Merge github.com:grpc/grpc into big_data

BUILD

@@ -375,6 +375,7 @@ cc_library(
     "src/core/surface/channel.c",
     "src/core/surface/channel_connectivity.c",
     "src/core/surface/channel_create.c",
+    "src/core/surface/channel_ping.c",
     "src/core/surface/completion_queue.c",
     "src/core/surface/event_string.c",
     "src/core/surface/init.c",
@@ -645,6 +646,7 @@ cc_library(
     "src/core/surface/channel.c",
     "src/core/surface/channel_connectivity.c",
     "src/core/surface/channel_create.c",
+    "src/core/surface/channel_ping.c",
     "src/core/surface/completion_queue.c",
     "src/core/surface/event_string.c",
     "src/core/surface/init.c",
@@ -1178,6 +1180,7 @@ objc_library(
     "src/core/surface/channel.c",
     "src/core/surface/channel_connectivity.c",
     "src/core/surface/channel_create.c",
+    "src/core/surface/channel_ping.c",
     "src/core/surface/completion_queue.c",
     "src/core/surface/event_string.c",
     "src/core/surface/init.c",

README.md

@@ -13,34 +13,28 @@ You can find more detailed documentation and examples in the [doc](doc) and [exa
 
 See grpc/INSTALL for installation instructions for various platforms.
 
-#Repository Structure
+#Repository Structure & Status
 
-This repository contains source code for gRPC libraries for multiple languages written on top
-of shared C core library [src/core] (src/core).
+This repository contains source code for gRPC libraries for multiple languages written on top of shared C core library [src/core] (src/core).
 
-   * C++ source code: [src/cpp] (src/cpp)
-   * Ruby source code: [src/ruby] (src/ruby)
-   * NodeJS source code: [src/node] (src/node)
-   * Python source code: [src/python] (src/python)
-   * PHP source code: [src/php] (src/php)
-   * C# source code: [src/csharp] (src/csharp)
-   * Objective-C source code: [src/objective-c] (src/objective-c)
+Libraries in different languages are in different state of development. We are seeking contributions for all of these libraries.
 
+| Language                | Source                              | Status                          |
+|-------------------------|-------------------------------------|---------------------------------|
+| Shared C [core library] | [src/core] (src/core)               | Beta - the surface API is stable |
+| C++                     | [src/cpp] (src/cpp)                 | Beta - the surface API is stable |
+| Ruby                    | [src/ruby] (src/ruby)               | Beta - the surface API is stable |
+| NodeJS                  | [src/node] (src/node)               | Beta - the surface API is stable |
+| Python                  | [src/python] (src/python)           | Beta - the surface API is stable |
+| PHP                     | [src/php] (src/php)                 | Beta - the surface API is stable |
+| C#                      | [src/csharp] (src/csharp)           | Beta - the surface API is stable |
+| Objective-C             | [src/objective-c] (src/objective-c) | Beta - the surface API is stable |
+
+<small>
 Java source code is in [grpc-java] (http://github.com/grpc/grpc-java) repository.
 Go source code is in [grpc-go] (http://github.com/grpc/grpc-go) repository.
+</small>
 
-#Current Status of libraries
-
-Libraries in different languages are in different state of development. We are seeking contributions for all of these libraries.
-
-   * shared C core library [src/core] (src/core) : Beta - the surface API is stable
-   * C++ Library: [src/cpp] (src/cpp) : Beta - the surface API is stable
-   * Ruby Library: [src/ruby] (src/ruby) : Beta - the surface API is stable
-   * NodeJS Library: [src/node] (src/node) : Beta - the surface API is stable
-   * Python Library: [src/python] (src/python) : Beta - the surface API is stable
-   * C# Library: [src/csharp] (src/csharp) : Beta - the surface API is stable
-   * Objective-C Library: [src/objective-c] (src/objective-c): Beta - the surface API is stable
-   * PHP Library: [src/php] (src/php) : Beta - the surface API is stable
 
 #Overview
 

binding.gyp

@@ -260,6 +260,7 @@
         'src/core/surface/channel.c',
         'src/core/surface/channel_connectivity.c',
         'src/core/surface/channel_create.c',
+        'src/core/surface/channel_ping.c',
         'src/core/surface/completion_queue.c',
         'src/core/surface/event_string.c',
         'src/core/surface/init.c',

build.yaml

@@ -307,6 +307,7 @@ filegroups:
   - src/core/surface/channel.c
   - src/core/surface/channel_connectivity.c
   - src/core/surface/channel_create.c
+  - src/core/surface/channel_ping.c
   - src/core/surface/completion_queue.c
   - src/core/surface/event_string.c
   - src/core/surface/init.c
@@ -809,6 +810,16 @@ libs:
   - winsock
   - global
 targets:
+- name: algorithm_test
+  build: test
+  language: c
+  src:
+  - test/core/compression/algorithm_test.c
+  deps:
+  - grpc_test_util
+  - grpc
+  - gpr_test_util
+  - gpr
 - name: alloc_test
   build: test
   language: c
@@ -897,6 +908,16 @@ targets:
   - grpc
   - gpr_test_util
   - gpr
+- name: dns_resolver_test
+  build: test
+  language: c
+  src:
+  - test/core/client_config/resolvers/dns_resolver_test.c
+  deps:
+  - grpc_test_util
+  - grpc
+  - gpr_test_util
+  - gpr
 - name: dualstack_socket_test
   build: test
   language: c
@@ -1357,6 +1378,18 @@ targets:
   - mac
   - linux
   - posix
+- name: httpscli_test
+  build: test
+  language: c
+  src:
+  - test/core/httpcli/httpscli_test.c
+  deps:
+  - grpc_test_util
+  - grpc
+  - gpr_test_util
+  - gpr
+  platforms:
+  - linux
 - name: init_test
   build: test
   language: c
@@ -1396,6 +1429,16 @@ targets:
   - grpc
   - gpr_test_util
   - gpr
+- name: json_stream_error_test
+  build: test
+  language: c
+  src:
+  - test/core/json/json_stream_error_test.c
+  deps:
+  - grpc_test_util
+  - grpc
+  - gpr_test_util
+  - gpr
 - name: json_test
   build: test
   language: c
@@ -1488,6 +1531,16 @@ targets:
   - grpc
   - gpr_test_util
   - gpr
+- name: secure_channel_create_test
+  build: test
+  language: c
+  src:
+  - test/core/surface/secure_channel_create_test.c
+  deps:
+  - grpc_test_util
+  - grpc
+  - gpr_test_util
+  - gpr
 - name: secure_endpoint_test
   build: test
   language: c
@@ -1498,6 +1551,26 @@ targets:
   - grpc
   - gpr_test_util
   - gpr
+- name: server_chttp2_test
+  build: test
+  language: c
+  src:
+  - test/core/surface/server_chttp2_test.c
+  deps:
+  - grpc_test_util
+  - grpc
+  - gpr_test_util
+  - gpr
+- name: server_test
+  build: test
+  language: c
+  src:
+  - test/core/surface/server_test.c
+  deps:
+  - grpc_test_util
+  - grpc
+  - gpr_test_util
+  - gpr
 - name: set_initial_connect_string_test
   build: test
   language: c
@@ -1509,6 +1582,16 @@ targets:
   - grpc
   - gpr_test_util
   - gpr
+- name: sockaddr_resolver_test
+  build: test
+  language: c
+  src:
+  - test/core/client_config/resolvers/sockaddr_resolver_test.c
+  deps:
+  - grpc_test_util
+  - grpc
+  - gpr_test_util
+  - gpr
 - name: sockaddr_utils_test
   build: test
   language: c
@@ -1519,6 +1602,20 @@ targets:
   - grpc
   - gpr_test_util
   - gpr
+- name: socket_utils_test
+  build: test
+  language: c
+  src:
+  - test/core/iomgr/socket_utils_test.c
+  deps:
+  - grpc_test_util
+  - grpc
+  - gpr_test_util
+  - gpr
+  platforms:
+  - mac
+  - linux
+  - posix
 - name: tcp_client_posix_test
   build: test
   language: c
@@ -1611,6 +1708,16 @@ targets:
   - grpc
   - gpr_test_util
   - gpr
+- name: transport_connectivity_state_test
+  build: test
+  language: c
+  src:
+  - test/core/transport/connectivity_state_test.c
+  deps:
+  - grpc_test_util
+  - grpc
+  - gpr_test_util
+  - gpr
 - name: transport_metadata_test
   build: test
   language: c

doc/PROTOCOL-HTTP2.md

@@ -45,7 +45,7 @@ Request-Headers are delivered as HTTP2 headers in HEADERS + CONTINUATION frames.
 * **Custom-Metadata** → Binary-Header / ASCII-Header
 * **Binary-Header** → {Header-Name "-bin" } {_base64 encoded value_}
 * **ASCII-Header** → Header-Name ASCII-Value
-* **Header-Name** → 1\*( %x30-39 / %x61-7A / "\_" / "-") ; 0-9 a-z \_ -
+* **Header-Name** → 1\*( %x30-39 / %x61-7A / "\_" / "-" / ".") ; 0-9 a-z \_ - .
 * **ASCII-Value** → 1\*( %x20-%x7E ) ; space and printable ASCII
 
 

examples/cpp/helloworld/README.md

@@ -41,7 +41,7 @@ message from the remote client containing the user's name, then send back
 a greeting in a single `HelloReply`. This is the simplest type of RPC you
 can specify in gRPC - we'll look at some other types later in this document.
 
-```
+```protobuf
 syntax = "proto3";
 
 option java_package = "ex.grpc";
@@ -93,20 +93,20 @@ $ protoc -I ../../protos/ --cpp_out=. ../../protos/helloworld.proto
   channel can be created with the target address, credentials to use and
   arguments as follows
 
-    ```
+    ```cpp
     auto channel = CreateChannel("localhost:50051", InsecureChannelCredentials());
     ```
 
 - Create a stub. A stub implements the rpc methods of a service and in the
   generated code, a method is provided to created a stub with a channel:
 
-    ```
+    ```cpp
     auto stub = helloworld::Greeter::NewStub(channel);
     ```
 
 - Make a unary rpc, with `ClientContext` and request/response proto messages.
 
-    ```
+    ```cpp
     ClientContext context;
     HelloRequest request;
     request.set_name("hello");
@@ -116,7 +116,7 @@ $ protoc -I ../../protos/ --cpp_out=. ../../protos/helloworld.proto
 
 - Check returned status and response.
 
-    ```
+    ```cpp
     if (status.ok()) {
       // check reply.message()
     } else {
@@ -130,7 +130,7 @@ For a working example, refer to [greeter_client.cc](greeter_client.cc).
 
 - Implement the service interface
 
-    ```
+    ```cpp
     class GreeterServiceImpl final : public Greeter::Service {
       Status SayHello(ServerContext* context, const HelloRequest* request,
           HelloReply* reply) override {
@@ -144,7 +144,7 @@ For a working example, refer to [greeter_client.cc](greeter_client.cc).
 
 - Build a server exporting the service
 
-    ```
+    ```cpp
     GreeterServiceImpl service;
     ServerBuilder builder;
     builder.AddListeningPort("0.0.0.0:50051", grpc::InsecureServerCredentials());
@@ -170,14 +170,14 @@ The channel and stub creation code is the same as the sync client.
 - Initiate the rpc and create a handle for the rpc. Bind the rpc to a
   `CompletionQueue`.
 
-    ```
+    ```cpp
     CompletionQueue cq;
     auto rpc = stub->AsyncSayHello(&context, request, &cq);
     ```
 
 - Ask for reply and final status, with a unique tag
 
-    ```
+    ```cpp
     Status status;
     rpc->Finish(&reply, &status, (void*)1);
     ```
@@ -185,7 +185,7 @@ The channel and stub creation code is the same as the sync client.
 - Wait for the completion queue to return the next tag. The reply and status are
   ready once the tag passed into the corresponding `Finish()` call is returned.
 
-    ```
+    ```cpp
     void* got_tag;
     bool ok = false;
     cq.Next(&got_tag, &ok);
@@ -203,7 +203,7 @@ completion queue to return the tag. The basic flow is
 
 - Build a server exporting the async service
 
-    ```
+    ```cpp
     helloworld::Greeter::AsyncService service;
     ServerBuilder builder;
     builder.AddListeningPort("0.0.0.0:50051", InsecureServerCredentials());
@@ -214,7 +214,7 @@ completion queue to return the tag. The basic flow is
 
 - Request one rpc
 
-    ```
+    ```cpp
     ServerContext context;
     HelloRequest request;
     ServerAsyncResponseWriter<HelloReply> responder;
@@ -224,7 +224,7 @@ completion queue to return the tag. The basic flow is
 - Wait for the completion queue to return the tag. The context, request and
   responder are ready once the tag is retrieved.
 
-    ```
+    ```cpp
     HelloReply reply;
     Status status;
     void* got_tag;
@@ -239,7 +239,7 @@ completion queue to return the tag. The basic flow is
 - Wait for the completion queue to return the tag. The rpc is finished when the
   tag is back.
 
-    ```
+    ```cpp
     void* got_tag;
     bool ok = false;
     cq.Next(&got_tag, &ok);

gRPC.podspec

@@ -386,6 +386,7 @@ Pod::Spec.new do |s|
                       'src/core/surface/channel.c',
                       'src/core/surface/channel_connectivity.c',
                       'src/core/surface/channel_create.c',
+                      'src/core/surface/channel_ping.c',
                       'src/core/surface/completion_queue.c',
                       'src/core/surface/event_string.c',
                       'src/core/surface/init.c',

include/grpc++/client_context.h

@@ -268,7 +268,7 @@ class ClientContext {
   /// \return The call's peer URI.
   grpc::string peer() const;
 
-  /// Get and set census context
+  /// Get and set census context.
   void set_census_context(struct census_context* ccp) { census_context_ = ccp; }
   struct census_context* census_context() const {
     return census_context_;
@@ -280,6 +280,17 @@ class ClientContext {
   /// There is no guarantee the call will be cancelled.
   void TryCancel();
 
+  /// Global Callbacks
+  ///
+  /// Can be set exactly once per application to install hooks whenever
+  /// a client context is constructed and destructed.
+  class GlobalCallbacks {
+   public:
+    virtual void DefaultConstructor(ClientContext* context) = 0;
+    virtual void Destructor(ClientContext* context) = 0;
+  };
+  static void SetGlobalCallbacks(GlobalCallbacks* callbacks);
+
  private:
   // Disallow copy and assign.
   ClientContext(const ClientContext&);

include/grpc++/impl/rpc_service_method.h

@@ -34,6 +34,7 @@
 #ifndef GRPCXX_IMPL_RPC_SERVICE_METHOD_H
 #define GRPCXX_IMPL_RPC_SERVICE_METHOD_H
 
+#include <climits>
 #include <functional>
 #include <map>
 #include <memory>
@@ -251,7 +252,11 @@ class RpcService {
   void AddMethod(RpcServiceMethod* method) { methods_.emplace_back(method); }
 
   RpcServiceMethod* GetMethod(int i) { return methods_[i].get(); }
-  int GetMethodCount() const { return methods_.size(); }
+  int GetMethodCount() const {
+    // On win x64, int is only 32bit
+    GPR_ASSERT(methods_.size() <= INT_MAX);
+    return (int)methods_.size();
+  }
 
  private:
   std::vector<std::unique_ptr<RpcServiceMethod>> methods_;

include/grpc/compression.h

@@ -79,12 +79,6 @@ int grpc_compression_algorithm_parse(const char *name, size_t name_length,
 int grpc_compression_algorithm_name(grpc_compression_algorithm algorithm,
                                     char **name);
 
-/** Returns the compression level corresponding to \a algorithm.
- *
- * It abort()s for unknown algorithms. */
-grpc_compression_level grpc_compression_level_for_algorithm(
-    grpc_compression_algorithm algorithm);
-
 /** Returns the compression algorithm corresponding to \a level.
  *
  * It abort()s for unknown levels . */

include/grpc/grpc.h

@@ -531,6 +531,11 @@ grpc_call *grpc_channel_create_call(grpc_channel *channel,
                                     const char *method, const char *host,
                                     gpr_timespec deadline, void *reserved);
 
+/** Ping the channels peer (load balanced channels will select one sub-channel
+    to ping); if the channel is not connected, posts a failed. */
+void grpc_channel_ping(grpc_channel *channel, grpc_completion_queue *cq,
+                       void *tag, void *reserved);
+
 /** Pre-register a method/host pair on a channel. */
 void *grpc_channel_register_call(grpc_channel *channel, const char *method,
                                  const char *host, void *reserved);

include/grpc/support/alloc.h

@@ -41,9 +41,9 @@ extern "C" {
 #endif
 
 typedef struct gpr_allocation_functions {
- void *(*malloc_fn)(size_t size);
- void *(*realloc_fn)(void *ptr, size_t size);
- void (*free_fn)(void *ptr);
+  void *(*malloc_fn)(size_t size);
+  void *(*realloc_fn)(void *ptr, size_t size);
+  void (*free_fn)(void *ptr);
 } gpr_allocation_functions;
 
 /* malloc, never returns NULL */

include/grpc/support/cmdline.h

@@ -83,8 +83,12 @@ void gpr_cmdline_add_string(gpr_cmdline *cl, const char *name, const char *help,
 void gpr_cmdline_on_extra_arg(
     gpr_cmdline *cl, const char *name, const char *help,
     void (*on_extra_arg)(void *user_data, const char *arg), void *user_data);
-/* Parse the command line */
-void gpr_cmdline_parse(gpr_cmdline *cl, int argc, char **argv);
+/* Enable surviving failure: default behavior is to exit the process */
+void gpr_cmdline_set_survive_failure(gpr_cmdline *cl);
+/* Parse the command line; returns 1 on success, on failure either dies
+   (by default) or returns 0 if gpr_cmdline_set_survive_failure() has been
+   called */
+int gpr_cmdline_parse(gpr_cmdline *cl, int argc, char **argv);
 /* Destroy the parser */
 void gpr_cmdline_destroy(gpr_cmdline *cl);
 /* Get a string describing usage */

include/grpc/support/time.h

@@ -61,8 +61,8 @@ typedef enum {
 } gpr_clock_type;
 
 typedef struct gpr_timespec {
-  time_t tv_sec;
-  int tv_nsec;
+  gpr_int64 tv_sec;
+  gpr_int32 tv_nsec;
   /** Against which clock was this time measured? (or GPR_TIMESPAN if
       this is a relative time meaure) */
   gpr_clock_type clock_type;

src/core/census/context.h

@@ -36,10 +36,12 @@
 
 #include <grpc/census.h>
 
+#define GRPC_CENSUS_MAX_ON_THE_WIRE_TAG_BYTES 2048
+
 /* census_context is the in-memory representation of information needed to
  * maintain tracing, RPC statistics and resource usage information. */
 struct census_context {
-  census_tag_set *tags;  /* Opaque data structure for census tags. */
+  census_tag_set *tags; /* Opaque data structure for census tags. */
 };
 
 #endif /* GRPC_INTERNAL_CORE_CENSUS_CONTEXT_H */

src/core/census/grpc_filter.c

@@ -115,8 +115,11 @@ static void server_mutate_op(grpc_call_element *elem,
 static void server_start_transport_op(grpc_exec_ctx *exec_ctx,
                                       grpc_call_element *elem,
                                       grpc_transport_stream_op *op) {
+  /* TODO(ctiller): this code fails. I don't know why. I expect it's
+                    incomplete, and someone should look at it soon.
+
   call_data *calld = elem->call_data;
-  GPR_ASSERT((calld->op_id.upper != 0) || (calld->op_id.lower != 0));
+  GPR_ASSERT((calld->op_id.upper != 0) || (calld->op_id.lower != 0)); */
   server_mutate_op(elem, op);
   grpc_call_next_op(exec_ctx, elem, op);
 }

src/core/channel/channel_stack.c

@@ -101,11 +101,12 @@ grpc_call_element *grpc_call_stack_element(grpc_call_stack *call_stack,
   return CALL_ELEMS_FROM_STACK(call_stack) + index;
 }
 
-void grpc_channel_stack_init(grpc_exec_ctx *exec_ctx,
+void grpc_channel_stack_init(grpc_exec_ctx *exec_ctx, int initial_refs,
+                             grpc_iomgr_cb_func destroy, void *destroy_arg,
                              const grpc_channel_filter **filters,
-                             size_t filter_count, grpc_channel *master,
+                             size_t filter_count,
                              const grpc_channel_args *channel_args,
-                             grpc_channel_stack *stack) {
+                             const char *name, grpc_channel_stack *stack) {
   size_t call_size =
       ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(grpc_call_stack)) +
       ROUND_UP_TO_ALIGNMENT_SIZE(filter_count * sizeof(grpc_call_element));
@@ -115,6 +116,8 @@ void grpc_channel_stack_init(grpc_exec_ctx *exec_ctx,
   size_t i;
 
   stack->count = filter_count;
+  GRPC_STREAM_REF_INIT(&stack->refcount, initial_refs, destroy, destroy_arg,
+                       name);
   elems = CHANNEL_ELEMS_FROM_STACK(stack);
   user_data =
       ((char *)elems) +
@@ -122,7 +125,7 @@ void grpc_channel_stack_init(grpc_exec_ctx *exec_ctx,
 
   /* init per-filter data */
   for (i = 0; i < filter_count; i++) {
-    args.master = master;
+    args.channel_stack = stack;
     args.channel_args = channel_args;
     args.is_first = i == 0;
     args.is_last = i == (filter_count - 1);
@@ -166,15 +169,15 @@ void grpc_call_stack_init(grpc_exec_ctx *exec_ctx,
   size_t i;
 
   call_stack->count = count;
-  gpr_ref_init(&call_stack->refcount.refs, initial_refs);
-  grpc_closure_init(&call_stack->refcount.destroy, destroy, destroy_arg);
+  GRPC_STREAM_REF_INIT(&call_stack->refcount, initial_refs, destroy,
+                       destroy_arg, "CALL_STACK");
   call_elems = CALL_ELEMS_FROM_STACK(call_stack);
   user_data = ((char *)call_elems) +
               ROUND_UP_TO_ALIGNMENT_SIZE(count * sizeof(grpc_call_element));
 
   /* init per-filter data */
   for (i = 0; i < count; i++) {
-    args.refcount = &call_stack->refcount;
+    args.call_stack = call_stack;
     args.server_transport_data = transport_server_data;
     args.context = context;
     call_elems[i].filter = channel_elems[i].filter;

src/core/channel/channel_stack.h

@@ -51,15 +51,18 @@
 typedef struct grpc_channel_element grpc_channel_element;
 typedef struct grpc_call_element grpc_call_element;
 
+typedef struct grpc_channel_stack grpc_channel_stack;
+typedef struct grpc_call_stack grpc_call_stack;
+
 typedef struct {
-  grpc_channel *master;
+  grpc_channel_stack *channel_stack;
   const grpc_channel_args *channel_args;
   int is_first;
   int is_last;
 } grpc_channel_element_args;
 
 typedef struct {
-  grpc_stream_refcount *refcount;
+  grpc_call_stack *call_stack;
   const void *server_transport_data;
   grpc_call_context_element *context;
 } grpc_call_element_args;
@@ -144,23 +147,24 @@ struct grpc_call_element {
 
 /* A channel stack tracks a set of related filters for one channel, and
    guarantees they live within a single malloc() allocation */
-typedef struct {
+struct grpc_channel_stack {
+  grpc_stream_refcount refcount;
   size_t count;
   /* Memory required for a call stack (computed at channel stack
      initialization) */
   size_t call_stack_size;
-} grpc_channel_stack;
+};
 
 /* A call stack tracks a set of related filters for one call, and guarantees
    they live within a single malloc() allocation */
-typedef struct {
+struct grpc_call_stack {
   /* shared refcount for this channel stack.
      MUST be the first element: the underlying code calls destroy
      with the address of the refcount, but higher layers prefer to think
      about the address of the call stack itself. */
   grpc_stream_refcount refcount;
   size_t count;
-} grpc_call_stack;
+};
 
 /* Get a channel element given a channel stack and its index */
 grpc_channel_element *grpc_channel_stack_element(grpc_channel_stack *stack,
@@ -175,11 +179,11 @@ grpc_call_element *grpc_call_stack_element(grpc_call_stack *stack, size_t i);
 size_t grpc_channel_stack_size(const grpc_channel_filter **filters,
                                size_t filter_count);
 /* Initialize a channel stack given some filters */
-void grpc_channel_stack_init(grpc_exec_ctx *exec_ctx,
+void grpc_channel_stack_init(grpc_exec_ctx *exec_ctx, int initial_refs,
+                             grpc_iomgr_cb_func destroy, void *destroy_arg,
                              const grpc_channel_filter **filters,
-                             size_t filter_count, grpc_channel *master,
-                             const grpc_channel_args *args,
-                             grpc_channel_stack *stack);
+                             size_t filter_count, const grpc_channel_args *args,
+                             const char *name, grpc_channel_stack *stack);
 /* Destroy a channel stack */
 void grpc_channel_stack_destroy(grpc_exec_ctx *exec_ctx,
                                 grpc_channel_stack *stack);
@@ -199,14 +203,23 @@ void grpc_call_stack_set_pollset(grpc_exec_ctx *exec_ctx,
                                  grpc_pollset *pollset);
 
 #ifdef GRPC_STREAM_REFCOUNT_DEBUG
-#define grpc_call_stack_ref(call_stack, reason) \
+#define GRPC_CALL_STACK_REF(call_stack, reason) \
   grpc_stream_ref(&(call_stack)->refcount, reason)
-#define grpc_call_stack_unref(exec_ctx, call_stack, reason) \
+#define GRPC_CALL_STACK_UNREF(exec_ctx, call_stack, reason) \
   grpc_stream_unref(exec_ctx, &(call_stack)->refcount, reason)
+#define GRPC_CHANNEL_STACK_REF(channel_stack, reason) \
+  grpc_stream_ref(&(channel_stack)->refcount, reason)
+#define GRPC_CHANNEL_STACK_UNREF(exec_ctx, channel_stack, reason) \
+  grpc_stream_unref(exec_ctx, &(channel_stack)->refcount, reason)
 #else
-#define grpc_call_stack_ref(call_stack) grpc_stream_ref(&(call_stack)->refcount)
-#define grpc_call_stack_unref(exec_ctx, call_stack) \
+#define GRPC_CALL_STACK_REF(call_stack, reason) \
+  grpc_stream_ref(&(call_stack)->refcount)
+#define GRPC_CALL_STACK_UNREF(exec_ctx, call_stack, reason) \
   grpc_stream_unref(exec_ctx, &(call_stack)->refcount)
+#define GRPC_CHANNEL_STACK_REF(channel_stack, reason) \
+  grpc_stream_ref(&(channel_stack)->refcount)
+#define GRPC_CHANNEL_STACK_UNREF(exec_ctx, channel_stack, reason) \
+  grpc_stream_unref(exec_ctx, &(channel_stack)->refcount)
 #endif
 
 /* Destroy a call stack */

src/core/channel/client_channel.c

@@ -59,11 +59,6 @@ typedef struct client_channel_channel_data {
   grpc_resolver *resolver;
   /** have we started resolving this channel */
   int started_resolving;
-  /** master channel - the grpc_channel instance that ultimately owns
-      this channel_data via its channel stack.
-      We occasionally use this to bump the refcount on the master channel
-      to keep ourselves alive through an asynchronous operation. */
-  grpc_channel *master;
 
   /** mutex protecting client configuration, including all
       variables below in this data structure */
@@ -81,8 +76,10 @@ typedef struct client_channel_channel_data {
   grpc_connectivity_state_tracker state_tracker;
   /** when an lb_policy arrives, should we try to exit idle */
   int exit_idle_when_lb_policy_arrives;
-  /** pollset_set of interested parties in a new connection */
-  grpc_pollset_set pollset_set;
+  /** owning stack */
+  grpc_channel_stack *owning_stack;
+  /** interested parties */
+  grpc_pollset_set interested_parties;
 } channel_data;
 
 /** We create one watcher for each new lb_policy that is returned from a
@@ -103,9 +100,7 @@ typedef struct {
 } waiting_call;
 
 static char *cc_get_peer(grpc_exec_ctx *exec_ctx, grpc_call_element *elem) {
-  channel_data *chand = elem->channel_data;
-  return grpc_subchannel_call_holder_get_peer(exec_ctx, elem->call_data,
-                                              chand->master);
+  return grpc_subchannel_call_holder_get_peer(exec_ctx, elem->call_data);
 }
 
 static void cc_start_transport_stream_op(grpc_exec_ctx *exec_ctx,
@@ -121,10 +116,18 @@ static void watch_lb_policy(grpc_exec_ctx *exec_ctx, channel_data *chand,
 
 static void on_lb_policy_state_changed_locked(
     grpc_exec_ctx *exec_ctx, lb_policy_connectivity_watcher *w) {
+  grpc_connectivity_state publish_state = w->state;
   /* check if the notification is for a stale policy */
   if (w->lb_policy != w->chand->lb_policy) return;
 
-  grpc_connectivity_state_set(exec_ctx, &w->chand->state_tracker, w->state,
+  if (publish_state == GRPC_CHANNEL_FATAL_FAILURE &&
+      w->chand->resolver != NULL) {
+    publish_state = GRPC_CHANNEL_TRANSIENT_FAILURE;
+    grpc_resolver_channel_saw_error(exec_ctx, w->chand->resolver);
+    GRPC_LB_POLICY_UNREF(exec_ctx, w->chand->lb_policy, "channel");
+    w->chand->lb_policy = NULL;
+  }
+  grpc_connectivity_state_set(exec_ctx, &w->chand->state_tracker, publish_state,
                               "lb_changed");
   if (w->state != GRPC_CHANNEL_FATAL_FAILURE) {
     watch_lb_policy(exec_ctx, w->chand, w->lb_policy, w->state);
@@ -139,7 +142,7 @@ static void on_lb_policy_state_changed(grpc_exec_ctx *exec_ctx, void *arg,
   on_lb_policy_state_changed_locked(exec_ctx, w);
   gpr_mu_unlock(&w->chand->mu_config);
 
-  GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, w->chand->master, "watch_lb_policy");
+  GRPC_CHANNEL_STACK_UNREF(exec_ctx, w->chand->owning_stack, "watch_lb_policy");
   gpr_free(w);
 }
 
@@ -147,7 +150,7 @@ static void watch_lb_policy(grpc_exec_ctx *exec_ctx, channel_data *chand,
                             grpc_lb_policy *lb_policy,
                             grpc_connectivity_state current_state) {
   lb_policy_connectivity_watcher *w = gpr_malloc(sizeof(*w));
-  GRPC_CHANNEL_INTERNAL_REF(chand->master, "watch_lb_policy");
+  GRPC_CHANNEL_STACK_REF(chand->owning_stack, "watch_lb_policy");
 
   w->chand = chand;
   grpc_closure_init(&w->on_changed, on_lb_policy_state_changed, w);
@@ -179,6 +182,11 @@ static void cc_on_config_changed(grpc_exec_ctx *exec_ctx, void *arg,
 
   chand->incoming_configuration = NULL;
 
+  if (lb_policy != NULL) {
+    grpc_pollset_set_add_pollset_set(exec_ctx, &lb_policy->interested_parties,
+                                     &chand->interested_parties);
+  }
+
   gpr_mu_lock(&chand->mu_config);
   old_lb_policy = chand->lb_policy;
   chand->lb_policy = lb_policy;
@@ -200,7 +208,7 @@ static void cc_on_config_changed(grpc_exec_ctx *exec_ctx, void *arg,
       watch_lb_policy(exec_ctx, chand, lb_policy, state);
     }
     gpr_mu_unlock(&chand->mu_config);
-    GRPC_CHANNEL_INTERNAL_REF(chand->master, "resolver");
+    GRPC_CHANNEL_STACK_REF(chand->owning_stack, "resolver");
     grpc_resolver_next(exec_ctx, resolver, &chand->incoming_configuration,
                        &chand->on_config_changed);
     GRPC_RESOLVER_UNREF(exec_ctx, resolver, "channel-next");
@@ -222,7 +230,9 @@ static void cc_on_config_changed(grpc_exec_ctx *exec_ctx, void *arg,
   }
 
   if (old_lb_policy != NULL) {
-    grpc_lb_policy_shutdown(exec_ctx, old_lb_policy);
+    grpc_pollset_set_del_pollset_set(exec_ctx,
+                                     &old_lb_policy->interested_parties,
+                                     &chand->interested_parties);
     GRPC_LB_POLICY_UNREF(exec_ctx, old_lb_policy, "channel");
   }
 
@@ -230,20 +240,22 @@ static void cc_on_config_changed(grpc_exec_ctx *exec_ctx, void *arg,
     GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "config_change");
   }
 
-  GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, chand->master, "resolver");
+  GRPC_CHANNEL_STACK_UNREF(exec_ctx, chand->owning_stack, "resolver");
 }
 
 static void cc_start_transport_op(grpc_exec_ctx *exec_ctx,
                                   grpc_channel_element *elem,
                                   grpc_transport_op *op) {
-  grpc_lb_policy *lb_policy = NULL;
   channel_data *chand = elem->channel_data;
   grpc_resolver *destroy_resolver = NULL;
 
   grpc_exec_ctx_enqueue(exec_ctx, op->on_consumed, 1);
 
   GPR_ASSERT(op->set_accept_stream == NULL);
-  GPR_ASSERT(op->bind_pollset == NULL);
+  if (op->bind_pollset != NULL) {
+    grpc_pollset_set_add_pollset(exec_ctx, &chand->interested_parties,
+                                 op->bind_pollset);
+  }
 
   gpr_mu_lock(&chand->mu_config);
   if (op->on_connectivity_state_change != NULL) {
@@ -254,9 +266,14 @@ static void cc_start_transport_op(grpc_exec_ctx *exec_ctx,
     op->connectivity_state = NULL;
   }
 
-  lb_policy = chand->lb_policy;
-  if (lb_policy) {
-    GRPC_LB_POLICY_REF(lb_policy, "broadcast");
+  if (op->send_ping != NULL) {
+    if (chand->lb_policy == NULL) {
+      grpc_exec_ctx_enqueue(exec_ctx, op->send_ping, 0);
+    } else {
+      grpc_lb_policy_ping_one(exec_ctx, chand->lb_policy, op->send_ping);
+      op->bind_pollset = NULL;
+    }
+    op->send_ping = NULL;
   }
 
   if (op->disconnect && chand->resolver != NULL) {
@@ -265,7 +282,9 @@ static void cc_start_transport_op(grpc_exec_ctx *exec_ctx,
     destroy_resolver = chand->resolver;
     chand->resolver = NULL;
     if (chand->lb_policy != NULL) {
-      grpc_lb_policy_shutdown(exec_ctx, chand->lb_policy);
+      grpc_pollset_set_del_pollset_set(exec_ctx,
+                                       &chand->lb_policy->interested_parties,
+                                       &chand->interested_parties);
       GRPC_LB_POLICY_UNREF(exec_ctx, chand->lb_policy, "channel");
       chand->lb_policy = NULL;
     }
@@ -276,16 +295,11 @@ static void cc_start_transport_op(grpc_exec_ctx *exec_ctx,
     grpc_resolver_shutdown(exec_ctx, destroy_resolver);
     GRPC_RESOLVER_UNREF(exec_ctx, destroy_resolver, "channel");
   }
-
-  if (lb_policy) {
-    grpc_lb_policy_broadcast(exec_ctx, lb_policy, op);
-    GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "broadcast");
-  }
 }
 
 typedef struct {
   grpc_metadata_batch *initial_metadata;
-  grpc_subchannel **subchannel;
+  grpc_connected_subchannel **connected_subchannel;
   grpc_closure *on_ready;
   grpc_call_element *elem;
   grpc_closure closure;
@@ -293,17 +307,17 @@ typedef struct {
 
 static int cc_pick_subchannel(grpc_exec_ctx *exec_ctx, void *arg,
                               grpc_metadata_batch *initial_metadata,
-                              grpc_subchannel **subchannel,
+                              grpc_connected_subchannel **connected_subchannel,
                               grpc_closure *on_ready);
 
 static void continue_picking(grpc_exec_ctx *exec_ctx, void *arg, int success) {
   continue_picking_args *cpa = arg;
   if (!success) {
     grpc_exec_ctx_enqueue(exec_ctx, cpa->on_ready, 0);
-  } else if (cpa->subchannel == NULL) {
+  } else if (cpa->connected_subchannel == NULL) {
     /* cancelled, do nothing */
   } else if (cc_pick_subchannel(exec_ctx, cpa->elem, cpa->initial_metadata,
-                                cpa->subchannel, cpa->on_ready)) {
+                                cpa->connected_subchannel, cpa->on_ready)) {
     grpc_exec_ctx_enqueue(exec_ctx, cpa->on_ready, 1);
   }
   gpr_free(cpa);
@@ -311,7 +325,7 @@ static void continue_picking(grpc_exec_ctx *exec_ctx, void *arg, int success) {
 
 static int cc_pick_subchannel(grpc_exec_ctx *exec_ctx, void *elemp,
                               grpc_metadata_batch *initial_metadata,
-                              grpc_subchannel **subchannel,
+                              grpc_connected_subchannel **connected_subchannel,
                               grpc_closure *on_ready) {
   grpc_call_element *elem = elemp;
   channel_data *chand = elem->channel_data;
@@ -319,18 +333,19 @@ static int cc_pick_subchannel(grpc_exec_ctx *exec_ctx, void *elemp,
   continue_picking_args *cpa;
   grpc_closure *closure;
 
-  GPR_ASSERT(subchannel);
+  GPR_ASSERT(connected_subchannel);
 
   gpr_mu_lock(&chand->mu_config);
   if (initial_metadata == NULL) {
     if (chand->lb_policy != NULL) {
-      grpc_lb_policy_cancel_pick(exec_ctx, chand->lb_policy, subchannel);
+      grpc_lb_policy_cancel_pick(exec_ctx, chand->lb_policy,
+                                 connected_subchannel);
     }
     for (closure = chand->waiting_for_config_closures.head; closure != NULL;
          closure = grpc_closure_next(closure)) {
       cpa = closure->cb_arg;
-      if (cpa->subchannel == subchannel) {
-        cpa->subchannel = NULL;
+      if (cpa->connected_subchannel == connected_subchannel) {
+        cpa->connected_subchannel = NULL;
         grpc_exec_ctx_enqueue(exec_ctx, cpa->on_ready, 0);
       }
     }
@@ -338,21 +353,22 @@ static int cc_pick_subchannel(grpc_exec_ctx *exec_ctx, void *elemp,
     return 1;
   }
   if (chand->lb_policy != NULL) {
-    int r = grpc_lb_policy_pick(exec_ctx, chand->lb_policy, calld->pollset,
-                                initial_metadata, subchannel, on_ready);
+    int r =
+        grpc_lb_policy_pick(exec_ctx, chand->lb_policy, calld->pollset,
+                            initial_metadata, connected_subchannel, on_ready);
     gpr_mu_unlock(&chand->mu_config);
     return r;
   }
   if (chand->resolver != NULL && !chand->started_resolving) {
     chand->started_resolving = 1;
-    GRPC_CHANNEL_INTERNAL_REF(chand->master, "resolver");
+    GRPC_CHANNEL_STACK_REF(chand->owning_stack, "resolver");
     grpc_resolver_next(exec_ctx, chand->resolver,
                        &chand->incoming_configuration,
                        &chand->on_config_changed);
   }
   cpa = gpr_malloc(sizeof(*cpa));
   cpa->initial_metadata = initial_metadata;
-  cpa->subchannel = subchannel;
+  cpa->connected_subchannel = connected_subchannel;
   cpa->on_ready = on_ready;
   cpa->elem = elem;
   grpc_closure_init(&cpa->closure, continue_picking, cpa);
@@ -364,7 +380,8 @@ static int cc_pick_subchannel(grpc_exec_ctx *exec_ctx, void *elemp,
 /* Constructor for call_data */
 static void init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
                            grpc_call_element_args *args) {
-  grpc_subchannel_call_holder_init(elem->call_data, cc_pick_subchannel, elem);
+  grpc_subchannel_call_holder_init(elem->call_data, cc_pick_subchannel, elem,
+                                   args->call_stack);
 }
 
 /* Destructor for call_data */
@@ -385,12 +402,12 @@ static void init_channel_elem(grpc_exec_ctx *exec_ctx,
   GPR_ASSERT(elem->filter == &grpc_client_channel_filter);
 
   gpr_mu_init(&chand->mu_config);
-  chand->master = args->master;
-  grpc_pollset_set_init(&chand->pollset_set);
   grpc_closure_init(&chand->on_config_changed, cc_on_config_changed, chand);
+  chand->owning_stack = args->channel_stack;
 
   grpc_connectivity_state_init(&chand->state_tracker, GRPC_CHANNEL_IDLE,
                                "client_channel");
+  grpc_pollset_set_init(&chand->interested_parties);
 }
 
 /* Destructor for channel_data */
@@ -403,10 +420,13 @@ static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
     GRPC_RESOLVER_UNREF(exec_ctx, chand->resolver, "channel");
   }
   if (chand->lb_policy != NULL) {
+    grpc_pollset_set_del_pollset_set(exec_ctx,
+                                     &chand->lb_policy->interested_parties,
+                                     &chand->interested_parties);
     GRPC_LB_POLICY_UNREF(exec_ctx, chand->lb_policy, "channel");
   }
   grpc_connectivity_state_destroy(exec_ctx, &chand->state_tracker);
-  grpc_pollset_set_destroy(&chand->pollset_set);
+  grpc_pollset_set_destroy(&chand->interested_parties);
   gpr_mu_destroy(&chand->mu_config);
 }
 
@@ -435,7 +455,7 @@ void grpc_client_channel_set_resolver(grpc_exec_ctx *exec_ctx,
   if (!grpc_closure_list_empty(chand->waiting_for_config_closures) ||
       chand->exit_idle_when_lb_policy_arrives) {
     chand->started_resolving = 1;
-    GRPC_CHANNEL_INTERNAL_REF(chand->master, "resolver");
+    GRPC_CHANNEL_STACK_REF(chand->owning_stack, "resolver");
     grpc_resolver_next(exec_ctx, resolver, &chand->incoming_configuration,
                        &chand->on_config_changed);
   }
@@ -454,7 +474,7 @@ grpc_connectivity_state grpc_client_channel_check_connectivity_state(
     } else {
       chand->exit_idle_when_lb_policy_arrives = 1;
       if (!chand->started_resolving && chand->resolver != NULL) {
-        GRPC_CHANNEL_INTERNAL_REF(chand->master, "resolver");
+        GRPC_CHANNEL_STACK_REF(chand->owning_stack, "resolver");
         chand->started_resolving = 1;
         grpc_resolver_next(exec_ctx, chand->resolver,
                            &chand->incoming_configuration,
@@ -466,32 +486,39 @@ grpc_connectivity_state grpc_client_channel_check_connectivity_state(
   return out;
 }
 
+typedef struct {
+  channel_data *chand;
+  grpc_pollset *pollset;
+  grpc_closure *on_complete;
+  grpc_closure my_closure;
+} external_connectivity_watcher;
+
+static void on_external_watch_complete(grpc_exec_ctx *exec_ctx, void *arg,
+                                       int iomgr_success) {
+  external_connectivity_watcher *w = arg;
+  grpc_closure *follow_up = w->on_complete;
+  grpc_pollset_set_del_pollset(exec_ctx, &w->chand->interested_parties,
+                               w->pollset);
+  GRPC_CHANNEL_STACK_UNREF(exec_ctx, w->chand->owning_stack,
+                           "external_connectivity_watcher");
+  gpr_free(w);
+  follow_up->cb(exec_ctx, follow_up->cb_arg, iomgr_success);
+}
+
 void grpc_client_channel_watch_connectivity_state(
-    grpc_exec_ctx *exec_ctx, grpc_channel_element *elem,
+    grpc_exec_ctx *exec_ctx, grpc_channel_element *elem, grpc_pollset *pollset,
     grpc_connectivity_state *state, grpc_closure *on_complete) {
   channel_data *chand = elem->channel_data;
+  external_connectivity_watcher *w = gpr_malloc(sizeof(*w));
+  w->chand = chand;
+  w->pollset = pollset;
+  w->on_complete = on_complete;
+  grpc_pollset_set_add_pollset(exec_ctx, &chand->interested_parties, pollset);
+  grpc_closure_init(&w->my_closure, on_external_watch_complete, w);
+  GRPC_CHANNEL_STACK_REF(w->chand->owning_stack,
+                         "external_connectivity_watcher");
   gpr_mu_lock(&chand->mu_config);
   grpc_connectivity_state_notify_on_state_change(
-      exec_ctx, &chand->state_tracker, state, on_complete);
+      exec_ctx, &chand->state_tracker, state, &w->my_closure);
   gpr_mu_unlock(&chand->mu_config);
 }
-
-grpc_pollset_set *grpc_client_channel_get_connecting_pollset_set(
-    grpc_channel_element *elem) {
-  channel_data *chand = elem->channel_data;
-  return &chand->pollset_set;
-}
-
-void grpc_client_channel_add_interested_party(grpc_exec_ctx *exec_ctx,
-                                              grpc_channel_element *elem,
-                                              grpc_pollset *pollset) {
-  channel_data *chand = elem->channel_data;
-  grpc_pollset_set_add_pollset(exec_ctx, &chand->pollset_set, pollset);
-}
-
-void grpc_client_channel_del_interested_party(grpc_exec_ctx *exec_ctx,
-                                              grpc_channel_element *elem,
-                                              grpc_pollset *pollset) {
-  channel_data *chand = elem->channel_data;
-  grpc_pollset_set_del_pollset(exec_ctx, &chand->pollset_set, pollset);
-}

src/core/channel/client_channel.h

@@ -57,17 +57,7 @@ grpc_connectivity_state grpc_client_channel_check_connectivity_state(
     grpc_exec_ctx *exec_ctx, grpc_channel_element *elem, int try_to_connect);
 
 void grpc_client_channel_watch_connectivity_state(
-    grpc_exec_ctx *exec_ctx, grpc_channel_element *elem,
+    grpc_exec_ctx *exec_ctx, grpc_channel_element *elem, grpc_pollset *pollset,
     grpc_connectivity_state *state, grpc_closure *on_complete);
 
-grpc_pollset_set *grpc_client_channel_get_connecting_pollset_set(
-    grpc_channel_element *elem);
-
-void grpc_client_channel_add_interested_party(grpc_exec_ctx *exec_ctx,
-                                              grpc_channel_element *channel,
-                                              grpc_pollset *pollset);
-void grpc_client_channel_del_interested_party(grpc_exec_ctx *exec_ctx,
-                                              grpc_channel_element *channel,
-                                              grpc_pollset *pollset);
-
 #endif /* GRPC_INTERNAL_CORE_CHANNEL_CLIENT_CHANNEL_H */

src/core/channel/client_uchannel.c

@@ -58,13 +58,13 @@ typedef struct client_uchannel_channel_data {
       this channel_data via its channel stack.
       We occasionally use this to bump the refcount on the master channel
       to keep ourselves alive through an asynchronous operation. */
-  grpc_channel *master;
+  grpc_channel_stack *owning_stack;
 
   /** connectivity state being tracked */
   grpc_connectivity_state_tracker state_tracker;
 
   /** the subchannel wrapped by the microchannel */
-  grpc_subchannel *subchannel;
+  grpc_connected_subchannel *connected_subchannel;
 
   /** the callback used to stay subscribed to subchannel connectivity
    * notifications */
@@ -84,15 +84,13 @@ static void monitor_subchannel(grpc_exec_ctx *exec_ctx, void *arg,
   grpc_connectivity_state_set(exec_ctx, &chand->state_tracker,
                               chand->subchannel_connectivity,
                               "uchannel_monitor_subchannel");
-  grpc_subchannel_notify_on_state_change(exec_ctx, chand->subchannel,
-                                         &chand->subchannel_connectivity,
-                                         &chand->connectivity_cb);
+  grpc_connected_subchannel_notify_on_state_change(
+      exec_ctx, chand->connected_subchannel, NULL,
+      &chand->subchannel_connectivity, &chand->connectivity_cb);
 }
 
 static char *cuc_get_peer(grpc_exec_ctx *exec_ctx, grpc_call_element *elem) {
-  channel_data *chand = elem->channel_data;
-  return grpc_subchannel_call_holder_get_peer(exec_ctx, elem->call_data,
-                                              chand->master);
+  return grpc_subchannel_call_holder_get_peer(exec_ctx, elem->call_data);
 }
 
 static void cuc_start_transport_stream_op(grpc_exec_ctx *exec_ctx,
@@ -128,11 +126,11 @@ static void cuc_start_transport_op(grpc_exec_ctx *exec_ctx,
 
 static int cuc_pick_subchannel(grpc_exec_ctx *exec_ctx, void *arg,
                                grpc_metadata_batch *initial_metadata,
-                               grpc_subchannel **subchannel,
+                               grpc_connected_subchannel **connected_subchannel,
                                grpc_closure *on_ready) {
   channel_data *chand = arg;
   GPR_ASSERT(initial_metadata != NULL);
-  *subchannel = chand->subchannel;
+  *connected_subchannel = chand->connected_subchannel;
   return 1;
 }
 
@@ -140,7 +138,7 @@ static int cuc_pick_subchannel(grpc_exec_ctx *exec_ctx, void *arg,
 static void cuc_init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
                                grpc_call_element_args *args) {
   grpc_subchannel_call_holder_init(elem->call_data, cuc_pick_subchannel,
-                                   elem->channel_data);
+                                   elem->channel_data, args->call_stack);
 }
 
 /* Destructor for call_data */
@@ -158,7 +156,7 @@ static void cuc_init_channel_elem(grpc_exec_ctx *exec_ctx,
   grpc_closure_init(&chand->connectivity_cb, monitor_subchannel, chand);
   GPR_ASSERT(args->is_last);
   GPR_ASSERT(elem->filter == &grpc_client_uchannel_filter);
-  chand->master = args->master;
+  chand->owning_stack = args->channel_stack;
   grpc_connectivity_state_init(&chand->state_tracker, GRPC_CHANNEL_IDLE,
                                "client_uchannel");
   gpr_mu_init(&chand->mu_state);
@@ -168,10 +166,14 @@ static void cuc_init_channel_elem(grpc_exec_ctx *exec_ctx,
 static void cuc_destroy_channel_elem(grpc_exec_ctx *exec_ctx,
                                      grpc_channel_element *elem) {
   channel_data *chand = elem->channel_data;
-  grpc_subchannel_state_change_unsubscribe(exec_ctx, chand->subchannel,
-                                           &chand->connectivity_cb);
+  /* cancel subscription */
+  grpc_connected_subchannel_notify_on_state_change(
+      exec_ctx, chand->connected_subchannel, NULL, NULL,
+      &chand->connectivity_cb);
   grpc_connectivity_state_destroy(exec_ctx, &chand->state_tracker);
   gpr_mu_destroy(&chand->mu_state);
+  GRPC_CONNECTED_SUBCHANNEL_UNREF(exec_ctx, chand->connected_subchannel,
+                                  "uchannel");
 }
 
 static void cuc_set_pollset(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
@@ -191,23 +193,14 @@ grpc_connectivity_state grpc_client_uchannel_check_connectivity_state(
     grpc_exec_ctx *exec_ctx, grpc_channel_element *elem, int try_to_connect) {
   channel_data *chand = elem->channel_data;
   grpc_connectivity_state out;
-  out = grpc_connectivity_state_check(&chand->state_tracker);
   gpr_mu_lock(&chand->mu_state);
-  if (out == GRPC_CHANNEL_IDLE && try_to_connect) {
-    grpc_connectivity_state_set(exec_ctx, &chand->state_tracker,
-                                GRPC_CHANNEL_CONNECTING,
-                                "uchannel_connecting_changed");
-    chand->subchannel_connectivity = out;
-    grpc_subchannel_notify_on_state_change(exec_ctx, chand->subchannel,
-                                           &chand->subchannel_connectivity,
-                                           &chand->connectivity_cb);
-  }
+  out = grpc_connectivity_state_check(&chand->state_tracker);
   gpr_mu_unlock(&chand->mu_state);
   return out;
 }
 
 void grpc_client_uchannel_watch_connectivity_state(
-    grpc_exec_ctx *exec_ctx, grpc_channel_element *elem,
+    grpc_exec_ctx *exec_ctx, grpc_channel_element *elem, grpc_pollset *pollset,
     grpc_connectivity_state *state, grpc_closure *on_complete) {
   channel_data *chand = elem->channel_data;
   gpr_mu_lock(&chand->mu_state);
@@ -216,40 +209,11 @@ void grpc_client_uchannel_watch_connectivity_state(
   gpr_mu_unlock(&chand->mu_state);
 }
 
-grpc_pollset_set *grpc_client_uchannel_get_connecting_pollset_set(
-    grpc_channel_element *elem) {
-  channel_data *chand = elem->channel_data;
-  grpc_channel_element *parent_elem;
-  gpr_mu_lock(&chand->mu_state);
-  parent_elem = grpc_channel_stack_last_element(grpc_channel_get_channel_stack(
-      grpc_subchannel_get_master(chand->subchannel)));
-  gpr_mu_unlock(&chand->mu_state);
-  return grpc_client_channel_get_connecting_pollset_set(parent_elem);
-}
-
-void grpc_client_uchannel_add_interested_party(grpc_exec_ctx *exec_ctx,
-                                               grpc_channel_element *elem,
-                                               grpc_pollset *pollset) {
-  grpc_pollset_set *master_pollset_set =
-      grpc_client_uchannel_get_connecting_pollset_set(elem);
-  grpc_pollset_set_add_pollset(exec_ctx, master_pollset_set, pollset);
-}
-
-void grpc_client_uchannel_del_interested_party(grpc_exec_ctx *exec_ctx,
-                                               grpc_channel_element *elem,
-                                               grpc_pollset *pollset) {
-  grpc_pollset_set *master_pollset_set =
-      grpc_client_uchannel_get_connecting_pollset_set(elem);
-  grpc_pollset_set_del_pollset(exec_ctx, master_pollset_set, pollset);
-}
-
 grpc_channel *grpc_client_uchannel_create(grpc_subchannel *subchannel,
                                           grpc_channel_args *args) {
   grpc_channel *channel = NULL;
 #define MAX_FILTERS 3
   const grpc_channel_filter *filters[MAX_FILTERS];
-  grpc_channel *master = grpc_subchannel_get_master(subchannel);
-  char *target = grpc_channel_get_target(master);
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   size_t n = 0;
 
@@ -261,19 +225,19 @@ grpc_channel *grpc_client_uchannel_create(grpc_subchannel *subchannel,
   GPR_ASSERT(n <= MAX_FILTERS);
 
   channel =
-      grpc_channel_create_from_filters(&exec_ctx, target, filters, n, args, 1);
+      grpc_channel_create_from_filters(&exec_ctx, NULL, filters, n, args, 1);
 
-  gpr_free(target);
   return channel;
 }
 
-void grpc_client_uchannel_set_subchannel(grpc_channel *uchannel,
-                                         grpc_subchannel *subchannel) {
+void grpc_client_uchannel_set_connected_subchannel(
+    grpc_channel *uchannel, grpc_connected_subchannel *connected_subchannel) {
   grpc_channel_element *elem =
       grpc_channel_stack_last_element(grpc_channel_get_channel_stack(uchannel));
   channel_data *chand = elem->channel_data;
   GPR_ASSERT(elem->filter == &grpc_client_uchannel_filter);
   gpr_mu_lock(&chand->mu_state);
-  chand->subchannel = subchannel;
+  chand->connected_subchannel = connected_subchannel;
+  GRPC_CONNECTED_SUBCHANNEL_REF(connected_subchannel, "uchannel");
   gpr_mu_unlock(&chand->mu_state);
 }

src/core/channel/client_uchannel.h

@@ -48,23 +48,13 @@ grpc_connectivity_state grpc_client_uchannel_check_connectivity_state(
     grpc_exec_ctx *exec_ctx, grpc_channel_element *elem, int try_to_connect);
 
 void grpc_client_uchannel_watch_connectivity_state(
-    grpc_exec_ctx *exec_ctx, grpc_channel_element *elem,
+    grpc_exec_ctx *exec_ctx, grpc_channel_element *elem, grpc_pollset *pollset,
     grpc_connectivity_state *state, grpc_closure *on_complete);
 
-grpc_pollset_set *grpc_client_uchannel_get_connecting_pollset_set(
-    grpc_channel_element *elem);
-
-void grpc_client_uchannel_add_interested_party(grpc_exec_ctx *exec_ctx,
-                                               grpc_channel_element *channel,
-                                               grpc_pollset *pollset);
-void grpc_client_uchannel_del_interested_party(grpc_exec_ctx *exec_ctx,
-                                               grpc_channel_element *channel,
-                                               grpc_pollset *pollset);
-
 grpc_channel *grpc_client_uchannel_create(grpc_subchannel *subchannel,
                                           grpc_channel_args *args);
 
-void grpc_client_uchannel_set_subchannel(grpc_channel *uchannel,
-                                         grpc_subchannel *subchannel);
+void grpc_client_uchannel_set_connected_subchannel(
+    grpc_channel *uchannel, grpc_connected_subchannel *connected_subchannel);
 
 #endif /* GRPC_INTERNAL_CORE_CHANNEL_CLIENT_MICROCHANNEL_H */

src/core/channel/compress_filter.c

@@ -288,8 +288,7 @@ static void init_channel_elem(grpc_exec_ctx *exec_ctx,
 
 /* Destructor for channel data */
 static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
-                                 grpc_channel_element *elem) {
-}
+                                 grpc_channel_element *elem) {}
 
 const grpc_channel_filter grpc_compress_filter = {
     compress_start_transport_stream_op, grpc_channel_next_op, sizeof(call_data),

src/core/channel/connected_channel.c

@@ -89,9 +89,9 @@ static void init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
   int r;
 
   GPR_ASSERT(elem->filter == &grpc_connected_channel_filter);
-  r = grpc_transport_init_stream(exec_ctx, chand->transport,
-                                 TRANSPORT_STREAM_FROM_CALL_DATA(calld),
-                                 args->refcount, args->server_transport_data);
+  r = grpc_transport_init_stream(
+      exec_ctx, chand->transport, TRANSPORT_STREAM_FROM_CALL_DATA(calld),
+      &args->call_stack->refcount, args->server_transport_data);
   GPR_ASSERT(r == 0);
 }
 

src/core/channel/http_server_filter.c

@@ -224,8 +224,7 @@ static void init_channel_elem(grpc_exec_ctx *exec_ctx,
 
 /* Destructor for channel data */
 static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
-                                 grpc_channel_element *elem) {
-}
+                                 grpc_channel_element *elem) {}
 
 const grpc_channel_filter grpc_http_server_filter = {
     hs_start_transport_op, grpc_channel_next_op, sizeof(call_data),

src/core/channel/subchannel_call_holder.c

@@ -44,7 +44,6 @@
 
 static void subchannel_ready(grpc_exec_ctx *exec_ctx, void *holder,
                              int success);
-static void call_ready(grpc_exec_ctx *exec_ctx, void *holder, int success);
 static void retry_ops(grpc_exec_ctx *exec_ctx, void *retry_ops_args,
                       int success);
 
@@ -58,16 +57,17 @@ static void retry_waiting_locked(grpc_exec_ctx *exec_ctx,
 void grpc_subchannel_call_holder_init(
     grpc_subchannel_call_holder *holder,
     grpc_subchannel_call_holder_pick_subchannel pick_subchannel,
-    void *pick_subchannel_arg) {
+    void *pick_subchannel_arg, grpc_call_stack *owning_call) {
   gpr_atm_rel_store(&holder->subchannel_call, 0);
   holder->pick_subchannel = pick_subchannel;
   holder->pick_subchannel_arg = pick_subchannel_arg;
   gpr_mu_init(&holder->mu);
-  holder->subchannel = NULL;
+  holder->connected_subchannel = NULL;
   holder->waiting_ops = NULL;
   holder->waiting_ops_count = 0;
   holder->waiting_ops_capacity = 0;
   holder->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING;
+  holder->owning_call = owning_call;
 }
 
 void grpc_subchannel_call_holder_destroy(grpc_exec_ctx *exec_ctx,
@@ -125,13 +125,9 @@ retry:
         case GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING:
           fail_locked(exec_ctx, holder);
           break;
-        case GRPC_SUBCHANNEL_CALL_HOLDER_CREATING_CALL:
-          grpc_subchannel_cancel_create_call(exec_ctx, holder->subchannel,
-                                             &holder->subchannel_call);
-          break;
         case GRPC_SUBCHANNEL_CALL_HOLDER_PICKING_SUBCHANNEL:
           holder->pick_subchannel(exec_ctx, holder->pick_subchannel_arg, NULL,
-                                  &holder->subchannel, NULL);
+                                  &holder->connected_subchannel, NULL);
           break;
       }
       gpr_mu_unlock(&holder->mu);
@@ -142,28 +138,27 @@ retry:
   }
   /* if we don't have a subchannel, try to get one */
   if (holder->creation_phase == GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING &&
-      holder->subchannel == NULL && op->send_initial_metadata != NULL) {
+      holder->connected_subchannel == NULL &&
+      op->send_initial_metadata != NULL) {
     holder->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_PICKING_SUBCHANNEL;
     grpc_closure_init(&holder->next_step, subchannel_ready, holder);
-    if (holder->pick_subchannel(exec_ctx, holder->pick_subchannel_arg,
-                                op->send_initial_metadata, &holder->subchannel,
-                                &holder->next_step)) {
+    GRPC_CALL_STACK_REF(holder->owning_call, "pick_subchannel");
+    if (holder->pick_subchannel(
+            exec_ctx, holder->pick_subchannel_arg, op->send_initial_metadata,
+            &holder->connected_subchannel, &holder->next_step)) {
       holder->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING;
+      GRPC_CALL_STACK_UNREF(exec_ctx, holder->owning_call, "pick_subchannel");
     }
   }
   /* if we've got a subchannel, then let's ask it to create a call */
   if (holder->creation_phase == GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING &&
-      holder->subchannel != NULL) {
-    holder->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_CREATING_CALL;
-    grpc_closure_init(&holder->next_step, call_ready, holder);
-    if (grpc_subchannel_create_call(exec_ctx, holder->subchannel,
-                                    holder->pollset, &holder->subchannel_call,
-                                    &holder->next_step)) {
-      /* got one immediately - continue the op (and any waiting ops) */
-      holder->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING;
-      retry_waiting_locked(exec_ctx, holder);
-      goto retry;
-    }
+      holder->connected_subchannel != NULL) {
+    gpr_atm_rel_store(
+        &holder->subchannel_call,
+        (gpr_atm)(gpr_uintptr)grpc_connected_subchannel_create_call(
+            exec_ctx, holder->connected_subchannel, holder->pollset));
+    retry_waiting_locked(exec_ctx, holder);
+    goto retry;
   }
   /* nothing to be done but wait */
   add_waiting_locked(holder, op);
@@ -179,36 +174,18 @@ static void subchannel_ready(grpc_exec_ctx *exec_ctx, void *arg, int success) {
              GRPC_SUBCHANNEL_CALL_HOLDER_PICKING_SUBCHANNEL);
   call = GET_CALL(holder);
   GPR_ASSERT(call == NULL || call == CANCELLED_CALL);
-  if (holder->subchannel == NULL) {
-    holder->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING;
+  holder->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING;
+  if (holder->connected_subchannel == NULL) {
     fail_locked(exec_ctx, holder);
   } else {
-    grpc_closure_init(&holder->next_step, call_ready, holder);
-    if (grpc_subchannel_create_call(exec_ctx, holder->subchannel,
-                                    holder->pollset, &holder->subchannel_call,
-                                    &holder->next_step)) {
-      holder->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING;
-      /* got one immediately - continue the op (and any waiting ops) */
-      retry_waiting_locked(exec_ctx, holder);
-    }
-  }
-  gpr_mu_unlock(&holder->mu);
-}
-
-static void call_ready(grpc_exec_ctx *exec_ctx, void *arg, int success) {
-  grpc_subchannel_call_holder *holder = arg;
-  GPR_TIMER_BEGIN("call_ready", 0);
-  gpr_mu_lock(&holder->mu);
-  GPR_ASSERT(holder->creation_phase ==
-             GRPC_SUBCHANNEL_CALL_HOLDER_CREATING_CALL);
-  holder->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING;
-  if (GET_CALL(holder) != NULL) {
+    gpr_atm_rel_store(
+        &holder->subchannel_call,
+        (gpr_atm)(gpr_uintptr)grpc_connected_subchannel_create_call(
+            exec_ctx, holder->connected_subchannel, holder->pollset));
     retry_waiting_locked(exec_ctx, holder);
-  } else {
-    fail_locked(exec_ctx, holder);
   }
   gpr_mu_unlock(&holder->mu);
-  GPR_TIMER_END("call_ready", 0);
+  GRPC_CALL_STACK_UNREF(exec_ctx, holder->owning_call, "pick_subchannel");
 }
 
 typedef struct {
@@ -270,14 +247,13 @@ static void fail_locked(grpc_exec_ctx *exec_ctx,
   holder->waiting_ops_count = 0;
 }
 
-char *grpc_subchannel_call_holder_get_peer(grpc_exec_ctx *exec_ctx,
-                                           grpc_subchannel_call_holder *holder,
-                                           grpc_channel *master) {
+char *grpc_subchannel_call_holder_get_peer(
+    grpc_exec_ctx *exec_ctx, grpc_subchannel_call_holder *holder) {
   grpc_subchannel_call *subchannel_call = GET_CALL(holder);
 
   if (subchannel_call) {
     return grpc_subchannel_call_get_peer(exec_ctx, subchannel_call);
   } else {
-    return grpc_channel_get_target(master);
+    return NULL;
   }
 }

src/core/channel/subchannel_call_holder.h

@@ -42,12 +42,11 @@
     called when the subchannel is available) */
 typedef int (*grpc_subchannel_call_holder_pick_subchannel)(
     grpc_exec_ctx *exec_ctx, void *arg, grpc_metadata_batch *initial_metadata,
-    grpc_subchannel **subchannel, grpc_closure *on_ready);
+    grpc_connected_subchannel **connected_subchannel, grpc_closure *on_ready);
 
 typedef enum {
   GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING,
-  GRPC_SUBCHANNEL_CALL_HOLDER_PICKING_SUBCHANNEL,
-  GRPC_SUBCHANNEL_CALL_HOLDER_CREATING_CALL
+  GRPC_SUBCHANNEL_CALL_HOLDER_PICKING_SUBCHANNEL
 } grpc_subchannel_call_holder_creation_phase;
 
 /** Wrapper for holding a pointer to grpc_subchannel_call, and the
@@ -71,7 +70,7 @@ typedef struct grpc_subchannel_call_holder {
   gpr_mu mu;
 
   grpc_subchannel_call_holder_creation_phase creation_phase;
-  grpc_subchannel *subchannel;
+  grpc_connected_subchannel *connected_subchannel;
   grpc_pollset *pollset;
 
   grpc_transport_stream_op *waiting_ops;
@@ -79,12 +78,14 @@ typedef struct grpc_subchannel_call_holder {
   size_t waiting_ops_capacity;
 
   grpc_closure next_step;
+
+  grpc_call_stack *owning_call;
 } grpc_subchannel_call_holder;
 
 void grpc_subchannel_call_holder_init(
     grpc_subchannel_call_holder *holder,
     grpc_subchannel_call_holder_pick_subchannel pick_subchannel,
-    void *pick_subchannel_arg);
+    void *pick_subchannel_arg, grpc_call_stack *owning_call);
 void grpc_subchannel_call_holder_destroy(grpc_exec_ctx *exec_ctx,
                                          grpc_subchannel_call_holder *holder);
 
@@ -92,7 +93,6 @@ void grpc_subchannel_call_holder_perform_op(grpc_exec_ctx *exec_ctx,
                                             grpc_subchannel_call_holder *holder,
                                             grpc_transport_stream_op *op);
 char *grpc_subchannel_call_holder_get_peer(grpc_exec_ctx *exec_ctx,
-                                           grpc_subchannel_call_holder *holder,
-                                           grpc_channel *master);
+                                           grpc_subchannel_call_holder *holder);
 
 #endif

src/core/client_config/lb_policies/pick_first.c

@@ -42,7 +42,7 @@
 typedef struct pending_pick {
   struct pending_pick *next;
   grpc_pollset *pollset;
-  grpc_subchannel **target;
+  grpc_connected_subchannel **target;
   grpc_closure *on_complete;
 } pending_pick;
 
@@ -60,7 +60,7 @@ typedef struct {
   /** the selected channel
       TODO(ctiller): this should be atomically set so we don't
                      need to take a mutex in the common case */
-  grpc_subchannel *selected;
+  grpc_connected_subchannel *selected;
   /** have we started picking? */
   int started_picking;
   /** are we shut down? */
@@ -76,24 +76,6 @@ typedef struct {
   grpc_connectivity_state_tracker state_tracker;
 } pick_first_lb_policy;
 
-static void del_interested_parties_locked(grpc_exec_ctx *exec_ctx,
-                                          pick_first_lb_policy *p) {
-  pending_pick *pp;
-  for (pp = p->pending_picks; pp; pp = pp->next) {
-    grpc_subchannel_del_interested_party(
-        exec_ctx, p->subchannels[p->checking_subchannel], pp->pollset);
-  }
-}
-
-static void add_interested_parties_locked(grpc_exec_ctx *exec_ctx,
-                                          pick_first_lb_policy *p) {
-  pending_pick *pp;
-  for (pp = p->pending_picks; pp; pp = pp->next) {
-    grpc_subchannel_add_interested_party(
-        exec_ctx, p->subchannels[p->checking_subchannel], pp->pollset);
-  }
-}
-
 void pf_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
   size_t i;
@@ -102,7 +84,7 @@ void pf_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
     GRPC_SUBCHANNEL_UNREF(exec_ctx, p->subchannels[i], "pick_first");
   }
   if (p->selected) {
-    GRPC_SUBCHANNEL_UNREF(exec_ctx, p->selected, "picked_first");
+    GRPC_CONNECTED_SUBCHANNEL_UNREF(exec_ctx, p->selected, "picked_first");
   }
   grpc_connectivity_state_destroy(exec_ctx, &p->state_tracker);
   gpr_free(p->subchannels);
@@ -114,16 +96,26 @@ void pf_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
   pending_pick *pp;
   gpr_mu_lock(&p->mu);
-  del_interested_parties_locked(exec_ctx, p);
   p->shutdown = 1;
   pp = p->pending_picks;
   p->pending_picks = NULL;
   grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
                               GRPC_CHANNEL_FATAL_FAILURE, "shutdown");
+  /* cancel subscription */
+  if (p->selected != NULL) {
+    grpc_connected_subchannel_notify_on_state_change(
+        exec_ctx, p->selected, NULL, NULL, &p->connectivity_changed);
+  } else {
+    grpc_subchannel_notify_on_state_change(
+        exec_ctx, p->subchannels[p->checking_subchannel], NULL, NULL,
+        &p->connectivity_changed);
+  }
   gpr_mu_unlock(&p->mu);
   while (pp != NULL) {
     pending_pick *next = pp->next;
     *pp->target = NULL;
+    grpc_pollset_set_del_pollset(exec_ctx, &p->base.interested_parties,
+                                 pp->pollset);
     grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, 1);
     gpr_free(pp);
     pp = next;
@@ -131,7 +123,7 @@ void pf_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
 }
 
 static void pf_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
-                           grpc_subchannel **target) {
+                           grpc_connected_subchannel **target) {
   pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
   pending_pick *pp;
   gpr_mu_lock(&p->mu);
@@ -140,8 +132,8 @@ static void pf_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
   while (pp != NULL) {
     pending_pick *next = pp->next;
     if (pp->target == target) {
-      grpc_subchannel_del_interested_party(
-          exec_ctx, p->subchannels[p->checking_subchannel], pp->pollset);
+      grpc_pollset_set_del_pollset(exec_ctx, &p->base.interested_parties,
+                                   pp->pollset);
       *target = NULL;
       grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, 0);
       gpr_free(pp);
@@ -158,10 +150,11 @@ static void start_picking(grpc_exec_ctx *exec_ctx, pick_first_lb_policy *p) {
   p->started_picking = 1;
   p->checking_subchannel = 0;
   p->checking_connectivity = GRPC_CHANNEL_IDLE;
-  GRPC_LB_POLICY_REF(&p->base, "pick_first_connectivity");
+  GRPC_LB_POLICY_WEAK_REF(&p->base, "pick_first_connectivity");
   grpc_subchannel_notify_on_state_change(
       exec_ctx, p->subchannels[p->checking_subchannel],
-      &p->checking_connectivity, &p->connectivity_changed);
+      &p->base.interested_parties, &p->checking_connectivity,
+      &p->connectivity_changed);
 }
 
 void pf_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
@@ -174,8 +167,8 @@ void pf_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
 }
 
 int pf_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, grpc_pollset *pollset,
-            grpc_metadata_batch *initial_metadata, grpc_subchannel **target,
-            grpc_closure *on_complete) {
+            grpc_metadata_batch *initial_metadata,
+            grpc_connected_subchannel **target, grpc_closure *on_complete) {
   pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
   pending_pick *pp;
   gpr_mu_lock(&p->mu);
@@ -187,8 +180,8 @@ int pf_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, grpc_pollset *pollset,
     if (!p->started_picking) {
       start_picking(exec_ctx, p);
     }
-    grpc_subchannel_add_interested_party(
-        exec_ctx, p->subchannels[p->checking_subchannel], pollset);
+    grpc_pollset_set_add_pollset(exec_ctx, &p->base.interested_parties,
+                                 pollset);
     pp = gpr_malloc(sizeof(*pp));
     pp->next = p->pending_picks;
     pp->pollset = pollset;
@@ -204,25 +197,17 @@ static void destroy_subchannels(grpc_exec_ctx *exec_ctx, void *arg,
                                 int iomgr_success) {
   pick_first_lb_policy *p = arg;
   size_t i;
-  grpc_transport_op op;
   size_t num_subchannels = p->num_subchannels;
   grpc_subchannel **subchannels;
-  grpc_subchannel *exclude_subchannel;
 
   gpr_mu_lock(&p->mu);
   subchannels = p->subchannels;
   p->num_subchannels = 0;
   p->subchannels = NULL;
-  exclude_subchannel = p->selected;
   gpr_mu_unlock(&p->mu);
-  GRPC_LB_POLICY_UNREF(exec_ctx, &p->base, "destroy_subchannels");
+  GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "destroy_subchannels");
 
   for (i = 0; i < num_subchannels; i++) {
-    if (subchannels[i] != exclude_subchannel) {
-      memset(&op, 0, sizeof(op));
-      op.disconnect = 1;
-      grpc_subchannel_process_transport_op(exec_ctx, subchannels[i], &op);
-    }
     GRPC_SUBCHANNEL_UNREF(exec_ctx, subchannels[i], "pick_first");
   }
 
@@ -232,23 +217,28 @@ static void destroy_subchannels(grpc_exec_ctx *exec_ctx, void *arg,
 static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
                                     int iomgr_success) {
   pick_first_lb_policy *p = arg;
+  grpc_subchannel *selected_subchannel;
   pending_pick *pp;
 
   gpr_mu_lock(&p->mu);
 
   if (p->shutdown) {
     gpr_mu_unlock(&p->mu);
-    GRPC_LB_POLICY_UNREF(exec_ctx, &p->base, "pick_first_connectivity");
+    GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "pick_first_connectivity");
     return;
   } else if (p->selected != NULL) {
+    if (p->checking_connectivity == GRPC_CHANNEL_TRANSIENT_FAILURE) {
+      /* if the selected channel goes bad, we're done */
+      p->checking_connectivity = GRPC_CHANNEL_FATAL_FAILURE;
+    }
     grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
                                 p->checking_connectivity, "selected_changed");
     if (p->checking_connectivity != GRPC_CHANNEL_FATAL_FAILURE) {
-      grpc_subchannel_notify_on_state_change(exec_ctx, p->selected,
-                                             &p->checking_connectivity,
-                                             &p->connectivity_changed);
+      grpc_connected_subchannel_notify_on_state_change(
+          exec_ctx, p->selected, &p->base.interested_parties,
+          &p->checking_connectivity, &p->connectivity_changed);
     } else {
-      GRPC_LB_POLICY_UNREF(exec_ctx, &p->base, "pick_first_connectivity");
+      GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "pick_first_connectivity");
     }
   } else {
   loop:
@@ -256,39 +246,41 @@ static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
       case GRPC_CHANNEL_READY:
         grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
                                     GRPC_CHANNEL_READY, "connecting_ready");
-        p->selected = p->subchannels[p->checking_subchannel];
-        GRPC_SUBCHANNEL_REF(p->selected, "picked_first");
+        selected_subchannel = p->subchannels[p->checking_subchannel];
+        p->selected =
+            grpc_subchannel_get_connected_subchannel(selected_subchannel);
+        GPR_ASSERT(p->selected);
+        GRPC_CONNECTED_SUBCHANNEL_REF(p->selected, "picked_first");
         /* drop the pick list: we are connected now */
-        GRPC_LB_POLICY_REF(&p->base, "destroy_subchannels");
+        GRPC_LB_POLICY_WEAK_REF(&p->base, "destroy_subchannels");
         grpc_exec_ctx_enqueue(exec_ctx,
                               grpc_closure_create(destroy_subchannels, p), 1);
         /* update any calls that were waiting for a pick */
         while ((pp = p->pending_picks)) {
           p->pending_picks = pp->next;
           *pp->target = p->selected;
-          grpc_subchannel_del_interested_party(exec_ctx, p->selected,
-                                               pp->pollset);
+          grpc_pollset_set_del_pollset(exec_ctx, &p->base.interested_parties,
+                                       pp->pollset);
           grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, 1);
           gpr_free(pp);
         }
-        grpc_subchannel_notify_on_state_change(exec_ctx, p->selected,
-                                               &p->checking_connectivity,
-                                               &p->connectivity_changed);
+        grpc_connected_subchannel_notify_on_state_change(
+            exec_ctx, p->selected, &p->base.interested_parties,
+            &p->checking_connectivity, &p->connectivity_changed);
         break;
       case GRPC_CHANNEL_TRANSIENT_FAILURE:
         grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
                                     GRPC_CHANNEL_TRANSIENT_FAILURE,
                                     "connecting_transient_failure");
-        del_interested_parties_locked(exec_ctx, p);
         p->checking_subchannel =
             (p->checking_subchannel + 1) % p->num_subchannels;
         p->checking_connectivity = grpc_subchannel_check_connectivity(
             p->subchannels[p->checking_subchannel]);
-        add_interested_parties_locked(exec_ctx, p);
         if (p->checking_connectivity == GRPC_CHANNEL_TRANSIENT_FAILURE) {
           grpc_subchannel_notify_on_state_change(
               exec_ctx, p->subchannels[p->checking_subchannel],
-              &p->checking_connectivity, &p->connectivity_changed);
+              &p->base.interested_parties, &p->checking_connectivity,
+              &p->connectivity_changed);
         } else {
           goto loop;
         }
@@ -300,13 +292,13 @@ static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
                                     "connecting_changed");
         grpc_subchannel_notify_on_state_change(
             exec_ctx, p->subchannels[p->checking_subchannel],
-            &p->checking_connectivity, &p->connectivity_changed);
+            &p->base.interested_parties, &p->checking_connectivity,
+            &p->connectivity_changed);
         break;
       case GRPC_CHANNEL_FATAL_FAILURE:
-        del_interested_parties_locked(exec_ctx, p);
-        GPR_SWAP(grpc_subchannel *, p->subchannels[p->checking_subchannel],
-                 p->subchannels[p->num_subchannels - 1]);
         p->num_subchannels--;
+        GPR_SWAP(grpc_subchannel *, p->subchannels[p->checking_subchannel],
+                 p->subchannels[p->num_subchannels]);
         GRPC_SUBCHANNEL_UNREF(exec_ctx, p->subchannels[p->num_subchannels],
                               "pick_first");
         if (p->num_subchannels == 0) {
@@ -319,7 +311,8 @@ static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
             grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, 1);
             gpr_free(pp);
           }
-          GRPC_LB_POLICY_UNREF(exec_ctx, &p->base, "pick_first_connectivity");
+          GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base,
+                                    "pick_first_connectivity");
         } else {
           grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
                                       GRPC_CHANNEL_TRANSIENT_FAILURE,
@@ -327,7 +320,6 @@ static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
           p->checking_subchannel %= p->num_subchannels;
           p->checking_connectivity = grpc_subchannel_check_connectivity(
               p->subchannels[p->checking_subchannel]);
-          add_interested_parties_locked(exec_ctx, p);
           goto loop;
         }
     }
@@ -336,39 +328,6 @@ static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
   gpr_mu_unlock(&p->mu);
 }
 
-static void pf_broadcast(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
-                         grpc_transport_op *op) {
-  pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
-  size_t i;
-  size_t n;
-  grpc_subchannel **subchannels;
-  grpc_subchannel *selected;
-
-  gpr_mu_lock(&p->mu);
-  n = p->num_subchannels;
-  subchannels = gpr_malloc(n * sizeof(*subchannels));
-  selected = p->selected;
-  if (selected) {
-    GRPC_SUBCHANNEL_REF(selected, "pf_broadcast_to_selected");
-  }
-  for (i = 0; i < n; i++) {
-    subchannels[i] = p->subchannels[i];
-    GRPC_SUBCHANNEL_REF(subchannels[i], "pf_broadcast");
-  }
-  gpr_mu_unlock(&p->mu);
-
-  for (i = 0; i < n; i++) {
-    if (selected == subchannels[i]) continue;
-    grpc_subchannel_process_transport_op(exec_ctx, subchannels[i], op);
-    GRPC_SUBCHANNEL_UNREF(exec_ctx, subchannels[i], "pf_broadcast");
-  }
-  if (p->selected) {
-    grpc_subchannel_process_transport_op(exec_ctx, selected, op);
-    GRPC_SUBCHANNEL_UNREF(exec_ctx, selected, "pf_broadcast_to_selected");
-  }
-  gpr_free(subchannels);
-}
-
 static grpc_connectivity_state pf_check_connectivity(grpc_exec_ctx *exec_ctx,
                                                      grpc_lb_policy *pol) {
   pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
@@ -389,9 +348,21 @@ void pf_notify_on_state_change(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
   gpr_mu_unlock(&p->mu);
 }
 
+void pf_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
+                 grpc_closure *closure) {
+  pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
+  gpr_mu_lock(&p->mu);
+  if (p->selected) {
+    grpc_connected_subchannel_ping(exec_ctx, p->selected, closure);
+  } else {
+    grpc_exec_ctx_enqueue(exec_ctx, closure, 0);
+  }
+  gpr_mu_unlock(&p->mu);
+}
+
 static const grpc_lb_policy_vtable pick_first_lb_policy_vtable = {
-    pf_destroy, pf_shutdown, pf_pick, pf_cancel_pick, pf_exit_idle,
-    pf_broadcast, pf_check_connectivity, pf_notify_on_state_change};
+    pf_destroy, pf_shutdown, pf_pick, pf_cancel_pick, pf_ping_one, pf_exit_idle,
+    pf_check_connectivity, pf_notify_on_state_change};
 
 static void pick_first_factory_ref(grpc_lb_policy_factory *factory) {}
 

src/core/client_config/lb_policies/round_robin.c

@@ -38,6 +38,8 @@
 #include <grpc/support/alloc.h>
 #include "src/core/transport/connectivity_state.h"
 
+typedef struct round_robin_lb_policy round_robin_lb_policy;
+
 int grpc_lb_round_robin_trace = 0;
 
 /** List of entities waiting for a pick.
@@ -46,7 +48,7 @@ int grpc_lb_round_robin_trace = 0;
 typedef struct pending_pick {
   struct pending_pick *next;
   grpc_pollset *pollset;
-  grpc_subchannel **target;
+  grpc_connected_subchannel **target;
   grpc_closure *on_complete;
 } pending_pick;
 
@@ -58,22 +60,27 @@ typedef struct ready_list {
 } ready_list;
 
 typedef struct {
-  size_t subchannel_idx; /**< Index over p->subchannels */
-  void *p;               /**< round_robin_lb_policy instance */
-} connectivity_changed_cb_arg;
-
-typedef struct {
+  /** index within policy->subchannels */
+  size_t index;
+  /** backpointer to owning policy */
+  round_robin_lb_policy *policy;
+  /** subchannel itself */
+  grpc_subchannel *subchannel;
+  /** notification that connectivity has changed on subchannel */
+  grpc_closure connectivity_changed_closure;
+  /** this subchannels current position in subchannel->ready_list */
+  ready_list *ready_list_node;
+  /** last observed connectivity */
+  grpc_connectivity_state connectivity_state;
+} subchannel_data;
+
+struct round_robin_lb_policy {
   /** base policy: must be first */
   grpc_lb_policy base;
 
   /** all our subchannels */
-  grpc_subchannel **subchannels;
   size_t num_subchannels;
-
-  /** Callbacks, one per subchannel being watched, to be called when their
-   * respective connectivity changes */
-  grpc_closure *connectivity_changed_cbs;
-  connectivity_changed_cb_arg *cb_args;
+  subchannel_data **subchannels;
 
   /** mutex protecting remaining members */
   gpr_mu mu;
@@ -81,8 +88,6 @@ typedef struct {
   int started_picking;
   /** are we shutting down? */
   int shutdown;
-  /** Connectivity state of the subchannels being watched */
-  grpc_connectivity_state *subchannel_connectivity;
   /** List of picks that are waiting on connectivity */
   pending_pick *pending_picks;
 
@@ -93,13 +98,7 @@ typedef struct {
   ready_list ready_list;
   /** Last pick from the ready list. */
   ready_list *ready_list_last_pick;
-
-  /** Subchannel index to ready_list node.
-   *
-   * Kept in order to remove nodes from the ready list associated with a
-   * subchannel */
-  ready_list **subchannel_index_to_readylist_node;
-} round_robin_lb_policy;
+};
 
 /** Returns the next subchannel from the connected list or NULL if the list is
  * empty.
@@ -144,9 +143,9 @@ static void advance_last_picked_locked(round_robin_lb_policy *p) {
 /** Prepends (relative to the root at p->ready_list) the connected subchannel \a
  * csc to the list of ready subchannels. */
 static ready_list *add_connected_sc_locked(round_robin_lb_policy *p,
-                                           grpc_subchannel *csc) {
+                                           grpc_subchannel *sc) {
   ready_list *new_elem = gpr_malloc(sizeof(ready_list));
-  new_elem->subchannel = csc;
+  new_elem->subchannel = sc;
   if (p->ready_list.prev == NULL) {
     /* first element */
     new_elem->next = &p->ready_list;
@@ -160,7 +159,7 @@ static ready_list *add_connected_sc_locked(round_robin_lb_policy *p,
     p->ready_list.prev = new_elem;
   }
   if (grpc_lb_round_robin_trace) {
-    gpr_log(GPR_DEBUG, "[READYLIST] ADDING NODE %p (SC %p)", new_elem, csc);
+    gpr_log(GPR_DEBUG, "[READYLIST] ADDING NODE %p (SC %p)", new_elem, sc);
   }
   return new_elem;
 }
@@ -200,28 +199,15 @@ static void remove_disconnected_sc_locked(round_robin_lb_policy *p,
   gpr_free(node);
 }
 
-static void del_interested_parties_locked(grpc_exec_ctx *exec_ctx,
-                                          round_robin_lb_policy *p,
-                                          const size_t subchannel_idx) {
-  pending_pick *pp;
-  for (pp = p->pending_picks; pp; pp = pp->next) {
-    grpc_subchannel_del_interested_party(
-        exec_ctx, p->subchannels[subchannel_idx], pp->pollset);
-  }
-}
-
 void rr_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
   size_t i;
   ready_list *elem;
   for (i = 0; i < p->num_subchannels; i++) {
-    del_interested_parties_locked(exec_ctx, p, i);
-  }
-  for (i = 0; i < p->num_subchannels; i++) {
-    GRPC_SUBCHANNEL_UNREF(exec_ctx, p->subchannels[i], "round_robin");
+    subchannel_data *sd = p->subchannels[i];
+    GRPC_SUBCHANNEL_UNREF(exec_ctx, sd->subchannel, "round_robin");
+    gpr_free(sd);
   }
-  gpr_free(p->connectivity_changed_cbs);
-  gpr_free(p->subchannel_connectivity);
 
   grpc_connectivity_state_destroy(exec_ctx, &p->state_tracker);
   gpr_free(p->subchannels);
@@ -237,20 +223,15 @@ void rr_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
     gpr_free(elem);
     elem = tmp;
   }
-  gpr_free(p->subchannel_index_to_readylist_node);
-  gpr_free(p->cb_args);
   gpr_free(p);
 }
 
 void rr_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
-  size_t i;
   round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
   pending_pick *pp;
-  gpr_mu_lock(&p->mu);
+  size_t i;
 
-  for (i = 0; i < p->num_subchannels; i++) {
-    del_interested_parties_locked(exec_ctx, p, i);
-  }
+  gpr_mu_lock(&p->mu);
 
   p->shutdown = 1;
   while ((pp = p->pending_picks)) {
@@ -261,24 +242,26 @@ void rr_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   }
   grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
                               GRPC_CHANNEL_FATAL_FAILURE, "shutdown");
+  for (i = 0; i < p->num_subchannels; i++) {
+    subchannel_data *sd = p->subchannels[i];
+    grpc_subchannel_notify_on_state_change(exec_ctx, sd->subchannel, NULL, NULL,
+                                           &sd->connectivity_changed_closure);
+  }
   gpr_mu_unlock(&p->mu);
 }
 
 static void rr_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
-                           grpc_subchannel **target) {
+                           grpc_connected_subchannel **target) {
   round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
   pending_pick *pp;
-  size_t i;
   gpr_mu_lock(&p->mu);
   pp = p->pending_picks;
   p->pending_picks = NULL;
   while (pp != NULL) {
     pending_pick *next = pp->next;
     if (pp->target == target) {
-      for (i = 0; i < p->num_subchannels; i++) {
-        grpc_subchannel_add_interested_party(exec_ctx, p->subchannels[i],
-                                             pp->pollset);
-      }
+      grpc_pollset_set_del_pollset(exec_ctx, &p->base.interested_parties,
+                                   pp->pollset);
       *target = NULL;
       grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, 0);
       gpr_free(pp);
@@ -295,12 +278,16 @@ static void start_picking(grpc_exec_ctx *exec_ctx, round_robin_lb_policy *p) {
   size_t i;
   p->started_picking = 1;
 
+  gpr_log(GPR_DEBUG, "LB_POLICY: p=%p num_subchannels=%d", p,
+          p->num_subchannels);
+
   for (i = 0; i < p->num_subchannels; i++) {
-    p->subchannel_connectivity[i] = GRPC_CHANNEL_IDLE;
-    grpc_subchannel_notify_on_state_change(exec_ctx, p->subchannels[i],
-                                           &p->subchannel_connectivity[i],
-                                           &p->connectivity_changed_cbs[i]);
-    GRPC_LB_POLICY_REF(&p->base, "round_robin_connectivity");
+    subchannel_data *sd = p->subchannels[i];
+    sd->connectivity_state = GRPC_CHANNEL_IDLE;
+    grpc_subchannel_notify_on_state_change(
+        exec_ctx, sd->subchannel, &p->base.interested_parties,
+        &sd->connectivity_state, &sd->connectivity_changed_closure);
+    GRPC_LB_POLICY_WEAK_REF(&p->base, "round_robin_connectivity");
   }
 }
 
@@ -314,18 +301,18 @@ void rr_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
 }
 
 int rr_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, grpc_pollset *pollset,
-            grpc_metadata_batch *initial_metadata, grpc_subchannel **target,
-            grpc_closure *on_complete) {
-  size_t i;
+            grpc_metadata_batch *initial_metadata,
+            grpc_connected_subchannel **target, grpc_closure *on_complete) {
   round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
   pending_pick *pp;
   ready_list *selected;
   gpr_mu_lock(&p->mu);
   if ((selected = peek_next_connected_locked(p))) {
     gpr_mu_unlock(&p->mu);
-    *target = selected->subchannel;
+    *target = grpc_subchannel_get_connected_subchannel(selected->subchannel);
     if (grpc_lb_round_robin_trace) {
-      gpr_log(GPR_DEBUG, "[RR PICK] TARGET <-- SUBCHANNEL %p (NODE %p)",
+      gpr_log(GPR_DEBUG,
+              "[RR PICK] TARGET <-- CONNECTED SUBCHANNEL %p (NODE %p)",
               selected->subchannel, selected);
     }
     /* only advance the last picked pointer if the selection was used */
@@ -335,10 +322,8 @@ int rr_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, grpc_pollset *pollset,
     if (!p->started_picking) {
       start_picking(exec_ctx, p);
     }
-    for (i = 0; i < p->num_subchannels; i++) {
-      grpc_subchannel_add_interested_party(exec_ctx, p->subchannels[i],
-                                           pollset);
-    }
+    grpc_pollset_set_add_pollset(exec_ctx, &p->base.interested_parties,
+                                 pollset);
     pp = gpr_malloc(sizeof(*pp));
     pp->next = p->pending_picks;
     pp->pollset = pollset;
@@ -352,33 +337,25 @@ int rr_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, grpc_pollset *pollset,
 
 static void rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
                                     int iomgr_success) {
-  connectivity_changed_cb_arg *cb_arg = arg;
-  round_robin_lb_policy *p = cb_arg->p;
-  /* index over p->subchannels of this cb's subchannel */
-  const size_t this_idx = cb_arg->subchannel_idx;
+  subchannel_data *sd = arg;
+  round_robin_lb_policy *p = sd->policy;
   pending_pick *pp;
   ready_list *selected;
 
   int unref = 0;
 
-  /* connectivity state of this cb's subchannel */
-  grpc_connectivity_state *this_connectivity;
-
   gpr_mu_lock(&p->mu);
 
-  this_connectivity = &p->subchannel_connectivity[this_idx];
-
   if (p->shutdown) {
     unref = 1;
   } else {
-    switch (*this_connectivity) {
+    switch (sd->connectivity_state) {
       case GRPC_CHANNEL_READY:
         grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
                                     GRPC_CHANNEL_READY, "connecting_ready");
         /* add the newly connected subchannel to the list of connected ones.
          * Note that it goes to the "end of the line". */
-        p->subchannel_index_to_readylist_node[this_idx] =
-            add_connected_sc_locked(p, p->subchannels[this_idx]);
+        sd->ready_list_node = add_connected_sc_locked(p, sd->subchannel);
         /* at this point we know there's at least one suitable subchannel. Go
          * ahead and pick one and notify the pending suitors in
          * p->pending_picks. This preemtively replicates rr_pick()'s actions. */
@@ -390,60 +367,60 @@ static void rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
         }
         while ((pp = p->pending_picks)) {
           p->pending_picks = pp->next;
-          *pp->target = selected->subchannel;
+          *pp->target =
+              grpc_subchannel_get_connected_subchannel(selected->subchannel);
           if (grpc_lb_round_robin_trace) {
             gpr_log(GPR_DEBUG,
                     "[RR CONN CHANGED] TARGET <-- SUBCHANNEL %p (NODE %p)",
                     selected->subchannel, selected);
           }
-          grpc_subchannel_del_interested_party(exec_ctx, selected->subchannel,
-                                               pp->pollset);
+          grpc_pollset_set_del_pollset(exec_ctx, &p->base.interested_parties,
+                                       pp->pollset);
           grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, 1);
           gpr_free(pp);
         }
         grpc_subchannel_notify_on_state_change(
-            exec_ctx, p->subchannels[this_idx], this_connectivity,
-            &p->connectivity_changed_cbs[this_idx]);
+            exec_ctx, sd->subchannel, &p->base.interested_parties,
+            &sd->connectivity_state, &sd->connectivity_changed_closure);
         break;
       case GRPC_CHANNEL_CONNECTING:
       case GRPC_CHANNEL_IDLE:
         grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
-                                    *this_connectivity, "connecting_changed");
+                                    sd->connectivity_state,
+                                    "connecting_changed");
         grpc_subchannel_notify_on_state_change(
-            exec_ctx, p->subchannels[this_idx], this_connectivity,
-            &p->connectivity_changed_cbs[this_idx]);
+            exec_ctx, sd->subchannel, &p->base.interested_parties,
+            &sd->connectivity_state, &sd->connectivity_changed_closure);
         break;
       case GRPC_CHANNEL_TRANSIENT_FAILURE:
-        del_interested_parties_locked(exec_ctx, p, this_idx);
         /* renew state notification */
         grpc_subchannel_notify_on_state_change(
-            exec_ctx, p->subchannels[this_idx], this_connectivity,
-            &p->connectivity_changed_cbs[this_idx]);
+            exec_ctx, sd->subchannel, &p->base.interested_parties,
+            &sd->connectivity_state, &sd->connectivity_changed_closure);
 
         /* remove from ready list if still present */
-        if (p->subchannel_index_to_readylist_node[this_idx] != NULL) {
-          remove_disconnected_sc_locked(
-              p, p->subchannel_index_to_readylist_node[this_idx]);
-          p->subchannel_index_to_readylist_node[this_idx] = NULL;
+        if (sd->ready_list_node != NULL) {
+          remove_disconnected_sc_locked(p, sd->ready_list_node);
+          sd->ready_list_node = NULL;
         }
         grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
                                     GRPC_CHANNEL_TRANSIENT_FAILURE,
                                     "connecting_transient_failure");
         break;
       case GRPC_CHANNEL_FATAL_FAILURE:
-        del_interested_parties_locked(exec_ctx, p, this_idx);
-        if (p->subchannel_index_to_readylist_node[this_idx] != NULL) {
-          remove_disconnected_sc_locked(
-              p, p->subchannel_index_to_readylist_node[this_idx]);
-          p->subchannel_index_to_readylist_node[this_idx] = NULL;
+        if (sd->ready_list_node != NULL) {
+          remove_disconnected_sc_locked(p, sd->ready_list_node);
+          sd->ready_list_node = NULL;
         }
 
-        GPR_SWAP(grpc_subchannel *, p->subchannels[this_idx],
-                 p->subchannels[p->num_subchannels - 1]);
         p->num_subchannels--;
-        GRPC_SUBCHANNEL_UNREF(exec_ctx, p->subchannels[p->num_subchannels],
-                              "round_robin");
+        GPR_SWAP(subchannel_data *, p->subchannels[sd->index],
+                 p->subchannels[p->num_subchannels]);
+        GRPC_SUBCHANNEL_UNREF(exec_ctx, sd->subchannel, "round_robin");
+        p->subchannels[sd->index]->index = sd->index;
+        gpr_free(sd);
 
+        unref = 1;
         if (p->num_subchannels == 0) {
           grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
                                       GRPC_CHANNEL_FATAL_FAILURE,
@@ -454,7 +431,6 @@ static void rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
             grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, 1);
             gpr_free(pp);
           }
-          unref = 1;
         } else {
           grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
                                       GRPC_CHANNEL_TRANSIENT_FAILURE,
@@ -466,31 +442,8 @@ static void rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
   gpr_mu_unlock(&p->mu);
 
   if (unref) {
-    GRPC_LB_POLICY_UNREF(exec_ctx, &p->base, "round_robin_connectivity");
-  }
-}
-
-static void rr_broadcast(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
-                         grpc_transport_op *op) {
-  round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
-  size_t i;
-  size_t n;
-  grpc_subchannel **subchannels;
-
-  gpr_mu_lock(&p->mu);
-  n = p->num_subchannels;
-  subchannels = gpr_malloc(n * sizeof(*subchannels));
-  for (i = 0; i < n; i++) {
-    subchannels[i] = p->subchannels[i];
-    GRPC_SUBCHANNEL_REF(subchannels[i], "rr_broadcast");
-  }
-  gpr_mu_unlock(&p->mu);
-
-  for (i = 0; i < n; i++) {
-    grpc_subchannel_process_transport_op(exec_ctx, subchannels[i], op);
-    GRPC_SUBCHANNEL_UNREF(exec_ctx, subchannels[i], "rr_broadcast");
+    GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "round_robin_connectivity");
   }
-  gpr_free(subchannels);
 }
 
 static grpc_connectivity_state rr_check_connectivity(grpc_exec_ctx *exec_ctx,
@@ -514,9 +467,25 @@ static void rr_notify_on_state_change(grpc_exec_ctx *exec_ctx,
   gpr_mu_unlock(&p->mu);
 }
 
+static void rr_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
+                        grpc_closure *closure) {
+  round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
+  ready_list *selected;
+  grpc_connected_subchannel *target;
+  gpr_mu_lock(&p->mu);
+  if ((selected = peek_next_connected_locked(p))) {
+    gpr_mu_unlock(&p->mu);
+    target = grpc_subchannel_get_connected_subchannel(selected->subchannel);
+    grpc_connected_subchannel_ping(exec_ctx, target, closure);
+  } else {
+    gpr_mu_unlock(&p->mu);
+    grpc_exec_ctx_enqueue(exec_ctx, closure, 0);
+  }
+}
+
 static const grpc_lb_policy_vtable round_robin_lb_policy_vtable = {
-    rr_destroy, rr_shutdown, rr_pick, rr_cancel_pick, rr_exit_idle,
-    rr_broadcast, rr_check_connectivity, rr_notify_on_state_change};
+    rr_destroy, rr_shutdown, rr_pick, rr_cancel_pick, rr_ping_one, rr_exit_idle,
+    rr_check_connectivity, rr_notify_on_state_change};
 
 static void round_robin_factory_ref(grpc_lb_policy_factory *factory) {}
 
@@ -529,27 +498,22 @@ static grpc_lb_policy *create_round_robin(grpc_lb_policy_factory *factory,
   GPR_ASSERT(args->num_subchannels > 0);
   memset(p, 0, sizeof(*p));
   grpc_lb_policy_init(&p->base, &round_robin_lb_policy_vtable);
-  p->subchannels =
-      gpr_malloc(sizeof(grpc_subchannel *) * args->num_subchannels);
   p->num_subchannels = args->num_subchannels;
+  p->subchannels = gpr_malloc(sizeof(*p->subchannels) * p->num_subchannels);
+  memset(p->subchannels, 0, sizeof(*p->subchannels) * p->num_subchannels);
   grpc_connectivity_state_init(&p->state_tracker, GRPC_CHANNEL_IDLE,
                                "round_robin");
-  memcpy(p->subchannels, args->subchannels,
-         sizeof(grpc_subchannel *) * args->num_subchannels);
 
   gpr_mu_init(&p->mu);
-  p->connectivity_changed_cbs =
-      gpr_malloc(sizeof(grpc_closure) * args->num_subchannels);
-  p->subchannel_connectivity =
-      gpr_malloc(sizeof(grpc_connectivity_state) * args->num_subchannels);
-
-  p->cb_args =
-      gpr_malloc(sizeof(connectivity_changed_cb_arg) * args->num_subchannels);
   for (i = 0; i < args->num_subchannels; i++) {
-    p->cb_args[i].subchannel_idx = i;
-    p->cb_args[i].p = p;
-    grpc_closure_init(&p->connectivity_changed_cbs[i], rr_connectivity_changed,
-                      &p->cb_args[i]);
+    subchannel_data *sd = gpr_malloc(sizeof(*sd));
+    memset(sd, 0, sizeof(*sd));
+    p->subchannels[i] = sd;
+    sd->policy = p;
+    sd->index = i;
+    sd->subchannel = args->subchannels[i];
+    grpc_closure_init(&sd->connectivity_changed_closure,
+                      rr_connectivity_changed, sd);
   }
 
   /* The (dummy node) root of the ready list */
@@ -558,10 +522,6 @@ static grpc_lb_policy *create_round_robin(grpc_lb_policy_factory *factory,
   p->ready_list.next = NULL;
   p->ready_list_last_pick = &p->ready_list;
 
-  p->subchannel_index_to_readylist_node =
-      gpr_malloc(sizeof(grpc_subchannel *) * args->num_subchannels);
-  memset(p->subchannel_index_to_readylist_node, 0,
-         sizeof(grpc_subchannel *) * args->num_subchannels);
   return &p->base;
 }
 

src/core/client_config/lb_policy.c

@@ -33,63 +33,94 @@
 
 #include "src/core/client_config/lb_policy.h"
 
+#define WEAK_REF_BITS 16
+
 void grpc_lb_policy_init(grpc_lb_policy *policy,
                          const grpc_lb_policy_vtable *vtable) {
   policy->vtable = vtable;
-  gpr_ref_init(&policy->refs, 1);
+  gpr_atm_no_barrier_store(&policy->ref_pair, 1 << WEAK_REF_BITS);
+  grpc_pollset_set_init(&policy->interested_parties);
 }
 
 #ifdef GRPC_LB_POLICY_REFCOUNT_DEBUG
-void grpc_lb_policy_ref(grpc_lb_policy *policy, const char *file, int line,
-                        const char *reason) {
-  gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "LB_POLICY:%p   ref %d -> %d %s",
-          policy, (int)policy->refs.count, (int)policy->refs.count + 1, reason);
+#define REF_FUNC_EXTRA_ARGS , const char *file, int line, const char *reason
+#define REF_MUTATE_EXTRA_ARGS REF_FUNC_EXTRA_ARGS, const char *purpose
+#define REF_FUNC_PASS_ARGS(new_reason) , file, line, new_reason
+#define REF_MUTATE_PASS_ARGS(purpose) , file, line, reason, purpose
 #else
-void grpc_lb_policy_ref(grpc_lb_policy *policy) {
+#define REF_FUNC_EXTRA_ARGS
+#define REF_MUTATE_EXTRA_ARGS
+#define REF_FUNC_PASS_ARGS(new_reason)
+#define REF_MUTATE_PASS_ARGS(x)
 #endif
-  gpr_ref(&policy->refs);
-}
 
+static gpr_atm ref_mutate(grpc_lb_policy *c, gpr_atm delta,
+                          int barrier REF_MUTATE_EXTRA_ARGS) {
+  gpr_atm old_val = barrier ? gpr_atm_full_fetch_add(&c->ref_pair, delta)
+                            : gpr_atm_no_barrier_fetch_add(&c->ref_pair, delta);
 #ifdef GRPC_LB_POLICY_REFCOUNT_DEBUG
-void grpc_lb_policy_unref(grpc_lb_policy *policy,
-                          grpc_closure_list *closure_list, const char *file,
-                          int line, const char *reason) {
-  gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "LB_POLICY:%p unref %d -> %d %s",
-          policy, (int)policy->refs.count, (int)policy->refs.count - 1, reason);
-#else
-void grpc_lb_policy_unref(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy) {
+  gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG,
+          "LB_POLICY: %p % 12s 0x%08x -> 0x%08x [%s]", c, purpose, old_val,
+          old_val + delta, reason);
 #endif
-  if (gpr_unref(&policy->refs)) {
-    policy->vtable->destroy(exec_ctx, policy);
+  return old_val;
+}
+
+void grpc_lb_policy_ref(grpc_lb_policy *policy REF_FUNC_EXTRA_ARGS) {
+  ref_mutate(policy, 1 << WEAK_REF_BITS, 0 REF_MUTATE_PASS_ARGS("STRONG_REF"));
+}
+
+void grpc_lb_policy_unref(grpc_exec_ctx *exec_ctx,
+                          grpc_lb_policy *policy REF_FUNC_EXTRA_ARGS) {
+  gpr_atm old_val =
+      ref_mutate(policy, (gpr_atm)1 - (gpr_atm)(1 << WEAK_REF_BITS),
+                 1 REF_MUTATE_PASS_ARGS("STRONG_UNREF"));
+  gpr_atm mask = ~(gpr_atm)((1 << WEAK_REF_BITS) - 1);
+  gpr_atm check = 1 << WEAK_REF_BITS;
+  if ((old_val & mask) == check) {
+    policy->vtable->shutdown(exec_ctx, policy);
   }
+  grpc_lb_policy_weak_unref(exec_ctx,
+                            policy REF_FUNC_PASS_ARGS("strong-unref"));
 }
 
-void grpc_lb_policy_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy) {
-  policy->vtable->shutdown(exec_ctx, policy);
+void grpc_lb_policy_weak_ref(grpc_lb_policy *policy REF_FUNC_EXTRA_ARGS) {
+  ref_mutate(policy, 1, 0 REF_MUTATE_PASS_ARGS("WEAK_REF"));
+}
+
+void grpc_lb_policy_weak_unref(grpc_exec_ctx *exec_ctx,
+                               grpc_lb_policy *policy REF_FUNC_EXTRA_ARGS) {
+  gpr_atm old_val =
+      ref_mutate(policy, -(gpr_atm)1, 1 REF_MUTATE_PASS_ARGS("WEAK_UNREF"));
+  if (old_val == 1) {
+    grpc_pollset_set_destroy(&policy->interested_parties);
+    policy->vtable->destroy(exec_ctx, policy);
+  }
 }
 
 int grpc_lb_policy_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
                         grpc_pollset *pollset,
                         grpc_metadata_batch *initial_metadata,
-                        grpc_subchannel **target, grpc_closure *on_complete) {
+                        grpc_connected_subchannel **target,
+                        grpc_closure *on_complete) {
   return policy->vtable->pick(exec_ctx, policy, pollset, initial_metadata,
                               target, on_complete);
 }
 
 void grpc_lb_policy_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
-                                grpc_subchannel **target) {
+                                grpc_connected_subchannel **target) {
   policy->vtable->cancel_pick(exec_ctx, policy, target);
 }
 
-void grpc_lb_policy_broadcast(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
-                              grpc_transport_op *op) {
-  policy->vtable->broadcast(exec_ctx, policy, op);
-}
-
 void grpc_lb_policy_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy) {
   policy->vtable->exit_idle(exec_ctx, policy);
 }
 
+void grpc_lb_policy_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
+                             grpc_closure *closure) {
+  policy->vtable->ping_one(exec_ctx, policy, closure);
+}
+
 void grpc_lb_policy_notify_on_state_change(grpc_exec_ctx *exec_ctx,
                                            grpc_lb_policy *policy,
                                            grpc_connectivity_state *state,

src/core/client_config/lb_policy.h

@@ -47,7 +47,8 @@ typedef void (*grpc_lb_completion)(void *cb_arg, grpc_subchannel *subchannel,
 
 struct grpc_lb_policy {
   const grpc_lb_policy_vtable *vtable;
-  gpr_refcount refs;
+  gpr_atm ref_pair;
+  grpc_pollset_set interested_parties;
 };
 
 struct grpc_lb_policy_vtable {
@@ -58,17 +59,16 @@ struct grpc_lb_policy_vtable {
   /** implement grpc_lb_policy_pick */
   int (*pick)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
               grpc_pollset *pollset, grpc_metadata_batch *initial_metadata,
-              grpc_subchannel **target, grpc_closure *on_complete);
+              grpc_connected_subchannel **target, grpc_closure *on_complete);
   void (*cancel_pick)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
-                      grpc_subchannel **target);
+                      grpc_connected_subchannel **target);
+
+  void (*ping_one)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
+                   grpc_closure *closure);
 
   /** try to enter a READY connectivity state */
   void (*exit_idle)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
 
-  /** broadcast a transport op to all subchannels */
-  void (*broadcast)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
-                    grpc_transport_op *op);
-
   /** check the current connectivity of the lb_policy */
   grpc_connectivity_state (*check_connectivity)(grpc_exec_ctx *exec_ctx,
                                                 grpc_lb_policy *policy);
@@ -81,29 +81,39 @@ struct grpc_lb_policy_vtable {
                                  grpc_closure *closure);
 };
 
+/*#define GRPC_LB_POLICY_REFCOUNT_DEBUG*/
 #ifdef GRPC_LB_POLICY_REFCOUNT_DEBUG
 #define GRPC_LB_POLICY_REF(p, r) \
   grpc_lb_policy_ref((p), __FILE__, __LINE__, (r))
 #define GRPC_LB_POLICY_UNREF(exec_ctx, p, r) \
   grpc_lb_policy_unref((exec_ctx), (p), __FILE__, __LINE__, (r))
+#define GRPC_LB_POLICY_WEAK_REF(p, r) \
+  grpc_lb_policy_weak_ref((p), __FILE__, __LINE__, (r))
+#define GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, p, r) \
+  grpc_lb_policy_weak_unref((exec_ctx), (p), __FILE__, __LINE__, (r))
 void grpc_lb_policy_ref(grpc_lb_policy *policy, const char *file, int line,
                         const char *reason);
 void grpc_lb_policy_unref(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
                           const char *file, int line, const char *reason);
+void grpc_lb_policy_weak_ref(grpc_lb_policy *policy, const char *file, int line,
+                             const char *reason);
+void grpc_lb_policy_weak_unref(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
+                               const char *file, int line, const char *reason);
 #else
 #define GRPC_LB_POLICY_REF(p, r) grpc_lb_policy_ref((p))
 #define GRPC_LB_POLICY_UNREF(cl, p, r) grpc_lb_policy_unref((cl), (p))
+#define GRPC_LB_POLICY_WEAK_REF(p, r) grpc_lb_policy_weak_ref((p))
+#define GRPC_LB_POLICY_WEAK_UNREF(cl, p, r) grpc_lb_policy_weak_unref((cl), (p))
 void grpc_lb_policy_ref(grpc_lb_policy *policy);
 void grpc_lb_policy_unref(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
+void grpc_lb_policy_weak_ref(grpc_lb_policy *policy);
+void grpc_lb_policy_weak_unref(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
 #endif
 
 /** called by concrete implementations to initialize the base struct */
 void grpc_lb_policy_init(grpc_lb_policy *policy,
                          const grpc_lb_policy_vtable *vtable);
 
-/** Start shutting down (fail any pending picks) */
-void grpc_lb_policy_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
-
 /** Given initial metadata in \a initial_metadata, find an appropriate
     target for this rpc, and 'return' it by calling \a on_complete after setting
     \a target.
@@ -111,13 +121,14 @@ void grpc_lb_policy_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
 int grpc_lb_policy_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
                         grpc_pollset *pollset,
                         grpc_metadata_batch *initial_metadata,
-                        grpc_subchannel **target, grpc_closure *on_complete);
+                        grpc_connected_subchannel **target,
+                        grpc_closure *on_complete);
 
-void grpc_lb_policy_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
-                                grpc_subchannel **target);
+void grpc_lb_policy_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
+                             grpc_closure *closure);
 
-void grpc_lb_policy_broadcast(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
-                              grpc_transport_op *op);
+void grpc_lb_policy_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
+                                grpc_connected_subchannel **target);
 
 void grpc_lb_policy_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
 

src/core/client_config/resolver.c

@@ -71,11 +71,8 @@ void grpc_resolver_shutdown(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver) {
 }
 
 void grpc_resolver_channel_saw_error(grpc_exec_ctx *exec_ctx,
-                                     grpc_resolver *resolver,
-                                     struct sockaddr *failing_address,
-                                     int failing_address_len) {
-  resolver->vtable->channel_saw_error(exec_ctx, resolver, failing_address,
-                                      failing_address_len);
+                                     grpc_resolver *resolver) {
+  resolver->vtable->channel_saw_error(exec_ctx, resolver);
 }
 
 void grpc_resolver_next(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,

src/core/client_config/resolver.h

@@ -35,8 +35,8 @@
 #define GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVER_H
 
 #include "src/core/client_config/client_config.h"
+#include "src/core/client_config/subchannel.h"
 #include "src/core/iomgr/iomgr.h"
-#include "src/core/iomgr/sockaddr.h"
 
 typedef struct grpc_resolver grpc_resolver;
 typedef struct grpc_resolver_vtable grpc_resolver_vtable;
@@ -51,9 +51,7 @@ struct grpc_resolver {
 struct grpc_resolver_vtable {
   void (*destroy)(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver);
   void (*shutdown)(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver);
-  void (*channel_saw_error)(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
-                            struct sockaddr *failing_address,
-                            int failing_address_len);
+  void (*channel_saw_error)(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver);
   void (*next)(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
                grpc_client_config **target_config, grpc_closure *on_complete);
 };
@@ -81,9 +79,7 @@ void grpc_resolver_shutdown(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver);
 /** Notification that the channel has seen an error on some address.
     Can be used as a hint that re-resolution is desirable soon. */
 void grpc_resolver_channel_saw_error(grpc_exec_ctx *exec_ctx,
-                                     grpc_resolver *resolver,
-                                     struct sockaddr *failing_address,
-                                     int failing_address_len);
+                                     grpc_resolver *resolver);
 
 /** Get the next client config. Called by the channel to fetch a new
     configuration. Expected to set *target_config with a new configuration,

src/core/client_config/resolvers/dns_resolver.c

@@ -80,9 +80,7 @@ static void dns_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
                                          dns_resolver *r);
 
 static void dns_shutdown(grpc_exec_ctx *exec_ctx, grpc_resolver *r);
-static void dns_channel_saw_error(grpc_exec_ctx *exec_ctx, grpc_resolver *r,
-                                  struct sockaddr *failing_address,
-                                  int failing_address_len);
+static void dns_channel_saw_error(grpc_exec_ctx *exec_ctx, grpc_resolver *r);
 static void dns_next(grpc_exec_ctx *exec_ctx, grpc_resolver *r,
                      grpc_client_config **target_config,
                      grpc_closure *on_complete);
@@ -102,8 +100,7 @@ static void dns_shutdown(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver) {
 }
 
 static void dns_channel_saw_error(grpc_exec_ctx *exec_ctx,
-                                  grpc_resolver *resolver, struct sockaddr *sa,
-                                  int len) {
+                                  grpc_resolver *resolver) {
   dns_resolver *r = (dns_resolver *)resolver;
   gpr_mu_lock(&r->mu);
   if (!r->resolving) {

src/core/client_config/resolvers/sockaddr_resolver.c

@@ -83,9 +83,7 @@ static void sockaddr_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
 
 static void sockaddr_shutdown(grpc_exec_ctx *exec_ctx, grpc_resolver *r);
 static void sockaddr_channel_saw_error(grpc_exec_ctx *exec_ctx,
-                                       grpc_resolver *r,
-                                       struct sockaddr *failing_address,
-                                       int failing_address_len);
+                                       grpc_resolver *r);
 static void sockaddr_next(grpc_exec_ctx *exec_ctx, grpc_resolver *r,
                           grpc_client_config **target_config,
                           grpc_closure *on_complete);
@@ -107,8 +105,13 @@ static void sockaddr_shutdown(grpc_exec_ctx *exec_ctx,
 }
 
 static void sockaddr_channel_saw_error(grpc_exec_ctx *exec_ctx,
-                                       grpc_resolver *resolver,
-                                       struct sockaddr *sa, int len) {}
+                                       grpc_resolver *resolver) {
+  sockaddr_resolver *r = (sockaddr_resolver *)resolver;
+  gpr_mu_lock(&r->mu);
+  r->published = 0;
+  sockaddr_maybe_finish_next_locked(exec_ctx, r);
+  gpr_mu_unlock(&r->mu);
+}
 
 static void sockaddr_next(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
                           grpc_client_config **target_config,
@@ -344,6 +347,9 @@ static grpc_resolver *sockaddr_create(
   gpr_slice_buffer_destroy(&path_parts);
   gpr_slice_unref(path_slice);
   if (errors_found) {
+    gpr_free(r->lb_policy_name);
+    gpr_free(r->addrs);
+    gpr_free(r->addrs_len);
     gpr_free(r);
     return NULL;
   }

src/core/client_config/resolvers/zookeeper_resolver.c

@@ -96,9 +96,7 @@ static void zookeeper_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
 
 static void zookeeper_shutdown(grpc_exec_ctx *exec_ctx, grpc_resolver *r);
 static void zookeeper_channel_saw_error(grpc_exec_ctx *exec_ctx,
-                                        grpc_resolver *r,
-                                        struct sockaddr *failing_address,
-                                        int failing_address_len);
+                                        grpc_resolver *r);
 static void zookeeper_next(grpc_exec_ctx *exec_ctx, grpc_resolver *r,
                            grpc_client_config **target_config,
                            grpc_closure *on_complete);
@@ -125,8 +123,7 @@ static void zookeeper_shutdown(grpc_exec_ctx *exec_ctx,
 }
 
 static void zookeeper_channel_saw_error(grpc_exec_ctx *exec_ctx,
-                                        grpc_resolver *resolver,
-                                        struct sockaddr *sa, int len) {
+                                        grpc_resolver *resolver) {
   zookeeper_resolver *r = (zookeeper_resolver *)resolver;
   gpr_mu_lock(&r->mu);
   if (r->resolving == 0) {

src/core/client_config/subchannel.h

@@ -41,6 +41,7 @@
 /** A (sub-)channel that knows how to connect to exactly one target
     address. Provides a target for load balancing. */
 typedef struct grpc_subchannel grpc_subchannel;
+typedef struct grpc_connected_subchannel grpc_connected_subchannel;
 typedef struct grpc_subchannel_call grpc_subchannel_call;
 typedef struct grpc_subchannel_args grpc_subchannel_args;
 
@@ -49,6 +50,14 @@ typedef struct grpc_subchannel_args grpc_subchannel_args;
   grpc_subchannel_ref((p), __FILE__, __LINE__, (r))
 #define GRPC_SUBCHANNEL_UNREF(cl, p, r) \
   grpc_subchannel_unref((cl), (p), __FILE__, __LINE__, (r))
+#define GRPC_SUBCHANNEL_WEAK_REF(p, r) \
+  grpc_subchannel_weak_ref((p), __FILE__, __LINE__, (r))
+#define GRPC_SUBCHANNEL_WEAK_UNREF(cl, p, r) \
+  grpc_subchannel_weak_unref((cl), (p), __FILE__, __LINE__, (r))
+#define GRPC_CONNECTED_SUBCHANNEL_REF(p, r) \
+  grpc_connected_subchannel_ref((p), __FILE__, __LINE__, (r))
+#define GRPC_CONNECTED_SUBCHANNEL_UNREF(cl, p, r) \
+  grpc_connected_subchannel_unref((cl), (p), __FILE__, __LINE__, (r))
 #define GRPC_SUBCHANNEL_CALL_REF(p, r) \
   grpc_subchannel_call_ref((p), __FILE__, __LINE__, (r))
 #define GRPC_SUBCHANNEL_CALL_UNREF(cl, p, r) \
@@ -58,6 +67,12 @@ typedef struct grpc_subchannel_args grpc_subchannel_args;
 #else
 #define GRPC_SUBCHANNEL_REF(p, r) grpc_subchannel_ref((p))
 #define GRPC_SUBCHANNEL_UNREF(cl, p, r) grpc_subchannel_unref((cl), (p))
+#define GRPC_SUBCHANNEL_WEAK_REF(p, r) grpc_subchannel_weak_ref((p))
+#define GRPC_SUBCHANNEL_WEAK_UNREF(cl, p, r) \
+  grpc_subchannel_weak_unref((cl), (p))
+#define GRPC_CONNECTED_SUBCHANNEL_REF(p, r) grpc_connected_subchannel_ref((p))
+#define GRPC_CONNECTED_SUBCHANNEL_UNREF(cl, p, r) \
+  grpc_connected_subchannel_unref((cl), (p))
 #define GRPC_SUBCHANNEL_CALL_REF(p, r) grpc_subchannel_call_ref((p))
 #define GRPC_SUBCHANNEL_CALL_UNREF(cl, p, r) \
   grpc_subchannel_call_unref((cl), (p))
@@ -69,33 +84,31 @@ void grpc_subchannel_ref(grpc_subchannel *channel
 void grpc_subchannel_unref(grpc_exec_ctx *exec_ctx,
                            grpc_subchannel *channel
                                GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
+void grpc_subchannel_weak_ref(grpc_subchannel *channel
+                                  GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
+void grpc_subchannel_weak_unref(grpc_exec_ctx *exec_ctx,
+                                grpc_subchannel *channel
+                                    GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
+void grpc_connected_subchannel_ref(grpc_connected_subchannel *channel
+                                       GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
+void grpc_connected_subchannel_unref(grpc_exec_ctx *exec_ctx,
+                                     grpc_connected_subchannel *channel
+                                         GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
 void grpc_subchannel_call_ref(grpc_subchannel_call *call
                                   GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
 void grpc_subchannel_call_unref(grpc_exec_ctx *exec_ctx,
                                 grpc_subchannel_call *call
                                     GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
 
-/** construct a subchannel call (possibly asynchronously).
- *
- * If the returned status is 1, the call will return immediately and \a target
- * will point to a connected \a subchannel_call instance. Note that \a notify
- * will \em not be invoked in this case.
- * Otherwise, if the returned status is 0, the subchannel call will be created
- * asynchronously, invoking the \a notify callback upon completion. */
-int grpc_subchannel_create_call(grpc_exec_ctx *exec_ctx,
-                                grpc_subchannel *subchannel,
-                                grpc_pollset *pollset, gpr_atm *target,
-                                grpc_closure *notify);
-
-/** cancel \a call in the waiting state. */
-void grpc_subchannel_cancel_create_call(grpc_exec_ctx *exec_ctx,
-                                        grpc_subchannel *subchannel,
-                                        gpr_atm *target);
+/** construct a subchannel call */
+grpc_subchannel_call *grpc_connected_subchannel_create_call(
+    grpc_exec_ctx *exec_ctx, grpc_connected_subchannel *connected_subchannel,
+    grpc_pollset *pollset);
 
 /** process a transport level op */
-void grpc_subchannel_process_transport_op(grpc_exec_ctx *exec_ctx,
-                                          grpc_subchannel *subchannel,
-                                          grpc_transport_op *op);
+void grpc_connected_subchannel_process_transport_op(
+    grpc_exec_ctx *exec_ctx, grpc_connected_subchannel *subchannel,
+    grpc_transport_op *op);
 
 /** poll the current connectivity state of a channel */
 grpc_connectivity_state grpc_subchannel_check_connectivity(
@@ -103,26 +116,22 @@ grpc_connectivity_state grpc_subchannel_check_connectivity(
 
 /** call notify when the connectivity state of a channel changes from *state.
     Updates *state with the new state of the channel */
-void grpc_subchannel_notify_on_state_change(grpc_exec_ctx *exec_ctx,
-                                            grpc_subchannel *channel,
-                                            grpc_connectivity_state *state,
-                                            grpc_closure *notify);
-
-/** Remove \a subscribed_notify from the list of closures to be called on a
- * state change if present, returning 1. Otherwise, nothing is done and return
- * 0. */
-int grpc_subchannel_state_change_unsubscribe(grpc_exec_ctx *exec_ctx,
-                                             grpc_subchannel *channel,
-                                             grpc_closure *subscribed_notify);
-
-/** express interest in \a channel's activities through \a pollset. */
-void grpc_subchannel_add_interested_party(grpc_exec_ctx *exec_ctx,
-                                          grpc_subchannel *channel,
-                                          grpc_pollset *pollset);
-/** stop following \a channel's activity through \a pollset. */
-void grpc_subchannel_del_interested_party(grpc_exec_ctx *exec_ctx,
-                                          grpc_subchannel *channel,
-                                          grpc_pollset *pollset);
+void grpc_subchannel_notify_on_state_change(
+    grpc_exec_ctx *exec_ctx, grpc_subchannel *channel,
+    grpc_pollset_set *interested_parties, grpc_connectivity_state *state,
+    grpc_closure *notify);
+void grpc_connected_subchannel_notify_on_state_change(
+    grpc_exec_ctx *exec_ctx, grpc_connected_subchannel *channel,
+    grpc_pollset_set *interested_parties, grpc_connectivity_state *state,
+    grpc_closure *notify);
+void grpc_connected_subchannel_ping(grpc_exec_ctx *exec_ctx,
+                                    grpc_connected_subchannel *channel,
+                                    grpc_closure *notify);
+
+/** retrieve the grpc_connected_subchannel - or NULL if called before
+    the subchannel becomes connected */
+grpc_connected_subchannel *grpc_subchannel_get_connected_subchannel(
+    grpc_subchannel *subchannel);
 
 /** continue processing a transport op */
 void grpc_subchannel_call_process_op(grpc_exec_ctx *exec_ctx,
@@ -147,15 +156,10 @@ struct grpc_subchannel_args {
   /** Address to connect to */
   struct sockaddr *addr;
   size_t addr_len;
-  /** master channel */
-  grpc_channel *master;
 };
 
 /** create a subchannel given a connector */
 grpc_subchannel *grpc_subchannel_create(grpc_connector *connector,
                                         grpc_subchannel_args *args);
 
-/** Return the master channel associated with the subchannel */
-grpc_channel *grpc_subchannel_get_master(grpc_subchannel *subchannel);
-
 #endif /* GRPC_INTERNAL_CORE_CLIENT_CONFIG_SUBCHANNEL_H */

src/core/compression/algorithm.c

@@ -119,8 +119,8 @@ grpc_mdelem *grpc_compression_encoding_mdelem(
       return GRPC_MDELEM_GRPC_ENCODING_DEFLATE;
     case GRPC_COMPRESS_GZIP:
       return GRPC_MDELEM_GRPC_ENCODING_GZIP;
-    case GRPC_COMPRESS_ALGORITHMS_COUNT:
-      return NULL;
+    default:
+      break;
   }
   return NULL;
 }
@@ -139,25 +139,9 @@ grpc_compression_algorithm grpc_compression_algorithm_for_level(
     case GRPC_COMPRESS_LEVEL_HIGH:
       return GRPC_COMPRESS_DEFLATE;
     default:
-      /* we shouldn't be making it here */
-      abort();
-      return GRPC_COMPRESS_NONE;
-  }
-}
-
-grpc_compression_level grpc_compression_level_for_algorithm(
-    grpc_compression_algorithm algorithm) {
-  grpc_compression_level clevel;
-  GRPC_API_TRACE("grpc_compression_level_for_algorithm(algorithm=%d)", 1,
-                 ((int)algorithm));
-  for (clevel = GRPC_COMPRESS_LEVEL_NONE; clevel < GRPC_COMPRESS_LEVEL_COUNT;
-       ++clevel) {
-    if (grpc_compression_algorithm_for_level(clevel) == algorithm) {
-      return clevel;
-    }
+      break;
   }
-  abort();
-  return GRPC_COMPRESS_LEVEL_NONE;
+  GPR_UNREACHABLE_CODE(return GRPC_COMPRESS_NONE);
 }
 
 void grpc_compression_options_init(grpc_compression_options *opts) {

src/core/compression/message_compress.c

@@ -69,8 +69,8 @@ static int zlib_body(z_stream* zs, gpr_slice_buffer* input,
         zs->next_out = GPR_SLICE_START_PTR(outbuf);
       }
       r = flate(zs, flush);
-      if (r == Z_STREAM_ERROR) {
-        gpr_log(GPR_INFO, "zlib: stream error");
+      if (r < 0 && r != Z_BUF_ERROR /* not fatal */) {
+        gpr_log(GPR_INFO, "zlib error (%d)", r);
         goto error;
       }
     } while (zs->avail_out == 0);
@@ -91,13 +91,11 @@ error:
   return 0;
 }
 
-static void *zalloc_gpr(void* opaque, unsigned int items, unsigned int size) {
+static void* zalloc_gpr(void* opaque, unsigned int items, unsigned int size) {
   return gpr_malloc(items * size);
 }
 
-static void zfree_gpr(void* opaque, void *address) {
-  gpr_free(address);
-}
+static void zfree_gpr(void* opaque, void* address) { gpr_free(address); }
 
 static int zlib_compress(gpr_slice_buffer* input, gpr_slice_buffer* output,
                          int gzip) {
@@ -111,10 +109,7 @@ static int zlib_compress(gpr_slice_buffer* input, gpr_slice_buffer* output,
   zs.zfree = zfree_gpr;
   r = deflateInit2(&zs, Z_DEFAULT_COMPRESSION, Z_DEFLATED, 15 | (gzip ? 16 : 0),
                    8, Z_DEFAULT_STRATEGY);
-  if (r != Z_OK) {
-    gpr_log(GPR_ERROR, "deflateInit2 returns %d", r);
-    return 0;
-  }
+  GPR_ASSERT(r == Z_OK);
   r = zlib_body(&zs, input, output, deflate) && output->length < input->length;
   if (!r) {
     for (i = count_before; i < output->count; i++) {
@@ -138,10 +133,7 @@ static int zlib_decompress(gpr_slice_buffer* input, gpr_slice_buffer* output,
   zs.zalloc = zalloc_gpr;
   zs.zfree = zfree_gpr;
   r = inflateInit2(&zs, 15 | (gzip ? 16 : 0));
-  if (r != Z_OK) {
-    gpr_log(GPR_ERROR, "inflateInit2 returns %d", r);
-    return 0;
-  }
+  GPR_ASSERT(r == Z_OK);
   r = zlib_body(&zs, input, output, inflate);
   if (!r) {
     for (i = count_before; i < output->count; i++) {
@@ -163,7 +155,7 @@ static int copy(gpr_slice_buffer* input, gpr_slice_buffer* output) {
 }
 
 static int compress_inner(grpc_compression_algorithm algorithm,
-                   gpr_slice_buffer* input, gpr_slice_buffer* output) {
+                          gpr_slice_buffer* input, gpr_slice_buffer* output) {
   switch (algorithm) {
     case GRPC_COMPRESS_NONE:
       /* the fallback path always needs to be send uncompressed: we simply

src/core/httpcli/httpcli.c

@@ -53,6 +53,7 @@ typedef struct {
   size_t next_address;
   grpc_endpoint *ep;
   char *host;
+  char *ssl_host_override;
   gpr_timespec deadline;
   int have_read_byte;
   const grpc_httpcli_handshaker *handshaker;
@@ -106,6 +107,7 @@ static void finish(grpc_exec_ctx *exec_ctx, internal_request *req,
   }
   gpr_slice_unref(req->request_text);
   gpr_free(req->host);
+  gpr_free(req->ssl_host_override);
   grpc_iomgr_unregister_object(&req->iomgr_obj);
   gpr_slice_buffer_destroy(&req->incoming);
   gpr_slice_buffer_destroy(&req->outgoing);
@@ -180,8 +182,10 @@ static void on_connected(grpc_exec_ctx *exec_ctx, void *arg, int success) {
     next_address(exec_ctx, req);
     return;
   }
-  req->handshaker->handshake(exec_ctx, req, req->ep, req->host,
-                             on_handshake_done);
+  req->handshaker->handshake(
+      exec_ctx, req, req->ep,
+      req->ssl_host_override ? req->ssl_host_override : req->host,
+      on_handshake_done);
 }
 
 static void next_address(grpc_exec_ctx *exec_ctx, internal_request *req) {
@@ -231,6 +235,7 @@ static void internal_request_begin(
   gpr_slice_buffer_init(&req->outgoing);
   grpc_iomgr_register_object(&req->iomgr_obj, name);
   req->host = gpr_strdup(request->host);
+  req->ssl_host_override = gpr_strdup(request->ssl_host_override);
 
   grpc_pollset_set_add_pollset(exec_ctx, &req->context->pollset_set,
                                req->pollset);

src/core/httpcli/httpcli.h

@@ -74,6 +74,8 @@ extern const grpc_httpcli_handshaker grpc_httpcli_ssl;
 typedef struct grpc_httpcli_request {
   /* The host name to connect to */
   char *host;
+  /* The host to verify in the SSL handshake (or NULL) */
+  char *ssl_host_override;
   /* The path of the resource to fetch */
   char *path;
   /* Additional headers: count and key/values; the following are supplied

src/core/iomgr/fd_posix.c

@@ -43,6 +43,7 @@
 
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
 #include <grpc/support/useful.h>
 
 #define CLOSURE_NOT_READY ((grpc_closure *)0)
@@ -158,7 +159,10 @@ void grpc_fd_global_shutdown(void) {
 
 grpc_fd *grpc_fd_create(int fd, const char *name) {
   grpc_fd *r = alloc_fd(fd);
-  grpc_iomgr_register_object(&r->iomgr_object, name);
+  char *name2;
+  gpr_asprintf(&name2, "%s fd=%d", name, fd);
+  grpc_iomgr_register_object(&r->iomgr_object, name2);
+  gpr_free(name2);
 #ifdef GRPC_FD_REF_COUNT_DEBUG
   gpr_log(GPR_DEBUG, "FD %d %p create %s", fd, r, name);
 #endif

src/core/iomgr/fd_posix.h

@@ -170,6 +170,7 @@ void grpc_fd_become_readable(grpc_exec_ctx *exec_ctx, grpc_fd *fd);
 void grpc_fd_become_writable(grpc_exec_ctx *exec_ctx, grpc_fd *fd);
 
 /* Reference counting for fds */
+/*#define GRPC_FD_REF_COUNT_DEBUG*/
 #ifdef GRPC_FD_REF_COUNT_DEBUG
 void grpc_fd_ref(grpc_fd *fd, const char *reason, const char *file, int line);
 void grpc_fd_unref(grpc_fd *fd, const char *reason, const char *file, int line);

src/core/iomgr/pollset_multipoller_with_epoll.c

@@ -123,26 +123,6 @@ static void multipoll_with_epoll_pollset_add_fd(grpc_exec_ctx *exec_ctx,
   }
 }
 
-static void multipoll_with_epoll_pollset_del_fd(grpc_exec_ctx *exec_ctx,
-                                                grpc_pollset *pollset,
-                                                grpc_fd *fd,
-                                                int and_unlock_pollset) {
-  pollset_hdr *h = pollset->data.ptr;
-  int err;
-
-  if (and_unlock_pollset) {
-    gpr_mu_unlock(&pollset->mu);
-  }
-
-  /* Note that this can race with concurrent poll, but that should be fine since
-   * at worst it creates a spurious read event on a reused grpc_fd object. */
-  err = epoll_ctl(h->epoll_fd, EPOLL_CTL_DEL, fd->fd, NULL);
-  if (err < 0) {
-    gpr_log(GPR_ERROR, "epoll_ctl del for %d failed: %s", fd->fd,
-            strerror(errno));
-  }
-}
-
 /* TODO(klempner): We probably want to turn this down a bit */
 #define GRPC_EPOLL_MAX_EVENTS 1000
 
@@ -235,7 +215,7 @@ static void multipoll_with_epoll_pollset_destroy(grpc_pollset *pollset) {
 }
 
 static const grpc_pollset_vtable multipoll_with_epoll_pollset = {
-    multipoll_with_epoll_pollset_add_fd, multipoll_with_epoll_pollset_del_fd,
+    multipoll_with_epoll_pollset_add_fd,
     multipoll_with_epoll_pollset_maybe_work_and_unlock,
     multipoll_with_epoll_pollset_finish_shutdown,
     multipoll_with_epoll_pollset_destroy};

src/core/iomgr/pollset_multipoller_with_poll_posix.c

@@ -82,23 +82,6 @@ exit:
   }
 }
 
-static void multipoll_with_poll_pollset_del_fd(grpc_exec_ctx *exec_ctx,
-                                               grpc_pollset *pollset,
-                                               grpc_fd *fd,
-                                               int and_unlock_pollset) {
-  /* will get removed next poll cycle */
-  pollset_hdr *h = pollset->data.ptr;
-  if (h->del_count == h->del_capacity) {
-    h->del_capacity = GPR_MAX(h->del_capacity + 8, h->del_count * 3 / 2);
-    h->dels = gpr_realloc(h->dels, sizeof(grpc_fd *) * h->del_capacity);
-  }
-  h->dels[h->del_count++] = fd;
-  GRPC_FD_REF(fd, "multipoller_del");
-  if (and_unlock_pollset) {
-    gpr_mu_unlock(&pollset->mu);
-  }
-}
-
 static void multipoll_with_poll_pollset_maybe_work_and_unlock(
     grpc_exec_ctx *exec_ctx, grpc_pollset *pollset, grpc_pollset_worker *worker,
     gpr_timespec deadline, gpr_timespec now) {
@@ -212,7 +195,7 @@ static void multipoll_with_poll_pollset_destroy(grpc_pollset *pollset) {
 }
 
 static const grpc_pollset_vtable multipoll_with_poll_pollset = {
-    multipoll_with_poll_pollset_add_fd, multipoll_with_poll_pollset_del_fd,
+    multipoll_with_poll_pollset_add_fd,
     multipoll_with_poll_pollset_maybe_work_and_unlock,
     multipoll_with_poll_pollset_finish_shutdown,
     multipoll_with_poll_pollset_destroy};

src/core/iomgr/pollset_posix.c

@@ -232,21 +232,7 @@ void grpc_pollset_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
   gpr_mu_lock(&pollset->mu);
   pollset->vtable->add_fd(exec_ctx, pollset, fd, 1);
 /* the following (enabled only in debug) will reacquire and then release
-   our lock - meaning that if the unlocking flag passed to del_fd above is
-   not respected, the code will deadlock (in a way that we have a chance of
-   debugging) */
-#ifndef NDEBUG
-  gpr_mu_lock(&pollset->mu);
-  gpr_mu_unlock(&pollset->mu);
-#endif
-}
-
-void grpc_pollset_del_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
-                         grpc_fd *fd) {
-  gpr_mu_lock(&pollset->mu);
-  pollset->vtable->del_fd(exec_ctx, pollset, fd, 1);
-/* the following (enabled only in debug) will reacquire and then release
-   our lock - meaning that if the unlocking flag passed to del_fd above is
+   our lock - meaning that if the unlocking flag passed to add_fd above is
    not respected, the code will deadlock (in a way that we have a chance of
    debugging) */
 #ifndef NDEBUG
@@ -547,19 +533,6 @@ exit:
   }
 }
 
-static void basic_pollset_del_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
-                                 grpc_fd *fd, int and_unlock_pollset) {
-  GPR_ASSERT(fd);
-  if (fd == pollset->data.ptr) {
-    GRPC_FD_UNREF(pollset->data.ptr, "basicpoll");
-    pollset->data.ptr = NULL;
-  }
-
-  if (and_unlock_pollset) {
-    gpr_mu_unlock(&pollset->mu);
-  }
-}
-
 static void basic_pollset_maybe_work_and_unlock(grpc_exec_ctx *exec_ctx,
                                                 grpc_pollset *pollset,
                                                 grpc_pollset_worker *worker,
@@ -651,9 +624,8 @@ static void basic_pollset_destroy(grpc_pollset *pollset) {
 }
 
 static const grpc_pollset_vtable basic_pollset = {
-    basic_pollset_add_fd, basic_pollset_del_fd,
-    basic_pollset_maybe_work_and_unlock, basic_pollset_destroy,
-    basic_pollset_destroy};
+    basic_pollset_add_fd, basic_pollset_maybe_work_and_unlock,
+    basic_pollset_destroy, basic_pollset_destroy};
 
 static void become_basic_pollset(grpc_pollset *pollset, grpc_fd *fd_or_null) {
   pollset->vtable = &basic_pollset;

src/core/iomgr/pollset_posix.h

@@ -86,8 +86,6 @@ typedef struct grpc_pollset {
 struct grpc_pollset_vtable {
   void (*add_fd)(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
                  struct grpc_fd *fd, int and_unlock_pollset);
-  void (*del_fd)(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
-                 struct grpc_fd *fd, int and_unlock_pollset);
   void (*maybe_work_and_unlock)(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
                                 grpc_pollset_worker *worker,
                                 gpr_timespec deadline, gpr_timespec now);
@@ -100,10 +98,6 @@ struct grpc_pollset_vtable {
 /* Add an fd to a pollset */
 void grpc_pollset_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
                          struct grpc_fd *fd);
-/* Force remove an fd from a pollset (normally they are removed on the next
-   poll after an fd is orphaned) */
-void grpc_pollset_del_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
-                         struct grpc_fd *fd);
 
 /* Returns the fd to listen on for kicks */
 int grpc_kick_read_fd(grpc_pollset *p);

src/core/iomgr/pollset_set.h

@@ -49,13 +49,19 @@
 #include "src/core/iomgr/pollset_set_windows.h"
 #endif
 
-void grpc_pollset_set_init(grpc_pollset_set* pollset_set);
-void grpc_pollset_set_destroy(grpc_pollset_set* pollset_set);
-void grpc_pollset_set_add_pollset(grpc_exec_ctx* exec_ctx,
-                                  grpc_pollset_set* pollset_set,
-                                  grpc_pollset* pollset);
-void grpc_pollset_set_del_pollset(grpc_exec_ctx* exec_ctx,
-                                  grpc_pollset_set* pollset_set,
-                                  grpc_pollset* pollset);
+void grpc_pollset_set_init(grpc_pollset_set *pollset_set);
+void grpc_pollset_set_destroy(grpc_pollset_set *pollset_set);
+void grpc_pollset_set_add_pollset(grpc_exec_ctx *exec_ctx,
+                                  grpc_pollset_set *pollset_set,
+                                  grpc_pollset *pollset);
+void grpc_pollset_set_del_pollset(grpc_exec_ctx *exec_ctx,
+                                  grpc_pollset_set *pollset_set,
+                                  grpc_pollset *pollset);
+void grpc_pollset_set_add_pollset_set(grpc_exec_ctx *exec_ctx,
+                                      grpc_pollset_set *bag,
+                                      grpc_pollset_set *item);
+void grpc_pollset_set_del_pollset_set(grpc_exec_ctx *exec_ctx,
+                                      grpc_pollset_set *bag,
+                                      grpc_pollset_set *item);
 
 #endif /* GRPC_INTERNAL_CORE_IOMGR_POLLSET_H */

src/core/iomgr/pollset_set_posix.c

@@ -52,9 +52,10 @@ void grpc_pollset_set_destroy(grpc_pollset_set *pollset_set) {
   size_t i;
   gpr_mu_destroy(&pollset_set->mu);
   for (i = 0; i < pollset_set->fd_count; i++) {
-    GRPC_FD_UNREF(pollset_set->fds[i], "pollset");
+    GRPC_FD_UNREF(pollset_set->fds[i], "pollset_set");
   }
   gpr_free(pollset_set->pollsets);
+  gpr_free(pollset_set->pollset_sets);
   gpr_free(pollset_set->fds);
 }
 
@@ -73,7 +74,7 @@ void grpc_pollset_set_add_pollset(grpc_exec_ctx *exec_ctx,
   pollset_set->pollsets[pollset_set->pollset_count++] = pollset;
   for (i = 0, j = 0; i < pollset_set->fd_count; i++) {
     if (grpc_fd_is_orphaned(pollset_set->fds[i])) {
-      GRPC_FD_UNREF(pollset_set->fds[i], "pollset");
+      GRPC_FD_UNREF(pollset_set->fds[i], "pollset_set");
     } else {
       grpc_pollset_add_fd(exec_ctx, pollset, pollset_set->fds[i]);
       pollset_set->fds[j++] = pollset_set->fds[i];
@@ -99,6 +100,46 @@ void grpc_pollset_set_del_pollset(grpc_exec_ctx *exec_ctx,
   gpr_mu_unlock(&pollset_set->mu);
 }
 
+void grpc_pollset_set_add_pollset_set(grpc_exec_ctx *exec_ctx,
+                                      grpc_pollset_set *bag,
+                                      grpc_pollset_set *item) {
+  size_t i, j;
+  gpr_mu_lock(&bag->mu);
+  if (bag->pollset_set_count == bag->pollset_set_capacity) {
+    bag->pollset_set_capacity = GPR_MAX(8, 2 * bag->pollset_set_capacity);
+    bag->pollset_sets =
+        gpr_realloc(bag->pollset_sets,
+                    bag->pollset_set_capacity * sizeof(*bag->pollset_sets));
+  }
+  bag->pollset_sets[bag->pollset_set_count++] = item;
+  for (i = 0, j = 0; i < bag->fd_count; i++) {
+    if (grpc_fd_is_orphaned(bag->fds[i])) {
+      GRPC_FD_UNREF(bag->fds[i], "pollset_set");
+    } else {
+      grpc_pollset_set_add_fd(exec_ctx, item, bag->fds[i]);
+      bag->fds[j++] = bag->fds[i];
+    }
+  }
+  bag->fd_count = j;
+  gpr_mu_unlock(&bag->mu);
+}
+
+void grpc_pollset_set_del_pollset_set(grpc_exec_ctx *exec_ctx,
+                                      grpc_pollset_set *bag,
+                                      grpc_pollset_set *item) {
+  size_t i;
+  gpr_mu_lock(&bag->mu);
+  for (i = 0; i < bag->pollset_set_count; i++) {
+    if (bag->pollset_sets[i] == item) {
+      bag->pollset_set_count--;
+      GPR_SWAP(grpc_pollset_set *, bag->pollset_sets[i],
+               bag->pollset_sets[bag->pollset_set_count]);
+      break;
+    }
+  }
+  gpr_mu_unlock(&bag->mu);
+}
+
 void grpc_pollset_set_add_fd(grpc_exec_ctx *exec_ctx,
                              grpc_pollset_set *pollset_set, grpc_fd *fd) {
   size_t i;
@@ -113,6 +154,9 @@ void grpc_pollset_set_add_fd(grpc_exec_ctx *exec_ctx,
   for (i = 0; i < pollset_set->pollset_count; i++) {
     grpc_pollset_add_fd(exec_ctx, pollset_set->pollsets[i], fd);
   }
+  for (i = 0; i < pollset_set->pollset_set_count; i++) {
+    grpc_pollset_set_add_fd(exec_ctx, pollset_set->pollset_sets[i], fd);
+  }
   gpr_mu_unlock(&pollset_set->mu);
 }
 
@@ -129,6 +173,9 @@ void grpc_pollset_set_del_fd(grpc_exec_ctx *exec_ctx,
       break;
     }
   }
+  for (i = 0; i < pollset_set->pollset_set_count; i++) {
+    grpc_pollset_set_del_fd(exec_ctx, pollset_set->pollset_sets[i], fd);
+  }
   gpr_mu_unlock(&pollset_set->mu);
 }
 

src/core/iomgr/pollset_set_posix.h

@@ -44,6 +44,10 @@ typedef struct grpc_pollset_set {
   size_t pollset_capacity;
   grpc_pollset **pollsets;
 
+  size_t pollset_set_count;
+  size_t pollset_set_capacity;
+  struct grpc_pollset_set **pollset_sets;
+
   size_t fd_count;
   size_t fd_capacity;
   grpc_fd **fds;

src/core/iomgr/pollset_set_windows.c

@@ -49,4 +49,12 @@ void grpc_pollset_set_del_pollset(grpc_exec_ctx* exec_ctx,
                                   grpc_pollset_set* pollset_set,
                                   grpc_pollset* pollset) {}
 
+void grpc_pollset_set_add_pollset_set(grpc_exec_ctx* exec_ctx,
+                                      grpc_pollset_set* bag,
+                                      grpc_pollset_set* item) {}
+
+void grpc_pollset_set_del_pollset_set(grpc_exec_ctx* exec_ctx,
+                                      grpc_pollset_set* bag,
+                                      grpc_pollset_set* item) {}
+
 #endif /* GPR_WINSOCK_SOCKET */

src/core/iomgr/tcp_server_posix.c

@@ -532,8 +532,12 @@ void grpc_tcp_server_start(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s,
 }
 
 int grpc_tcp_listener_get_port(grpc_tcp_listener *listener) {
-  grpc_tcp_listener *sp = listener;
-  return sp->port;
+  if (listener != NULL) {
+    grpc_tcp_listener *sp = listener;
+    return sp->port;
+  } else {
+    return 0;
+  }
 }
 
 void grpc_tcp_listener_ref(grpc_tcp_listener *listener) {

src/core/iomgr/tcp_server_windows.c

@@ -486,8 +486,12 @@ void grpc_tcp_server_start(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s,
 }
 
 int grpc_tcp_listener_get_port(grpc_tcp_listener *listener) {
-  grpc_tcp_listener *sp = listener;
-  return sp->port;
+  if (listener != NULL) {
+    grpc_tcp_listener *sp = listener;
+    return sp->port;
+  } else {
+    return 0;
+  }
 }
 
 void grpc_tcp_listener_ref(grpc_tcp_listener *listener) {

src/core/iomgr/tcp_windows.c

@@ -197,7 +197,8 @@ static void win_read(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
 
   tcp->read_slice = gpr_slice_malloc(8192);
 
-  buffer.len = GPR_SLICE_LENGTH(tcp->read_slice);
+  buffer.len = (ULONG)GPR_SLICE_LENGTH(
+      tcp->read_slice);  // we know slice size fits in 32bit.
   buffer.buf = (char *)GPR_SLICE_START_PTR(tcp->read_slice);
 
   TCP_REF(tcp, "read");
@@ -273,6 +274,7 @@ static void win_write(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
   WSABUF local_buffers[16];
   WSABUF *allocated = NULL;
   WSABUF *buffers = local_buffers;
+  size_t len;
 
   if (tcp->shutting_down) {
     grpc_exec_ctx_enqueue(exec_ctx, cb, 0);
@@ -281,19 +283,21 @@ static void win_write(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
 
   tcp->write_cb = cb;
   tcp->write_slices = slices;
-
+  GPR_ASSERT(tcp->write_slices->count <= UINT_MAX);
   if (tcp->write_slices->count > GPR_ARRAY_SIZE(local_buffers)) {
     buffers = (WSABUF *)gpr_malloc(sizeof(WSABUF) * tcp->write_slices->count);
     allocated = buffers;
   }
 
   for (i = 0; i < tcp->write_slices->count; i++) {
-    buffers[i].len = GPR_SLICE_LENGTH(tcp->write_slices->slices[i]);
+    len = GPR_SLICE_LENGTH(tcp->write_slices->slices[i]);
+    GPR_ASSERT(len <= ULONG_MAX);
+    buffers[i].len = (ULONG)len;
     buffers[i].buf = (char *)GPR_SLICE_START_PTR(tcp->write_slices->slices[i]);
   }
 
   /* First, let's try a synchronous, non-blocking write. */
-  status = WSASend(socket->socket, buffers, tcp->write_slices->count,
+  status = WSASend(socket->socket, buffers, (DWORD)tcp->write_slices->count,
                    &bytes_sent, 0, NULL, NULL);
   info->wsa_error = status == 0 ? 0 : WSAGetLastError();
 
@@ -322,7 +326,7 @@ static void win_write(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
   /* If we got a WSAEWOULDBLOCK earlier, then we need to re-do the same
      operation, this time asynchronously. */
   memset(&socket->write_info.overlapped, 0, sizeof(OVERLAPPED));
-  status = WSASend(socket->socket, buffers, tcp->write_slices->count,
+  status = WSASend(socket->socket, buffers, (DWORD)tcp->write_slices->count,
                    &bytes_sent, 0, &socket->write_info.overlapped, NULL);
   if (allocated) gpr_free(allocated);
 

src/core/iomgr/timer.c

@@ -126,8 +126,8 @@ static double ts_to_dbl(gpr_timespec ts) {
 
 static gpr_timespec dbl_to_ts(double d) {
   gpr_timespec ts;
-  ts.tv_sec = (time_t)d;
-  ts.tv_nsec = (int)(1e9 * (d - (double)ts.tv_sec));
+  ts.tv_sec = (gpr_int64)d;
+  ts.tv_nsec = (gpr_int32)(1e9 * (d - (double)ts.tv_sec));
   ts.clock_type = GPR_TIMESPAN;
   return ts;
 }
@@ -343,11 +343,3 @@ int grpc_timer_check(grpc_exec_ctx *exec_ctx, gpr_timespec now,
       exec_ctx, now, next,
       gpr_time_cmp(now, gpr_inf_future(now.clock_type)) != 0);
 }
-
-gpr_timespec grpc_timer_list_next_timeout(void) {
-  gpr_timespec out;
-  gpr_mu_lock(&g_mu);
-  out = g_shard_queue[0]->min_deadline;
-  gpr_mu_unlock(&g_mu);
-  return out;
-}

src/core/iomgr/timer_internal.h

@@ -54,8 +54,6 @@ int grpc_timer_check(grpc_exec_ctx* exec_ctx, gpr_timespec now,
 void grpc_timer_list_init(gpr_timespec now);
 void grpc_timer_list_shutdown(grpc_exec_ctx* exec_ctx);
 
-gpr_timespec grpc_timer_list_next_timeout(void);
-
 /* the following must be implemented by each iomgr implementation */
 
 void grpc_kick_poller(void);

src/core/iomgr/udp_server.c

@@ -38,6 +38,7 @@
 
 #include <grpc/support/port_platform.h>
 
+#ifdef GRPC_NEED_UDP
 #ifdef GPR_POSIX_SOCKET
 
 #include "src/core/iomgr/udp_server.h"
@@ -435,3 +436,4 @@ void grpc_udp_server_write(server_port *sp, const char *buffer, size_t buf_len,
 }
 
 #endif
+#endif

src/core/iomgr/wakeup_fd_posix.c

@@ -40,19 +40,17 @@
 #include <stddef.h>
 
 static const grpc_wakeup_fd_vtable *wakeup_fd_vtable = NULL;
+int grpc_allow_specialized_wakeup_fd = 1;
 
 void grpc_wakeup_fd_global_init(void) {
-  if (grpc_specialized_wakeup_fd_vtable.check_availability()) {
+  if (grpc_allow_specialized_wakeup_fd &&
+      grpc_specialized_wakeup_fd_vtable.check_availability()) {
     wakeup_fd_vtable = &grpc_specialized_wakeup_fd_vtable;
   } else {
     wakeup_fd_vtable = &grpc_pipe_wakeup_fd_vtable;
   }
 }
 
-void grpc_wakeup_fd_global_init_force_fallback(void) {
-  wakeup_fd_vtable = &grpc_pipe_wakeup_fd_vtable;
-}
-
 void grpc_wakeup_fd_global_destroy(void) { wakeup_fd_vtable = NULL; }
 
 void grpc_wakeup_fd_init(grpc_wakeup_fd *fd_info) {

src/core/iomgr/wakeup_fd_posix.h

@@ -85,6 +85,8 @@ struct grpc_wakeup_fd {
   int write_fd;
 };
 
+extern int grpc_allow_specialized_wakeup_fd;
+
 #define GRPC_WAKEUP_FD_GET_READ_FD(fd_info) ((fd_info)->read_fd)
 
 void grpc_wakeup_fd_init(grpc_wakeup_fd* fd_info);

src/core/iomgr/workqueue_posix.c

@@ -103,6 +103,9 @@ void grpc_workqueue_add_to_pollset(grpc_exec_ctx *exec_ctx,
 
 void grpc_workqueue_flush(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue) {
   gpr_mu_lock(&workqueue->mu);
+  if (grpc_closure_list_empty(workqueue->closure_list)) {
+    grpc_wakeup_fd_wakeup(&workqueue->wakeup_fd);
+  }
   grpc_closure_list_move(&exec_ctx->closure_list, &workqueue->closure_list);
   gpr_mu_unlock(&workqueue->mu);
 }

src/core/json/json_reader.c

@@ -35,6 +35,8 @@
 
 #include <grpc/support/port_platform.h>
 
+#include <grpc/support/log.h>
+
 #include "src/core/json/json_reader.h"
 
 static void json_reader_string_clear(grpc_json_reader *reader) {
@@ -224,13 +226,13 @@ grpc_json_reader_status grpc_json_reader_run(grpc_json_reader *reader) {
                   reader->in_array = 1;
                   break;
                 case GRPC_JSON_TOP_LEVEL:
-                  if (reader->depth != 0) return GRPC_JSON_INTERNAL_ERROR;
+                  GPR_ASSERT(reader->depth == 0);
                   reader->in_object = 0;
                   reader->in_array = 0;
                   reader->state = GRPC_JSON_STATE_END;
                   break;
                 default:
-                  return GRPC_JSON_INTERNAL_ERROR;
+                  GPR_UNREACHABLE_CODE(return GRPC_JSON_INTERNAL_ERROR);
               }
             }
             break;
@@ -279,8 +281,7 @@ grpc_json_reader_status grpc_json_reader_run(grpc_json_reader *reader) {
             break;
 
           case GRPC_JSON_STATE_OBJECT_KEY_STRING:
-            if (reader->unicode_high_surrogate != 0)
-              return GRPC_JSON_PARSE_ERROR;
+            GPR_ASSERT(reader->unicode_high_surrogate == 0);
             if (c == '"') {
               reader->state = GRPC_JSON_STATE_OBJECT_KEY_END;
               json_reader_set_key(reader);
@@ -461,7 +462,7 @@ grpc_json_reader_status grpc_json_reader_run(grpc_json_reader *reader) {
                 }
                 break;
               default:
-                return GRPC_JSON_INTERNAL_ERROR;
+                GPR_UNREACHABLE_CODE(return GRPC_JSON_INTERNAL_ERROR);
             }
             break;
 
@@ -641,7 +642,7 @@ grpc_json_reader_status grpc_json_reader_run(grpc_json_reader *reader) {
               case ',':
               case '}':
               case ']':
-                return GRPC_JSON_INTERNAL_ERROR;
+                GPR_UNREACHABLE_CODE(return GRPC_JSON_INTERNAL_ERROR);
                 break;
 
               default:
@@ -655,5 +656,5 @@ grpc_json_reader_status grpc_json_reader_run(grpc_json_reader *reader) {
     }
   }
 
-  return GRPC_JSON_INTERNAL_ERROR;
+  GPR_UNREACHABLE_CODE(return GRPC_JSON_INTERNAL_ERROR);
 }

src/core/json/json_string.c

@@ -353,7 +353,7 @@ static void json_dump_recursive(grpc_json_writer *writer, grpc_json *json,
         grpc_json_writer_value_raw_with_len(writer, "null", 4);
         break;
       default:
-        abort();
+        GPR_UNREACHABLE_CODE(abort());
     }
     json = json->next;
   }

src/core/profiling/basic_timers.c

@@ -141,10 +141,11 @@ static void write_log(gpr_timer_log *log) {
       entry->tm = gpr_time_0(entry->tm.clock_type);
     }
     fprintf(output_file,
-            "{\"t\": %ld.%09d, \"thd\": \"%d\", \"type\": \"%c\", \"tag\": "
+            "{\"t\": %lld.%09d, \"thd\": \"%d\", \"type\": \"%c\", \"tag\": "
             "\"%s\", \"file\": \"%s\", \"line\": %d, \"imp\": %d}\n",
-            entry->tm.tv_sec, entry->tm.tv_nsec, entry->thd, entry->type,
-            entry->tagstr, entry->file, entry->line, entry->important);
+            (long long)entry->tm.tv_sec, (int)entry->tm.tv_nsec, entry->thd,
+            entry->type, entry->tagstr, entry->file, entry->line,
+            entry->important);
   }
 }
 

src/core/security/credentials.c

@@ -39,7 +39,7 @@
 #include "src/core/channel/channel_args.h"
 #include "src/core/channel/http_client_filter.h"
 #include "src/core/httpcli/httpcli.h"
-#include "src/core/iomgr/iomgr.h"
+#include "src/core/iomgr/executor.h"
 #include "src/core/json/json.h"
 #include "src/core/support/string.h"
 #include "src/core/surface/api_trace.h"
@@ -48,7 +48,6 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 #include <grpc/support/sync.h>
-#include <grpc/support/thd.h>
 #include <grpc/support/time.h>
 
 /* -- Common. -- */
@@ -511,10 +510,11 @@ grpc_call_credentials *grpc_service_account_jwt_access_credentials_create(
       "grpc_service_account_jwt_access_credentials_create("
       "json_key=%s, "
       "token_lifetime="
-      "gpr_timespec { tv_sec: %ld, tv_nsec: %d, clock_type: %d }, "
+      "gpr_timespec { tv_sec: %lld, tv_nsec: %d, clock_type: %d }, "
       "reserved=%p)",
-      5, (json_key, (long)token_lifetime.tv_sec, token_lifetime.tv_nsec,
-          (int)token_lifetime.clock_type, reserved));
+      5,
+      (json_key, (long long)token_lifetime.tv_sec, (int)token_lifetime.tv_nsec,
+       (int)token_lifetime.clock_type, reserved));
   GPR_ASSERT(reserved == NULL);
   return grpc_service_account_jwt_access_credentials_create_from_auth_json_key(
       grpc_auth_json_key_create_from_string(json_key), token_lifetime);
@@ -792,15 +792,14 @@ static void md_only_test_destruct(grpc_call_credentials *creds) {
   grpc_credentials_md_store_unref(c->md_store);
 }
 
-static void on_simulated_token_fetch_done(void *user_data) {
+static void on_simulated_token_fetch_done(grpc_exec_ctx *exec_ctx,
+                                          void *user_data, int success) {
   grpc_credentials_metadata_request *r =
       (grpc_credentials_metadata_request *)user_data;
   grpc_md_only_test_credentials *c = (grpc_md_only_test_credentials *)r->creds;
-  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
-  r->cb(&exec_ctx, r->user_data, c->md_store->entries, c->md_store->num_entries,
+  r->cb(exec_ctx, r->user_data, c->md_store->entries, c->md_store->num_entries,
         GRPC_CREDENTIALS_OK);
   grpc_credentials_metadata_request_destroy(r);
-  grpc_exec_ctx_finish(&exec_ctx);
 }
 
 static void md_only_test_get_request_metadata(
@@ -810,10 +809,10 @@ static void md_only_test_get_request_metadata(
   grpc_md_only_test_credentials *c = (grpc_md_only_test_credentials *)creds;
 
   if (c->is_async) {
-    gpr_thd_id thd_id;
     grpc_credentials_metadata_request *cb_arg =
         grpc_credentials_metadata_request_create(creds, cb, user_data);
-    gpr_thd_new(&thd_id, on_simulated_token_fetch_done, cb_arg, NULL);
+    grpc_executor_enqueue(
+        grpc_closure_create(on_simulated_token_fetch_done, cb_arg), 1);
   } else {
     cb(exec_ctx, user_data, c->md_store->entries, 1, GRPC_CREDENTIALS_OK);
   }

src/core/security/credentials.h

@@ -93,6 +93,14 @@ typedef enum {
 /* It is the caller's responsibility to gpr_free the result if not NULL. */
 char *grpc_get_well_known_google_credentials_file_path(void);
 
+/* Implementation function for the different platforms. */
+char *grpc_get_well_known_google_credentials_file_path_impl(void);
+
+/* Override for testing only. Not thread-safe */
+typedef char *(*grpc_well_known_credentials_path_getter)(void);
+void grpc_override_well_known_credentials_path_getter(
+    grpc_well_known_credentials_path_getter getter);
+
 /* --- grpc_channel_credentials. --- */
 
 typedef struct {
@@ -201,6 +209,7 @@ grpc_credentials_status
 grpc_oauth2_token_fetcher_credentials_parse_server_response(
     const struct grpc_httpcli_response *response,
     grpc_credentials_md_store **token_md, gpr_timespec *token_lifetime);
+
 void grpc_flush_cached_google_default_credentials(void);
 
 /* Metadata-only credentials with the specified key and value where

src/core/security/credentials_posix.c

@@ -44,7 +44,7 @@
 #include "src/core/support/env.h"
 #include "src/core/support/string.h"
 
-char *grpc_get_well_known_google_credentials_file_path(void) {
+char *grpc_get_well_known_google_credentials_file_path_impl(void) {
   char *result = NULL;
   char *home = gpr_getenv("HOME");
   if (home == NULL) {

src/core/security/credentials_win32.c

@@ -44,7 +44,7 @@
 #include "src/core/support/env.h"
 #include "src/core/support/string.h"
 
-char *grpc_get_well_known_google_credentials_file_path(void) {
+char *grpc_get_well_known_google_credentials_file_path_impl(void) {
   char *result = NULL;
   char *appdata_path = gpr_getenv("APPDATA");
   if (appdata_path == NULL) {

src/core/security/google_default_credentials.c

@@ -241,5 +241,20 @@ void grpc_flush_cached_google_default_credentials(void) {
     grpc_channel_credentials_unref(default_credentials);
     default_credentials = NULL;
   }
+  compute_engine_detection_done = 0;
   gpr_mu_unlock(&g_mu);
 }
+
+/* -- Well known credentials path. -- */
+
+static grpc_well_known_credentials_path_getter creds_path_getter = NULL;
+
+char *grpc_get_well_known_google_credentials_file_path(void) {
+  if (creds_path_getter != NULL) return creds_path_getter();
+  return grpc_get_well_known_google_credentials_file_path_impl();
+}
+
+void grpc_override_well_known_credentials_path_getter(
+    grpc_well_known_credentials_path_getter getter) {
+  creds_path_getter = getter;
+}

src/core/security/json_token.c

@@ -215,8 +215,8 @@ static char *encoded_jwt_claim(const grpc_auth_json_key *json_key,
     gpr_log(GPR_INFO, "Cropping token lifetime to maximum allowed value.");
     expiration = gpr_time_add(now, grpc_max_auth_token_lifetime);
   }
-  gpr_ltoa(now.tv_sec, now_str);
-  gpr_ltoa(expiration.tv_sec, expiration_str);
+  gpr_int64toa(now.tv_sec, now_str);
+  gpr_int64toa(expiration.tv_sec, expiration_str);
 
   child =
       create_child(NULL, json, "iss", json_key->client_email, GRPC_JSON_STRING);

src/core/security/server_secure_chttp2.c

@@ -209,7 +209,7 @@ int grpc_server_add_secure_http2_port(grpc_server *server, const char *addr,
         tcp, (struct sockaddr *)&resolved->addrs[i].addr,
         resolved->addrs[i].len);
     port_temp = grpc_tcp_listener_get_port(listener);
-    if (port_temp >= 0) {
+    if (port_temp > 0) {
       if (port_num == -1) {
         port_num = port_temp;
       } else {

src/core/statistics/window_stats.c

@@ -94,7 +94,7 @@ static gpr_int64 timespec_to_ns(const gpr_timespec ts) {
   if (ts.tv_sec > max_seconds) {
     return GPR_INT64_MAX - 1;
   }
-  return (gpr_int64)ts.tv_sec * GPR_NS_PER_SEC + ts.tv_nsec;
+  return ts.tv_sec * GPR_NS_PER_SEC + ts.tv_nsec;
 }
 
 static void cws_initialize_statistic(void *statistic,

src/core/support/cmdline.c

@@ -62,11 +62,13 @@ struct gpr_cmdline {
   void (*extra_arg)(void *user_data, const char *arg);
   void *extra_arg_user_data;
 
-  void (*state)(gpr_cmdline *cl, char *arg);
+  int (*state)(gpr_cmdline *cl, char *arg);
   arg *cur_arg;
+
+  int survive_failure;
 };
 
-static void normal_state(gpr_cmdline *cl, char *arg);
+static int normal_state(gpr_cmdline *cl, char *arg);
 
 gpr_cmdline *gpr_cmdline_create(const char *description) {
   gpr_cmdline *cl = gpr_malloc(sizeof(gpr_cmdline));
@@ -78,6 +80,10 @@ gpr_cmdline *gpr_cmdline_create(const char *description) {
   return cl;
 }
 
+void gpr_cmdline_set_survive_failure(gpr_cmdline *cl) {
+  cl->survive_failure = 1;
+}
+
 void gpr_cmdline_destroy(gpr_cmdline *cl) {
   while (cl->args) {
     arg *a = cl->args;
@@ -185,16 +191,22 @@ char *gpr_cmdline_usage_string(gpr_cmdline *cl, const char *argv0) {
   return tmp;
 }
 
-static void print_usage_and_die(gpr_cmdline *cl) {
+static int print_usage_and_die(gpr_cmdline *cl) {
   char *usage = gpr_cmdline_usage_string(cl, cl->argv0);
   fprintf(stderr, "%s", usage);
   gpr_free(usage);
-  exit(1);
+  if (!cl->survive_failure) {
+    exit(1);
+  }
+  return 0;
 }
 
-static void extra_state(gpr_cmdline *cl, char *str) {
-  if (!cl->extra_arg) print_usage_and_die(cl);
+static int extra_state(gpr_cmdline *cl, char *str) {
+  if (!cl->extra_arg) {
+    return print_usage_and_die(cl);
+  }
   cl->extra_arg(cl->extra_arg_user_data, str);
+  return 1;
 }
 
 static arg *find_arg(gpr_cmdline *cl, char *name) {
@@ -208,13 +220,13 @@ static arg *find_arg(gpr_cmdline *cl, char *name) {
 
   if (!a) {
     fprintf(stderr, "Unknown argument: %s\n", name);
-    print_usage_and_die(cl);
+    return NULL;
   }
 
   return a;
 }
 
-static void value_state(gpr_cmdline *cl, char *str) {
+static int value_state(gpr_cmdline *cl, char *str) {
   long intval;
   char *end;
 
@@ -226,7 +238,7 @@ static void value_state(gpr_cmdline *cl, char *str) {
       if (*end || intval < INT_MIN || intval > INT_MAX) {
         fprintf(stderr, "expected integer, got '%s' for %s\n", str,
                 cl->cur_arg->name);
-        print_usage_and_die(cl);
+        return print_usage_and_die(cl);
       }
       *(int *)cl->cur_arg->value = (int)intval;
       break;
@@ -238,7 +250,7 @@ static void value_state(gpr_cmdline *cl, char *str) {
       } else {
         fprintf(stderr, "expected boolean, got '%s' for %s\n", str,
                 cl->cur_arg->name);
-        print_usage_and_die(cl);
+        return print_usage_and_die(cl);
       }
       break;
     case ARGTYPE_STRING:
@@ -247,16 +259,18 @@ static void value_state(gpr_cmdline *cl, char *str) {
   }
 
   cl->state = normal_state;
+  return 1;
 }
 
-static void normal_state(gpr_cmdline *cl, char *str) {
+static int normal_state(gpr_cmdline *cl, char *str) {
   char *eq = NULL;
   char *tmp = NULL;
   char *arg_name = NULL;
+  int r = 1;
 
   if (0 == strcmp(str, "-help") || 0 == strcmp(str, "--help") ||
       0 == strcmp(str, "-h")) {
-    print_usage_and_die(cl);
+    return print_usage_and_die(cl);
   }
 
   cl->cur_arg = NULL;
@@ -266,7 +280,7 @@ static void normal_state(gpr_cmdline *cl, char *str) {
       if (str[2] == 0) {
         /* handle '--' to move to just extra args */
         cl->state = extra_state;
-        return;
+        return 1;
       }
       str += 2;
     } else {
@@ -277,12 +291,15 @@ static void normal_state(gpr_cmdline *cl, char *str) {
       /* str is of the form '--no-foo' - it's a flag disable */
       str += 3;
       cl->cur_arg = find_arg(cl, str);
+      if (cl->cur_arg == NULL) {
+        return print_usage_and_die(cl);
+      }
       if (cl->cur_arg->type != ARGTYPE_BOOL) {
         fprintf(stderr, "%s is not a flag argument\n", str);
-        print_usage_and_die(cl);
+        return print_usage_and_die(cl);
       }
       *(int *)cl->cur_arg->value = 0;
-      return; /* early out */
+      return 1; /* early out */
     }
     eq = strchr(str, '=');
     if (eq != NULL) {
@@ -294,9 +311,12 @@ static void normal_state(gpr_cmdline *cl, char *str) {
       arg_name = str;
     }
     cl->cur_arg = find_arg(cl, arg_name);
+    if (cl->cur_arg == NULL) {
+      return print_usage_and_die(cl);
+    }
     if (eq != NULL) {
       /* str was of the type --foo=value, parse the value */
-      value_state(cl, eq + 1);
+      r = value_state(cl, eq + 1);
     } else if (cl->cur_arg->type != ARGTYPE_BOOL) {
       /* flag types don't have a '--foo value' variant, other types do */
       cl->state = value_state;
@@ -305,19 +325,23 @@ static void normal_state(gpr_cmdline *cl, char *str) {
       *(int *)cl->cur_arg->value = 1;
     }
   } else {
-    extra_state(cl, str);
+    r = extra_state(cl, str);
   }
 
   gpr_free(tmp);
+  return r;
 }
 
-void gpr_cmdline_parse(gpr_cmdline *cl, int argc, char **argv) {
+int gpr_cmdline_parse(gpr_cmdline *cl, int argc, char **argv) {
   int i;
 
   GPR_ASSERT(argc >= 1);
   cl->argv0 = argv[0];
 
   for (i = 1; i < argc; i++) {
-    cl->state(cl, argv[i]);
+    if (!cl->state(cl, argv[i])) {
+      return 0;
+    }
   }
+  return 1;
 }

src/core/support/log_linux.c

@@ -76,16 +76,18 @@ void gpr_default_log(gpr_log_func_args *args) {
   char *prefix;
   const char *display_file;
   char time_buffer[64];
+  time_t timer;
   gpr_timespec now = gpr_now(GPR_CLOCK_REALTIME);
   struct tm tm;
 
+  timer = (time_t)now.tv_sec;
   final_slash = strrchr(args->file, '/');
   if (final_slash == NULL)
     display_file = args->file;
   else
     display_file = final_slash + 1;
 
-  if (!localtime_r(&now.tv_sec, &tm)) {
+  if (!localtime_r(&timer, &tm)) {
     strcpy(time_buffer, "error:localtime");
   } else if (0 ==
              strftime(time_buffer, sizeof(time_buffer), "%m%d %H:%M:%S", &tm)) {

src/core/support/log_posix.c

@@ -75,16 +75,18 @@ void gpr_default_log(gpr_log_func_args *args) {
   char *final_slash;
   const char *display_file;
   char time_buffer[64];
+  time_t timer;
   gpr_timespec now = gpr_now(GPR_CLOCK_REALTIME);
   struct tm tm;
 
+  timer = (time_t)now.tv_sec;
   final_slash = strrchr(args->file, '/');
   if (final_slash == NULL)
     display_file = args->file;
   else
     display_file = final_slash + 1;
 
-  if (!localtime_r(&now.tv_sec, &tm)) {
+  if (!localtime_r(&timer, &tm)) {
     strcpy(time_buffer, "error:localtime");
   } else if (0 ==
              strftime(time_buffer, sizeof(time_buffer), "%m%d %H:%M:%S", &tm)) {

src/core/support/log_win32.c

@@ -84,16 +84,18 @@ void gpr_default_log(gpr_log_func_args *args) {
   char *final_slash;
   const char *display_file;
   char time_buffer[64];
+  time_t timer;
   gpr_timespec now = gpr_now(GPR_CLOCK_REALTIME);
   struct tm tm;
 
+  timer = (time_t)now.tv_sec;
   final_slash = strrchr(args->file, '\\');
   if (final_slash == NULL)
     display_file = args->file;
   else
     display_file = final_slash + 1;
 
-  if (localtime_s(&tm, &now.tv_sec)) {
+  if (localtime_s(&tm, &timer)) {
     strcpy(time_buffer, "error:localtime");
   } else if (0 ==
              strftime(time_buffer, sizeof(time_buffer), "%m%d %H:%M:%S", &tm)) {
@@ -104,6 +106,7 @@ void gpr_default_log(gpr_log_func_args *args) {
           gpr_log_severity_string(args->severity), time_buffer,
           (int)(now.tv_nsec), GetCurrentThreadId(), display_file, args->line,
           args->message);
+  fflush(stderr);
 }
 
 char *gpr_format_message(DWORD messageid) {

src/core/support/stack_lockfree.c

@@ -128,8 +128,8 @@ int gpr_stack_lockfree_push(gpr_stack_lockfree *stack, int entry) {
     gpr_atm old_val;
 
     old_val = gpr_atm_no_barrier_fetch_add(&stack->pushed[pushed_index],
-                                           (gpr_atm)(1UL << pushed_bit));
-    GPR_ASSERT((old_val & (gpr_atm)(1UL << pushed_bit)) == 0);
+                                           ((gpr_atm)1 << pushed_bit));
+    GPR_ASSERT((old_val & (((gpr_atm)1) << pushed_bit)) == 0);
   }
 #endif
 
@@ -166,8 +166,8 @@ int gpr_stack_lockfree_pop(gpr_stack_lockfree *stack) {
     gpr_atm old_val;
 
     old_val = gpr_atm_no_barrier_fetch_add(&stack->pushed[pushed_index],
-                                           -(gpr_atm)(1UL << pushed_bit));
-    GPR_ASSERT((old_val & (gpr_atm)(1UL << pushed_bit)) != 0);
+                                           -((gpr_atm)1 << pushed_bit));
+    GPR_ASSERT((old_val & (((gpr_atm)1) << pushed_bit)) != 0);
   }
 #endif
 

src/core/support/string.c

@@ -153,8 +153,8 @@ void gpr_reverse_bytes(char *str, int len) {
 }
 
 int gpr_ltoa(long value, char *string) {
+  long sign;
   int i = 0;
-  int neg = value < 0;
 
   if (value == 0) {
     string[0] = '0';
@@ -162,12 +162,33 @@ int gpr_ltoa(long value, char *string) {
     return 1;
   }
 
-  if (neg) value = -value;
+  sign = value < 0 ? -1 : 1;
   while (value) {
-    string[i++] = (char)('0' + value % 10);
+    string[i++] = (char)('0' + sign * (value % 10));
     value /= 10;
   }
-  if (neg) string[i++] = '-';
+  if (sign < 0) string[i++] = '-';
+  gpr_reverse_bytes(string, i);
+  string[i] = 0;
+  return i;
+}
+
+int gpr_int64toa(gpr_int64 value, char *string) {
+  gpr_int64 sign;
+  int i = 0;
+
+  if (value == 0) {
+    string[0] = '0';
+    string[1] = 0;
+    return 1;
+  }
+
+  sign = value < 0 ? -1 : 1;
+  while (value) {
+    string[i++] = (char)('0' + sign * (value % 10));
+    value /= 10;
+  }
+  if (sign < 0) string[i++] = '-';
   gpr_reverse_bytes(string, i);
   string[i] = 0;
   return i;

src/core/support/string.h

@@ -70,6 +70,16 @@ int gpr_parse_bytes_to_uint32(const char *data, size_t length,
    output must be at least GPR_LTOA_MIN_BUFSIZE bytes long. */
 int gpr_ltoa(long value, char *output);
 
+/* Minimum buffer size for calling int64toa */
+#define GPR_INT64TOA_MIN_BUFSIZE (3 * sizeof(gpr_int64))
+
+/* Convert an int64 to a string in base 10; returns the length of the
+output string (or 0 on failure).
+output must be at least GPR_INT64TOA_MIN_BUFSIZE bytes long.
+NOTE: This function ensures sufficient bit width even on Win x64,
+where long is 32bit is size.*/
+int gpr_int64toa(gpr_int64 value, char *output);
+
 /* Reverse a run of bytes */
 void gpr_reverse_bytes(char *str, int len);
 

src/core/support/time.c

@@ -56,22 +56,6 @@ gpr_timespec gpr_time_max(gpr_timespec a, gpr_timespec b) {
   return gpr_time_cmp(a, b) > 0 ? a : b;
 }
 
-/* There's no standard TIME_T_MIN and TIME_T_MAX, so we construct them.  The
-   following assumes that signed types are two's-complement and that bytes are
-   8 bits.  */
-
-/* The top bit of integral type t. */
-#define TOP_BIT_OF_TYPE(t) (((gpr_uintmax)1) << ((8 * sizeof(t)) - 1))
-
-/* Return whether integral type t is signed. */
-#define TYPE_IS_SIGNED(t) (((t)1) > (t) ~(t)0)
-
-/* The minimum and maximum value of integral type t. */
-#define TYPE_MIN(t) ((t)(TYPE_IS_SIGNED(t) ? TOP_BIT_OF_TYPE(t) : 0))
-#define TYPE_MAX(t)                                 \
-  ((t)(TYPE_IS_SIGNED(t) ? (TOP_BIT_OF_TYPE(t) - 1) \
-                         : ((TOP_BIT_OF_TYPE(t) - 1) << 1) + 1))
-
 gpr_timespec gpr_time_0(gpr_clock_type type) {
   gpr_timespec out;
   out.tv_sec = 0;
@@ -82,7 +66,7 @@ gpr_timespec gpr_time_0(gpr_clock_type type) {
 
 gpr_timespec gpr_inf_future(gpr_clock_type type) {
   gpr_timespec out;
-  out.tv_sec = TYPE_MAX(time_t);
+  out.tv_sec = INT64_MAX;
   out.tv_nsec = 0;
   out.clock_type = type;
   return out;
@@ -90,7 +74,7 @@ gpr_timespec gpr_inf_future(gpr_clock_type type) {
 
 gpr_timespec gpr_inf_past(gpr_clock_type type) {
   gpr_timespec out;
-  out.tv_sec = TYPE_MIN(time_t);
+  out.tv_sec = INT64_MIN;
   out.tv_nsec = 0;
   out.clock_type = type;
   return out;
@@ -108,11 +92,11 @@ gpr_timespec gpr_time_from_nanos(long ns, gpr_clock_type type) {
     result = gpr_inf_past(type);
   } else if (ns >= 0) {
     result.tv_sec = ns / GPR_NS_PER_SEC;
-    result.tv_nsec = (int)(ns - result.tv_sec * GPR_NS_PER_SEC);
+    result.tv_nsec = (gpr_int32)(ns - result.tv_sec * GPR_NS_PER_SEC);
   } else {
     /* Calculation carefully formulated to avoid any possible under/overflow. */
     result.tv_sec = (-(999999999 - (ns + GPR_NS_PER_SEC)) / GPR_NS_PER_SEC) - 1;
-    result.tv_nsec = (int)(ns - result.tv_sec * GPR_NS_PER_SEC);
+    result.tv_nsec = (gpr_int32)(ns - result.tv_sec * GPR_NS_PER_SEC);
   }
   return result;
 }
@@ -126,11 +110,11 @@ gpr_timespec gpr_time_from_micros(long us, gpr_clock_type type) {
     result = gpr_inf_past(type);
   } else if (us >= 0) {
     result.tv_sec = us / 1000000;
-    result.tv_nsec = (int)((us - result.tv_sec * 1000000) * 1000);
+    result.tv_nsec = (gpr_int32)((us - result.tv_sec * 1000000) * 1000);
   } else {
     /* Calculation carefully formulated to avoid any possible under/overflow. */
     result.tv_sec = (-(999999 - (us + 1000000)) / 1000000) - 1;
-    result.tv_nsec = (int)((us - result.tv_sec * 1000000) * 1000);
+    result.tv_nsec = (gpr_int32)((us - result.tv_sec * 1000000) * 1000);
   }
   return result;
 }
@@ -144,11 +128,11 @@ gpr_timespec gpr_time_from_millis(long ms, gpr_clock_type type) {
     result = gpr_inf_past(type);
   } else if (ms >= 0) {
     result.tv_sec = ms / 1000;
-    result.tv_nsec = (int)((ms - result.tv_sec * 1000) * 1000000);
+    result.tv_nsec = (gpr_int32)((ms - result.tv_sec * 1000) * 1000000);
   } else {
     /* Calculation carefully formulated to avoid any possible under/overflow. */
     result.tv_sec = (-(999 - (ms + 1000)) / 1000) - 1;
-    result.tv_nsec = (int)((ms - result.tv_sec * 1000) * 1000000);
+    result.tv_nsec = (gpr_int32)((ms - result.tv_sec * 1000) * 1000000);
   }
   return result;
 }
@@ -197,7 +181,7 @@ gpr_timespec gpr_time_from_hours(long h, gpr_clock_type type) {
 
 gpr_timespec gpr_time_add(gpr_timespec a, gpr_timespec b) {
   gpr_timespec sum;
-  int inc = 0;
+  gpr_int64 inc = 0;
   GPR_ASSERT(b.clock_type == GPR_TIMESPAN);
   sum.clock_type = a.clock_type;
   sum.tv_nsec = a.tv_nsec + b.tv_nsec;
@@ -205,17 +189,17 @@ gpr_timespec gpr_time_add(gpr_timespec a, gpr_timespec b) {
     sum.tv_nsec -= GPR_NS_PER_SEC;
     inc++;
   }
-  if (a.tv_sec == TYPE_MAX(time_t) || a.tv_sec == TYPE_MIN(time_t)) {
+  if (a.tv_sec == INT64_MAX || a.tv_sec == INT64_MIN) {
     sum = a;
-  } else if (b.tv_sec == TYPE_MAX(time_t) ||
-             (b.tv_sec >= 0 && a.tv_sec >= TYPE_MAX(time_t) - b.tv_sec)) {
+  } else if (b.tv_sec == INT64_MAX ||
+             (b.tv_sec >= 0 && a.tv_sec >= INT64_MAX - b.tv_sec)) {
     sum = gpr_inf_future(sum.clock_type);
-  } else if (b.tv_sec == TYPE_MIN(time_t) ||
-             (b.tv_sec <= 0 && a.tv_sec <= TYPE_MIN(time_t) - b.tv_sec)) {
+  } else if (b.tv_sec == INT64_MIN ||
+             (b.tv_sec <= 0 && a.tv_sec <= INT64_MIN - b.tv_sec)) {
     sum = gpr_inf_past(sum.clock_type);
   } else {
     sum.tv_sec = a.tv_sec + b.tv_sec;
-    if (inc != 0 && sum.tv_sec == TYPE_MAX(time_t) - 1) {
+    if (inc != 0 && sum.tv_sec == INT64_MAX - 1) {
       sum = gpr_inf_future(sum.clock_type);
     } else {
       sum.tv_sec += inc;
@@ -226,7 +210,7 @@ gpr_timespec gpr_time_add(gpr_timespec a, gpr_timespec b) {
 
 gpr_timespec gpr_time_sub(gpr_timespec a, gpr_timespec b) {
   gpr_timespec diff;
-  int dec = 0;
+  gpr_int64 dec = 0;
   if (b.clock_type == GPR_TIMESPAN) {
     diff.clock_type = a.clock_type;
   } else {
@@ -238,17 +222,17 @@ gpr_timespec gpr_time_sub(gpr_timespec a, gpr_timespec b) {
     diff.tv_nsec += GPR_NS_PER_SEC;
     dec++;
   }
-  if (a.tv_sec == TYPE_MAX(time_t) || a.tv_sec == TYPE_MIN(time_t)) {
+  if (a.tv_sec == INT64_MAX || a.tv_sec == INT64_MIN) {
     diff = a;
-  } else if (b.tv_sec == TYPE_MIN(time_t) ||
-             (b.tv_sec <= 0 && a.tv_sec >= TYPE_MAX(time_t) + b.tv_sec)) {
+  } else if (b.tv_sec == INT64_MIN ||
+             (b.tv_sec <= 0 && a.tv_sec >= INT64_MAX + b.tv_sec)) {
     diff = gpr_inf_future(GPR_CLOCK_REALTIME);
-  } else if (b.tv_sec == TYPE_MAX(time_t) ||
-             (b.tv_sec >= 0 && a.tv_sec <= TYPE_MIN(time_t) + b.tv_sec)) {
+  } else if (b.tv_sec == INT64_MAX ||
+             (b.tv_sec >= 0 && a.tv_sec <= INT64_MIN + b.tv_sec)) {
     diff = gpr_inf_past(GPR_CLOCK_REALTIME);
   } else {
     diff.tv_sec = a.tv_sec - b.tv_sec;
-    if (dec != 0 && diff.tv_sec == TYPE_MIN(time_t) + 1) {
+    if (dec != 0 && diff.tv_sec == INT64_MIN + 1) {
       diff = gpr_inf_past(GPR_CLOCK_REALTIME);
     } else {
       diff.tv_sec -= dec;
@@ -297,11 +281,11 @@ gpr_timespec gpr_convert_clock_type(gpr_timespec t, gpr_clock_type clock_type) {
   }
 
   if (t.tv_nsec == 0) {
-    if (t.tv_sec == TYPE_MAX(time_t)) {
+    if (t.tv_sec == INT64_MAX) {
       t.clock_type = clock_type;
       return t;
     }
-    if (t.tv_sec == TYPE_MIN(time_t)) {
+    if (t.tv_sec == INT64_MIN) {
       t.clock_type = clock_type;
       return t;
     }

src/core/support/time_posix.c

@@ -45,7 +45,11 @@
 
 static struct timespec timespec_from_gpr(gpr_timespec gts) {
   struct timespec rv;
-  rv.tv_sec = gts.tv_sec;
+  if (sizeof(time_t) < sizeof(gpr_int64)) {
+    /* fine to assert, as this is only used in gpr_sleep_until */
+    GPR_ASSERT(gts.tv_sec <= INT32_MAX && gts.tv_sec >= INT32_MIN);
+  }
+  rv.tv_sec = (time_t)gts.tv_sec;
   rv.tv_nsec = gts.tv_nsec;
   return rv;
 }
@@ -53,9 +57,14 @@ static struct timespec timespec_from_gpr(gpr_timespec gts) {
 #if _POSIX_TIMERS > 0
 static gpr_timespec gpr_from_timespec(struct timespec ts,
                                       gpr_clock_type clock_type) {
+  /*
+   * timespec.tv_sec can have smaller size than gpr_timespec.tv_sec,
+   * but we are only using this function to implement gpr_now
+   * so there's no need to handle "infinity" values.
+   */
   gpr_timespec rv;
   rv.tv_sec = ts.tv_sec;
-  rv.tv_nsec = (int)ts.tv_nsec;
+  rv.tv_nsec = (gpr_int32)ts.tv_nsec;
   rv.clock_type = clock_type;
   return rv;
 }
@@ -110,8 +119,8 @@ gpr_timespec gpr_now(gpr_clock_type clock) {
       break;
     case GPR_CLOCK_MONOTONIC:
       now_dbl = (mach_absolute_time() - g_time_start) * g_time_scale;
-      now.tv_sec = (time_t)(now_dbl * 1e-9);
-      now.tv_nsec = (int)(now_dbl - ((double)now.tv_sec) * 1e9);
+      now.tv_sec = (gpr_int64)(now_dbl * 1e-9);
+      now.tv_nsec = (gpr_int32)(now_dbl - ((double)now.tv_sec) * 1e9);
       break;
     case GPR_CLOCK_PRECISE:
       gpr_precise_clock_now(&now);

src/core/support/time_precise.c

@@ -75,8 +75,8 @@ void gpr_precise_clock_now(gpr_timespec *clk) {
   gpr_get_cycle_counter(&counter);
   secs = (double)(counter - start_cycle) / cycles_per_second;
   clk->clock_type = GPR_CLOCK_PRECISE;
-  clk->tv_sec = (time_t)secs;
-  clk->tv_nsec = (int)(1e9 * (secs - (double)clk->tv_sec));
+  clk->tv_sec = (gpr_int64)secs;
+  clk->tv_nsec = (gpr_int32)(1e9 * (secs - (double)clk->tv_sec));
 }
 
 #else  /* GRPC_TIMERS_RDTSC */

src/core/support/time_win32.c

@@ -62,15 +62,15 @@ gpr_timespec gpr_now(gpr_clock_type clock) {
   switch (clock) {
     case GPR_CLOCK_REALTIME:
       _ftime_s(&now_tb);
-      now_tv.tv_sec = now_tb.time;
+      now_tv.tv_sec = (gpr_int64)now_tb.time;
       now_tv.tv_nsec = now_tb.millitm * 1000000;
       break;
     case GPR_CLOCK_MONOTONIC:
     case GPR_CLOCK_PRECISE:
       QueryPerformanceCounter(&timestamp);
       now_dbl = (timestamp.QuadPart - g_start_time.QuadPart) * g_time_scale;
-      now_tv.tv_sec = (time_t)now_dbl;
-      now_tv.tv_nsec = (int)((now_dbl - (double)now_tv.tv_sec) * 1e9);
+      now_tv.tv_sec = (gpr_int64)now_dbl;
+      now_tv.tv_nsec = (gpr_int32)((now_dbl - (double)now_tv.tv_sec) * 1e9);
       break;
   }
   return now_tv;

src/core/surface/call.c

@@ -336,26 +336,19 @@ void grpc_call_set_completion_queue(grpc_exec_ctx *exec_ctx, grpc_call *call,
                               grpc_cq_pollset(cq));
 }
 
-grpc_completion_queue *grpc_call_get_completion_queue(grpc_call *call) {
-  return call->cq;
-}
-
 #ifdef GRPC_STREAM_REFCOUNT_DEBUG
-void grpc_call_internal_ref(grpc_call *c, const char *reason) {
-  grpc_call_stack_ref(CALL_STACK_FROM_CALL(c), reason);
-}
-void grpc_call_internal_unref(grpc_exec_ctx *exec_ctx, grpc_call *c,
-                              const char *reason) {
-  grpc_call_stack_unref(exec_ctx, CALL_STACK_FROM_CALL(c), reason);
-}
+#define REF_REASON reason
+#define REF_ARG , const char *reason
 #else
-void grpc_call_internal_ref(grpc_call *c) {
-  grpc_call_stack_ref(CALL_STACK_FROM_CALL(c));
+#define REF_REASON ""
+#define REF_ARG
+#endif
+void grpc_call_internal_ref(grpc_call *c REF_ARG) {
+  GRPC_CALL_STACK_REF(CALL_STACK_FROM_CALL(c), REF_REASON);
 }
-void grpc_call_internal_unref(grpc_exec_ctx *exec_ctx, grpc_call *c) {
-  grpc_call_stack_unref(exec_ctx, CALL_STACK_FROM_CALL(c));
+void grpc_call_internal_unref(grpc_exec_ctx *exec_ctx, grpc_call *c REF_ARG) {
+  GRPC_CALL_STACK_UNREF(exec_ctx, CALL_STACK_FROM_CALL(c), REF_REASON);
 }
-#endif
 
 static void destroy_call(grpc_exec_ctx *exec_ctx, void *call, int success) {
   size_t i;
@@ -742,8 +735,15 @@ static void execute_op(grpc_exec_ctx *exec_ctx, grpc_call *call,
 char *grpc_call_get_peer(grpc_call *call) {
   grpc_call_element *elem = CALL_ELEM_FROM_CALL(call, 0);
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
-  char *result = elem->filter->get_peer(&exec_ctx, elem);
+  char *result;
   GRPC_API_TRACE("grpc_call_get_peer(%p)", 1, (call));
+  result = elem->filter->get_peer(&exec_ctx, elem);
+  if (result == NULL) {
+    result = grpc_channel_get_target(call->channel);
+  }
+  if (result == NULL) {
+    result = gpr_strdup("unknown");
+  }
   grpc_exec_ctx_finish(&exec_ctx);
   return result;
 }
@@ -974,11 +974,19 @@ static void receiving_slice_ready(grpc_exec_ctx *exec_ctx, void *bctlp,
   batch_control *bctl = bctlp;
   grpc_call *call = bctl->call;
 
-  GPR_ASSERT(success);
-  gpr_slice_buffer_add(&(*call->receiving_buffer)->data.raw.slice_buffer,
-                       call->receiving_slice);
-
-  continue_receiving_slices(exec_ctx, bctl);
+  if (success) {
+    gpr_slice_buffer_add(&(*call->receiving_buffer)->data.raw.slice_buffer,
+                         call->receiving_slice);
+    continue_receiving_slices(exec_ctx, bctl);
+  } else {
+    grpc_byte_stream_destroy(call->receiving_stream);
+    call->receiving_stream = NULL;
+    grpc_byte_buffer_destroy(*call->receiving_buffer);
+    *call->receiving_buffer = NULL;
+    if (gpr_unref(&bctl->steps_to_complete)) {
+      post_batch_completion(exec_ctx, bctl);
+    }
+  }
 }
 
 static void finish_batch(grpc_exec_ctx *exec_ctx, void *bctlp, int success) {
@@ -1060,6 +1068,7 @@ static void receiving_stream_ready(grpc_exec_ctx *exec_ctx, void *bctlp,
 
   if (call->receiving_stream == NULL) {
     *call->receiving_buffer = NULL;
+    call->receiving_message = 0; 
     if (gpr_unref(&bctl->steps_to_complete)) {
       post_batch_completion(exec_ctx, bctl);
     }
@@ -1070,6 +1079,7 @@ static void receiving_stream_ready(grpc_exec_ctx *exec_ctx, void *bctlp,
     grpc_byte_stream_destroy(exec_ctx, call->receiving_stream);
     call->receiving_stream = NULL;
     *call->receiving_buffer = NULL;
+    call->receiving_message = 0; 
     if (gpr_unref(&bctl->steps_to_complete)) {
       post_batch_completion(exec_ctx, bctl);
     }
@@ -1119,11 +1129,12 @@ static grpc_call_error call_start_batch(grpc_exec_ctx *exec_ctx,
     GRPC_CALL_INTERNAL_REF(call, "completion");
     bctl->success = 1;
     if (!is_notify_tag_closure) {
-      grpc_cq_begin_op(call->cq);
+      grpc_cq_begin_op(call->cq, notify_tag);
     }
     gpr_mu_unlock(&call->mu);
     post_batch_completion(exec_ctx, bctl);
-    return GRPC_CALL_OK;
+    error = GRPC_CALL_OK;
+    goto done;
   }
 
   /* rewrite batch ops into a transport op */
@@ -1333,7 +1344,7 @@ static grpc_call_error call_start_batch(grpc_exec_ctx *exec_ctx,
 
   GRPC_CALL_INTERNAL_REF(call, "completion");
   if (!is_notify_tag_closure) {
-    grpc_cq_begin_op(call->cq);
+    grpc_cq_begin_op(call->cq, notify_tag);
   }
   gpr_ref_init(&bctl->steps_to_complete, num_completion_callbacks_needed);
 

src/core/surface/call.h

@@ -58,7 +58,6 @@ grpc_call *grpc_call_create(grpc_channel *channel, grpc_call *parent_call,
 
 void grpc_call_set_completion_queue(grpc_exec_ctx *exec_ctx, grpc_call *call,
                                     grpc_completion_queue *cq);
-grpc_completion_queue *grpc_call_get_completion_queue(grpc_call *call);
 
 #ifdef GRPC_STREAM_REFCOUNT_DEBUG
 void grpc_call_internal_ref(grpc_call *call, const char *reason);

src/core/surface/call_log_batch.c

@@ -116,4 +116,3 @@ void grpc_call_log_batch(char *file, int line, gpr_log_severity severity,
     gpr_free(tmp);
   }
 }
-

src/core/surface/channel.c

@@ -63,7 +63,6 @@ typedef struct registered_call {
 
 struct grpc_channel {
   int is_client;
-  gpr_refcount refs;
   gpr_uint32 max_message_length;
   grpc_mdelem *default_authority;
 
@@ -81,6 +80,8 @@ struct grpc_channel {
 /* the protobuf library will (by default) start warning at 100megs */
 #define DEFAULT_MAX_MESSAGE_LENGTH (100 * 1024 * 1024)
 
+static void destroy_channel(grpc_exec_ctx *exec_ctx, void *arg, int success);
+
 grpc_channel *grpc_channel_create_from_filters(
     grpc_exec_ctx *exec_ctx, const char *target,
     const grpc_channel_filter **filters, size_t num_filters,
@@ -93,8 +94,6 @@ grpc_channel *grpc_channel_create_from_filters(
   channel->target = gpr_strdup(target);
   GPR_ASSERT(grpc_is_initialized() && "call grpc_init()");
   channel->is_client = is_client;
-  /* decremented by grpc_channel_destroy */
-  gpr_ref_init(&channel->refs, 1);
   gpr_mu_init(&channel->registered_call_mu);
   channel->registered_calls = NULL;
 
@@ -153,7 +152,9 @@ grpc_channel *grpc_channel_create_from_filters(
     gpr_free(default_authority);
   }
 
-  grpc_channel_stack_init(exec_ctx, filters, num_filters, channel, args,
+  grpc_channel_stack_init(exec_ctx, 1, destroy_channel, channel, filters,
+                          num_filters, args,
+                          is_client ? "CLIENT_CHANNEL" : "SERVER_CHANNEL",
                           CHANNEL_STACK_FROM_CHANNEL(channel));
 
   return channel;
@@ -194,11 +195,11 @@ grpc_call *grpc_channel_create_call(grpc_channel *channel,
       "grpc_channel_create_call("
       "channel=%p, parent_call=%p, propagation_mask=%x, cq=%p, method=%s, "
       "host=%s, "
-      "deadline=gpr_timespec { tv_sec: %ld, tv_nsec: %d, clock_type: %d }, "
+      "deadline=gpr_timespec { tv_sec: %lld, tv_nsec: %d, clock_type: %d }, "
       "reserved=%p)",
       10, (channel, parent_call, (unsigned)propagation_mask, cq, method, host,
-           (long)deadline.tv_sec, deadline.tv_nsec, (int)deadline.clock_type,
-           reserved));
+           (long long)deadline.tv_sec, (int)deadline.tv_nsec,
+           (int)deadline.clock_type, reserved));
   GPR_ASSERT(!reserved);
   return grpc_channel_create_call_internal(
       channel, parent_call, propagation_mask, cq,
@@ -238,11 +239,11 @@ grpc_call *grpc_channel_create_registered_call(
       "grpc_channel_create_registered_call("
       "channel=%p, parent_call=%p, propagation_mask=%x, completion_queue=%p, "
       "registered_call_handle=%p, "
-      "deadline=gpr_timespec { tv_sec: %ld, tv_nsec: %d, clock_type: %d }, "
+      "deadline=gpr_timespec { tv_sec: %lld, tv_nsec: %d, clock_type: %d }, "
       "reserved=%p)",
       9, (channel, parent_call, (unsigned)propagation_mask, completion_queue,
-          registered_call_handle, (long)deadline.tv_sec, deadline.tv_nsec,
-          (int)deadline.clock_type, reserved));
+          registered_call_handle, (long long)deadline.tv_sec,
+          (int)deadline.tv_nsec, (int)deadline.clock_type, reserved));
   GPR_ASSERT(!reserved);
   return grpc_channel_create_call_internal(
       channel, parent_call, propagation_mask, completion_queue,
@@ -250,17 +251,25 @@ grpc_call *grpc_channel_create_registered_call(
       rc->authority ? GRPC_MDELEM_REF(rc->authority) : NULL, deadline);
 }
 
-#ifdef GRPC_CHANNEL_REF_COUNT_DEBUG
-void grpc_channel_internal_ref(grpc_channel *c, const char *reason) {
-  gpr_log(GPR_DEBUG, "CHANNEL:   ref %p %d -> %d [%s]", c, c->refs.count,
-          c->refs.count + 1, reason);
+#ifdef GRPC_STREAM_REFCOUNT_DEBUG
+#define REF_REASON reason
+#define REF_ARG , const char *reason
 #else
-void grpc_channel_internal_ref(grpc_channel *c) {
+#define REF_REASON ""
+#define REF_ARG
 #endif
-  gpr_ref(&c->refs);
+void grpc_channel_internal_ref(grpc_channel *c REF_ARG) {
+  GRPC_CHANNEL_STACK_REF(CHANNEL_STACK_FROM_CHANNEL(c), REF_REASON);
 }
 
-static void destroy_channel(grpc_exec_ctx *exec_ctx, grpc_channel *channel) {
+void grpc_channel_internal_unref(grpc_exec_ctx *exec_ctx,
+                                 grpc_channel *c REF_ARG) {
+  GRPC_CHANNEL_STACK_UNREF(exec_ctx, CHANNEL_STACK_FROM_CHANNEL(c), REF_REASON);
+}
+
+static void destroy_channel(grpc_exec_ctx *exec_ctx, void *arg,
+                            int iomgr_success) {
+  grpc_channel *channel = arg;
   grpc_channel_stack_destroy(exec_ctx, CHANNEL_STACK_FROM_CHANNEL(channel));
   while (channel->registered_calls) {
     registered_call *rc = channel->registered_calls;
@@ -279,20 +288,6 @@ static void destroy_channel(grpc_exec_ctx *exec_ctx, grpc_channel *channel) {
   gpr_free(channel);
 }
 
-#ifdef GRPC_CHANNEL_REF_COUNT_DEBUG
-void grpc_channel_internal_unref(grpc_exec_ctx *exec_ctx, grpc_channel *channel,
-                                 const char *reason) {
-  gpr_log(GPR_DEBUG, "CHANNEL: unref %p %d -> %d [%s]", channel,
-          channel->refs.count, channel->refs.count - 1, reason);
-#else
-void grpc_channel_internal_unref(grpc_exec_ctx *exec_ctx,
-                                 grpc_channel *channel) {
-#endif
-  if (gpr_unref(&channel->refs)) {
-    destroy_channel(exec_ctx, channel);
-  }
-}
-
 void grpc_channel_destroy(grpc_channel *channel) {
   grpc_transport_op op;
   grpc_channel_element *elem;

src/core/surface/channel.h

@@ -53,7 +53,7 @@ grpc_mdelem *grpc_channel_get_reffed_status_elem(grpc_channel *channel,
                                                  int status_code);
 gpr_uint32 grpc_channel_get_max_message_length(grpc_channel *channel);
 
-#ifdef GRPC_CHANNEL_REF_COUNT_DEBUG
+#ifdef GRPC_STREAM_REFCOUNT_DEBUG
 void grpc_channel_internal_ref(grpc_channel *channel, const char *reason);
 void grpc_channel_internal_unref(grpc_exec_ctx *exec_ctx, grpc_channel *channel,
                                  const char *reason);

src/core/surface/channel_connectivity.c

@@ -83,7 +83,6 @@ typedef struct {
   gpr_mu mu;
   callback_phase phase;
   int success;
-  int removed;
   grpc_closure on_complete;
   grpc_timer alarm;
   grpc_connectivity_state state;
@@ -135,30 +134,15 @@ static void finished_completion(grpc_exec_ctx *exec_ctx, void *pw,
 static void partly_done(grpc_exec_ctx *exec_ctx, state_watcher *w,
                         int due_to_completion) {
   int delete = 0;
-  grpc_channel_element *client_channel_elem = NULL;
 
-  gpr_mu_lock(&w->mu);
-  if (w->removed == 0) {
-    w->removed = 1;
-    client_channel_elem = grpc_channel_stack_last_element(
-        grpc_channel_get_channel_stack(w->channel));
-    if (client_channel_elem->filter == &grpc_client_channel_filter) {
-      grpc_client_channel_del_interested_party(exec_ctx, client_channel_elem,
-                                               grpc_cq_pollset(w->cq));
-    } else {
-      grpc_client_uchannel_del_interested_party(exec_ctx, client_channel_elem,
-                                                grpc_cq_pollset(w->cq));
-    }
-  }
-  gpr_mu_unlock(&w->mu);
   if (due_to_completion) {
-    gpr_mu_lock(&w->mu);
-    w->success = 1;
-    gpr_mu_unlock(&w->mu);
     grpc_timer_cancel(exec_ctx, &w->alarm);
   }
 
   gpr_mu_lock(&w->mu);
+  if (due_to_completion) {
+    w->success = 1;
+  }
   switch (w->phase) {
     case WAITING:
       w->phase = CALLING_BACK;
@@ -200,19 +184,18 @@ void grpc_channel_watch_connectivity_state(
   GRPC_API_TRACE(
       "grpc_channel_watch_connectivity_state("
       "channel=%p, last_observed_state=%d, "
-      "deadline=gpr_timespec { tv_sec: %ld, tv_nsec: %d, clock_type: %d }, "
+      "deadline=gpr_timespec { tv_sec: %lld, tv_nsec: %d, clock_type: %d }, "
       "cq=%p, tag=%p)",
-      7, (channel, (int)last_observed_state, (long)deadline.tv_sec,
-          deadline.tv_nsec, (int)deadline.clock_type, cq, tag));
+      7, (channel, (int)last_observed_state, (long long)deadline.tv_sec,
+          (int)deadline.tv_nsec, (int)deadline.clock_type, cq, tag));
 
-  grpc_cq_begin_op(cq);
+  grpc_cq_begin_op(cq, tag);
 
   gpr_mu_init(&w->mu);
   grpc_closure_init(&w->on_complete, watch_complete, w);
   w->phase = WAITING;
   w->state = last_observed_state;
   w->success = 0;
-  w->removed = 0;
   w->cq = cq;
   w->tag = tag;
   w->channel = channel;
@@ -223,16 +206,14 @@ void grpc_channel_watch_connectivity_state(
 
   if (client_channel_elem->filter == &grpc_client_channel_filter) {
     GRPC_CHANNEL_INTERNAL_REF(channel, "watch_channel_connectivity");
-    grpc_client_channel_add_interested_party(&exec_ctx, client_channel_elem,
-                                             grpc_cq_pollset(cq));
     grpc_client_channel_watch_connectivity_state(&exec_ctx, client_channel_elem,
-                                                 &w->state, &w->on_complete);
+                                                 grpc_cq_pollset(cq), &w->state,
+                                                 &w->on_complete);
   } else if (client_channel_elem->filter == &grpc_client_uchannel_filter) {
     GRPC_CHANNEL_INTERNAL_REF(channel, "watch_uchannel_connectivity");
-    grpc_client_uchannel_add_interested_party(&exec_ctx, client_channel_elem,
-                                              grpc_cq_pollset(cq));
     grpc_client_uchannel_watch_connectivity_state(
-        &exec_ctx, client_channel_elem, &w->state, &w->on_complete);
+        &exec_ctx, client_channel_elem, grpc_cq_pollset(cq), &w->state,
+        &w->on_complete);
   }
 
   grpc_exec_ctx_finish(&exec_ctx);

src/core/surface/channel_create.c

@@ -171,7 +171,6 @@ static grpc_subchannel *subchannel_factory_create_subchannel(
   c->base.vtable = &connector_vtable;
   gpr_ref_init(&c->refs, 1);
   args->args = final_args;
-  args->master = f->master;
   s = grpc_subchannel_create(&c->base, args);
   grpc_connector_unref(exec_ctx, &c->base);
   grpc_channel_args_destroy(final_args);

src/core/surface/channel_ping.c

@@ -0,0 +1,79 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/surface/channel.h"
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+
+#include "src/core/surface/api_trace.h"
+#include "src/core/surface/completion_queue.h"
+
+typedef struct {
+  grpc_closure closure;
+  void *tag;
+  grpc_completion_queue *cq;
+  grpc_cq_completion completion_storage;
+} ping_result;
+
+static void ping_destroy(grpc_exec_ctx *exec_ctx, void *arg,
+                         grpc_cq_completion *storage) {
+  gpr_free(arg);
+}
+
+static void ping_done(grpc_exec_ctx *exec_ctx, void *arg, int success) {
+  ping_result *pr = arg;
+  grpc_cq_end_op(exec_ctx, pr->cq, pr->tag, success, ping_destroy, pr,
+                 &pr->completion_storage);
+}
+
+void grpc_channel_ping(grpc_channel *channel, grpc_completion_queue *cq,
+                       void *tag, void *reserved) {
+  grpc_transport_op op;
+  ping_result *pr = gpr_malloc(sizeof(*pr));
+  grpc_channel_element *top_elem =
+      grpc_channel_stack_element(grpc_channel_get_channel_stack(channel), 0);
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  GPR_ASSERT(reserved == NULL);
+  memset(&op, 0, sizeof(op));
+  pr->tag = tag;
+  pr->cq = cq;
+  grpc_closure_init(&pr->closure, ping_done, pr);
+  op.send_ping = &pr->closure;
+  op.bind_pollset = grpc_cq_pollset(cq);
+  grpc_cq_begin_op(cq, tag);
+  top_elem->filter->start_transport_op(&exec_ctx, top_elem, &op);
+  grpc_exec_ctx_finish(&exec_ctx);
+}

src/core/surface/completion_queue.c

@@ -73,6 +73,12 @@ struct grpc_completion_queue {
   plucker pluckers[GRPC_MAX_COMPLETION_QUEUE_PLUCKERS];
   grpc_closure pollset_shutdown_done;
 
+#ifndef NDEBUG
+  void **outstanding_tags;
+  size_t outstanding_tag_count;
+  size_t outstanding_tag_capacity;
+#endif
+
   grpc_completion_queue *next_free;
 };
 
@@ -89,6 +95,9 @@ void grpc_cq_global_shutdown(void) {
   while (g_freelist) {
     grpc_completion_queue *next = g_freelist->next_free;
     grpc_pollset_destroy(&g_freelist->pollset);
+#ifndef NDEBUG
+    gpr_free(g_freelist->outstanding_tags);
+#endif
     gpr_free(g_freelist);
     g_freelist = next;
   }
@@ -117,6 +126,10 @@ grpc_completion_queue *grpc_completion_queue_create(void *reserved) {
 
     cc = gpr_malloc(sizeof(grpc_completion_queue));
     grpc_pollset_init(&cc->pollset);
+#ifndef NDEBUG
+    cc->outstanding_tags = NULL;
+    cc->outstanding_tag_capacity = 0;
+#endif
   } else {
     cc = g_freelist;
     g_freelist = g_freelist->next_free;
@@ -134,6 +147,9 @@ grpc_completion_queue *grpc_completion_queue_create(void *reserved) {
   cc->shutdown_called = 0;
   cc->is_server_cq = 0;
   cc->num_pluckers = 0;
+#ifndef NDEBUG
+  cc->outstanding_tag_count = 0;
+#endif
   grpc_closure_init(&cc->pollset_shutdown_done, on_pollset_shutdown_done, cc);
 
   GPR_TIMER_END("grpc_completion_queue_create", 0);
@@ -176,10 +192,17 @@ void grpc_cq_internal_unref(grpc_completion_queue *cc) {
   }
 }
 
-void grpc_cq_begin_op(grpc_completion_queue *cc) {
+void grpc_cq_begin_op(grpc_completion_queue *cc, void *tag) {
 #ifndef NDEBUG
   gpr_mu_lock(GRPC_POLLSET_MU(&cc->pollset));
   GPR_ASSERT(!cc->shutdown_called);
+  if (cc->outstanding_tag_count == cc->outstanding_tag_capacity) {
+    cc->outstanding_tag_capacity = GPR_MAX(4, 2 * cc->outstanding_tag_capacity);
+    cc->outstanding_tags =
+        gpr_realloc(cc->outstanding_tags, sizeof(*cc->outstanding_tags) *
+                                              cc->outstanding_tag_capacity);
+  }
+  cc->outstanding_tags[cc->outstanding_tag_count++] = tag;
   gpr_mu_unlock(GRPC_POLLSET_MU(&cc->pollset));
 #endif
   gpr_ref(&cc->pending_events);
@@ -196,6 +219,9 @@ void grpc_cq_end_op(grpc_exec_ctx *exec_ctx, grpc_completion_queue *cc,
   int shutdown;
   int i;
   grpc_pollset_worker *pluck_worker;
+#ifndef NDEBUG
+  int found = 0;
+#endif
 
   GPR_TIMER_BEGIN("grpc_cq_end_op", 0);
 
@@ -206,6 +232,18 @@ void grpc_cq_end_op(grpc_exec_ctx *exec_ctx, grpc_completion_queue *cc,
       ((gpr_uintptr)&cc->completed_head) | ((gpr_uintptr)(success != 0));
 
   gpr_mu_lock(GRPC_POLLSET_MU(&cc->pollset));
+#ifndef NDEBUG
+  for (i = 0; i < (int)cc->outstanding_tag_count; i++) {
+    if (cc->outstanding_tags[i] == tag) {
+      cc->outstanding_tag_count--;
+      GPR_SWAP(void *, cc->outstanding_tags[i],
+               cc->outstanding_tags[cc->outstanding_tag_count]);
+      found = 1;
+      break;
+    }
+  }
+  GPR_ASSERT(found);
+#endif
   shutdown = gpr_unref(&cc->pending_events);
   if (!shutdown) {
     cc->completed_tail->next =
@@ -247,10 +285,10 @@ grpc_event grpc_completion_queue_next(grpc_completion_queue *cc,
   GRPC_API_TRACE(
       "grpc_completion_queue_next("
       "cc=%p, "
-      "deadline=gpr_timespec { tv_sec: %ld, tv_nsec: %d, clock_type: %d }, "
+      "deadline=gpr_timespec { tv_sec: %lld, tv_nsec: %d, clock_type: %d }, "
       "reserved=%p)",
-      5, (cc, (long)deadline.tv_sec, deadline.tv_nsec, (int)deadline.clock_type,
-          reserved));
+      5, (cc, (long long)deadline.tv_sec, (int)deadline.tv_nsec,
+          (int)deadline.clock_type, reserved));
   GPR_ASSERT(!reserved);
 
   deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC);
@@ -335,9 +373,9 @@ grpc_event grpc_completion_queue_pluck(grpc_completion_queue *cc, void *tag,
   GRPC_API_TRACE(
       "grpc_completion_queue_pluck("
       "cc=%p, tag=%p, "
-      "deadline=gpr_timespec { tv_sec: %ld, tv_nsec: %d, clock_type: %d }, "
+      "deadline=gpr_timespec { tv_sec: %lld, tv_nsec: %d, clock_type: %d }, "
       "reserved=%p)",
-      6, (cc, tag, (long)deadline.tv_sec, deadline.tv_nsec,
+      6, (cc, tag, (long long)deadline.tv_sec, (int)deadline.tv_nsec,
           (int)deadline.clock_type, reserved));
   GPR_ASSERT(!reserved);
 

src/core/surface/completion_queue.h

@@ -68,10 +68,12 @@ void grpc_cq_internal_unref(grpc_completion_queue *cc);
 #endif
 
 /* Flag that an operation is beginning: the completion channel will not finish
-   shutdown until a corrensponding grpc_cq_end_* call is made */
-void grpc_cq_begin_op(grpc_completion_queue *cc);
+   shutdown until a corrensponding grpc_cq_end_* call is made.
+   \a tag is currently used only in debug builds. */
+void grpc_cq_begin_op(grpc_completion_queue *cc, void *tag);
 
-/* Queue a GRPC_OP_COMPLETED operation */
+/* Queue a GRPC_OP_COMPLETED operation; tag must correspond to the tag passed to
+   grpc_cq_begin_op */
 void grpc_cq_end_op(grpc_exec_ctx *exec_ctx, grpc_completion_queue *cc,
                     void *tag, int success,
                     void (*done)(grpc_exec_ctx *exec_ctx, void *done_arg,

src/core/surface/lame_client.c

@@ -49,7 +49,6 @@ typedef struct {
 } call_data;
 
 typedef struct {
-  grpc_channel *master;
   grpc_status_code error_code;
   const char *error_message;
 } channel_data;
@@ -84,8 +83,7 @@ static void lame_start_transport_stream_op(grpc_exec_ctx *exec_ctx,
 }
 
 static char *lame_get_peer(grpc_exec_ctx *exec_ctx, grpc_call_element *elem) {
-  channel_data *chand = elem->channel_data;
-  return grpc_channel_get_target(chand->master);
+  return NULL;
 }
 
 static void lame_start_transport_op(grpc_exec_ctx *exec_ctx,
@@ -111,10 +109,8 @@ static void destroy_call_elem(grpc_exec_ctx *exec_ctx,
 static void init_channel_elem(grpc_exec_ctx *exec_ctx,
                               grpc_channel_element *elem,
                               grpc_channel_element_args *args) {
-  channel_data *chand = elem->channel_data;
   GPR_ASSERT(args->is_first);
   GPR_ASSERT(args->is_last);
-  chand->master = args->master;
 }
 
 static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,

src/core/surface/secure_channel_create.c

@@ -228,7 +228,6 @@ static grpc_subchannel *subchannel_factory_create_subchannel(
   gpr_mu_init(&c->mu);
   gpr_ref_init(&c->refs, 1);
   args->args = final_args;
-  args->master = f->master;
   s = grpc_subchannel_create(&c->base, args);
   grpc_connector_unref(exec_ctx, &c->base);
   grpc_channel_args_destroy(final_args);
@@ -305,22 +304,22 @@ grpc_channel *grpc_secure_channel_create(grpc_channel_credentials *creds,
   f->master = channel;
   GRPC_CHANNEL_INTERNAL_REF(channel, "subchannel_factory");
   resolver = grpc_resolver_create(target, &f->base);
-  if (!resolver) {
-    grpc_exec_ctx_finish(&exec_ctx);
-    return NULL;
+  if (resolver) {
+    grpc_client_channel_set_resolver(
+        &exec_ctx, grpc_channel_get_channel_stack(channel), resolver);
+    GRPC_RESOLVER_UNREF(&exec_ctx, resolver, "create");
   }
-
-  grpc_client_channel_set_resolver(
-      &exec_ctx, grpc_channel_get_channel_stack(channel), resolver);
-  GRPC_RESOLVER_UNREF(&exec_ctx, resolver, "create");
   grpc_subchannel_factory_unref(&exec_ctx, &f->base);
   GRPC_SECURITY_CONNECTOR_UNREF(&security_connector->base, "channel_create");
-
   grpc_channel_args_destroy(args_copy);
   if (new_args_from_connector != NULL) {
     grpc_channel_args_destroy(new_args_from_connector);
   }
 
+  if (!resolver) {
+    GRPC_CHANNEL_INTERNAL_UNREF(&exec_ctx, channel, "subchannel_factory");
+    channel = NULL;
+  }
   grpc_exec_ctx_finish(&exec_ctx);
 
   return channel;

src/core/surface/server.c

@@ -1007,7 +1007,7 @@ void grpc_server_shutdown_and_notify(grpc_server *server,
 
   /* lock, and gather up some stuff to do */
   gpr_mu_lock(&server->mu_global);
-  grpc_cq_begin_op(cq);
+  grpc_cq_begin_op(cq, tag);
   if (server->shutdown_published) {
     grpc_cq_end_op(&exec_ctx, cq, tag, 1, done_published_shutdown, NULL,
                    gpr_malloc(sizeof(grpc_cq_completion)));
@@ -1176,7 +1176,7 @@ grpc_call_error grpc_server_request_call(
     error = GRPC_CALL_ERROR_NOT_SERVER_COMPLETION_QUEUE;
     goto done;
   }
-  grpc_cq_begin_op(cq_for_notification);
+  grpc_cq_begin_op(cq_for_notification, tag);
   details->reserved = NULL;
   rc->type = BATCH_CALL;
   rc->server = server;
@@ -1213,7 +1213,7 @@ grpc_call_error grpc_server_request_registered_call(
     error = GRPC_CALL_ERROR_NOT_SERVER_COMPLETION_QUEUE;
     goto done;
   }
-  grpc_cq_begin_op(cq_for_notification);
+  grpc_cq_begin_op(cq_for_notification, tag);
   rc->type = REGISTERED_CALL;
   rc->server = server;
   rc->tag = tag;

src/core/surface/server_chttp2.c

@@ -101,9 +101,7 @@ int grpc_server_add_insecure_http2_port(grpc_server *server, const char *addr) {
   }
 
   tcp = grpc_tcp_server_create();
-  if (!tcp) {
-    goto error;
-  }
+  GPR_ASSERT(tcp);
 
   for (i = 0; i < resolved->naddrs; i++) {
     grpc_tcp_listener *listener;
@@ -111,7 +109,7 @@ int grpc_server_add_insecure_http2_port(grpc_server *server, const char *addr) {
         tcp, (struct sockaddr *)&resolved->addrs[i].addr,
         resolved->addrs[i].len);
     port_temp = grpc_tcp_listener_get_port(listener);
-    if (port_temp >= 0) {
+    if (port_temp > 0) {
       if (port_num == -1) {
         port_num = port_temp;
       } else {

src/core/surface/server_create.c

@@ -32,14 +32,20 @@
  */
 
 #include <grpc/grpc.h>
+#include "src/core/census/grpc_filter.h"
+#include "src/core/channel/channel_args.h"
+#include "src/core/channel/compress_filter.h"
 #include "src/core/surface/api_trace.h"
 #include "src/core/surface/completion_queue.h"
 #include "src/core/surface/server.h"
-#include "src/core/channel/compress_filter.h"
 
 grpc_server *grpc_server_create(const grpc_channel_args *args, void *reserved) {
-  const grpc_channel_filter *filters[] = {&grpc_compress_filter};
+  const grpc_channel_filter *filters[3];
+  size_t num_filters = 0;
+  filters[num_filters++] = &grpc_compress_filter;
+  if (grpc_channel_args_is_census_enabled(args)) {
+    filters[num_filters++] = &grpc_server_census_filter;
+  }
   GRPC_API_TRACE("grpc_server_create(%p, %p)", 2, (args, reserved));
-  return grpc_server_create_from_filters(filters, GPR_ARRAY_SIZE(filters),
-                                         args);
+  return grpc_server_create_from_filters(filters, num_filters, args);
 }

src/core/transport/chttp2/frame_data.c

@@ -53,7 +53,8 @@ void grpc_chttp2_data_parser_destroy(grpc_exec_ctx *exec_ctx,
                                      grpc_chttp2_data_parser *parser) {
   grpc_byte_stream *bs;
   if (parser->parsing_frame) {
-    grpc_chttp2_incoming_byte_stream_finished(exec_ctx, parser->parsing_frame);
+    grpc_chttp2_incoming_byte_stream_finished(exec_ctx, parser->parsing_frame,
+                                              0, 1);
   }
   while (
       (bs = grpc_chttp2_incoming_frame_queue_pop(&parser->incoming_frames))) {
@@ -118,7 +119,7 @@ void grpc_chttp2_encode_data(gpr_uint32 id, gpr_slice_buffer *inbuf,
 
   hdr = gpr_slice_malloc(9);
   p = GPR_SLICE_START_PTR(hdr);
-  GPR_ASSERT(write_bytes < (1<<24));
+  GPR_ASSERT(write_bytes < (1 << 24));
   *p++ = (gpr_uint8)(write_bytes >> 16);
   *p++ = (gpr_uint8)(write_bytes >> 8);
   *p++ = (gpr_uint8)(write_bytes);
@@ -218,7 +219,8 @@ grpc_chttp2_parse_error grpc_chttp2_data_parser_parse(
         grpc_chttp2_incoming_byte_stream_push(
             exec_ctx, p->parsing_frame,
             gpr_slice_sub(slice, (size_t)(cur - beg), (size_t)(end - beg)));
-        grpc_chttp2_incoming_byte_stream_finished(exec_ctx, p->parsing_frame);
+        grpc_chttp2_incoming_byte_stream_finished(exec_ctx, p->parsing_frame, 1,
+                                                  1);
         p->parsing_frame = NULL;
         p->state = GRPC_CHTTP2_DATA_FH_0;
         return GRPC_CHTTP2_PARSE_OK;
@@ -227,7 +229,8 @@ grpc_chttp2_parse_error grpc_chttp2_data_parser_parse(
             exec_ctx, p->parsing_frame,
             gpr_slice_sub(slice, (size_t)(cur - beg),
                           (size_t)(cur + p->frame_size - beg)));
-        grpc_chttp2_incoming_byte_stream_finished(exec_ctx, p->parsing_frame);
+        grpc_chttp2_incoming_byte_stream_finished(exec_ctx, p->parsing_frame, 1,
+                                                  1);
         p->parsing_frame = NULL;
         cur += p->frame_size;
         goto fh_0; /* loop */