+void SubchannelData<SubchannelListType,
+                    SubchannelDataType>::ResetBackoffLocked() {
+  if (subchannel_ != nullptr) {
+    grpc_subchannel_reset_backoff(subchannel_);
+  }
+}
+
 template <typename SubchannelListType, typename SubchannelDataType>
 void SubchannelData<SubchannelListType,
                     SubchannelDataType>::StartConnectivityWatchLocked() {
@@ -544,6 +562,15 @@ void SubchannelList<SubchannelListType, SubchannelDataType>::ShutdownLocked() {
   }
 }
 
+template <typename SubchannelListType, typename SubchannelDataType>
+void SubchannelList<SubchannelListType,
+                    SubchannelDataType>::ResetBackoffLocked() {
+  for (size_t i = 0; i < subchannels_.size(); i++) {
+    SubchannelDataType* sd = &subchannels_[i];
+    sd->ResetBackoffLocked();
+  }
+}
+
 }  // namespace grpc_core
 
 #endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_SUBCHANNEL_LIST_H */

src/core/ext/filters/client_channel/resolver.h

@@ -94,6 +94,14 @@ class Resolver : public InternallyRefCountedWithTracing<Resolver> {
   /// throw away unselected subchannels.
   virtual void RequestReresolutionLocked() GRPC_ABSTRACT;
 
+  /// Resets the re-resolution backoff, if any.
+  /// This needs to be implemented only by pull-based implementations;
+  /// for push-based implementations, it will be a no-op.
+  /// TODO(roth): Pull the backoff code out of resolver and into
+  /// client_channel, so that it can be shared across resolver
+  /// implementations.  At that point, this method can go away.
+  virtual void ResetBackoffLocked() {}
+
   void Orphan() override {
     // Invoke ShutdownAndUnrefLocked() inside of the combiner.
     GRPC_CLOSURE_SCHED(

src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc

@@ -66,6 +66,8 @@ class AresDnsResolver : public Resolver {
 
   void RequestReresolutionLocked() override;
 
+  void ResetBackoffLocked() override;
+
   void ShutdownLocked() override;
 
  private:
@@ -187,6 +189,13 @@ void AresDnsResolver::RequestReresolutionLocked() {
   }
 }
 
+void AresDnsResolver::ResetBackoffLocked() {
+  if (have_next_resolution_timer_) {
+    grpc_timer_cancel(&next_resolution_timer_);
+  }
+  backoff_.Reset();
+}
+
 void AresDnsResolver::ShutdownLocked() {
   if (have_next_resolution_timer_) {
     grpc_timer_cancel(&next_resolution_timer_);

src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc

@@ -74,6 +74,8 @@ struct grpc_ares_ev_driver {
   bool shutting_down;
   /** request object that's using this ev driver */
   grpc_ares_request* request;
+  /** Owned by the ev_driver. Creates new GrpcPolledFd's */
+  grpc_core::UniquePtr<grpc_core::GrpcPolledFdFactory> polled_fd_factory;
 };
 
 static void grpc_ares_notify_on_event_locked(grpc_ares_ev_driver* ev_driver);
@@ -93,7 +95,7 @@ static void grpc_ares_ev_driver_unref(grpc_ares_ev_driver* ev_driver) {
     GRPC_COMBINER_UNREF(ev_driver->combiner, "free ares event driver");
     ares_destroy(ev_driver->channel);
     grpc_ares_complete_request_locked(ev_driver->request);
-    gpr_free(ev_driver);
+    grpc_core::Delete(ev_driver);
   }
 }
 
@@ -118,13 +120,11 @@ grpc_error* grpc_ares_ev_driver_create_locked(grpc_ares_ev_driver** ev_driver,
                                               grpc_pollset_set* pollset_set,
                                               grpc_combiner* combiner,
                                               grpc_ares_request* request) {
-  *ev_driver = static_cast<grpc_ares_ev_driver*>(
-      gpr_malloc(sizeof(grpc_ares_ev_driver)));
+  *ev_driver = grpc_core::New<grpc_ares_ev_driver>();
   ares_options opts;
   memset(&opts, 0, sizeof(opts));
   opts.flags |= ARES_FLAG_STAYOPEN;
   int status = ares_init_options(&(*ev_driver)->channel, &opts, ARES_OPT_FLAGS);
-  grpc_core::ConfigureAresChannelLocked(&(*ev_driver)->channel);
   gpr_log(GPR_DEBUG, "grpc_ares_ev_driver_create_locked");
   if (status != ARES_SUCCESS) {
     char* err_msg;
@@ -142,6 +142,10 @@ grpc_error* grpc_ares_ev_driver_create_locked(grpc_ares_ev_driver** ev_driver,
   (*ev_driver)->working = false;
   (*ev_driver)->shutting_down = false;
   (*ev_driver)->request = request;
+  (*ev_driver)->polled_fd_factory =
+      grpc_core::NewGrpcPolledFdFactory((*ev_driver)->combiner);
+  (*ev_driver)
+      ->polled_fd_factory->ConfigureAresChannelLocked((*ev_driver)->channel);
   return GRPC_ERROR_NONE;
 }
 
@@ -245,8 +249,9 @@ static void grpc_ares_notify_on_event_locked(grpc_ares_ev_driver* ev_driver) {
         // Create a new fd_node if sock[i] is not in the fd_node list.
         if (fdn == nullptr) {
           fdn = static_cast<fd_node*>(gpr_malloc(sizeof(fd_node)));
-          fdn->grpc_polled_fd = grpc_core::NewGrpcPolledFdLocked(
-              socks[i], ev_driver->pollset_set);
+          fdn->grpc_polled_fd =
+              ev_driver->polled_fd_factory->NewGrpcPolledFdLocked(
+                  socks[i], ev_driver->pollset_set, ev_driver->combiner);
           gpr_log(GPR_DEBUG, "new fd: %s", fdn->grpc_polled_fd->GetName());
           fdn->ev_driver = ev_driver;
           fdn->readable_registered = false;

src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h

@@ -81,10 +81,24 @@ class GrpcPolledFd {
   GRPC_ABSTRACT_BASE_CLASS
 };
 
-/* Creates a new wrapped fd for the current platform */
-GrpcPolledFd* NewGrpcPolledFdLocked(ares_socket_t as,
-                                    grpc_pollset_set* driver_pollset_set);
-void ConfigureAresChannelLocked(ares_channel* channel);
+/* A GrpcPolledFdFactory is 1-to-1 with and owned by the
+ * ares event driver. It knows how to create GrpcPolledFd's
+ * for the current platform, and the ares driver uses it for all of
+ * its fd's. */
+class GrpcPolledFdFactory {
+ public:
+  virtual ~GrpcPolledFdFactory() {}
+  /* Creates a new wrapped fd for the current platform */
+  virtual GrpcPolledFd* NewGrpcPolledFdLocked(
+      ares_socket_t as, grpc_pollset_set* driver_pollset_set,
+      grpc_combiner* combiner) GRPC_ABSTRACT;
+  /* Optionally configures the ares channel after creation */
+  virtual void ConfigureAresChannelLocked(ares_channel channel) GRPC_ABSTRACT;
+
+  GRPC_ABSTRACT_BASE_CLASS
+};
+
+UniquePtr<GrpcPolledFdFactory> NewGrpcPolledFdFactory(grpc_combiner* combiner);
 
 }  // namespace grpc_core
 

src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc

@@ -86,12 +86,20 @@ class GrpcPolledFdPosix : public GrpcPolledFd {
   grpc_pollset_set* driver_pollset_set_;
 };
 
-GrpcPolledFd* NewGrpcPolledFdLocked(ares_socket_t as,
-                                    grpc_pollset_set* driver_pollset_set) {
-  return grpc_core::New<GrpcPolledFdPosix>(as, driver_pollset_set);
-}
+class GrpcPolledFdFactoryPosix : public GrpcPolledFdFactory {
+ public:
+  GrpcPolledFd* NewGrpcPolledFdLocked(ares_socket_t as,
+                                      grpc_pollset_set* driver_pollset_set,
+                                      grpc_combiner* combiner) override {
+    return New<GrpcPolledFdPosix>(as, driver_pollset_set);
+  }
 
-void ConfigureAresChannelLocked(ares_channel* channel) {}
+  void ConfigureAresChannelLocked(ares_channel channel) override {}
+};
+
+UniquePtr<GrpcPolledFdFactory> NewGrpcPolledFdFactory(grpc_combiner* combiner) {
+  return UniquePtr<GrpcPolledFdFactory>(New<GrpcPolledFdFactoryPosix>());
+}
 
 }  // namespace grpc_core
 

src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc

@@ -21,38 +21,516 @@
 #if GRPC_ARES == 1 && defined(GPR_WINDOWS)
 
 #include <ares.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/log_windows.h>
+#include <grpc/support/string_util.h>
+#include <grpc/support/time.h>
 #include <string.h>
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/gprpp/memory.h"
+#include "src/core/lib/iomgr/combiner.h"
+#include "src/core/lib/iomgr/socket_windows.h"
+#include "src/core/lib/iomgr/tcp_windows.h"
+#include "src/core/lib/slice/slice_internal.h"
 
 #include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h"
+#include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
+
+/* TODO(apolcyn): remove this hack after fixing upstream.
+ * Our grpc/c-ares code on Windows uses the ares_set_socket_functions API,
+ * which uses "struct iovec" type, which on Windows is defined inside of
+ * a c-ares header that is not public.
+ * See https://github.com/c-ares/c-ares/issues/206. */
+struct iovec {
+  void* iov_base;
+  size_t iov_len;
+};
 
 namespace grpc_core {
 
-/* TODO: fill in the body of GrpcPolledFdWindows to enable c-ares on Windows.
-   This dummy implementation only allows grpc to compile on windows with
-   GRPC_ARES=1. */
+/* c-ares creates its own sockets and is meant to read them when readable and
+ * write them when writeable. To fit this socket usage model into the grpc
+ * windows poller (which gives notifications when attempted reads and writes are
+ * actually fulfilled rather than possible), this GrpcPolledFdWindows class
+ * takes advantage of the ares_set_socket_functions API and acts as a virtual
+ * socket. It holds its own read and write buffers which are written to and read
+ * from c-ares and are used with the grpc windows poller, and it, e.g.,
+ * manufactures virtual socket error codes when it e.g. needs to tell the c-ares
+ * library to wait for an async read. */
 class GrpcPolledFdWindows : public GrpcPolledFd {
  public:
-  GrpcPolledFdWindows() { abort(); }
-  ~GrpcPolledFdWindows() { abort(); }
+  enum WriteState {
+    WRITE_IDLE,
+    WRITE_REQUESTED,
+    WRITE_PENDING,
+    WRITE_WAITING_FOR_VERIFICATION_UPON_RETRY,
+  };
+
+  GrpcPolledFdWindows(ares_socket_t as, grpc_combiner* combiner)
+      : read_buf_(grpc_empty_slice()),
+        write_buf_(grpc_empty_slice()),
+        write_state_(WRITE_IDLE),
+        gotten_into_driver_list_(false) {
+    gpr_asprintf(&name_, "c-ares socket: %" PRIdPTR, as);
+    winsocket_ = grpc_winsocket_create(as, name_);
+    combiner_ = GRPC_COMBINER_REF(combiner, name_);
+    GRPC_CLOSURE_INIT(&outer_read_closure_,
+                      &GrpcPolledFdWindows::OnIocpReadable, this,
+                      grpc_combiner_scheduler(combiner_));
+    GRPC_CLOSURE_INIT(&outer_write_closure_,
+                      &GrpcPolledFdWindows::OnIocpWriteable, this,
+                      grpc_combiner_scheduler(combiner_));
+  }
+
+  ~GrpcPolledFdWindows() {
+    GRPC_COMBINER_UNREF(combiner_, name_);
+    grpc_slice_unref_internal(read_buf_);
+    grpc_slice_unref_internal(write_buf_);
+    GPR_ASSERT(read_closure_ == nullptr);
+    GPR_ASSERT(write_closure_ == nullptr);
+    grpc_winsocket_destroy(winsocket_);
+    gpr_free(name_);
+  }
+
+  void ScheduleAndNullReadClosure(grpc_error* error) {
+    GRPC_CLOSURE_SCHED(read_closure_, error);
+    read_closure_ = nullptr;
+  }
+
+  void ScheduleAndNullWriteClosure(grpc_error* error) {
+    GRPC_CLOSURE_SCHED(write_closure_, error);
+    write_closure_ = nullptr;
+  }
+
   void RegisterForOnReadableLocked(grpc_closure* read_closure) override {
-    abort();
+    GPR_ASSERT(read_closure_ == nullptr);
+    read_closure_ = read_closure;
+    GPR_ASSERT(GRPC_SLICE_LENGTH(read_buf_) == 0);
+    grpc_slice_unref_internal(read_buf_);
+    read_buf_ = GRPC_SLICE_MALLOC(4192);
+    WSABUF buffer;
+    buffer.buf = (char*)GRPC_SLICE_START_PTR(read_buf_);
+    buffer.len = GRPC_SLICE_LENGTH(read_buf_);
+    memset(&winsocket_->read_info.overlapped, 0, sizeof(OVERLAPPED));
+    recv_from_source_addr_len_ = sizeof(recv_from_source_addr_);
+    DWORD flags = 0;
+    if (WSARecvFrom(grpc_winsocket_wrapped_socket(winsocket_), &buffer, 1,
+                    nullptr, &flags, (sockaddr*)recv_from_source_addr_,
+                    &recv_from_source_addr_len_,
+                    &winsocket_->read_info.overlapped, nullptr)) {
+      char* msg = gpr_format_message(WSAGetLastError());
+      grpc_error* error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
+      GRPC_CARES_TRACE_LOG(
+          "RegisterForOnReadableLocked: WSARecvFrom error:|%s|. fd:|%s|", msg,
+          GetName());
+      gpr_free(msg);
+      if (WSAGetLastError() != WSA_IO_PENDING) {
+        ScheduleAndNullReadClosure(error);
+        return;
+      }
+    }
+    grpc_socket_notify_on_read(winsocket_, &outer_read_closure_);
   }
+
   void RegisterForOnWriteableLocked(grpc_closure* write_closure) override {
+    GRPC_CARES_TRACE_LOG(
+        "RegisterForOnWriteableLocked. fd:|%s|. Current write state: %d",
+        GetName(), write_state_);
+    GPR_ASSERT(write_closure_ == nullptr);
+    write_closure_ = write_closure;
+    switch (write_state_) {
+      case WRITE_IDLE:
+        ScheduleAndNullWriteClosure(GRPC_ERROR_NONE);
+        break;
+      case WRITE_REQUESTED:
+        write_state_ = WRITE_PENDING;
+        SendWriteBuf(nullptr, &winsocket_->write_info.overlapped);
+        grpc_socket_notify_on_write(winsocket_, &outer_write_closure_);
+        break;
+      case WRITE_PENDING:
+      case WRITE_WAITING_FOR_VERIFICATION_UPON_RETRY:
+        abort();
+    }
+  }
+
+  bool IsFdStillReadableLocked() override {
+    return GRPC_SLICE_LENGTH(read_buf_) > 0;
+  }
+
+  void ShutdownLocked(grpc_error* error) override {
+    grpc_winsocket_shutdown(winsocket_);
+  }
+
+  ares_socket_t GetWrappedAresSocketLocked() override {
+    return grpc_winsocket_wrapped_socket(winsocket_);
+  }
+
+  const char* GetName() override { return name_; }
+
+  ares_ssize_t RecvFrom(void* data, ares_socket_t data_len, int flags,
+                        struct sockaddr* from, ares_socklen_t* from_len) {
+    GRPC_CARES_TRACE_LOG(
+        "RecvFrom called on fd:|%s|. Current read buf length:|%d|", GetName(),
+        GRPC_SLICE_LENGTH(read_buf_));
+    if (GRPC_SLICE_LENGTH(read_buf_) == 0) {
+      WSASetLastError(WSAEWOULDBLOCK);
+      return -1;
+    }
+    ares_ssize_t bytes_read = 0;
+    for (size_t i = 0; i < GRPC_SLICE_LENGTH(read_buf_) && i < data_len; i++) {
+      ((char*)data)[i] = GRPC_SLICE_START_PTR(read_buf_)[i];
+      bytes_read++;
+    }
+    read_buf_ = grpc_slice_sub_no_ref(read_buf_, bytes_read,
+                                      GRPC_SLICE_LENGTH(read_buf_));
+    /* c-ares overloads this recv_from virtual socket function to receive
+     * data on both UDP and TCP sockets, and from is nullptr for TCP. */
+    if (from != nullptr) {
+      GPR_ASSERT(*from_len <= recv_from_source_addr_len_);
+      memcpy(from, &recv_from_source_addr_, recv_from_source_addr_len_);
+      *from_len = recv_from_source_addr_len_;
+    }
+    return bytes_read;
+  }
+
+  grpc_slice FlattenIovec(const struct iovec* iov, int iov_count) {
+    int total = 0;
+    for (int i = 0; i < iov_count; i++) {
+      total += iov[i].iov_len;
+    }
+    grpc_slice out = GRPC_SLICE_MALLOC(total);
+    size_t cur = 0;
+    for (int i = 0; i < iov_count; i++) {
+      for (int k = 0; k < iov[i].iov_len; k++) {
+        GRPC_SLICE_START_PTR(out)[cur++] = ((char*)iov[i].iov_base)[k];
+      }
+    }
+    return out;
+  }
+
+  int SendWriteBuf(LPDWORD bytes_sent_ptr, LPWSAOVERLAPPED overlapped) {
+    WSABUF buf;
+    buf.len = GRPC_SLICE_LENGTH(write_buf_);
+    buf.buf = (char*)GRPC_SLICE_START_PTR(write_buf_);
+    DWORD flags = 0;
+    int out = WSASend(grpc_winsocket_wrapped_socket(winsocket_), &buf, 1,
+                      bytes_sent_ptr, flags, overlapped, nullptr);
+    GRPC_CARES_TRACE_LOG(
+        "WSASend: name:%s. buf len:%d. bytes sent: %d. overlapped %p. return "
+        "val: %d",
+        GetName(), buf.len, *bytes_sent_ptr, overlapped, out);
+    return out;
+  }
+
+  ares_ssize_t TrySendWriteBufSyncNonBlocking() {
+    GPR_ASSERT(write_state_ == WRITE_IDLE);
+    ares_ssize_t total_sent;
+    DWORD bytes_sent = 0;
+    if (SendWriteBuf(&bytes_sent, nullptr) != 0) {
+      char* msg = gpr_format_message(WSAGetLastError());
+      GRPC_CARES_TRACE_LOG(
+          "TrySendWriteBufSyncNonBlocking: SendWriteBuf error:|%s|. fd:|%s|",
+          msg, GetName());
+      gpr_free(msg);
+      if (WSAGetLastError() == WSA_IO_PENDING) {
+        WSASetLastError(WSAEWOULDBLOCK);
+        write_state_ = WRITE_REQUESTED;
+      }
+    }
+    write_buf_ = grpc_slice_sub_no_ref(write_buf_, bytes_sent,
+                                       GRPC_SLICE_LENGTH(write_buf_));
+    return bytes_sent;
+  }
+
+  ares_ssize_t SendV(const struct iovec* iov, int iov_count) {
+    GRPC_CARES_TRACE_LOG("SendV called on fd:|%s|. Current write state: %d",
+                         GetName(), write_state_);
+    switch (write_state_) {
+      case WRITE_IDLE:
+        GPR_ASSERT(GRPC_SLICE_LENGTH(write_buf_) == 0);
+        grpc_slice_unref_internal(write_buf_);
+        write_buf_ = FlattenIovec(iov, iov_count);
+        return TrySendWriteBufSyncNonBlocking();
+      case WRITE_REQUESTED:
+      case WRITE_PENDING:
+        WSASetLastError(WSAEWOULDBLOCK);
+        return -1;
+      case WRITE_WAITING_FOR_VERIFICATION_UPON_RETRY:
+        grpc_slice currently_attempted = FlattenIovec(iov, iov_count);
+        GPR_ASSERT(GRPC_SLICE_LENGTH(currently_attempted) >=
+                   GRPC_SLICE_LENGTH(write_buf_));
+        ares_ssize_t total_sent = 0;
+        for (size_t i = 0; i < GRPC_SLICE_LENGTH(write_buf_); i++) {
+          GPR_ASSERT(GRPC_SLICE_START_PTR(currently_attempted)[i] ==
+                     GRPC_SLICE_START_PTR(write_buf_)[i]);
+          total_sent++;
+        }
+        grpc_slice_unref_internal(write_buf_);
+        write_buf_ =
+            grpc_slice_sub_no_ref(currently_attempted, total_sent,
+                                  GRPC_SLICE_LENGTH(currently_attempted));
+        write_state_ = WRITE_IDLE;
+        total_sent += TrySendWriteBufSyncNonBlocking();
+        return total_sent;
+    }
     abort();
   }
-  bool IsFdStillReadableLocked() override { abort(); }
-  void ShutdownLocked(grpc_error* error) override { abort(); }
-  ares_socket_t GetWrappedAresSocketLocked() override { abort(); }
-  const char* GetName() override { abort(); }
+
+  int Connect(const struct sockaddr* target, ares_socklen_t target_len) {
+    SOCKET s = grpc_winsocket_wrapped_socket(winsocket_);
+    GRPC_CARES_TRACE_LOG("Connect: fd:|%s|", GetName());
+    int out =
+        WSAConnect(s, target, target_len, nullptr, nullptr, nullptr, nullptr);
+    if (out != 0) {
+      char* msg = gpr_format_message(WSAGetLastError());
+      GRPC_CARES_TRACE_LOG("Connect error code:|%d|, msg:|%s|. fd:|%s|",
+                           WSAGetLastError(), msg, GetName());
+      gpr_free(msg);
+      // c-ares expects a posix-style connect API
+      out = -1;
+    }
+    return out;
+  }
+
+  static void OnIocpReadable(void* arg, grpc_error* error) {
+    GrpcPolledFdWindows* polled_fd = static_cast<GrpcPolledFdWindows*>(arg);
+    polled_fd->OnIocpReadableInner(error);
+  }
+
+  void OnIocpReadableInner(grpc_error* error) {
+    if (error == GRPC_ERROR_NONE) {
+      if (winsocket_->read_info.wsa_error != 0) {
+        /* WSAEMSGSIZE would be due to receiving more data
+         * than our read buffer's fixed capacity. Assume that
+         * the connection is TCP and read the leftovers
+         * in subsequent c-ares reads. */
+        if (winsocket_->read_info.wsa_error != WSAEMSGSIZE) {
+          GRPC_ERROR_UNREF(error);
+          char* msg = gpr_format_message(winsocket_->read_info.wsa_error);
+          GRPC_CARES_TRACE_LOG(
+              "OnIocpReadableInner. winsocket error:|%s|. fd:|%s|", msg,
+              GetName());
+          error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
+          gpr_free(msg);
+        }
+      }
+    }
+    if (error == GRPC_ERROR_NONE) {
+      read_buf_ = grpc_slice_sub_no_ref(read_buf_, 0,
+                                        winsocket_->read_info.bytes_transfered);
+    } else {
+      grpc_slice_unref_internal(read_buf_);
+      read_buf_ = grpc_empty_slice();
+    }
+    GRPC_CARES_TRACE_LOG(
+        "OnIocpReadable finishing. read buf length now:|%d|. :fd:|%s|",
+        GRPC_SLICE_LENGTH(read_buf_), GetName());
+    ScheduleAndNullReadClosure(error);
+  }
+
+  static void OnIocpWriteable(void* arg, grpc_error* error) {
+    GrpcPolledFdWindows* polled_fd = static_cast<GrpcPolledFdWindows*>(arg);
+    polled_fd->OnIocpWriteableInner(error);
+  }
+
+  void OnIocpWriteableInner(grpc_error* error) {
+    GRPC_CARES_TRACE_LOG("OnIocpWriteableInner. fd:|%s|", GetName());
+    if (error == GRPC_ERROR_NONE) {
+      if (winsocket_->write_info.wsa_error != 0) {
+        char* msg = gpr_format_message(winsocket_->write_info.wsa_error);
+        GRPC_CARES_TRACE_LOG(
+            "OnIocpWriteableInner. winsocket error:|%s|. fd:|%s|", msg,
+            GetName());
+        GRPC_ERROR_UNREF(error);
+        error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
+        gpr_free(msg);
+      }
+    }
+    GPR_ASSERT(write_state_ == WRITE_PENDING);
+    if (error == GRPC_ERROR_NONE) {
+      write_state_ = WRITE_WAITING_FOR_VERIFICATION_UPON_RETRY;
+      write_buf_ = grpc_slice_sub_no_ref(
+          write_buf_, 0, winsocket_->write_info.bytes_transfered);
+    } else {
+      grpc_slice_unref_internal(write_buf_);
+      write_buf_ = grpc_empty_slice();
+    }
+    ScheduleAndNullWriteClosure(error);
+  }
+
+  bool gotten_into_driver_list() const { return gotten_into_driver_list_; }
+  void set_gotten_into_driver_list() { gotten_into_driver_list_ = true; }
+
+  grpc_combiner* combiner_;
+  char recv_from_source_addr_[200];
+  ares_socklen_t recv_from_source_addr_len_;
+  grpc_slice read_buf_;
+  grpc_slice write_buf_;
+  grpc_closure* read_closure_ = nullptr;
+  grpc_closure* write_closure_ = nullptr;
+  grpc_closure outer_read_closure_;
+  grpc_closure outer_write_closure_;
+  grpc_winsocket* winsocket_;
+  WriteState write_state_;
+  char* name_ = nullptr;
+  bool gotten_into_driver_list_;
 };
 
-GrpcPolledFd* NewGrpcPolledFdLocked(ares_socket_t as,
-                                    grpc_pollset_set* driver_pollset_set) {
-  return nullptr;
-}
+struct SockToPolledFdEntry {
+  SockToPolledFdEntry(SOCKET s, GrpcPolledFdWindows* fd)
+      : socket(s), polled_fd(fd) {}
+  SOCKET socket;
+  GrpcPolledFdWindows* polled_fd;
+  SockToPolledFdEntry* next = nullptr;
+};
+
+/* A SockToPolledFdMap can make ares_socket_t types (SOCKET's on windows)
+ * to GrpcPolledFdWindow's, and is used to find the appropriate
+ * GrpcPolledFdWindows to handle a virtual socket call when c-ares makes that
+ * socket call on the ares_socket_t type. Instances are owned by and one-to-one
+ * with a GrpcPolledFdWindows factory and event driver */
+class SockToPolledFdMap {
+ public:
+  SockToPolledFdMap(grpc_combiner* combiner) {
+    combiner_ = GRPC_COMBINER_REF(combiner, "sock to polled fd map");
+  }
+
+  ~SockToPolledFdMap() {
+    GPR_ASSERT(head_ == nullptr);
+    GRPC_COMBINER_UNREF(combiner_, "sock to polled fd map");
+  }
+
+  void AddNewSocket(SOCKET s, GrpcPolledFdWindows* polled_fd) {
+    SockToPolledFdEntry* new_node = New<SockToPolledFdEntry>(s, polled_fd);
+    new_node->next = head_;
+    head_ = new_node;
+  }
+
+  GrpcPolledFdWindows* LookupPolledFd(SOCKET s) {
+    for (SockToPolledFdEntry* node = head_; node != nullptr;
+         node = node->next) {
+      if (node->socket == s) {
+        GPR_ASSERT(node->polled_fd != nullptr);
+        return node->polled_fd;
+      }
+    }
+    abort();
+  }
+
+  void RemoveEntry(SOCKET s) {
+    GPR_ASSERT(head_ != nullptr);
+    SockToPolledFdEntry** prev = &head_;
+    for (SockToPolledFdEntry* node = head_; node != nullptr;
+         node = node->next) {
+      if (node->socket == s) {
+        *prev = node->next;
+        Delete(node);
+        return;
+      }
+      prev = &node->next;
+    }
+    abort();
+  }
+
+  /* These virtual socket functions are called from within the c-ares
+   * library. These methods generally dispatch those socket calls to the
+   * appropriate methods. The virtual "socket" and "close" methods are
+   * special and instead create/add and remove/destroy GrpcPolledFdWindows
+   * objects.
+   */
+  static ares_socket_t Socket(int af, int type, int protocol, void* user_data) {
+    SockToPolledFdMap* map = static_cast<SockToPolledFdMap*>(user_data);
+    SOCKET s = WSASocket(af, type, protocol, nullptr, 0, WSA_FLAG_OVERLAPPED);
+    if (s == INVALID_SOCKET) {
+      return s;
+    }
+    grpc_tcp_set_non_block(s);
+    GrpcPolledFdWindows* polled_fd =
+        New<GrpcPolledFdWindows>(s, map->combiner_);
+    map->AddNewSocket(s, polled_fd);
+    return s;
+  }
+
+  static int Connect(ares_socket_t as, const struct sockaddr* target,
+                     ares_socklen_t target_len, void* user_data) {
+    SockToPolledFdMap* map = static_cast<SockToPolledFdMap*>(user_data);
+    GrpcPolledFdWindows* polled_fd = map->LookupPolledFd(as);
+    return polled_fd->Connect(target, target_len);
+  }
+
+  static ares_ssize_t SendV(ares_socket_t as, const struct iovec* iov,
+                            int iovec_count, void* user_data) {
+    SockToPolledFdMap* map = static_cast<SockToPolledFdMap*>(user_data);
+    GrpcPolledFdWindows* polled_fd = map->LookupPolledFd(as);
+    return polled_fd->SendV(iov, iovec_count);
+  }
+
+  static ares_ssize_t RecvFrom(ares_socket_t as, void* data, size_t data_len,
+                               int flags, struct sockaddr* from,
+                               ares_socklen_t* from_len, void* user_data) {
+    SockToPolledFdMap* map = static_cast<SockToPolledFdMap*>(user_data);
+    GrpcPolledFdWindows* polled_fd = map->LookupPolledFd(as);
+    return polled_fd->RecvFrom(data, data_len, flags, from, from_len);
+  }
+
+  static int CloseSocket(SOCKET s, void* user_data) {
+    SockToPolledFdMap* map = static_cast<SockToPolledFdMap*>(user_data);
+    GrpcPolledFdWindows* polled_fd = map->LookupPolledFd(s);
+    map->RemoveEntry(s);
+    // If a gRPC polled fd has not made it in to the driver's list yet, then
+    // the driver has not and will never see this socket.
+    if (!polled_fd->gotten_into_driver_list()) {
+      polled_fd->ShutdownLocked(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+          "Shut down c-ares fd before without it ever having made it into the "
+          "driver's list"));
+      return 0;
+    }
+    return 0;
+  }
+
+ private:
+  SockToPolledFdEntry* head_ = nullptr;
+  grpc_combiner* combiner_;
+};
+
+const struct ares_socket_functions custom_ares_sock_funcs = {
+    &SockToPolledFdMap::Socket /* socket */,
+    &SockToPolledFdMap::CloseSocket /* close */,
+    &SockToPolledFdMap::Connect /* connect */,
+    &SockToPolledFdMap::RecvFrom /* recvfrom */,
+    &SockToPolledFdMap::SendV /* sendv */,
+};
+
+class GrpcPolledFdFactoryWindows : public GrpcPolledFdFactory {
+ public:
+  GrpcPolledFdFactoryWindows(grpc_combiner* combiner)
+      : sock_to_polled_fd_map_(combiner) {}
+
+  GrpcPolledFd* NewGrpcPolledFdLocked(ares_socket_t as,
+                                      grpc_pollset_set* driver_pollset_set,
+                                      grpc_combiner* combiner) override {
+    GrpcPolledFdWindows* polled_fd = sock_to_polled_fd_map_.LookupPolledFd(as);
+    // Set a flag so that the virtual socket "close" method knows it
+    // doesn't need to call ShutdownLocked, since now the driver will.
+    polled_fd->set_gotten_into_driver_list();
+    return polled_fd;
+  }
 
-void ConfigureAresChannelLocked(ares_channel* channel) { abort(); }
+  void ConfigureAresChannelLocked(ares_channel channel) override {
+    ares_set_socket_functions(channel, &custom_ares_sock_funcs,
+                              &sock_to_polled_fd_map_);
+  }
+
+ private:
+  SockToPolledFdMap sock_to_polled_fd_map_;
+};
+
+UniquePtr<GrpcPolledFdFactory> NewGrpcPolledFdFactory(grpc_combiner* combiner) {
+  return UniquePtr<GrpcPolledFdFactory>(
+      New<GrpcPolledFdFactoryWindows>(combiner));
+}
 
 }  // namespace grpc_core
 

src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc

@@ -49,6 +49,8 @@ static gpr_mu g_init_mu;
 grpc_core::TraceFlag grpc_trace_cares_address_sorting(false,
                                                       "cares_address_sorting");
 
+grpc_core::TraceFlag grpc_trace_cares_resolver(false, "cares_resolver");
+
 struct grpc_ares_request {
   /** indicates the DNS server to use, if specified */
   struct ares_addr_port_node dns_server_addr;

src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h

@@ -28,6 +28,13 @@
 
 extern grpc_core::TraceFlag grpc_trace_cares_address_sorting;
 
+extern grpc_core::TraceFlag grpc_trace_cares_resolver;
+
+#define GRPC_CARES_TRACE_LOG(format, ...)                         \
+  if (grpc_trace_cares_resolver.enabled()) {                      \
+    gpr_log(GPR_DEBUG, "(c-ares resolver) " format, __VA_ARGS__); \
+  }
+
 typedef struct grpc_ares_request grpc_ares_request;
 
 /* Asynchronously resolve \a name. Use \a default_port if a port isn't

src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc

@@ -58,6 +58,8 @@ class NativeDnsResolver : public Resolver {
 
   void RequestReresolutionLocked() override;
 
+  void ResetBackoffLocked() override;
+
   void ShutdownLocked() override;
 
  private:
@@ -158,6 +160,13 @@ void NativeDnsResolver::RequestReresolutionLocked() {
   }
 }
 
+void NativeDnsResolver::ResetBackoffLocked() {
+  if (have_next_resolution_timer_) {
+    grpc_timer_cancel(&next_resolution_timer_);
+  }
+  backoff_.Reset();
+}
+
 void NativeDnsResolver::ShutdownLocked() {
   if (have_next_resolution_timer_) {
     grpc_timer_cancel(&next_resolution_timer_);

src/core/ext/filters/client_channel/subchannel.cc

@@ -132,6 +132,8 @@ struct grpc_subchannel {
   bool have_alarm;
   /** have we started the backoff loop */
   bool backoff_begun;
+  // reset_backoff() was called while alarm was pending
+  bool deferred_reset_backoff;
   /** our alarm */
   grpc_timer alarm;
 
@@ -453,6 +455,9 @@ static void on_alarm(void* arg, grpc_error* error) {
   if (c->disconnected) {
     error = GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING("Disconnected",
                                                              &error, 1);
+  } else if (c->deferred_reset_backoff) {
+    c->deferred_reset_backoff = false;
+    error = GRPC_ERROR_NONE;
   } else {
     GRPC_ERROR_REF(error);
   }
@@ -690,6 +695,19 @@ static void on_subchannel_connected(void* arg, grpc_error* error) {
   grpc_channel_args_destroy(delete_channel_args);
 }
 
+void grpc_subchannel_reset_backoff(grpc_subchannel* subchannel) {
+  gpr_mu_lock(&subchannel->mu);
+  if (subchannel->have_alarm) {
+    subchannel->deferred_reset_backoff = true;
+    grpc_timer_cancel(&subchannel->alarm);
+  } else {
+    subchannel->backoff_begun = false;
+    subchannel->backoff->Reset();
+    maybe_start_connecting_locked(subchannel);
+  }
+  gpr_mu_unlock(&subchannel->mu);
+}
+
 /*
  * grpc_subchannel_call implementation
  */

src/core/ext/filters/client_channel/subchannel.h

@@ -152,6 +152,13 @@ grpc_subchannel_get_connected_subchannel(grpc_subchannel* c);
 const grpc_subchannel_key* grpc_subchannel_get_key(
     const grpc_subchannel* subchannel);
 
+// Resets the connection backoff of the subchannel.
+// TODO(roth): Move connection backoff out of subchannels and up into LB
+// policy code (probably by adding a SubchannelGroup between
+// SubchannelList and SubchannelData), at which point this method can
+// go away.
+void grpc_subchannel_reset_backoff(grpc_subchannel* subchannel);
+
 /** continue processing a transport op */
 void grpc_subchannel_call_process_op(grpc_subchannel_call* subchannel_call,
                                      grpc_transport_stream_op_batch* op);

src/core/ext/filters/deadline/deadline_filter.cc

@@ -379,10 +379,10 @@ static bool maybe_add_deadline_filter(grpc_channel_stack_builder* builder,
 
 void grpc_deadline_filter_init(void) {
   grpc_channel_init_register_stage(
-      GRPC_CLIENT_DIRECT_CHANNEL, GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
+      GRPC_CLIENT_DIRECT_CHANNEL, GRPC_CHANNEL_INIT_PRIORITY_VERY_HIGH,
       maybe_add_deadline_filter, (void*)&grpc_client_deadline_filter);
   grpc_channel_init_register_stage(
-      GRPC_SERVER_CHANNEL, GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
+      GRPC_SERVER_CHANNEL, GRPC_CHANNEL_INIT_PRIORITY_VERY_HIGH,
       maybe_add_deadline_filter, (void*)&grpc_server_deadline_filter);
 }
 

src/core/ext/filters/http/client_authority_filter.cc

@@ -146,12 +146,12 @@ static bool add_client_authority_filter(grpc_channel_stack_builder* builder,
 }
 
 void grpc_client_authority_filter_init(void) {
-  grpc_channel_init_register_stage(GRPC_CLIENT_SUBCHANNEL, INT_MAX,
-                                   add_client_authority_filter,
-                                   (void*)&grpc_client_authority_filter);
-  grpc_channel_init_register_stage(GRPC_CLIENT_DIRECT_CHANNEL, INT_MAX,
-                                   add_client_authority_filter,
-                                   (void*)&grpc_client_authority_filter);
+  grpc_channel_init_register_stage(
+      GRPC_CLIENT_SUBCHANNEL, GRPC_CHANNEL_INIT_PRIORITY_HIGH,
+      add_client_authority_filter, (void*)&grpc_client_authority_filter);
+  grpc_channel_init_register_stage(
+      GRPC_CLIENT_DIRECT_CHANNEL, GRPC_CHANNEL_INIT_PRIORITY_HIGH,
+      add_client_authority_filter, (void*)&grpc_client_authority_filter);
 }
 
 void grpc_client_authority_filter_shutdown(void) {}

src/core/ext/filters/http/http_filters_plugin.cc

@@ -18,6 +18,7 @@
 
 #include <grpc/support/port_platform.h>
 
+#include <limits.h>
 #include <string.h>
 
 #include "src/core/ext/filters/http/client/http_client_filter.h"
@@ -51,15 +52,15 @@ static bool maybe_add_optional_filter(grpc_channel_stack_builder* builder,
   bool enable = grpc_channel_arg_get_bool(
       grpc_channel_args_find(channel_args, filtarg->control_channel_arg),
       !grpc_channel_args_want_minimal_stack(channel_args));
-  return enable ? grpc_channel_stack_builder_prepend_filter(
+  return enable ? grpc_channel_stack_builder_append_filter(
                       builder, filtarg->filter, nullptr, nullptr)
                 : true;
 }
 
-static bool maybe_add_required_filter(grpc_channel_stack_builder* builder,
-                                      void* arg) {
+static bool maybe_append_required_filter(grpc_channel_stack_builder* builder,
+                                         void* arg) {
   return is_building_http_like_transport(builder)
-             ? grpc_channel_stack_builder_prepend_filter(
+             ? grpc_channel_stack_builder_append_filter(
                    builder, static_cast<const grpc_channel_filter*>(arg),
                    nullptr, nullptr)
              : true;
@@ -67,23 +68,23 @@ static bool maybe_add_required_filter(grpc_channel_stack_builder* builder,
 
 void grpc_http_filters_init(void) {
   grpc_channel_init_register_stage(GRPC_CLIENT_SUBCHANNEL,
-                                   GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
+                                   GRPC_CHANNEL_INIT_PRIORITY_HIGH,
                                    maybe_add_optional_filter, &compress_filter);
   grpc_channel_init_register_stage(GRPC_CLIENT_DIRECT_CHANNEL,
-                                   GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
+                                   GRPC_CHANNEL_INIT_PRIORITY_HIGH,
                                    maybe_add_optional_filter, &compress_filter);
   grpc_channel_init_register_stage(GRPC_SERVER_CHANNEL,
-                                   GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
+                                   GRPC_CHANNEL_INIT_PRIORITY_HIGH,
                                    maybe_add_optional_filter, &compress_filter);
   grpc_channel_init_register_stage(
-      GRPC_CLIENT_SUBCHANNEL, GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
-      maybe_add_required_filter, (void*)&grpc_http_client_filter);
+      GRPC_CLIENT_SUBCHANNEL, GRPC_CHANNEL_INIT_PRIORITY_HIGH,
+      maybe_append_required_filter, (void*)&grpc_http_client_filter);
   grpc_channel_init_register_stage(
-      GRPC_CLIENT_DIRECT_CHANNEL, GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
-      maybe_add_required_filter, (void*)&grpc_http_client_filter);
+      GRPC_CLIENT_DIRECT_CHANNEL, GRPC_CHANNEL_INIT_PRIORITY_HIGH,
+      maybe_append_required_filter, (void*)&grpc_http_client_filter);
   grpc_channel_init_register_stage(
-      GRPC_SERVER_CHANNEL, GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
-      maybe_add_required_filter, (void*)&grpc_http_server_filter);
+      GRPC_SERVER_CHANNEL, GRPC_CHANNEL_INIT_PRIORITY_HIGH,
+      maybe_append_required_filter, (void*)&grpc_http_server_filter);
 }
 
 void grpc_http_filters_shutdown(void) {}

src/core/ext/filters/load_reporting/server_load_reporting_filter.cc

@@ -345,7 +345,8 @@ struct ServerLoadReportingFilterStaticRegistrar {
     if (registered) return;
     RegisterChannelFilter<ServerLoadReportingChannelData,
                           ServerLoadReportingCallData>(
-        "server_load_reporting", GRPC_SERVER_CHANNEL, INT_MAX,
+        "server_load_reporting", GRPC_SERVER_CHANNEL,
+        GRPC_CHANNEL_INIT_PRIORITY_LOW, true,
         MaybeAddServerLoadReportingFilter);
     // Access measures to ensure they are initialized. Otherwise, we can't
     // create any valid view before the first RPC.

src/core/ext/filters/max_age/max_age_filter.cc

@@ -536,7 +536,7 @@ static bool maybe_add_max_age_filter(grpc_channel_stack_builder* builder,
 
 void grpc_max_age_filter_init(void) {
   grpc_channel_init_register_stage(GRPC_SERVER_CHANNEL,
-                                   GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
+                                   GRPC_CHANNEL_INIT_PRIORITY_LOW,
                                    maybe_add_max_age_filter, nullptr);
 }
 

src/core/ext/filters/message_size/message_size_filter.cc

@@ -311,13 +311,13 @@ static bool maybe_add_message_size_filter(grpc_channel_stack_builder* builder,
 
 void grpc_message_size_filter_init(void) {
   grpc_channel_init_register_stage(GRPC_CLIENT_SUBCHANNEL,
-                                   GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
+                                   GRPC_CHANNEL_INIT_PRIORITY_LOW,
                                    maybe_add_message_size_filter, nullptr);
   grpc_channel_init_register_stage(GRPC_CLIENT_DIRECT_CHANNEL,
-                                   GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
+                                   GRPC_CHANNEL_INIT_PRIORITY_LOW,
                                    maybe_add_message_size_filter, nullptr);
   grpc_channel_init_register_stage(GRPC_SERVER_CHANNEL,
-                                   GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
+                                   GRPC_CHANNEL_INIT_PRIORITY_LOW,
                                    maybe_add_message_size_filter, nullptr);
 }
 

src/core/ext/transport/chttp2/transport/chttp2_transport.cc

@@ -813,11 +813,7 @@ static void set_write_state(grpc_chttp2_transport* t,
                                  write_state_name(st), reason));
   t->write_state = st;
   if (st == GRPC_CHTTP2_WRITE_STATE_IDLE) {
-    grpc_chttp2_stream* s;
-    while (grpc_chttp2_list_pop_waiting_for_write_stream(t, &s)) {
-      GRPC_CLOSURE_LIST_SCHED(&s->run_after_write);
-      GRPC_CHTTP2_STREAM_UNREF(s, "chttp2:write_closure_sched");
-    }
+    GRPC_CLOSURE_LIST_SCHED(&t->run_after_write);
     if (t->close_transport_on_writes_finished != nullptr) {
       grpc_error* err = t->close_transport_on_writes_finished;
       t->close_transport_on_writes_finished = nullptr;
@@ -1208,14 +1204,11 @@ void grpc_chttp2_complete_closure_step(grpc_chttp2_transport* t,
         grpc_error_add_child(closure->error_data.error, error);
   }
   if (closure->next_data.scratch < CLOSURE_BARRIER_FIRST_REF_BIT) {
-    if (s->seen_error || (t->write_state == GRPC_CHTTP2_WRITE_STATE_IDLE) ||
+    if ((t->write_state == GRPC_CHTTP2_WRITE_STATE_IDLE) ||
         !(closure->next_data.scratch & CLOSURE_BARRIER_MAY_COVER_WRITE)) {
       GRPC_CLOSURE_RUN(closure, closure->error_data.error);
     } else {
-      if (grpc_chttp2_list_add_waiting_for_write_stream(t, s)) {
-        GRPC_CHTTP2_STREAM_REF(s, "chttp2:pending_write_closure");
-      }
-      grpc_closure_list_append(&s->run_after_write, closure,
+      grpc_closure_list_append(&t->run_after_write, closure,
                                closure->error_data.error);
     }
   }
@@ -2016,10 +2009,6 @@ static void remove_stream(grpc_chttp2_transport* t, uint32_t id,
 
 void grpc_chttp2_cancel_stream(grpc_chttp2_transport* t, grpc_chttp2_stream* s,
                                grpc_error* due_to_error) {
-  GRPC_CLOSURE_LIST_SCHED(&s->run_after_write);
-  if (grpc_chttp2_list_remove_waiting_for_write_stream(t, s)) {
-    GRPC_CHTTP2_STREAM_UNREF(s, "chttp2:pending_write_closure");
-  }
   if (!t->is_client && !s->sent_trailing_metadata &&
       grpc_error_has_clear_grpc_status(due_to_error)) {
     close_from_api(t, s, due_to_error);

src/core/ext/transport/chttp2/transport/internal.h

@@ -54,8 +54,6 @@ typedef enum {
   /** streams that are waiting to start because there are too many concurrent
       streams on the connection */
   GRPC_CHTTP2_LIST_WAITING_FOR_CONCURRENCY,
-  /** streams with closures waiting to be run on a write **/
-  GRPC_CHTTP2_LIST_WAITING_FOR_WRITE,
   STREAM_LIST_COUNT /* must be last */
 } grpc_chttp2_stream_list_id;
 
@@ -433,6 +431,9 @@ struct grpc_chttp2_transport {
    */
   grpc_error* close_transport_on_writes_finished;
 
+  /* a list of closures to run after writes are finished */
+  grpc_closure_list run_after_write;
+
   /* buffer pool state */
   /** have we scheduled a benign cleanup? */
   bool benign_reclaimer_registered;
@@ -583,7 +584,6 @@ struct grpc_chttp2_stream {
 
   grpc_slice_buffer flow_controlled_buffer;
 
-  grpc_closure_list run_after_write;
   grpc_chttp2_write_cb* on_flow_controlled_cbs;
   grpc_chttp2_write_cb* on_write_finished_cbs;
   grpc_chttp2_write_cb* finish_after_write;
@@ -686,13 +686,6 @@ bool grpc_chttp2_list_pop_stalled_by_stream(grpc_chttp2_transport* t,
 bool grpc_chttp2_list_remove_stalled_by_stream(grpc_chttp2_transport* t,
                                                grpc_chttp2_stream* s);
 
-bool grpc_chttp2_list_add_waiting_for_write_stream(grpc_chttp2_transport* t,
-                                                   grpc_chttp2_stream* s);
-bool grpc_chttp2_list_pop_waiting_for_write_stream(grpc_chttp2_transport* t,
-                                                   grpc_chttp2_stream** s);
-bool grpc_chttp2_list_remove_waiting_for_write_stream(grpc_chttp2_transport* t,
-                                                      grpc_chttp2_stream* s);
-
 /********* Flow Control ***************/
 
 // Takes in a flow control action and performs all the needed operations.

src/core/ext/transport/chttp2/transport/stream_lists.cc

@@ -35,8 +35,6 @@ static const char* stream_list_id_string(grpc_chttp2_stream_list_id id) {
       return "stalled_by_stream";
     case GRPC_CHTTP2_LIST_WAITING_FOR_CONCURRENCY:
       return "waiting_for_concurrency";
-    case GRPC_CHTTP2_LIST_WAITING_FOR_WRITE:
-      return "waiting_for_write";
     case STREAM_LIST_COUNT:
       GPR_UNREACHABLE_CODE(return "unknown");
   }
@@ -216,18 +214,3 @@ bool grpc_chttp2_list_remove_stalled_by_stream(grpc_chttp2_transport* t,
                                                grpc_chttp2_stream* s) {
   return stream_list_maybe_remove(t, s, GRPC_CHTTP2_LIST_STALLED_BY_STREAM);
 }
-
-bool grpc_chttp2_list_add_waiting_for_write_stream(grpc_chttp2_transport* t,
-                                                   grpc_chttp2_stream* s) {
-  return stream_list_add(t, s, GRPC_CHTTP2_LIST_WAITING_FOR_WRITE);
-}
-
-bool grpc_chttp2_list_pop_waiting_for_write_stream(grpc_chttp2_transport* t,
-                                                   grpc_chttp2_stream** s) {
-  return stream_list_pop(t, s, GRPC_CHTTP2_LIST_WAITING_FOR_WRITE);
-}
-
-bool grpc_chttp2_list_remove_waiting_for_write_stream(grpc_chttp2_transport* t,
-                                                      grpc_chttp2_stream* s) {
-  return stream_list_maybe_remove(t, s, GRPC_CHTTP2_LIST_WAITING_FOR_WRITE);
-}

src/core/lib/channel/connected_channel.cc

@@ -230,8 +230,8 @@ static void bind_transport(grpc_channel_stack* channel_stack,
       grpc_transport_stream_size(static_cast<grpc_transport*>(t));
 }
 
-bool grpc_add_connected_filter(grpc_channel_stack_builder* builder,
-                               void* arg_must_be_null) {
+bool grpc_append_connected_filter(grpc_channel_stack_builder* builder,
+                                  void* arg_must_be_null) {
   GPR_ASSERT(arg_must_be_null == nullptr);
   grpc_transport* t = grpc_channel_stack_builder_get_transport(builder);
   GPR_ASSERT(t != nullptr);

src/core/lib/channel/connected_channel.h

@@ -25,8 +25,8 @@
 
 extern const grpc_channel_filter grpc_connected_filter;
 
-bool grpc_add_connected_filter(grpc_channel_stack_builder* builder,
-                               void* arg_must_be_null);
+bool grpc_append_connected_filter(grpc_channel_stack_builder* builder,
+                                  void* arg_must_be_null);
 
 /* Debug helper to dig the transport stream out of a call element */
 grpc_stream* grpc_connected_channel_get_stream(grpc_call_element* elem);

src/core/lib/iomgr/call_combiner.h

@@ -102,7 +102,10 @@ void grpc_call_combiner_stop(grpc_call_combiner* call_combiner,
 /// If \a closure is NULL, then no closure will be invoked on
 /// cancellation; this effectively unregisters the previously set closure.
 /// However, most filters will not need to explicitly unregister their
-/// callbacks, as this is done automatically when the call is destroyed.
+/// callbacks, as this is done automatically when the call is destroyed. Filters
+/// that schedule the cancellation closure on ExecCtx do not need to take a ref
+/// on the call stack to guarantee closure liveness. This is done by explicitly
+/// flushing ExecCtx after the unregistration during call destruction.
 void grpc_call_combiner_set_notify_on_cancel(grpc_call_combiner* call_combiner,
                                              grpc_closure* closure);
 

src/core/lib/iomgr/iocp_windows.cc

@@ -89,10 +89,15 @@ grpc_iocp_work_status grpc_iocp_work(grpc_millis deadline) {
   } else {
     abort();
   }
-  success = WSAGetOverlappedResult(socket->socket, &info->overlapped, &bytes,
-                                   FALSE, &flags);
-  info->bytes_transfered = bytes;
-  info->wsa_error = success ? 0 : WSAGetLastError();
+  if (socket->shutdown_called) {
+    info->bytes_transfered = 0;
+    info->wsa_error = WSA_OPERATION_ABORTED;
+  } else {
+    success = WSAGetOverlappedResult(socket->socket, &info->overlapped, &bytes,
+                                     FALSE, &flags);
+    info->bytes_transfered = bytes;
+    info->wsa_error = success ? 0 : WSAGetLastError();
+  }
   GPR_ASSERT(overlapped == &info->overlapped);
   grpc_socket_become_ready(socket, info);
   return GRPC_IOCP_WORK_WORK;

src/core/lib/iomgr/socket_windows.cc

@@ -52,6 +52,10 @@ grpc_winsocket* grpc_winsocket_create(SOCKET socket, const char* name) {
   return r;
 }
 
+SOCKET grpc_winsocket_wrapped_socket(grpc_winsocket* socket) {
+  return socket->socket;
+}
+
 /* Schedule a shutdown of the socket operations. Will call the pending
    operations to abort them. We need to do that this way because of the
    various callsites of that function, which happens to be in various

src/core/lib/iomgr/socket_windows.h

@@ -92,6 +92,8 @@ typedef struct grpc_winsocket {
    it will be responsible for closing it. */
 grpc_winsocket* grpc_winsocket_create(SOCKET socket, const char* name);
 
+SOCKET grpc_winsocket_wrapped_socket(grpc_winsocket* socket);
+
 /* Initiate an asynchronous shutdown of the socket. Will call off any pending
    operation to cancel them. */
 void grpc_winsocket_shutdown(grpc_winsocket* socket);

src/core/lib/iomgr/tcp_windows.cc

@@ -53,7 +53,7 @@
 
 extern grpc_core::TraceFlag grpc_tcp_trace;
 
-static grpc_error* set_non_block(SOCKET sock) {
+grpc_error* grpc_tcp_set_non_block(SOCKET sock) {
   int status;
   uint32_t param = 1;
   DWORD ret;
@@ -90,7 +90,7 @@ static grpc_error* enable_loopback_fast_path(SOCKET sock) {
 
 grpc_error* grpc_tcp_prepare_socket(SOCKET sock) {
   grpc_error* err;
-  err = set_non_block(sock);
+  err = grpc_tcp_set_non_block(sock);
   if (err != GRPC_ERROR_NONE) return err;
   err = set_dualstack(sock);
   if (err != GRPC_ERROR_NONE) return err;

src/core/lib/iomgr/tcp_windows.h

@@ -46,6 +46,8 @@ grpc_endpoint* grpc_tcp_create(grpc_winsocket* socket,
 
 grpc_error* grpc_tcp_prepare_socket(SOCKET sock);
 
+grpc_error* grpc_tcp_set_non_block(SOCKET sock);
+
 #endif
 
 #endif /* GRPC_CORE_LIB_IOMGR_TCP_WINDOWS_H */

src/core/lib/security/security_connector/load_system_roots.h

@@ -0,0 +1,29 @@
+/*
+ *
+ * Copyright 2018 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.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_SECURITY_SECURITY_CONNECTOR_LOAD_SYSTEM_ROOTS_H
+#define GRPC_CORE_LIB_SECURITY_SECURITY_CONNECTOR_LOAD_SYSTEM_ROOTS_H
+
+namespace grpc_core {
+
+// Returns a slice containing roots from the OS trust store
+grpc_slice LoadSystemRootCerts();
+
+}  // namespace grpc_core
+
+#endif /* GRPC_CORE_LIB_SECURITY_SECURITY_CONNECTOR_LOAD_SYSTEM_ROOTS_H */

src/core/lib/security/security_connector/load_system_roots_fallback.cc

@@ -0,0 +1,32 @@
+/*
+ *
+ * Copyright 2018 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 <grpc/support/port_platform.h>
+
+#include <grpc/slice_buffer.h>
+#include "src/core/lib/security/security_connector/load_system_roots.h"
+
+#ifndef GPR_LINUX
+
+namespace grpc_core {
+
+grpc_slice LoadSystemRootCerts() { return grpc_empty_slice(); }
+
+}  // namespace grpc_core
+
+#endif /* GPR_LINUX */

src/core/lib/security/security_connector/load_system_roots_linux.cc

@@ -0,0 +1,165 @@
+/*
+ *
+ * Copyright 2018 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 <grpc/support/port_platform.h>
+
+#include <grpc/slice_buffer.h>
+#include "src/core/lib/security/security_connector/load_system_roots_linux.h"
+
+#ifdef GPR_LINUX
+
+#include "src/core/lib/security/security_connector/load_system_roots.h"
+
+#include <dirent.h>
+#include <fcntl.h>
+#include <stdbool.h>
+#include <string.h>
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+
+#include "src/core/lib/gpr/env.h"
+#include "src/core/lib/gpr/string.h"
+#include "src/core/lib/gpr/useful.h"
+#include "src/core/lib/gprpp/inlined_vector.h"
+#include "src/core/lib/iomgr/load_file.h"
+
+namespace grpc_core {
+namespace {
+
+const char* kLinuxCertFiles[] = {
+    "/etc/ssl/certs/ca-certificates.crt", "/etc/pki/tls/certs/ca-bundle.crt",
+    "/etc/ssl/ca-bundle.pem", "/etc/pki/tls/cacert.pem",
+    "/etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem"};
+const char* kLinuxCertDirectories[] = {
+    "/etc/ssl/certs", "/system/etc/security/cacerts", "/usr/local/share/certs",
+    "/etc/pki/tls/certs", "/etc/openssl/certs"};
+
+grpc_slice GetSystemRootCerts() {
+  grpc_slice valid_bundle_slice = grpc_empty_slice();
+  size_t num_cert_files_ = GPR_ARRAY_SIZE(kLinuxCertFiles);
+  for (size_t i = 0; i < num_cert_files_; i++) {
+    grpc_error* error =
+        grpc_load_file(kLinuxCertFiles[i], 1, &valid_bundle_slice);
+    if (error == GRPC_ERROR_NONE) {
+      return valid_bundle_slice;
+    }
+  }
+  return grpc_empty_slice();
+}
+
+}  // namespace
+
+void GetAbsoluteFilePath(const char* valid_file_dir,
+                         const char* file_entry_name, char* path_buffer) {
+  if (valid_file_dir != nullptr && file_entry_name != nullptr) {
+    int path_len = snprintf(path_buffer, MAXPATHLEN, "%s/%s", valid_file_dir,
+                            file_entry_name);
+    if (path_len == 0) {
+      gpr_log(GPR_ERROR, "failed to get absolute path for file: %s",
+              file_entry_name);
+    }
+  }
+}
+
+grpc_slice CreateRootCertsBundle(const char* certs_directory) {
+  grpc_slice bundle_slice = grpc_empty_slice();
+  if (certs_directory == nullptr) {
+    return bundle_slice;
+  }
+  DIR* ca_directory = opendir(certs_directory);
+  if (ca_directory == nullptr) {
+    return bundle_slice;
+  }
+  struct FileData {
+    char path[MAXPATHLEN];
+    off_t size;
+  };
+  InlinedVector<FileData, 2> roots_filenames;
+  size_t total_bundle_size = 0;
+  struct dirent* directory_entry;
+  while ((directory_entry = readdir(ca_directory)) != nullptr) {
+    struct stat dir_entry_stat;
+    const char* file_entry_name = directory_entry->d_name;
+    FileData file_data;
+    GetAbsoluteFilePath(certs_directory, file_entry_name, file_data.path);
+    int stat_return = stat(file_data.path, &dir_entry_stat);
+    if (stat_return == -1 || !S_ISREG(dir_entry_stat.st_mode)) {
+      // no subdirectories.
+      if (stat_return == -1) {
+        gpr_log(GPR_ERROR, "failed to get status for file: %s", file_data.path);
+      }
+      continue;
+    }
+    file_data.size = dir_entry_stat.st_size;
+    total_bundle_size += file_data.size;
+    roots_filenames.push_back(file_data);
+  }
+  closedir(ca_directory);
+  char* bundle_string = static_cast<char*>(gpr_zalloc(total_bundle_size + 1));
+  size_t bytes_read = 0;
+  for (size_t i = 0; i < roots_filenames.size(); i++) {
+    int file_descriptor = open(roots_filenames[i].path, O_RDONLY);
+    if (file_descriptor != -1) {
+      // Read file into bundle.
+      size_t cert_file_size = roots_filenames[i].size;
+      int read_ret =
+          read(file_descriptor, bundle_string + bytes_read, cert_file_size);
+      if (read_ret != -1) {
+        bytes_read += read_ret;
+      } else {
+        gpr_log(GPR_ERROR, "failed to read file: %s", roots_filenames[i].path);
+      }
+    }
+  }
+  bundle_slice = grpc_slice_new(bundle_string, bytes_read, gpr_free);
+  return bundle_slice;
+}
+
+grpc_slice LoadSystemRootCerts() {
+  grpc_slice result = grpc_empty_slice();
+  // Prioritize user-specified custom directory if flag is set.
+  char* custom_dir = gpr_getenv("GRPC_SYSTEM_SSL_ROOTS_DIR");
+  if (custom_dir != nullptr) {
+    result = CreateRootCertsBundle(custom_dir);
+    gpr_free(custom_dir);
+  }
+  // If the custom directory is empty/invalid/not specified, fallback to
+  // distribution-specific directory.
+  if (GRPC_SLICE_IS_EMPTY(result)) {
+    result = GetSystemRootCerts();
+  }
+  if (GRPC_SLICE_IS_EMPTY(result)) {
+    for (size_t i = 0; i < GPR_ARRAY_SIZE(kLinuxCertDirectories); i++) {
+      result = CreateRootCertsBundle(kLinuxCertDirectories[i]);
+      if (!GRPC_SLICE_IS_EMPTY(result)) {
+        break;
+      }
+    }
+  }
+  return result;
+}
+
+}  // namespace grpc_core
+
+#endif /* GPR_LINUX */

src/core/lib/security/security_connector/load_system_roots_linux.h

@@ -0,0 +1,44 @@
+/*
+ *
+ * Copyright 2018 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.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_SECURITY_SECURITY_CONNECTOR_LOAD_SYSTEM_ROOTS_LINUX_H
+#define GRPC_CORE_LIB_SECURITY_SECURITY_CONNECTOR_LOAD_SYSTEM_ROOTS_LINUX_H
+
+#include <grpc/support/port_platform.h>
+
+#ifdef GPR_LINUX
+
+namespace grpc_core {
+
+// Creates a bundle slice containing the contents of all certificate files in
+// a directory.
+// Returns such slice.
+// Exposed for testing purposes only.
+grpc_slice CreateRootCertsBundle(const char* certs_directory);
+
+// Gets the absolute file path needed to load a certificate file.
+// Populates path_buffer, which must be of size MAXPATHLEN.
+// Exposed for testing purposes only.
+void GetAbsoluteFilePath(const char* valid_file_dir,
+                         const char* file_entry_name, char* path_buffer);
+
+}  // namespace grpc_core
+
+#endif /* GPR_LINUX */
+#endif /* GRPC_CORE_LIB_SECURITY_SECURITY_CONNECTOR_LOAD_SYSTEM_ROOTS_LINUX_H \
+        */

src/core/lib/security/security_connector/security_connector.cc

@@ -21,7 +21,6 @@
 #include "src/core/lib/security/security_connector/security_connector.h"
 
 #include <stdbool.h>
-#include <string.h>
 
 #include <grpc/slice_buffer.h>
 #include <grpc/support/alloc.h>
@@ -39,6 +38,7 @@
 #include "src/core/lib/security/credentials/credentials.h"
 #include "src/core/lib/security/credentials/fake/fake_credentials.h"
 #include "src/core/lib/security/credentials/ssl/ssl_credentials.h"
+#include "src/core/lib/security/security_connector/load_system_roots.h"
 #include "src/core/lib/security/transport/secure_endpoint.h"
 #include "src/core/lib/security/transport/security_handshaker.h"
 #include "src/core/lib/security/transport/target_authority_table.h"
@@ -57,6 +57,12 @@ static const char* installed_roots_path =
     INSTALL_PREFIX "/share/grpc/roots.pem";
 #endif
 
+/** Environment variable used as a flag to enable/disable loading system root
+    certificates from the OS trust store. */
+#ifndef GRPC_USE_SYSTEM_SSL_ROOTS_ENV_VAR
+#define GRPC_USE_SYSTEM_SSL_ROOTS_ENV_VAR "GRPC_USE_SYSTEM_SSL_ROOTS"
+#endif
+
 #ifndef TSI_OPENSSL_ALPN_SUPPORT
 #define TSI_OPENSSL_ALPN_SUPPORT 1
 #endif
@@ -1186,6 +1192,10 @@ const char* DefaultSslRootStore::GetPemRootCerts() {
 
 grpc_slice DefaultSslRootStore::ComputePemRootCerts() {
   grpc_slice result = grpc_empty_slice();
+  char* use_system_roots_env_value =
+      gpr_getenv(GRPC_USE_SYSTEM_SSL_ROOTS_ENV_VAR);
+  const bool use_system_roots = gpr_is_true(use_system_roots_env_value);
+  gpr_free(use_system_roots_env_value);
   // First try to load the roots from the environment.
   char* default_root_certs_path =
       gpr_getenv(GRPC_DEFAULT_SSL_ROOTS_FILE_PATH_ENV_VAR);
@@ -1207,7 +1217,11 @@ grpc_slice DefaultSslRootStore::ComputePemRootCerts() {
     }
     gpr_free(pem_root_certs);
   }
-  // Fall back to installed certs if needed.
+  // Try loading roots from OS trust store if flag is enabled.
+  if (GRPC_SLICE_IS_EMPTY(result) && use_system_roots) {
+    result = LoadSystemRootCerts();
+  }
+  // Fallback to roots manually shipped with gRPC.
   if (GRPC_SLICE_IS_EMPTY(result) &&
       ovrd_res != GRPC_SSL_ROOTS_OVERRIDE_FAIL_PERMANENTLY) {
     GRPC_LOG_IF_ERROR("load_file",

src/core/lib/security/transport/client_auth_filter.cc

@@ -167,7 +167,6 @@ static void cancel_get_request_metadata(void* arg, grpc_error* error) {
     grpc_call_credentials_cancel_get_request_metadata(
         calld->creds, &calld->md_array, GRPC_ERROR_REF(error));
   }
-  GRPC_CALL_STACK_UNREF(calld->owning_call, "cancel_get_request_metadata");
 }
 
 static void send_security_metadata(grpc_call_element* elem,
@@ -222,7 +221,6 @@ static void send_security_metadata(grpc_call_element* elem,
     GRPC_ERROR_UNREF(error);
   } else {
     // Async return; register cancellation closure with call combiner.
-    GRPC_CALL_STACK_REF(calld->owning_call, "cancel_get_request_metadata");
     grpc_call_combiner_set_notify_on_cancel(
         calld->call_combiner,
         GRPC_CLOSURE_INIT(&calld->get_request_metadata_cancel_closure,
@@ -265,7 +263,6 @@ static void cancel_check_call_host(void* arg, grpc_error* error) {
         chand->security_connector, &calld->async_result_closure,
         GRPC_ERROR_REF(error));
   }
-  GRPC_CALL_STACK_UNREF(calld->owning_call, "cancel_check_call_host");
 }
 
 static void auth_start_transport_stream_op_batch(
@@ -318,7 +315,6 @@ static void auth_start_transport_stream_op_batch(
         GRPC_ERROR_UNREF(error);
       } else {
         // Async return; register cancellation closure with call combiner.
-        GRPC_CALL_STACK_REF(calld->owning_call, "cancel_check_call_host");
         grpc_call_combiner_set_notify_on_cancel(
             calld->call_combiner,
             GRPC_CLOSURE_INIT(&calld->check_call_host_cancel_closure,

src/core/lib/security/transport/server_auth_filter.cc

@@ -156,7 +156,6 @@ static void cancel_call(void* arg, grpc_error* error) {
     on_md_processing_done_inner(elem, nullptr, 0, nullptr, 0,
                                 GRPC_ERROR_REF(error));
   }
-  GRPC_CALL_STACK_UNREF(calld->owning_call, "cancel_call");
 }
 
 static void recv_initial_metadata_ready(void* arg, grpc_error* error) {
@@ -168,7 +167,6 @@ static void recv_initial_metadata_ready(void* arg, grpc_error* error) {
     if (chand->creds != nullptr && chand->creds->processor.process != nullptr) {
       // We're calling out to the application, so we need to make sure
       // to drop the call combiner early if we get cancelled.
-      GRPC_CALL_STACK_REF(calld->owning_call, "cancel_call");
       GRPC_CLOSURE_INIT(&calld->cancel_closure, cancel_call, elem,
                         grpc_schedule_on_exec_ctx);
       grpc_call_combiner_set_notify_on_cancel(calld->call_combiner,

src/core/lib/surface/call.cc

@@ -613,8 +613,11 @@ void grpc_call_unref(grpc_call* c) {
     // Unset the call combiner cancellation closure.  This has the
     // effect of scheduling the previously set cancellation closure, if
     // any, so that it can release any internal references it may be
-    // holding to the call stack.
+    // holding to the call stack. Also flush the closures on exec_ctx so that
+    // filters that schedule cancel notification closures on exec_ctx do not
+    // need to take a ref of the call stack to guarantee closure liveness.
     grpc_call_combiner_set_notify_on_cancel(&c->call_combiner, nullptr);
+    grpc_core::ExecCtx::Get()->Flush();
   }
   GRPC_CALL_INTERNAL_UNREF(c, "destroy");
 }

src/core/lib/surface/channel.cc

@@ -281,6 +281,17 @@ void grpc_channel_get_info(grpc_channel* channel,
   elem->filter->get_channel_info(elem, channel_info);
 }
 
+void grpc_channel_reset_connect_backoff(grpc_channel* channel) {
+  grpc_core::ExecCtx exec_ctx;
+  GRPC_API_TRACE("grpc_channel_reset_connect_backoff(channel=%p)", 1,
+                 (channel));
+  grpc_transport_op* op = grpc_make_transport_op(nullptr);
+  op->reset_connect_backoff = true;
+  grpc_channel_element* elem =
+      grpc_channel_stack_element(CHANNEL_STACK_FROM_CHANNEL(channel), 0);
+  elem->filter->start_transport_op(elem, op);
+}
+
 static grpc_call* grpc_channel_create_call_internal(
     grpc_channel* channel, grpc_call* parent_call, uint32_t propagation_mask,
     grpc_completion_queue* cq, grpc_pollset_set* pollset_set_alternative,

src/core/lib/surface/channel_init.h

@@ -21,11 +21,37 @@
 
 #include <grpc/support/port_platform.h>
 
+#include <limits.h>
+
 #include "src/core/lib/channel/channel_stack_builder.h"
 #include "src/core/lib/surface/channel_stack_type.h"
 #include "src/core/lib/transport/transport.h"
 
-#define GRPC_CHANNEL_INIT_BUILTIN_PRIORITY 10000
+// Priority for channel registration functions to be used in
+// grpc_channel_init_register_stage().  The priority dictates the
+// order in which the registration functions run.
+//
+// When used to register a filter, the filter can either be appended or
+// prepended, thus dictating whether the filter goes at the top or bottom of
+// the stack. Higher priority functions can get closer to the top or bottom
+// of the stack than lower priority functions.
+enum {
+  // Default level. Most of filters should use this level if their location in
+  // the stack does not matter.
+  GRPC_CHANNEL_INIT_PRIORITY_LOW = 0,
+  // For filters that should be added after the group of filters with default
+  // priority, such as auth filters.
+  GRPC_CHANNEL_INIT_PRIORITY_MED = 10000,
+  // For filters that need to be close to top or bottom, such as protocol-level
+  // filters (client_authority, http-client, http-server).
+  GRPC_CHANNEL_INIT_PRIORITY_HIGH = 20000,
+  // For filters that need to be very close to the wire or surface, such as
+  // stats filters (census).
+  GRPC_CHANNEL_INIT_PRIORITY_VERY_HIGH = 30000,
+  // For things that have to happen last, such as connected channel filter or
+  // surface server filter. Consider as reserved for gRPC internals.
+  GRPC_CHANNEL_INIT_PRIORITY_MAX = INT_MAX
+};
 
 /// This module provides a way for plugins (and the grpc core library itself)
 /// to register mutators for channel stacks.

src/core/lib/surface/init.cc

@@ -70,11 +70,6 @@ static void do_basic_init(void) {
   g_initializations = 0;
 }
 
-static bool append_filter(grpc_channel_stack_builder* builder, void* arg) {
-  return grpc_channel_stack_builder_append_filter(
-      builder, static_cast<const grpc_channel_filter*>(arg), nullptr, nullptr);
-}
-
 static bool prepend_filter(grpc_channel_stack_builder* builder, void* arg) {
   return grpc_channel_stack_builder_prepend_filter(
       builder, static_cast<const grpc_channel_filter*>(arg), nullptr, nullptr);
@@ -82,19 +77,20 @@ static bool prepend_filter(grpc_channel_stack_builder* builder, void* arg) {
 
 static void register_builtin_channel_init() {
   grpc_channel_init_register_stage(GRPC_CLIENT_SUBCHANNEL,
-                                   GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
-                                   grpc_add_connected_filter, nullptr);
+                                   GRPC_CHANNEL_INIT_PRIORITY_MAX,
+                                   grpc_append_connected_filter, nullptr);
   grpc_channel_init_register_stage(GRPC_CLIENT_DIRECT_CHANNEL,
-                                   GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
-                                   grpc_add_connected_filter, nullptr);
+                                   GRPC_CHANNEL_INIT_PRIORITY_MAX,
+                                   grpc_append_connected_filter, nullptr);
   grpc_channel_init_register_stage(GRPC_SERVER_CHANNEL,
-                                   GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
-                                   grpc_add_connected_filter, nullptr);
+                                   GRPC_CHANNEL_INIT_PRIORITY_MAX,
+                                   grpc_append_connected_filter, nullptr);
   grpc_channel_init_register_stage(GRPC_CLIENT_LAME_CHANNEL,
-                                   GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
-                                   append_filter, (void*)&grpc_lame_filter);
-  grpc_channel_init_register_stage(GRPC_SERVER_CHANNEL, INT_MAX, prepend_filter,
-                                   (void*)&grpc_server_top_filter);
+                                   GRPC_CHANNEL_INIT_PRIORITY_MAX,
+                                   prepend_filter, (void*)&grpc_lame_filter);
+  grpc_channel_init_register_stage(
+      GRPC_SERVER_CHANNEL, GRPC_CHANNEL_INIT_PRIORITY_MAX, prepend_filter,
+      (void*)&grpc_server_top_filter);
 }
 
 typedef struct grpc_plugin {

src/core/lib/surface/init_secure.cc

@@ -67,14 +67,17 @@ static bool maybe_prepend_server_auth_filter(
 }
 
 void grpc_register_security_filters(void) {
-  // Register the auth client with a priority < INT_MAX to allow the authority
+  // Register the auth client with a medium priority to allow the authority
   // filter -on which the auth filter depends- to be higher on the channel
   // stack.
-  grpc_channel_init_register_stage(GRPC_CLIENT_SUBCHANNEL, INT_MAX - 1,
+  grpc_channel_init_register_stage(GRPC_CLIENT_SUBCHANNEL,
+                                   GRPC_CHANNEL_INIT_PRIORITY_MED,
                                    maybe_prepend_client_auth_filter, nullptr);
-  grpc_channel_init_register_stage(GRPC_CLIENT_DIRECT_CHANNEL, INT_MAX - 1,
+  grpc_channel_init_register_stage(GRPC_CLIENT_DIRECT_CHANNEL,
+                                   GRPC_CHANNEL_INIT_PRIORITY_MED,
                                    maybe_prepend_client_auth_filter, nullptr);
-  grpc_channel_init_register_stage(GRPC_SERVER_CHANNEL, INT_MAX,
+  grpc_channel_init_register_stage(GRPC_SERVER_CHANNEL,
+                                   GRPC_CHANNEL_INIT_PRIORITY_MED,
                                    maybe_prepend_server_auth_filter, nullptr);
 }
 

src/core/lib/transport/transport.h

@@ -282,6 +282,8 @@ typedef struct grpc_transport_op {
     /** Called when the ping ack is received */
     grpc_closure* on_ack;
   } send_ping;
+  // If true, will reset the channel's connection backoff.
+  bool reset_connect_backoff;
 
   /***************************************************************************
    * remaining fields are initialized and used at the discretion of the

src/core/tsi/alts/handshaker/alts_tsi_handshaker.cc

@@ -462,6 +462,14 @@ void alts_tsi_handshaker_handle_response(alts_tsi_handshaker* handshaker,
     set_unused_bytes(result, &handshaker->recv_bytes, resp->bytes_consumed);
   }
   grpc_status_code code = static_cast<grpc_status_code>(resp->status.code);
+  if (code != GRPC_STATUS_OK) {
+    grpc_slice* details = static_cast<grpc_slice*>(resp->status.details.arg);
+    if (details != nullptr) {
+      char* error_details = grpc_slice_to_c_string(*details);
+      gpr_log(GPR_ERROR, "Error from handshaker service:%s", error_details);
+      gpr_free(error_details);
+    }
+  }
   grpc_gcp_handshaker_resp_destroy(resp);
   cb(alts_tsi_utils_convert_to_tsi_result(code), user_data, bytes_to_send,
      bytes_to_send_size, result);

src/cpp/client/channel_cc.cc

@@ -84,6 +84,14 @@ grpc::string Channel::GetServiceConfigJSON() const {
                              &channel_info.service_config_json);
 }
 
+namespace experimental {
+
+void ChannelResetConnectionBackoff(Channel* channel) {
+  grpc_channel_reset_connect_backoff(channel->c_channel_);
+}
+
+}  // namespace experimental
+
 internal::Call Channel::CreateCall(const internal::RpcMethod& method,
                                    ClientContext* context,
                                    CompletionQueue* cq) {

src/cpp/common/channel_filter.cc

@@ -78,8 +78,13 @@ bool MaybeAddFilter(grpc_channel_stack_builder* builder, void* arg) {
         grpc_channel_stack_builder_get_channel_arguments(builder);
     if (!filter.include_filter(*args)) return true;
   }
-  return grpc_channel_stack_builder_prepend_filter(builder, &filter.filter,
-                                                   nullptr, nullptr);
+  if (filter.prepend) {
+    return grpc_channel_stack_builder_prepend_filter(builder, &filter.filter,
+                                                     nullptr, nullptr);
+  } else {
+    return grpc_channel_stack_builder_append_filter(builder, &filter.filter,
+                                                    nullptr, nullptr);
+  }
 }
 
 }  // namespace

src/cpp/common/channel_filter.h

@@ -36,7 +36,8 @@
 /// \c ChannelData. Then register the filter using something like this:
 /// \code{.cpp}
 ///   RegisterChannelFilter<MyChannelDataSubclass, MyCallDataSubclass>(
-///       "name-of-filter", GRPC_SERVER_CHANNEL, INT_MAX, nullptr);
+///       "name-of-filter", GRPC_SERVER_CHANNEL, GRPC_CHANNEL_INIT_PRIORITY_LOW,
+///       true, nullptr);
 /// \endcode
 
 namespace grpc {
@@ -351,6 +352,7 @@ class ChannelFilter final {
 struct FilterRecord {
   grpc_channel_stack_type stack_type;
   int priority;
+  bool prepend;
   std::function<bool(const grpc_channel_args&)> include_filter;
   grpc_channel_filter filter;
 };
@@ -363,12 +365,14 @@ void ChannelFilterPluginShutdown();
 
 /// Registers a new filter.
 /// Must be called by only one thread at a time.
+/// The \a prepend argument decides whether to prepend or append the filter.
 /// The \a include_filter argument specifies a function that will be called
 /// to determine at run-time whether or not to add the filter. If the
 /// value is nullptr, the filter will be added unconditionally.
 template <typename ChannelDataType, typename CallDataType>
 void RegisterChannelFilter(
     const char* name, grpc_channel_stack_type stack_type, int priority,
+    bool prepend,
     std::function<bool(const grpc_channel_args&)> include_filter) {
   // If we haven't been called before, initialize channel_filters and
   // call grpc_register_plugin().
@@ -383,6 +387,7 @@ void RegisterChannelFilter(
   internal::FilterRecord filter_record = {
       stack_type,
       priority,
+      prepend,
       include_filter,
       {FilterType::StartTransportStreamOpBatch, FilterType::StartTransportOp,
        FilterType::call_data_size, FilterType::InitCallElement,

src/cpp/ext/filters/census/grpc_plugin.cc

@@ -32,10 +32,12 @@ namespace grpc {
 
 void RegisterOpenCensusPlugin() {
   RegisterChannelFilter<CensusChannelData, CensusClientCallData>(
-      "opencensus_client", GRPC_CLIENT_CHANNEL, INT_MAX /* priority */,
+      "opencensus_client", GRPC_CLIENT_CHANNEL,
+      GRPC_CHANNEL_INIT_PRIORITY_VERY_HIGH, true /* prepend */,
       nullptr /* condition function */);
   RegisterChannelFilter<CensusChannelData, CensusServerCallData>(
-      "opencensus_server", GRPC_SERVER_CHANNEL, INT_MAX /* priority */,
+      "opencensus_server", GRPC_SERVER_CHANNEL,
+      GRPC_CHANNEL_INIT_PRIORITY_VERY_HIGH, true /* prepend */,
       nullptr /* condition function */);
 
   // Access measures to ensure they are initialized. Otherwise, creating a view

src/cpp/server/load_reporter/util.cc

@@ -20,6 +20,8 @@
 
 #include <grpcpp/ext/server_load_reporting.h>
 
+#include <cmath>
+
 #include <grpc/support/log.h>
 
 namespace grpc {

src/csharp/Grpc.Core/Grpc.Core.csproj

@@ -47,35 +47,35 @@
       <Pack>true</Pack>
     </Content>
     <Content Include="..\nativelibs\csharp_ext_linux_android_armeabi-v7a\libgrpc_csharp_ext.so">
-      <PackagePath>runtimes/monoandroid/armeabi-v7a/libgrpc_csharp_ext.so</PackagePath>
+      <PackagePath>native/android/armeabi-v7a/libgrpc_csharp_ext.so</PackagePath>
       <Pack>true</Pack>
     </Content>
     <Content Include="..\nativelibs\csharp_ext_linux_android_arm64-v8a\libgrpc_csharp_ext.so">
-      <PackagePath>runtimes/monoandroid/arm64-v8a/libgrpc_csharp_ext.so</PackagePath>
+      <PackagePath>native/android/arm64-v8a/libgrpc_csharp_ext.so</PackagePath>
       <Pack>true</Pack>
     </Content>
     <Content Include="..\nativelibs\csharp_ext_linux_android_x86\libgrpc_csharp_ext.so">
-      <PackagePath>runtimes/monoandroid/x86/libgrpc_csharp_ext.so</PackagePath>
+      <PackagePath>native/android/x86/libgrpc_csharp_ext.so</PackagePath>
       <Pack>true</Pack>
     </Content>
     <Content Include="..\nativelibs\csharp_ext_macos_ios\libgrpc_csharp_ext.a">
-      <PackagePath>runtimes/ios/native/libgrpc_csharp_ext.a</PackagePath>
+      <PackagePath>native/ios/universal/libgrpc_csharp_ext.a</PackagePath>
       <Pack>true</Pack>
     </Content>
     <Content Include="..\nativelibs\csharp_ext_macos_ios\libgrpc.a">
-      <PackagePath>runtimes/ios/native/libgrpc.a</PackagePath>
+      <PackagePath>native/ios/universal/libgrpc.a</PackagePath>
       <Pack>true</Pack>
     </Content>
     <Content Include="build\net45\Grpc.Core.targets">
       <PackagePath>build/net45/</PackagePath>
       <Pack>true</Pack>
     </Content>
-    <Content Include="build\MonoAndroid\Grpc.Core.targets">
-      <PackagePath>build/MonoAndroid/</PackagePath>
+    <Content Include="build\MonoAndroid10\Grpc.Core.targets">
+      <PackagePath>build/MonoAndroid10/</PackagePath>
       <Pack>true</Pack>
     </Content>
-    <Content Include="build\Xamarin.iOS\Grpc.Core.targets">
-      <PackagePath>build/Xamarin.iOS/</PackagePath>
+    <Content Include="build\Xamarin.iOS10\Grpc.Core.targets">
+      <PackagePath>build/Xamarin.iOS10/</PackagePath>
       <Pack>true</Pack>
     </Content>
   </ItemGroup>

src/csharp/Grpc.Core/GrpcEnvironment.cs

@@ -50,6 +50,7 @@ namespace Grpc.Core
         static int requestCallContextPoolThreadLocalCapacity = DefaultRequestCallContextPoolThreadLocalCapacity;
         static readonly HashSet<Channel> registeredChannels = new HashSet<Channel>();
         static readonly HashSet<Server> registeredServers = new HashSet<Server>();
+        static readonly AtomicCounter nativeInitCounter = new AtomicCounter();
 
         static ILogger logger = new LogLevelFilterLogger(new ConsoleLogger(), LogLevel.Off, true);
 
@@ -360,12 +361,25 @@ namespace Grpc.Core
 
         internal static void GrpcNativeInit()
         {
+            if (!IsNativeShutdownAllowed && nativeInitCounter.Count > 0)
+            {
+                // Normally grpc_init and grpc_shutdown calls should come in pairs (C core does reference counting),
+                // but in case we avoid grpc_shutdown calls altogether, calling grpc_init has no effect
+                // besides incrementing an internal C core counter that could theoretically overflow.
+                // To avoid this theoretical possibility we guard repeated calls to grpc_init()
+                // with a 64-bit atomic counter (that can't realistically overflow).
+                return;
+            }
             NativeMethods.Get().grpcsharp_init();
+            nativeInitCounter.Increment();
         }
 
         internal static void GrpcNativeShutdown()
         {
-            NativeMethods.Get().grpcsharp_shutdown();
+            if (IsNativeShutdownAllowed)
+            {
+                NativeMethods.Get().grpcsharp_shutdown();
+            }
         }
 
         /// <summary>
@@ -411,6 +425,14 @@ namespace Grpc.Core
             return GetThreadPoolSizeOrDefault();
         }
 
+        // On some platforms (specifically iOS), thread local variables in native code
+        // require initialization/destruction. By skipping the grpc_shutdown() call,
+        // we avoid a potential crash where grpc_shutdown() has already destroyed
+        // the thread local variables, but some C core's *_destroy() methods still
+        // need to run (e.g. they may be run by finalizer thread which is out of our control)
+        // For more context, see https://github.com/grpc/grpc/issues/16294
+        private static bool IsNativeShutdownAllowed => !PlatformApis.IsXamarinIOS && !PlatformApis.IsUnityIOS;
+
         private static class ShutdownHooks
         {
             static object staticLock = new object();

src/csharp/Grpc.Core/Internal/PlatformApis.cs

@@ -42,6 +42,7 @@ namespace Grpc.Core.Internal
         static readonly bool isMono;
         static readonly bool isNetCore;
         static readonly bool isUnity;
+        static readonly bool isUnityIOS;
         static readonly bool isXamarin;
         static readonly bool isXamarinIOS;
         static readonly bool isXamarinAndroid;
@@ -63,7 +64,25 @@ namespace Grpc.Core.Internal
             isNetCore = false;
 #endif
             isMono = Type.GetType("Mono.Runtime") != null;
-            isUnity = Type.GetType(UnityEngineApplicationClassName) != null;
+
+            // Unity
+            var unityApplicationClass = Type.GetType(UnityEngineApplicationClassName);
+            if (unityApplicationClass != null)
+            {
+                isUnity = true;
+                // Consult value of Application.platform via reflection
+                // https://docs.unity3d.com/ScriptReference/Application-platform.html
+                var platformProperty = unityApplicationClass.GetTypeInfo().GetProperty("platform");
+                var unityRuntimePlatform = platformProperty?.GetValue(null)?.ToString();
+                isUnityIOS = (unityRuntimePlatform == "IPhonePlayer");
+            }
+            else
+            {
+                isUnity = false;
+                isUnityIOS = false;
+            }
+
+            // Xamarin
             isXamarinIOS = Type.GetType(XamarinIOSObjectClassName) != null;
             isXamarinAndroid = Type.GetType(XamarinAndroidObjectClassName) != null;
             isXamarin = isXamarinIOS || isXamarinAndroid;
@@ -97,6 +116,14 @@ namespace Grpc.Core.Internal
             get { return isUnity; }
         }
 
+        /// <summary>
+        /// true if running on Unity iOS, false otherwise.
+        /// </summary>
+        public static bool IsUnityIOS
+        {
+            get { return isUnityIOS; }
+        }
+
         /// <summary>
         /// true if running on a Xamarin platform (either Xamarin.Android or Xamarin.iOS),
         /// false otherwise.

src/csharp/Grpc.Core/Version.csproj.include

@@ -2,6 +2,6 @@
 <Project>
   <PropertyGroup>
     <GrpcCsharpVersion>1.15.0-dev</GrpcCsharpVersion>
-    <GoogleProtobufVersion>3.5.1</GoogleProtobufVersion>
+    <GoogleProtobufVersion>3.6.1</GoogleProtobufVersion>
   </PropertyGroup>
 </Project>

src/csharp/Grpc.Core/build/MonoAndroid10/Grpc.Core.targets

@@ -1,25 +1,22 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <PropertyGroup>
-    <_GrpcCoreNugetNativePath Condition="'$(_GrpcCoreNugetNativePath)' == ''">$(MSBuildThisFileDirectory)..\..\</_GrpcCoreNugetNativePath>
-  </PropertyGroup>
 
   <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == 'MonoAndroid'">
-    <AndroidNativeLibrary Include="$(_GrpcCoreNugetNativePath)runtimes\monoandroid\arm64-v8a\libgrpc_csharp_ext.so">
+    <AndroidNativeLibrary Include="$(MSBuildThisFileDirectory)..\..\native\android\arm64-v8a\libgrpc_csharp_ext.so">
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>
       <Abi>arm64-v8a</Abi>
     </AndroidNativeLibrary>
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == 'MonoAndroid'">
-    <AndroidNativeLibrary Include="$(_GrpcCoreNugetNativePath)runtimes\monoandroid\armeabi-v7a\libgrpc_csharp_ext.so">
+    <AndroidNativeLibrary Include="$(MSBuildThisFileDirectory)..\..\native\android\armeabi-v7a\libgrpc_csharp_ext.so">
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>
       <Abi>armeabi-v7a</Abi>
     </AndroidNativeLibrary>
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == 'MonoAndroid'">
-    <AndroidNativeLibrary Include="$(_GrpcCoreNugetNativePath)runtimes\monoandroid\x86\libgrpc_csharp_ext.so">
+    <AndroidNativeLibrary Include="$(MSBuildThisFileDirectory)..\..\native\android\x86\libgrpc_csharp_ext.so">
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>
       <Abi>x86</Abi>
     </AndroidNativeLibrary>

src/csharp/Grpc.Core/build/Xamarin.iOS10/Grpc.Core.targets

@@ -2,11 +2,11 @@
 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
 
   <ItemGroup>
-    <NativeReference Include="$(MSBuildThisFileDirectory)..\..\runtimes\ios\native\libgrpc_csharp_ext.a">
+    <NativeReference Include="$(MSBuildThisFileDirectory)..\..\native\ios\universal\libgrpc_csharp_ext.a">
       <Kind>Static</Kind>
       <ForceLoad>True</ForceLoad>
     </NativeReference>
-    <NativeReference Include="$(MSBuildThisFileDirectory)..\..\runtimes\ios\native\libgrpc.a">
+    <NativeReference Include="$(MSBuildThisFileDirectory)..\..\native\ios\universal\libgrpc.a">
       <Kind>Static</Kind>
       <ForceLoad>True</ForceLoad>
     </NativeReference>

src/csharp/Grpc.IntegrationTesting/Control.cs

@@ -1039,14 +1039,14 @@ namespace Grpc.Testing {
     public ClientConfig(ClientConfig other) : this() {
       serverTargets_ = other.serverTargets_.Clone();
       clientType_ = other.clientType_;
-      SecurityParams = other.securityParams_ != null ? other.SecurityParams.Clone() : null;
+      securityParams_ = other.securityParams_ != null ? other.securityParams_.Clone() : null;
       outstandingRpcsPerChannel_ = other.outstandingRpcsPerChannel_;
       clientChannels_ = other.clientChannels_;
       asyncClientThreads_ = other.asyncClientThreads_;
       rpcType_ = other.rpcType_;
-      LoadParams = other.loadParams_ != null ? other.LoadParams.Clone() : null;
-      PayloadConfig = other.payloadConfig_ != null ? other.PayloadConfig.Clone() : null;
-      HistogramParams = other.histogramParams_ != null ? other.HistogramParams.Clone() : null;
+      loadParams_ = other.loadParams_ != null ? other.loadParams_.Clone() : null;
+      payloadConfig_ = other.payloadConfig_ != null ? other.payloadConfig_.Clone() : null;
+      histogramParams_ = other.histogramParams_ != null ? other.histogramParams_.Clone() : null;
       coreList_ = other.coreList_.Clone();
       coreLimit_ = other.coreLimit_;
       otherClientApi_ = other.otherClientApi_;
@@ -1647,7 +1647,7 @@ namespace Grpc.Testing {
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ClientStatus(ClientStatus other) : this() {
-      Stats = other.stats_ != null ? other.Stats.Clone() : null;
+      stats_ = other.stats_ != null ? other.stats_.Clone() : null;
       _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
@@ -2122,11 +2122,11 @@ namespace Grpc.Testing {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ServerConfig(ServerConfig other) : this() {
       serverType_ = other.serverType_;
-      SecurityParams = other.securityParams_ != null ? other.SecurityParams.Clone() : null;
+      securityParams_ = other.securityParams_ != null ? other.securityParams_.Clone() : null;
       port_ = other.port_;
       asyncServerThreads_ = other.asyncServerThreads_;
       coreLimit_ = other.coreLimit_;
-      PayloadConfig = other.payloadConfig_ != null ? other.PayloadConfig.Clone() : null;
+      payloadConfig_ = other.payloadConfig_ != null ? other.payloadConfig_.Clone() : null;
       coreList_ = other.coreList_.Clone();
       otherServerApi_ = other.otherServerApi_;
       threadsPerCq_ = other.threadsPerCq_;
@@ -2758,7 +2758,7 @@ namespace Grpc.Testing {
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ServerStatus(ServerStatus other) : this() {
-      Stats = other.stats_ != null ? other.Stats.Clone() : null;
+      stats_ = other.stats_ != null ? other.stats_.Clone() : null;
       port_ = other.port_;
       cores_ = other.cores_;
       _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
@@ -3293,9 +3293,9 @@ namespace Grpc.Testing {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Scenario(Scenario other) : this() {
       name_ = other.name_;
-      ClientConfig = other.clientConfig_ != null ? other.ClientConfig.Clone() : null;
+      clientConfig_ = other.clientConfig_ != null ? other.clientConfig_.Clone() : null;
       numClients_ = other.numClients_;
-      ServerConfig = other.serverConfig_ != null ? other.ServerConfig.Clone() : null;
+      serverConfig_ = other.serverConfig_ != null ? other.serverConfig_.Clone() : null;
       numServers_ = other.numServers_;
       warmupSeconds_ = other.warmupSeconds_;
       benchmarkSeconds_ = other.benchmarkSeconds_;
@@ -4422,12 +4422,12 @@ namespace Grpc.Testing {
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ScenarioResult(ScenarioResult other) : this() {
-      Scenario = other.scenario_ != null ? other.Scenario.Clone() : null;
-      Latencies = other.latencies_ != null ? other.Latencies.Clone() : null;
+      scenario_ = other.scenario_ != null ? other.scenario_.Clone() : null;
+      latencies_ = other.latencies_ != null ? other.latencies_.Clone() : null;
       clientStats_ = other.clientStats_.Clone();
       serverStats_ = other.serverStats_.Clone();
       serverCores_ = other.serverCores_.Clone();
-      Summary = other.summary_ != null ? other.Summary.Clone() : null;
+      summary_ = other.summary_ != null ? other.summary_.Clone() : null;
       clientSuccess_ = other.clientSuccess_.Clone();
       serverSuccess_ = other.serverSuccess_.Clone();
       requestResults_ = other.requestResults_.Clone();

src/csharp/Grpc.IntegrationTesting/EchoMessages.cs

@@ -28,7 +28,7 @@ namespace Grpc.Testing {
             "DGdycGMudGVzdGluZyIyCglEZWJ1Z0luZm8SFQoNc3RhY2tfZW50cmllcxgB",
             "IAMoCRIOCgZkZXRhaWwYAiABKAkiUAoLRXJyb3JTdGF0dXMSDAoEY29kZRgB",
             "IAEoBRIVCg1lcnJvcl9tZXNzYWdlGAIgASgJEhwKFGJpbmFyeV9lcnJvcl9k",
-            "ZXRhaWxzGAMgASgJIuIDCg1SZXF1ZXN0UGFyYW1zEhUKDWVjaG9fZGVhZGxp",
+            "ZXRhaWxzGAMgASgJIv8DCg1SZXF1ZXN0UGFyYW1zEhUKDWVjaG9fZGVhZGxp",
             "bmUYASABKAgSHgoWY2xpZW50X2NhbmNlbF9hZnRlcl91cxgCIAEoBRIeChZz",
             "ZXJ2ZXJfY2FuY2VsX2FmdGVyX3VzGAMgASgFEhUKDWVjaG9fbWV0YWRhdGEY",
             "BCABKAgSGgoSY2hlY2tfYXV0aF9jb250ZXh0GAUgASgIEh8KF3Jlc3BvbnNl",
@@ -39,18 +39,18 @@ namespace Grpc.Testing {
             "Zy5EZWJ1Z0luZm8SEgoKc2VydmVyX2RpZRgMIAEoCBIcChRiaW5hcnlfZXJy",
             "b3JfZGV0YWlscxgNIAEoCRIxCg5leHBlY3RlZF9lcnJvchgOIAEoCzIZLmdy",
             "cGMudGVzdGluZy5FcnJvclN0YXR1cxIXCg9zZXJ2ZXJfc2xlZXBfdXMYDyAB",
-            "KAUiSgoLRWNob1JlcXVlc3QSDwoHbWVzc2FnZRgBIAEoCRIqCgVwYXJhbRgC",
-            "IAEoCzIbLmdycGMudGVzdGluZy5SZXF1ZXN0UGFyYW1zIkYKDlJlc3BvbnNl",
-            "UGFyYW1zEhgKEHJlcXVlc3RfZGVhZGxpbmUYASABKAMSDAoEaG9zdBgCIAEo",
-            "CRIMCgRwZWVyGAMgASgJIkwKDEVjaG9SZXNwb25zZRIPCgdtZXNzYWdlGAEg",
-            "ASgJEisKBXBhcmFtGAIgASgLMhwuZ3JwYy50ZXN0aW5nLlJlc3BvbnNlUGFy",
-            "YW1zYgZwcm90bzM="));
+            "KAUSGwoTYmFja2VuZF9jaGFubmVsX2lkeBgQIAEoBSJKCgtFY2hvUmVxdWVz",
+            "dBIPCgdtZXNzYWdlGAEgASgJEioKBXBhcmFtGAIgASgLMhsuZ3JwYy50ZXN0",
+            "aW5nLlJlcXVlc3RQYXJhbXMiRgoOUmVzcG9uc2VQYXJhbXMSGAoQcmVxdWVz",
+            "dF9kZWFkbGluZRgBIAEoAxIMCgRob3N0GAIgASgJEgwKBHBlZXIYAyABKAki",
+            "TAoMRWNob1Jlc3BvbnNlEg8KB21lc3NhZ2UYASABKAkSKwoFcGFyYW0YAiAB",
+            "KAsyHC5ncnBjLnRlc3RpbmcuUmVzcG9uc2VQYXJhbXNiBnByb3RvMw=="));
       descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,
           new pbr::FileDescriptor[] { },
           new pbr::GeneratedClrTypeInfo(null, new pbr::GeneratedClrTypeInfo[] {
             new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Testing.DebugInfo), global::Grpc.Testing.DebugInfo.Parser, new[]{ "StackEntries", "Detail" }, null, null, null),
             new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Testing.ErrorStatus), global::Grpc.Testing.ErrorStatus.Parser, new[]{ "Code", "ErrorMessage", "BinaryErrorDetails" }, null, null, null),
-            new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Testing.RequestParams), global::Grpc.Testing.RequestParams.Parser, new[]{ "EchoDeadline", "ClientCancelAfterUs", "ServerCancelAfterUs", "EchoMetadata", "CheckAuthContext", "ResponseMessageLength", "EchoPeer", "ExpectedClientIdentity", "SkipCancelledCheck", "ExpectedTransportSecurityType", "DebugInfo", "ServerDie", "BinaryErrorDetails", "ExpectedError", "ServerSleepUs" }, null, null, null),
+            new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Testing.RequestParams), global::Grpc.Testing.RequestParams.Parser, new[]{ "EchoDeadline", "ClientCancelAfterUs", "ServerCancelAfterUs", "EchoMetadata", "CheckAuthContext", "ResponseMessageLength", "EchoPeer", "ExpectedClientIdentity", "SkipCancelledCheck", "ExpectedTransportSecurityType", "DebugInfo", "ServerDie", "BinaryErrorDetails", "ExpectedError", "ServerSleepUs", "BackendChannelIdx" }, null, null, null),
             new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Testing.EchoRequest), global::Grpc.Testing.EchoRequest.Parser, new[]{ "Message", "Param" }, null, null, null),
             new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Testing.ResponseParams), global::Grpc.Testing.ResponseParams.Parser, new[]{ "RequestDeadline", "Host", "Peer" }, null, null, null),
             new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Testing.EchoResponse), global::Grpc.Testing.EchoResponse.Parser, new[]{ "Message", "Param" }, null, null, null)
@@ -435,11 +435,12 @@ namespace Grpc.Testing {
       expectedClientIdentity_ = other.expectedClientIdentity_;
       skipCancelledCheck_ = other.skipCancelledCheck_;
       expectedTransportSecurityType_ = other.expectedTransportSecurityType_;
-      DebugInfo = other.debugInfo_ != null ? other.DebugInfo.Clone() : null;
+      debugInfo_ = other.debugInfo_ != null ? other.debugInfo_.Clone() : null;
       serverDie_ = other.serverDie_;
       binaryErrorDetails_ = other.binaryErrorDetails_;
-      ExpectedError = other.expectedError_ != null ? other.ExpectedError.Clone() : null;
+      expectedError_ = other.expectedError_ != null ? other.expectedError_.Clone() : null;
       serverSleepUs_ = other.serverSleepUs_;
+      backendChannelIdx_ = other.backendChannelIdx_;
       _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
@@ -622,6 +623,20 @@ namespace Grpc.Testing {
       }
     }
 
+    /// <summary>Field number for the "backend_channel_idx" field.</summary>
+    public const int BackendChannelIdxFieldNumber = 16;
+    private int backendChannelIdx_;
+    /// <summary>
+    /// which backend to send request to
+    /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public int BackendChannelIdx {
+      get { return backendChannelIdx_; }
+      set {
+        backendChannelIdx_ = value;
+      }
+    }
+
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as RequestParams);
@@ -650,6 +665,7 @@ namespace Grpc.Testing {
       if (BinaryErrorDetails != other.BinaryErrorDetails) return false;
       if (!object.Equals(ExpectedError, other.ExpectedError)) return false;
       if (ServerSleepUs != other.ServerSleepUs) return false;
+      if (BackendChannelIdx != other.BackendChannelIdx) return false;
       return Equals(_unknownFields, other._unknownFields);
     }
 
@@ -671,6 +687,7 @@ namespace Grpc.Testing {
       if (BinaryErrorDetails.Length != 0) hash ^= BinaryErrorDetails.GetHashCode();
       if (expectedError_ != null) hash ^= ExpectedError.GetHashCode();
       if (ServerSleepUs != 0) hash ^= ServerSleepUs.GetHashCode();
+      if (BackendChannelIdx != 0) hash ^= BackendChannelIdx.GetHashCode();
       if (_unknownFields != null) {
         hash ^= _unknownFields.GetHashCode();
       }
@@ -744,6 +761,10 @@ namespace Grpc.Testing {
         output.WriteRawTag(120);
         output.WriteInt32(ServerSleepUs);
       }
+      if (BackendChannelIdx != 0) {
+        output.WriteRawTag(128, 1);
+        output.WriteInt32(BackendChannelIdx);
+      }
       if (_unknownFields != null) {
         _unknownFields.WriteTo(output);
       }
@@ -797,6 +818,9 @@ namespace Grpc.Testing {
       if (ServerSleepUs != 0) {
         size += 1 + pb::CodedOutputStream.ComputeInt32Size(ServerSleepUs);
       }
+      if (BackendChannelIdx != 0) {
+        size += 2 + pb::CodedOutputStream.ComputeInt32Size(BackendChannelIdx);
+      }
       if (_unknownFields != null) {
         size += _unknownFields.CalculateSize();
       }
@@ -859,6 +883,9 @@ namespace Grpc.Testing {
       if (other.ServerSleepUs != 0) {
         ServerSleepUs = other.ServerSleepUs;
       }
+      if (other.BackendChannelIdx != 0) {
+        BackendChannelIdx = other.BackendChannelIdx;
+      }
       _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
@@ -936,6 +963,10 @@ namespace Grpc.Testing {
             ServerSleepUs = input.ReadInt32();
             break;
           }
+          case 128: {
+            BackendChannelIdx = input.ReadInt32();
+            break;
+          }
         }
       }
     }
@@ -968,7 +999,7 @@ namespace Grpc.Testing {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public EchoRequest(EchoRequest other) : this() {
       message_ = other.message_;
-      Param = other.param_ != null ? other.Param.Clone() : null;
+      param_ = other.param_ != null ? other.param_.Clone() : null;
       _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
@@ -1316,7 +1347,7 @@ namespace Grpc.Testing {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public EchoResponse(EchoResponse other) : this() {
       message_ = other.message_;
-      Param = other.param_ != null ? other.Param.Clone() : null;
+      param_ = other.param_ != null ? other.param_.Clone() : null;
       _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 

src/csharp/Grpc.IntegrationTesting/Messages.cs

@@ -77,7 +77,6 @@ namespace Grpc.Testing {
   }
   #region Enums
   /// <summary>
-  /// DEPRECATED, don't use. To be removed shortly.
   /// The type of payload that should be returned.
   /// </summary>
   public enum PayloadType {
@@ -269,7 +268,6 @@ namespace Grpc.Testing {
     public const int TypeFieldNumber = 1;
     private global::Grpc.Testing.PayloadType type_ = 0;
     /// <summary>
-    /// DEPRECATED, don't use. To be removed shortly.
     /// The type of data in body.
     /// </summary>
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -585,12 +583,12 @@ namespace Grpc.Testing {
     public SimpleRequest(SimpleRequest other) : this() {
       responseType_ = other.responseType_;
       responseSize_ = other.responseSize_;
-      Payload = other.payload_ != null ? other.Payload.Clone() : null;
+      payload_ = other.payload_ != null ? other.payload_.Clone() : null;
       fillUsername_ = other.fillUsername_;
       fillOauthScope_ = other.fillOauthScope_;
-      ResponseCompressed = other.responseCompressed_ != null ? other.ResponseCompressed.Clone() : null;
-      ResponseStatus = other.responseStatus_ != null ? other.ResponseStatus.Clone() : null;
-      ExpectCompressed = other.expectCompressed_ != null ? other.ExpectCompressed.Clone() : null;
+      responseCompressed_ = other.responseCompressed_ != null ? other.responseCompressed_.Clone() : null;
+      responseStatus_ = other.responseStatus_ != null ? other.responseStatus_.Clone() : null;
+      expectCompressed_ = other.expectCompressed_ != null ? other.expectCompressed_.Clone() : null;
       _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
@@ -603,7 +601,6 @@ namespace Grpc.Testing {
     public const int ResponseTypeFieldNumber = 1;
     private global::Grpc.Testing.PayloadType responseType_ = 0;
     /// <summary>
-    /// 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.
     /// </summary>
@@ -964,7 +961,7 @@ namespace Grpc.Testing {
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public SimpleResponse(SimpleResponse other) : this() {
-      Payload = other.payload_ != null ? other.Payload.Clone() : null;
+      payload_ = other.payload_ != null ? other.payload_.Clone() : null;
       username_ = other.username_;
       oauthScope_ = other.oauthScope_;
       _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
@@ -1168,8 +1165,8 @@ namespace Grpc.Testing {
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public StreamingInputCallRequest(StreamingInputCallRequest other) : this() {
-      Payload = other.payload_ != null ? other.Payload.Clone() : null;
-      ExpectCompressed = other.expectCompressed_ != null ? other.ExpectCompressed.Clone() : null;
+      payload_ = other.payload_ != null ? other.payload_.Clone() : null;
+      expectCompressed_ = other.expectCompressed_ != null ? other.expectCompressed_.Clone() : null;
       _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
@@ -1486,7 +1483,7 @@ namespace Grpc.Testing {
     public ResponseParameters(ResponseParameters other) : this() {
       size_ = other.size_;
       intervalUs_ = other.intervalUs_;
-      Compressed = other.compressed_ != null ? other.Compressed.Clone() : null;
+      compressed_ = other.compressed_ != null ? other.compressed_.Clone() : null;
       _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
@@ -1693,8 +1690,8 @@ namespace Grpc.Testing {
     public StreamingOutputCallRequest(StreamingOutputCallRequest other) : this() {
       responseType_ = other.responseType_;
       responseParameters_ = other.responseParameters_.Clone();
-      Payload = other.payload_ != null ? other.Payload.Clone() : null;
-      ResponseStatus = other.responseStatus_ != null ? other.ResponseStatus.Clone() : null;
+      payload_ = other.payload_ != null ? other.payload_.Clone() : null;
+      responseStatus_ = other.responseStatus_ != null ? other.responseStatus_.Clone() : null;
       _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
@@ -1707,7 +1704,6 @@ namespace Grpc.Testing {
     public const int ResponseTypeFieldNumber = 1;
     private global::Grpc.Testing.PayloadType responseType_ = 0;
     /// <summary>
-    /// 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
@@ -1927,7 +1923,7 @@ namespace Grpc.Testing {
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public StreamingOutputCallResponse(StreamingOutputCallResponse other) : this() {
-      Payload = other.payload_ != null ? other.Payload.Clone() : null;
+      payload_ = other.payload_ != null ? other.payload_.Clone() : null;
       _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 

src/csharp/Grpc.IntegrationTesting/Stats.cs

@@ -86,7 +86,7 @@ namespace Grpc.Testing {
       totalCpuTime_ = other.totalCpuTime_;
       idleCpuTime_ = other.idleCpuTime_;
       cqPollCount_ = other.cqPollCount_;
-      CoreStats = other.coreStats_ != null ? other.CoreStats.Clone() : null;
+      coreStats_ = other.coreStats_ != null ? other.coreStats_.Clone() : null;
       _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
@@ -993,13 +993,13 @@ namespace Grpc.Testing {
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ClientStats(ClientStats other) : this() {
-      Latencies = other.latencies_ != null ? other.Latencies.Clone() : null;
+      latencies_ = other.latencies_ != null ? other.latencies_.Clone() : null;
       timeElapsed_ = other.timeElapsed_;
       timeUser_ = other.timeUser_;
       timeSystem_ = other.timeSystem_;
       requestResults_ = other.requestResults_.Clone();
       cqPollCount_ = other.cqPollCount_;
-      CoreStats = other.coreStats_ != null ? other.CoreStats.Clone() : null;
+      coreStats_ = other.coreStats_ != null ? other.coreStats_.Clone() : null;
       _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 

src/csharp/Grpc.Reflection/Reflection.cs

@@ -610,7 +610,7 @@ namespace Grpc.Reflection.V1Alpha {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ServerReflectionResponse(ServerReflectionResponse other) : this() {
       validHost_ = other.validHost_;
-      OriginalRequest = other.originalRequest_ != null ? other.OriginalRequest.Clone() : null;
+      originalRequest_ = other.originalRequest_ != null ? other.originalRequest_.Clone() : null;
       switch (other.MessageResponseCase) {
         case MessageResponseOneofCase.FileDescriptorResponse:
           FileDescriptorResponse = other.FileDescriptorResponse.Clone();

src/csharp/build_unitypackage.bat

@@ -68,7 +68,9 @@ copy /Y Grpc.Core\bin\Release\net45\System.Interactive.Async.dll unitypackage\un
 copy /Y Grpc.HealthCheck\bin\Release\net45\Google.Protobuf.dll unitypackage\unitypackage_skeleton\Plugins\Google.Protobuf\lib\net45\Google.Protobuf.dll || goto :error
 
 @rem create a zipfile that will act as a Unity package
-powershell -Command "Add-Type -Assembly 'System.IO.Compression.FileSystem'; [System.IO.Compression.ZipFile]::CreateFromDirectory('unitypackage\unitypackage_skeleton', 'grpc_unity_package.zip');"
+cd unitypackage\unitypackage_skeleton
+zip -r ..\..\grpc_unity_package.zip Plugins
+cd ..\..
 copy /Y grpc_unity_package.zip ..\..\artifacts\grpc_unity_package.%VERSION%.zip || goto :error
 
 goto :EOF

src/csharp/experimental/README.md

@@ -17,6 +17,19 @@ Xamarin.iOS
 - supported architectures: arm64 (iPhone 6+) and x86_64 (iPhone simulator)
 
 # Unity
-gRPC C# currently doesn't support Unity, but some proof-of-concept
-work has been done. There is in-progress effort to provide users
-with a pre-built gRPC package that can be used in their projects.
+
+gRPC C# now has experimental support for Unity. Please try using gRPC with
+Unity and provide feedback!
+
+How to test gRPC in a Unity project
+1. Create a Unity project that targets .NET 4.x (Edit -> Project Settings -> Editor -> Scripting Runtime Version). gRPC uses APIs that are only available in .NET4.5+ so this is a requirement.
+2. Download the latest development build of `grpc_unity_package.VERSION.zip` from
+   [daily builds](https://packages.grpc.io/)
+3. Extract the `.zip` file in the `Assets` directory in your Unity project
+4. Unity IDE will pick up all the bundled files and add them to project automatically.
+   You should be able to use gRPC and Protobuf in your scripts from now on.
+
+What's currently bundled in the `grpc_unity_package`
+-  Grpc.Core and its dependencies
+-  Google.Protobuf
+-  Precompiled native libraries for Linux, MacOS, Windows, Android and iOS.

src/csharp/unitypackage/unitypackage_skeleton/Plugins/Grpc.Core/runtimes/android/arm64-v8a/libgrpc_csharp_ext.so.meta

@@ -1,5 +1,5 @@
 fileFormatVersion: 2
-guid: e5beceb1c8fb2403ab3dea319dcd9a2e
+guid: e1f44cc7ecd4244448817ccae6de42a3
 PluginImporter:
   externalObjects: {}
   serializedVersion: 2

src/csharp/unitypackage/unitypackage_skeleton/Plugins/Grpc.Core/runtimes/android/armeabi-v7a/libgrpc_csharp_ext.so.meta

@@ -1,5 +1,5 @@
 fileFormatVersion: 2
-guid: e5beceb1c8fb2403ab3dea319dcd9a2e
+guid: 04fe0e4dcf310416b991e57c99e5d55f
 PluginImporter:
   externalObjects: {}
   serializedVersion: 2

src/csharp/unitypackage/unitypackage_skeleton/Plugins/Grpc.Core/runtimes/android/x86/libgrpc_csharp_ext.so.meta

@@ -1,5 +1,5 @@
 fileFormatVersion: 2
-guid: e5beceb1c8fb2403ab3dea319dcd9a2e
+guid: 245e3d515096b414fbcdd1fd4160161a
 PluginImporter:
   externalObjects: {}
   serializedVersion: 2