Resolved merge conflicts with master

BUILD

@@ -52,7 +52,6 @@ cc_library(
     "src/core/support/string_win32.h",
     "src/core/support/thd_internal.h",
     "src/core/support/alloc.c",
-    "src/core/support/cancellable.c",
     "src/core/support/cmdline.c",
     "src/core/support/cpu_iphone.c",
     "src/core/support/cpu_linux.c",
@@ -96,7 +95,6 @@ cc_library(
     "include/grpc/support/atm_gcc_atomic.h",
     "include/grpc/support/atm_gcc_sync.h",
     "include/grpc/support/atm_win32.h",
-    "include/grpc/support/cancellable_platform.h",
     "include/grpc/support/cmdline.h",
     "include/grpc/support/cpu.h",
     "include/grpc/support/histogram.h",
@@ -202,6 +200,7 @@ cc_library(
     "src/core/iomgr/tcp_server.h",
     "src/core/iomgr/tcp_windows.h",
     "src/core/iomgr/time_averaged_stats.h",
+    "src/core/iomgr/udp_server.h",
     "src/core/iomgr/wakeup_fd_pipe.h",
     "src/core/iomgr/wakeup_fd_posix.h",
     "src/core/json/json.h",
@@ -326,6 +325,7 @@ cc_library(
     "src/core/iomgr/tcp_server_windows.c",
     "src/core/iomgr/tcp_windows.c",
     "src/core/iomgr/time_averaged_stats.c",
+    "src/core/iomgr/udp_server.c",
     "src/core/iomgr/wakeup_fd_eventfd.c",
     "src/core/iomgr/wakeup_fd_nospecial.c",
     "src/core/iomgr/wakeup_fd_pipe.c",
@@ -400,6 +400,7 @@ cc_library(
   ],
   deps = [
     "//external:libssl",
+    "//external:zlib",
     ":gpr",
   ],
 )
@@ -465,6 +466,7 @@ cc_library(
     "src/core/iomgr/tcp_server.h",
     "src/core/iomgr/tcp_windows.h",
     "src/core/iomgr/time_averaged_stats.h",
+    "src/core/iomgr/udp_server.h",
     "src/core/iomgr/wakeup_fd_pipe.h",
     "src/core/iomgr/wakeup_fd_posix.h",
     "src/core/json/json.h",
@@ -569,6 +571,7 @@ cc_library(
     "src/core/iomgr/tcp_server_windows.c",
     "src/core/iomgr/tcp_windows.c",
     "src/core/iomgr/time_averaged_stats.c",
+    "src/core/iomgr/udp_server.c",
     "src/core/iomgr/wakeup_fd_eventfd.c",
     "src/core/iomgr/wakeup_fd_nospecial.c",
     "src/core/iomgr/wakeup_fd_pipe.c",
@@ -646,6 +649,26 @@ cc_library(
 )
 
 
+cc_library(
+  name = "grpc_zookeeper",
+  srcs = [
+    "src/core/client_config/resolvers/zookeeper_resolver.h",
+    "src/core/client_config/resolvers/zookeeper_resolver.c",
+  ],
+  hdrs = [
+    "include/grpc/grpc_zookeeper.h",
+  ],
+  includes = [
+    "include",
+    ".",
+  ],
+  deps = [
+    ":gpr",
+    ":grpc",
+  ],
+)
+
+
 cc_library(
   name = "grpc++",
   srcs = [
@@ -887,7 +910,6 @@ objc_library(
   name = "gpr_objc",
   srcs = [
     "src/core/support/alloc.c",
-    "src/core/support/cancellable.c",
     "src/core/support/cmdline.c",
     "src/core/support/cpu_iphone.c",
     "src/core/support/cpu_linux.c",
@@ -931,7 +953,6 @@ objc_library(
     "include/grpc/support/atm_gcc_atomic.h",
     "include/grpc/support/atm_gcc_sync.h",
     "include/grpc/support/atm_win32.h",
-    "include/grpc/support/cancellable_platform.h",
     "include/grpc/support/cmdline.h",
     "include/grpc/support/cpu.h",
     "include/grpc/support/histogram.h",
@@ -1054,6 +1075,7 @@ objc_library(
     "src/core/iomgr/tcp_server_windows.c",
     "src/core/iomgr/tcp_windows.c",
     "src/core/iomgr/time_averaged_stats.c",
+    "src/core/iomgr/udp_server.c",
     "src/core/iomgr/wakeup_fd_eventfd.c",
     "src/core/iomgr/wakeup_fd_nospecial.c",
     "src/core/iomgr/wakeup_fd_pipe.c",
@@ -1191,6 +1213,7 @@ objc_library(
     "src/core/iomgr/tcp_server.h",
     "src/core/iomgr/tcp_windows.h",
     "src/core/iomgr/time_averaged_stats.h",
+    "src/core/iomgr/udp_server.h",
     "src/core/iomgr/wakeup_fd_pipe.h",
     "src/core/iomgr/wakeup_fd_posix.h",
     "src/core/json/json.h",

build.json

@@ -171,6 +171,7 @@
         "src/core/iomgr/tcp_server.h",
         "src/core/iomgr/tcp_windows.h",
         "src/core/iomgr/time_averaged_stats.h",
+        "src/core/iomgr/udp_server.h",
         "src/core/iomgr/wakeup_fd_pipe.h",
         "src/core/iomgr/wakeup_fd_posix.h",
         "src/core/json/json.h",
@@ -274,6 +275,7 @@
         "src/core/iomgr/tcp_server_windows.c",
         "src/core/iomgr/tcp_windows.c",
         "src/core/iomgr/time_averaged_stats.c",
+        "src/core/iomgr/udp_server.c",
         "src/core/iomgr/wakeup_fd_eventfd.c",
         "src/core/iomgr/wakeup_fd_nospecial.c",
         "src/core/iomgr/wakeup_fd_pipe.c",
@@ -367,7 +369,6 @@
         "include/grpc/support/atm_gcc_atomic.h",
         "include/grpc/support/atm_gcc_sync.h",
         "include/grpc/support/atm_win32.h",
-        "include/grpc/support/cancellable_platform.h",
         "include/grpc/support/cmdline.h",
         "include/grpc/support/cpu.h",
         "include/grpc/support/histogram.h",
@@ -402,7 +403,6 @@
       ],
       "src": [
         "src/core/support/alloc.c",
-        "src/core/support/cancellable.c",
         "src/core/support/cmdline.c",
         "src/core/support/cpu_iphone.c",
         "src/core/support/cpu_linux.c",
@@ -572,6 +572,29 @@
       "secure": "no",
       "vs_project_guid": "{46CEDFFF-9692-456A-AA24-38B5D6BCF4C5}"
     },
+    {
+      "name": "grpc_zookeeper",
+      "build": "all",
+      "language": "c",
+      "public_headers": [
+        "include/grpc/grpc_zookeeper.h"
+      ],
+      "headers": [
+        "src/core/client_config/resolvers/zookeeper_resolver.h"
+      ],
+      "src": [
+        "src/core/client_config/resolvers/zookeeper_resolver.c"
+      ],
+      "deps": [
+        "gpr",
+        "grpc"
+      ],
+      "external_deps": [
+        "zookeeper"
+      ],
+      "secure": "no",
+      "vs_project_guid": "{F14EBEC1-DC43-45D3-8A7D-1A47072EFE50}"
+    },
     {
       "name": "reconnect_server",
       "build": "private",
@@ -1106,18 +1129,6 @@
         "grpc"
       ]
     },
-    {
-      "name": "gpr_cancellable_test",
-      "build": "test",
-      "language": "c",
-      "src": [
-        "test/core/support/cancellable_test.c"
-      ],
-      "deps": [
-        "gpr_test_util",
-        "gpr"
-      ]
-    },
     {
       "name": "gpr_cmdline_test",
       "build": "test",
@@ -1875,6 +1886,23 @@
         "gpr"
       ]
     },
+    {
+      "name": "udp_server_test",
+      "build": "test",
+      "language": "c",
+      "src": [
+        "test/core/iomgr/udp_server_test.c"
+      ],
+      "deps": [
+        "grpc_test_util",
+        "grpc",
+        "gpr_test_util",
+        "gpr"
+      ],
+      "platforms": [
+        "posix"
+      ]
+    },
     {
       "name": "uri_parser_test",
       "build": "test",
@@ -2642,6 +2670,26 @@
         "gpr_test_util",
         "gpr"
       ]
+    },
+    {
+      "name": "zookeeper_test",
+      "build": "test",
+      "language": "c++",
+      "src": [
+        "test/cpp/end2end/zookeeper_test.cc"
+      ],
+      "deps": [
+        "grpc++_test_util",
+        "grpc_test_util",
+        "grpc++",
+        "grpc_zookeeper",
+        "grpc",
+        "gpr_test_util",
+        "gpr"
+      ],
+      "external_deps": [
+        "zookeeper"
+      ]
     }
   ]
 }

doc/connectivity-semantics-and-api.md

@@ -38,7 +38,7 @@ because the server is not yet available), the channel may spend increasingly
 large amounts of time in this state.
 
 IDLE: This is the state where the channel is not even trying to create a
-connection because of a lack of new or pending RPCs. New channels MAY be created
+connection because of a lack of new or pending RPCs. New RPCs  MAY be created
 in this state. Any attempt to start an RPC on the channel will push the channel
 out of this state to connecting. When there has been no RPC activity on a channel
 for a specified IDLE_TIMEOUT, i.e., no new or pending (active) RPCs for this

gRPC.podspec

@@ -73,7 +73,6 @@ Pod::Spec.new do |s|
                       'grpc/support/atm_gcc_atomic.h',
                       'grpc/support/atm_gcc_sync.h',
                       'grpc/support/atm_win32.h',
-                      'grpc/support/cancellable_platform.h',
                       'grpc/support/cmdline.h',
                       'grpc/support/cpu.h',
                       'grpc/support/histogram.h',
@@ -97,7 +96,6 @@ Pod::Spec.new do |s|
                       'grpc/support/tls_pthread.h',
                       'grpc/support/useful.h',
                       'src/core/support/alloc.c',
-                      'src/core/support/cancellable.c',
                       'src/core/support/cmdline.c',
                       'src/core/support/cpu_iphone.c',
                       'src/core/support/cpu_linux.c',
@@ -204,6 +202,7 @@ Pod::Spec.new do |s|
                       'src/core/iomgr/tcp_server.h',
                       'src/core/iomgr/tcp_windows.h',
                       'src/core/iomgr/time_averaged_stats.h',
+                      'src/core/iomgr/udp_server.h',
                       'src/core/iomgr/wakeup_fd_pipe.h',
                       'src/core/iomgr/wakeup_fd_posix.h',
                       'src/core/json/json.h',
@@ -335,6 +334,7 @@ Pod::Spec.new do |s|
                       'src/core/iomgr/tcp_server_windows.c',
                       'src/core/iomgr/tcp_windows.c',
                       'src/core/iomgr/time_averaged_stats.c',
+                      'src/core/iomgr/udp_server.c',
                       'src/core/iomgr/wakeup_fd_eventfd.c',
                       'src/core/iomgr/wakeup_fd_nospecial.c',
                       'src/core/iomgr/wakeup_fd_pipe.c',
@@ -471,6 +471,7 @@ Pod::Spec.new do |s|
                               'src/core/iomgr/tcp_server.h',
                               'src/core/iomgr/tcp_windows.h',
                               'src/core/iomgr/time_averaged_stats.h',
+                              'src/core/iomgr/udp_server.h',
                               'src/core/iomgr/wakeup_fd_pipe.h',
                               'src/core/iomgr/wakeup_fd_posix.h',
                               'src/core/json/json.h',

include/grpc++/client_context.h

@@ -218,15 +218,11 @@ class ClientContext {
   void set_call(grpc_call* call,
                 const std::shared_ptr<ChannelInterface>& channel);
 
-  grpc_completion_queue* cq() { return cq_; }
-  void set_cq(grpc_completion_queue* cq) { cq_ = cq; }
-
   grpc::string authority() { return authority_; }
 
   bool initial_metadata_received_;
   std::shared_ptr<ChannelInterface> channel_;
   grpc_call* call_;
-  grpc_completion_queue* cq_;
   gpr_timespec deadline_;
   grpc::string authority_;
   std::shared_ptr<Credentials> creds_;

include/grpc++/completion_queue.h

@@ -63,6 +63,7 @@ template <class ServiceType, class RequestType, class ResponseType>
 class ServerStreamingHandler;
 template <class ServiceType, class RequestType, class ResponseType>
 class BidiStreamingHandler;
+class UnknownMethodHandler;
 
 class ChannelInterface;
 class ClientContext;
@@ -138,6 +139,7 @@ class CompletionQueue : public GrpcLibrary {
   friend class ServerStreamingHandler;
   template <class ServiceType, class RequestType, class ResponseType>
   friend class BidiStreamingHandler;
+  friend class UnknownMethodHandler;
   friend class ::grpc::Server;
   friend class ::grpc::ServerContext;
   template <class InputMessage, class OutputMessage>

include/grpc++/impl/call.h

@@ -173,6 +173,7 @@ class CallOpSendInitialMetadata {
     grpc_op* op = &ops[(*nops)++];
     op->op = GRPC_OP_SEND_INITIAL_METADATA;
     op->flags = 0;
+    op->reserved = NULL;
     op->data.send_initial_metadata.count = initial_metadata_count_;
     op->data.send_initial_metadata.metadata = initial_metadata_;
   }
@@ -206,6 +207,7 @@ class CallOpSendMessage {
     grpc_op* op = &ops[(*nops)++];
     op->op = GRPC_OP_SEND_MESSAGE;
     op->flags = write_options_.flags();
+    op->reserved = NULL;
     op->data.send_message = send_buf_;
     // Flags are per-message: clear them after use.
     write_options_.Clear();
@@ -248,6 +250,7 @@ class CallOpRecvMessage {
     grpc_op* op = &ops[(*nops)++];
     op->op = GRPC_OP_RECV_MESSAGE;
     op->flags = 0;
+    op->reserved = NULL;
     op->data.recv_message = &recv_buf_;
   }
 
@@ -313,6 +316,7 @@ class CallOpGenericRecvMessage {
     grpc_op* op = &ops[(*nops)++];
     op->op = GRPC_OP_RECV_MESSAGE;
     op->flags = 0;
+    op->reserved = NULL;
     op->data.recv_message = &recv_buf_;
   }
 
@@ -350,6 +354,7 @@ class CallOpClientSendClose {
     grpc_op* op = &ops[(*nops)++];
     op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
     op->flags = 0;
+    op->reserved = NULL;
   }
   void FinishOp(bool* status, int max_message_size) { send_ = false; }
 
@@ -383,6 +388,7 @@ class CallOpServerSendStatus {
     op->data.send_status_from_server.status_details =
         send_status_details_.empty() ? nullptr : send_status_details_.c_str();
     op->flags = 0;
+    op->reserved = NULL;
   }
 
   void FinishOp(bool* status, int max_message_size) {
@@ -416,6 +422,7 @@ class CallOpRecvInitialMetadata {
     op->op = GRPC_OP_RECV_INITIAL_METADATA;
     op->data.recv_initial_metadata = &recv_initial_metadata_arr_;
     op->flags = 0;
+    op->reserved = NULL;
   }
   void FinishOp(bool* status, int max_message_size) {
     if (recv_initial_metadata_ == nullptr) return;
@@ -453,6 +460,7 @@ class CallOpClientRecvStatus {
     op->data.recv_status_on_client.status_details_capacity =
         &status_details_capacity_;
     op->flags = 0;
+    op->reserved = NULL;
   }
 
   void FinishOp(bool* status, int max_message_size) {

include/grpc++/impl/rpc_service_method.h

@@ -208,6 +208,21 @@ class BidiStreamingHandler : public MethodHandler {
   ServiceType* service_;
 };
 
+// Handle unknown method by returning UNIMPLEMENTED error.
+class UnknownMethodHandler : public MethodHandler {
+ public:
+  void RunHandler(const HandlerParameter& param) GRPC_FINAL {
+    Status status(StatusCode::UNIMPLEMENTED, "");
+    CallOpSet<CallOpSendInitialMetadata, CallOpServerSendStatus> ops;
+    if (!param.server_context->sent_initial_metadata_) {
+      ops.SendInitialMetadata(param.server_context->initial_metadata_);
+    }
+    ops.ServerSendStatus(param.server_context->trailing_metadata_, status);
+    param.call->PerformOps(&ops);
+    param.call->cq()->Pluck(&ops);
+  }
+};
+
 // Server side rpc method class
 class RpcServiceMethod : public RpcMethod {
  public:

include/grpc++/server.h

@@ -228,6 +228,8 @@ class Server GRPC_FINAL : public GrpcLibrary, private CallHook {
   grpc::condition_variable callback_cv_;
 
   std::list<SyncRequest>* sync_methods_;
+  std::unique_ptr<RpcServiceMethod> unknown_method_;
+  bool has_generic_service_;
 
   // Pointer to the c grpc server.
   grpc_server* const server_;

include/grpc++/server_context.h

@@ -73,6 +73,7 @@ template <class ServiceType, class RequestType, class ResponseType>
 class ServerStreamingHandler;
 template <class ServiceType, class RequestType, class ResponseType>
 class BidiStreamingHandler;
+class UnknownMethodHandler;
 
 class Call;
 class CallOpBuffer;
@@ -159,6 +160,7 @@ class ServerContext {
   friend class ServerStreamingHandler;
   template <class ServiceType, class RequestType, class ResponseType>
   friend class BidiStreamingHandler;
+  friend class UnknownMethodHandler;
   friend class ::grpc::ClientContext;
 
   // Prevent copying.

include/grpc/byte_buffer.h

@@ -47,8 +47,12 @@ typedef enum {
 } grpc_byte_buffer_type;
 
 struct grpc_byte_buffer {
+  void *reserved;
   grpc_byte_buffer_type type;
   union {
+    struct {
+      void *reserved[8];
+    } reserved;
     struct {
       grpc_compression_algorithm compression;
       gpr_slice_buffer slice_buffer;

include/grpc/census.h

@@ -104,6 +104,61 @@ int census_context_deserialize(const char *buffer, census_context **context);
  * future census calls will result in undefined behavior. */
 void census_context_destroy(census_context *context);
 
+/* Max number of characters in tag key */
+#define CENSUS_MAX_TAG_KEY_LENGTH 20
+/* Max number of tag value characters */
+#define CENSUS_MAX_TAG_VALUE_LENGTH 50
+
+/* A Census tag set is a collection of key:value string pairs; these form the
+   basis against which Census metrics will be recorded. Keys are unique within
+   a tag set. All contexts have an associated tag set. */
+typedef struct census_tag_set census_tag_set;
+
+/* Returns a pointer to a newly created, empty tag set. If size_hint > 0,
+   indicates that the tag set is intended to hold approximately that number
+   of tags. */
+census_tag_set *census_tag_set_create(size_t size_hint);
+
+/* Add a new tag key/value to an existing tag set; if the tag key already exists
+   in the tag set, then its value is overwritten with the new one. Can also be
+   used to delete a tag, by specifying a NULL value. If key is NULL, returns
+   the number of tags in the tag set.
+   Return values:
+   -1: invalid length key or value
+   non-negative value: the number of tags in the tag set. */
+int census_tag_set_add(census_tag_set *tags, const char *key,
+                       const char *value);
+
+/* Destroys a tag set. This function must be called to prevent memory leaks.
+   Once called, the tag set cannot be used again. */
+void census_tag_set_destroy(census_tag_set *tags);
+
+/* Get a contexts tag set. */
+census_tag_set *census_context_tag_set(census_context *context);
+
+/* A read-only representation of a tag for use by census clients. */
+typedef struct {
+  size_t key_len;    /* Number of bytes in tag key. */
+  const char *key;   /* A pointer to the tag key. May not be null-terminated. */
+  size_t value_len;  /* Number of bytes in tag value. */
+  const char *value; /* Pointer to the tag value. May not be null-terminated. */
+} census_tag_const;
+
+/* Used to iterate through a tag sets contents. */
+typedef struct census_tag_set_iterator census_tag_set_iterator;
+
+/* Open a tag set for iteration. The tag set must not be modified while
+   iteration is ongoing. Returns an iterator for use in following functions. */
+census_tag_set_iterator *census_tag_set_open(census_tag_set *tags);
+
+/* Get the next tag in the tag set, by writing into the 'tag' argument. Returns
+   1 if there is a "next" tag, 0 if there are no more tags. */
+int census_tag_set_next(census_tag_set_iterator *it, census_tag_const *tag);
+
+/* Close an iterator opened by census_tag_set_open(). The iterator will be
+   invalidated, and should not be used once close is called. */
+void census_tag_set_close(census_tag_set_iterator *it);
+
 /* A census statistic to be recorded comprises two parts: an ID for the
  * particular statistic and the value to be recorded against it. */
 typedef struct {

include/grpc/grpc.h

@@ -202,13 +202,14 @@ typedef struct grpc_metadata {
   const char *key;
   const char *value;
   size_t value_length;
+  gpr_uint32 flags;
 
   /** The following fields are reserved for grpc internal use.
       There is no need to initialize them, and they will be set to garbage
      during
       calls to grpc. */
   struct {
-    void *obfuscated[3];
+    void *obfuscated[4];
   } internal_data;
 } grpc_metadata;
 
@@ -251,6 +252,7 @@ typedef struct {
   char *host;
   size_t host_capacity;
   gpr_timespec deadline;
+  void *reserved;
 } grpc_call_details;
 
 void grpc_call_details_init(grpc_call_details *details);
@@ -306,7 +308,13 @@ typedef struct grpc_op {
   grpc_op_type op;
   /** Write flags bitset for grpc_begin_messages */
   gpr_uint32 flags;
+  /** Reserved for future usage */
+  void *reserved;
   union {
+    /** Reserved for future usage */
+    struct {
+      void *reserved[8];
+    } reserved;
     struct {
       size_t count;
       grpc_metadata *metadata;
@@ -368,6 +376,23 @@ typedef struct grpc_op {
   } data;
 } grpc_op;
 
+/** Registers a plugin to be initialized and destroyed with the library.
+
+    The \a init and \a destroy functions will be invoked as part of 
+    \a grpc_init() and \a grpc_shutdown(), respectively. 
+    Note that these functions can be invoked an arbitrary number of times
+    (and hence so will \a init and \a destroy).
+    It is safe to pass NULL to either argument. Plugins are destroyed in 
+    the reverse order they were initialized. */
+void grpc_register_plugin(void (*init)(void), void (*destroy)(void));
+
+/** Frees the memory used by all the plugin information.
+
+    While grpc_init and grpc_shutdown can be called multiple times, the plugins
+    won't be unregistered and their memory cleaned up unless you call that
+    function. Using atexit(grpc_unregister_all_plugins) is a valid method. */
+void grpc_unregister_all_plugins();
+
 /* Propagation bits: this can be bitwise or-ed to form propagation_mask for
  * grpc_call */
 /** Propagate deadline */
@@ -380,8 +405,8 @@ typedef struct grpc_op {
 
 /* Default propagation mask: clients of the core API are encouraged to encode
    deltas from this in their implementations... ie write:
-   GRPC_PROPAGATE_DEFAULTS & ~GRPC_PROPAGATE_DEADLINE to disable deadline 
-   propagation. Doing so gives flexibility in the future to define new 
+   GRPC_PROPAGATE_DEFAULTS & ~GRPC_PROPAGATE_DEADLINE to disable deadline
+   propagation. Doing so gives flexibility in the future to define new
    propagation types that are default inherited or not. */
 #define GRPC_PROPAGATE_DEFAULTS                                                \
   ((gpr_uint32)((                                                              \
@@ -408,7 +433,7 @@ void grpc_shutdown(void);
 const char *grpc_version_string(void);
 
 /** Create a completion queue */
-grpc_completion_queue *grpc_completion_queue_create(void);
+grpc_completion_queue *grpc_completion_queue_create(void *reserved);
 
 /** Blocks until an event is available, the completion queue is being shut down,
     or deadline is reached.
@@ -419,7 +444,7 @@ grpc_completion_queue *grpc_completion_queue_create(void);
     Callers must not call grpc_completion_queue_next and
     grpc_completion_queue_pluck simultaneously on the same completion queue. */
 grpc_event grpc_completion_queue_next(grpc_completion_queue *cq,
-                                      gpr_timespec deadline);
+                                      gpr_timespec deadline, void *reserved);
 
 /** Blocks until an event with tag 'tag' is available, the completion queue is
     being shutdown or deadline is reached.
@@ -428,12 +453,12 @@ grpc_event grpc_completion_queue_next(grpc_completion_queue *cq,
     otherwise a grpc_event describing the event that occurred.
 
     Callers must not call grpc_completion_queue_next and
-    grpc_completion_queue_pluck simultaneously on the same completion queue. 
-    
+    grpc_completion_queue_pluck simultaneously on the same completion queue.
+
     Completion queues support a maximum of GRPC_MAX_COMPLETION_QUEUE_PLUCKERS
     concurrently executing plucks at any time. */
 grpc_event grpc_completion_queue_pluck(grpc_completion_queue *cq, void *tag,
-                                       gpr_timespec deadline);
+                                       gpr_timespec deadline, void *reserved);
 
 /** Maximum number of outstanding grpc_completion_queue_pluck executions per
     completion queue */
@@ -469,24 +494,24 @@ void grpc_channel_watch_connectivity_state(
     completions are sent to 'completion_queue'. 'method' and 'host' need only
     live through the invocation of this function.
     If parent_call is non-NULL, it must be a server-side call. It will be used
-    to propagate properties from the server call to this new client call. 
+    to propagate properties from the server call to this new client call.
     */
 grpc_call *grpc_channel_create_call(grpc_channel *channel,
                                     grpc_call *parent_call,
                                     gpr_uint32 propagation_mask,
                                     grpc_completion_queue *completion_queue,
                                     const char *method, const char *host,
-                                    gpr_timespec deadline);
+                                    gpr_timespec deadline, 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);
+                                 const char *host, void *reserved);
 
 /** Create a call given a handle returned from grpc_channel_register_call */
 grpc_call *grpc_channel_create_registered_call(
     grpc_channel *channel, grpc_call *parent_call, gpr_uint32 propagation_mask,
     grpc_completion_queue *completion_queue, void *registered_call_handle,
-    gpr_timespec deadline);
+    gpr_timespec deadline, void *reserved);
 
 /** Start a batch of operations defined in the array ops; when complete, post a
     completion of type 'tag' to the completion queue bound to the call.
@@ -500,7 +525,7 @@ grpc_call *grpc_channel_create_registered_call(
     containing just send operations independently from batches containing just
     receive operations. */
 grpc_call_error grpc_call_start_batch(grpc_call *call, const grpc_op *ops,
-                                      size_t nops, void *tag);
+                                      size_t nops, void *tag, void *reserved);
 
 /** Returns a newly allocated string representing the endpoint to which this
     call is communicating with. The string is in the uri format accepted by
@@ -532,7 +557,8 @@ char *grpc_channel_get_target(grpc_channel *channel);
     more on this. The data in 'args' need only live through the invocation of
     this function. */
 grpc_channel *grpc_insecure_channel_create(const char *target,
-                                           const grpc_channel_args *args);
+                                           const grpc_channel_args *args,
+                                           void *reserved);
 
 /** Create a lame client: this client fails every operation attempted on it. */
 grpc_channel *grpc_lame_client_channel_create(const char *target);
@@ -551,7 +577,7 @@ void grpc_channel_destroy(grpc_channel *channel);
     THREAD-SAFETY grpc_call_cancel and grpc_call_cancel_with_status
     are thread-safe, and can be called at any point before grpc_call_destroy
     is called.*/
-grpc_call_error grpc_call_cancel(grpc_call *call);
+grpc_call_error grpc_call_cancel(grpc_call *call, void *reserved);
 
 /** Called by clients to cancel an RPC on the server.
     Can be called multiple times, from any thread.
@@ -561,7 +587,8 @@ grpc_call_error grpc_call_cancel(grpc_call *call);
     remote endpoint. */
 grpc_call_error grpc_call_cancel_with_status(grpc_call *call,
                                              grpc_status_code status,
-                                             const char *description);
+                                             const char *description,
+                                             void *reserved);
 
 /** Destroy a call.
     THREAD SAFETY: grpc_call_destroy is thread-compatible */
@@ -600,14 +627,16 @@ grpc_call_error grpc_server_request_registered_call(
     be specified with args. If no additional configuration is needed, args can
     be NULL. See grpc_channel_args for more. The data in 'args' need only live
     through the invocation of this function. */
-grpc_server *grpc_server_create(const grpc_channel_args *args);
+grpc_server *grpc_server_create(const grpc_channel_args *args,
+                                void *reserved);
 
 /** Register a completion queue with the server. Must be done for any
     notification completion queue that is passed to grpc_server_request_*_call
     and to grpc_server_shutdown_and_notify. Must be performed prior to
     grpc_server_start. */
 void grpc_server_register_completion_queue(grpc_server *server,
-                                           grpc_completion_queue *cq);
+                                           grpc_completion_queue *cq,
+                                           void *reserved);
 
 /** Add a HTTP2 over plaintext over tcp listener.
     Returns bound port number on success, 0 on failure.

include/grpc/support/cancellable_platform.h → include/grpc/grpc_zookeeper.h

@@ -31,26 +31,29 @@
  *
  */
 
-#ifndef GRPC_SUPPORT_CANCELLABLE_PLATFORM_H
-#define GRPC_SUPPORT_CANCELLABLE_PLATFORM_H
+/** Support zookeeper as alternative name system in addition to DNS
+ *  Zookeeper name in gRPC is represented as a URI:
+ *  zookeeper://host:port/path/service/instance
+ *
+ *  Where zookeeper is the name system scheme
+ *  host:port is the address of a zookeeper server
+ *  /path/service/instance is the zookeeper name to be resolved
+ *
+ *  Refer doc/naming.md for more details
+ */
+
+#ifndef GRPC_GRPC_ZOOKEEPER_H
+#define GRPC_GRPC_ZOOKEEPER_H
 
-#include <grpc/support/atm.h>
-#include <grpc/support/sync.h>
+#ifdef __cplusplus
+extern "C" {
+#endif
 
-struct gpr_cancellable_list_ {
-  /* a doubly-linked list on cancellable's waiters queue */
-  struct gpr_cancellable_list_ *next;
-  struct gpr_cancellable_list_ *prev;
-  /* The following two fields are arguments to gpr_cv_cancellable_wait() */
-  gpr_mu *mu;
-  gpr_cv *cv;
-};
+/** Register zookeeper name resolver in grpc */
+void grpc_zookeeper_register();
 
-/* Internal definition of gpr_cancellable. */
-typedef struct {
-  gpr_mu mu; /* protects waiters and modifications to cancelled */
-  gpr_atm cancelled;
-  struct gpr_cancellable_list_ waiters;
-} gpr_cancellable;
+#ifdef __cplusplus
+}
+#endif
 
-#endif  /* GRPC_SUPPORT_CANCELLABLE_PLATFORM_H */
+#endif /* GRPC_GRPC_ZOOKEEPER_H */

include/grpc/support/port_platform.h

@@ -173,6 +173,8 @@
 #endif /* _LP64 */
 #elif defined(__APPLE__)
 #include <TargetConditionals.h>
+/* Provides IPV6_RECVPKTINFO */
+#define __APPLE_USE_RFC_3542
 #ifndef _BSD_SOURCE
 #define _BSD_SOURCE
 #endif

include/grpc/support/sync.h

@@ -65,7 +65,6 @@
 #endif
 
 #include <grpc/support/time.h> /* for gpr_timespec */
-#include <grpc/support/cancellable_platform.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -121,11 +120,6 @@ void gpr_cv_destroy(gpr_cv *cv);
    holds an exclusive lock on *mu.  */
 int gpr_cv_wait(gpr_cv *cv, gpr_mu *mu, gpr_timespec abs_deadline);
 
-/* Behave like gpr_cv_wait(cv, mu, abs_deadline), except behave as though
-   the deadline has expired if *c is cancelled. */
-int gpr_cv_cancellable_wait(gpr_cv *cv, gpr_mu *mu, gpr_timespec abs_deadline,
-                            gpr_cancellable *c);
-
 /* If any threads are waiting on *cv, wake at least one.
    Clients may treat this as an optimization of gpr_cv_broadcast()
    for use in the case where waking more than one waiter is not useful.
@@ -135,28 +129,6 @@ void gpr_cv_signal(gpr_cv *cv);
 /* Wake all threads waiting on *cv.  Requires:  *cv initialized.  */
 void gpr_cv_broadcast(gpr_cv *cv);
 
-/* --- Cancellation ---
-   A gpr_cancellable can be used with gpr_cv_cancellable_wait()
-   or gpr_event_cancellable_wait() cancel pending waits. */
-
-/* Initialize *c. */
-void gpr_cancellable_init(gpr_cancellable *c);
-
-/* Cause *c no longer to be initialized, freeing any memory in use.  Requires:
-   *c initialized; no other concurrent operation on *c.  */
-void gpr_cancellable_destroy(gpr_cancellable *c);
-
-/* Return non-zero iff *c has been cancelled.  Requires *c initialized.
-   This call is faster than acquiring a mutex on most platforms. */
-int gpr_cancellable_is_cancelled(gpr_cancellable *c);
-
-/* Cancel *c.  If *c was not previously cancelled, cause
-   gpr_cancellable_init() to return non-zero, and outstanding and future
-   calls to gpr_cv_cancellable_wait() and gpr_event_cancellable_wait() to
-   return immediately indicating a timeout has occurred; otherwise do nothing.
-   Requires *c initialized.*/
-void gpr_cancellable_cancel(gpr_cancellable *c);
-
 /* --- One-time initialization ---
 
    gpr_once must be declared with static storage class, and initialized with
@@ -199,11 +171,6 @@ void *gpr_event_get(gpr_event *ev);
    on most platforms.  */
 void *gpr_event_wait(gpr_event *ev, gpr_timespec abs_deadline);
 
-/* Behave like gpr_event_wait(ev, abs_deadline), except behave as though
-   the deadline has expired if *c is cancelled. */
-void *gpr_event_cancellable_wait(gpr_event *ev, gpr_timespec abs_deadline,
-                                 gpr_cancellable *c);
-
 /* --- Reference counting ---
 
    These calls act on the type gpr_refcount.  It requires no destruction.  */

src/compiler/csharp_generator_helpers.h

@@ -41,7 +41,7 @@ namespace grpc_csharp_generator {
 
 inline bool ServicesFilename(const grpc::protobuf::FileDescriptor *file,
                              grpc::string *file_name_or_error) {
-  *file_name_or_error = grpc_generator::FileNameInUpperCamel(file) + "Grpc.cs";
+  *file_name_or_error = grpc_generator::FileNameInUpperCamel(file, false) + "Grpc.cs";
   return true;
 }
 

src/compiler/generator_helpers.h

@@ -125,16 +125,23 @@ inline grpc::string LowerUnderscoreToUpperCamel(grpc::string str) {
   return result;
 }
 
-inline grpc::string FileNameInUpperCamel(const grpc::protobuf::FileDescriptor *file) {
+inline grpc::string FileNameInUpperCamel(const grpc::protobuf::FileDescriptor *file,
+                                         bool include_package_path) {
   std::vector<grpc::string> tokens = tokenize(StripProto(file->name()), "/");
   grpc::string result = "";
-  for (unsigned int i = 0; i < tokens.size() - 1; i++) {
-    result += tokens[i] + "/";
+  if (include_package_path) {
+    for (unsigned int i = 0; i < tokens.size() - 1; i++) {
+      result += tokens[i] + "/";
+    }
   }
   result += LowerUnderscoreToUpperCamel(tokens.back());
   return result;
 }
 
+inline grpc::string FileNameInUpperCamel(const grpc::protobuf::FileDescriptor *file) {
+  return FileNameInUpperCamel(file, true);
+}
+
 enum MethodType {
   METHODTYPE_NO_STREAMING,
   METHODTYPE_CLIENT_STREAMING,

src/compiler/objective_c_generator.cc

@@ -44,7 +44,6 @@ using ::google::protobuf::compiler::objectivec::ClassName;
 using ::grpc::protobuf::io::Printer;
 using ::grpc::protobuf::MethodDescriptor;
 using ::grpc::protobuf::ServiceDescriptor;
-using ::grpc::string;
 using ::std::map;
 
 namespace grpc_objective_c_generator {
@@ -52,7 +51,7 @@ namespace {
 
 void PrintProtoRpcDeclarationAsPragma(Printer *printer,
                                       const MethodDescriptor *method,
-                                      map<string, string> vars) {
+                                      map< ::grpc::string, ::grpc::string> vars) {
   vars["client_stream"] = method->client_streaming() ? "stream " : "";
   vars["server_stream"] = method->server_streaming() ? "stream " : "";
 
@@ -62,7 +61,7 @@ void PrintProtoRpcDeclarationAsPragma(Printer *printer,
 }
 
 void PrintMethodSignature(Printer *printer, const MethodDescriptor *method,
-                          const map<string, string> &vars) {
+                          const map< ::grpc::string, ::grpc::string> &vars) {
   // TODO(jcanizales): Print method comments.
 
   printer->Print(vars, "- ($return_type$)$method_name$With");
@@ -85,7 +84,7 @@ void PrintMethodSignature(Printer *printer, const MethodDescriptor *method,
 }
 
 void PrintSimpleSignature(Printer *printer, const MethodDescriptor *method,
-                          map<string, string> vars) {
+                          map< ::grpc::string, ::grpc::string> vars) {
   vars["method_name"] =
       grpc_generator::LowercaseFirstLetter(vars["method_name"]);
   vars["return_type"] = "void";
@@ -93,14 +92,14 @@ void PrintSimpleSignature(Printer *printer, const MethodDescriptor *method,
 }
 
 void PrintAdvancedSignature(Printer *printer, const MethodDescriptor *method,
-                            map<string, string> vars) {
+                            map< ::grpc::string, ::grpc::string> vars) {
   vars["method_name"] = "RPCTo" + vars["method_name"];
   vars["return_type"] = "ProtoRPC *";
   PrintMethodSignature(printer, method, vars);
 }
 
-inline map<string, string> GetMethodVars(const MethodDescriptor *method) {
-  map<string, string> res;
+inline map< ::grpc::string, ::grpc::string> GetMethodVars(const MethodDescriptor *method) {
+  map< ::grpc::string, ::grpc::string> res;
   res["method_name"] = method->name();
   res["request_type"] = method->input_type()->name();
   res["response_type"] = method->output_type()->name();
@@ -110,7 +109,7 @@ inline map<string, string> GetMethodVars(const MethodDescriptor *method) {
 }
 
 void PrintMethodDeclarations(Printer *printer, const MethodDescriptor *method) {
-  map<string, string> vars = GetMethodVars(method);
+  map< ::grpc::string, ::grpc::string> vars = GetMethodVars(method);
 
   PrintProtoRpcDeclarationAsPragma(printer, method, vars);
 
@@ -121,7 +120,7 @@ void PrintMethodDeclarations(Printer *printer, const MethodDescriptor *method) {
 }
 
 void PrintSimpleImplementation(Printer *printer, const MethodDescriptor *method,
-                               map<string, string> vars) {
+                               map< ::grpc::string, ::grpc::string> vars) {
   printer->Print("{\n");
   printer->Print(vars, "  [[self RPCTo$method_name$With");
   if (method->client_streaming()) {
@@ -139,7 +138,7 @@ void PrintSimpleImplementation(Printer *printer, const MethodDescriptor *method,
 
 void PrintAdvancedImplementation(Printer *printer,
                                  const MethodDescriptor *method,
-                                 map<string, string> vars) {
+                                 map< ::grpc::string, ::grpc::string> vars) {
   printer->Print("{\n");
   printer->Print(vars, "  return [self RPCToMethod:@\"$method_name$\"\n");
 
@@ -164,7 +163,7 @@ void PrintAdvancedImplementation(Printer *printer,
 
 void PrintMethodImplementations(Printer *printer,
                                 const MethodDescriptor *method) {
-  map<string, string> vars = GetMethodVars(method);
+  map< ::grpc::string, ::grpc::string> vars = GetMethodVars(method);
 
   PrintProtoRpcDeclarationAsPragma(printer, method, vars);
 
@@ -179,14 +178,14 @@ void PrintMethodImplementations(Printer *printer,
 
 }  // namespace
 
-string GetHeader(const ServiceDescriptor *service) {
-  string output;
+::grpc::string GetHeader(const ServiceDescriptor *service) {
+  ::grpc::string output;
   {
     // Scope the output stream so it closes and finalizes output to the string.
     grpc::protobuf::io::StringOutputStream output_stream(&output);
     Printer printer(&output_stream, '$');
 
-    map<string, string> vars = {{"service_class", ServiceClassName(service)}};
+    map< ::grpc::string, ::grpc::string> vars = {{"service_class", ServiceClassName(service)}};
 
     printer.Print(vars, "@protocol $service_class$ <NSObject>\n\n");
 
@@ -209,14 +208,14 @@ string GetHeader(const ServiceDescriptor *service) {
   return output;
 }
 
-string GetSource(const ServiceDescriptor *service) {
-  string output;
+::grpc::string GetSource(const ServiceDescriptor *service) {
+ ::grpc::string output;
   {
     // Scope the output stream so it closes and finalizes output to the string.
     grpc::protobuf::io::StringOutputStream output_stream(&output);
     Printer printer(&output_stream, '$');
 
-    map<string, string> vars = {{"service_name", service->name()},
+    map< ::grpc::string,::grpc::string> vars = {{"service_name", service->name()},
                                 {"service_class", ServiceClassName(service)},
                                 {"package", service->file()->package()}};
 

src/compiler/objective_c_plugin.cc

@@ -39,44 +39,43 @@
 #include "src/compiler/objective_c_generator.h"
 #include "src/compiler/objective_c_generator_helpers.h"
 
-using ::grpc::string;
-
 class ObjectiveCGrpcGenerator : public grpc::protobuf::compiler::CodeGenerator {
  public:
   ObjectiveCGrpcGenerator() {}
   virtual ~ObjectiveCGrpcGenerator() {}
 
   virtual bool Generate(const grpc::protobuf::FileDescriptor *file,
-                        const string &parameter,
+                        const ::grpc::string &parameter,
                         grpc::protobuf::compiler::GeneratorContext *context,
-                        string *error) const {
+                        ::grpc::string *error) const {
 
     if (file->service_count() == 0) {
       // No services.  Do nothing.
       return true;
     }
 
-    string file_name = grpc_generator::FileNameInUpperCamel(file);
-    string prefix = file->options().objc_class_prefix();
+    ::grpc::string file_name = grpc_generator::FileNameInUpperCamel(file);
+    ::grpc::string prefix = file->options().objc_class_prefix();
 
     {
       // Generate .pbrpc.h
 
-      string imports = string("#import \"") + file_name + ".pbobjc.h\"\n\n"
+      ::grpc::string imports = ::grpc::string("#import \"") + file_name +
+        ".pbobjc.h\"\n\n"
         "#import <ProtoRPC/ProtoService.h>\n"
         "#import <RxLibrary/GRXWriteable.h>\n"
         "#import <RxLibrary/GRXWriter.h>\n";
 
       // TODO(jcanizales): Instead forward-declare the input and output types
       // and import the files in the .pbrpc.m
-      string proto_imports;
+      ::grpc::string proto_imports;
       for (int i = 0; i < file->dependency_count(); i++) {
-        string header = grpc_objective_c_generator::MessageHeaderName(
+        ::grpc::string header = grpc_objective_c_generator::MessageHeaderName(
             file->dependency(i));
-        proto_imports += string("#import \"") + header + "\"\n";
+        proto_imports += ::grpc::string("#import \"") + header + "\"\n";
       }
 
-      string declarations;
+      ::grpc::string declarations;
       for (int i = 0; i < file->service_count(); i++) {
         const grpc::protobuf::ServiceDescriptor *service = file->service(i);
         declarations += grpc_objective_c_generator::GetHeader(service);
@@ -89,11 +88,12 @@ class ObjectiveCGrpcGenerator : public grpc::protobuf::compiler::CodeGenerator {
     {
       // Generate .pbrpc.m
 
-      string imports = string("#import \"") + file_name + ".pbrpc.h\"\n\n"
+      ::grpc::string imports = ::grpc::string("#import \"") + file_name +
+        ".pbrpc.h\"\n\n"
         "#import <ProtoRPC/ProtoRPC.h>\n"
         "#import <RxLibrary/GRXWriter+Immediate.h>\n";
 
-      string definitions;
+      ::grpc::string definitions;
       for (int i = 0; i < file->service_count(); i++) {
         const grpc::protobuf::ServiceDescriptor *service = file->service(i);
         definitions += grpc_objective_c_generator::GetSource(service);
@@ -108,7 +108,7 @@ class ObjectiveCGrpcGenerator : public grpc::protobuf::compiler::CodeGenerator {
  private:
   // Write the given code into the given file.
   void Write(grpc::protobuf::compiler::GeneratorContext *context,
-              const string &filename, const string &code) const {
+              const ::grpc::string &filename, const ::grpc::string &code) const {
     std::unique_ptr<grpc::protobuf::io::ZeroCopyOutputStream> output(
         context->Open(filename));
     grpc::protobuf::io::CodedOutputStream coded_out(output.get());

src/core/client_config/resolvers/zookeeper_resolver.c

@@ -0,0 +1,501 @@
+/*
+ *
+ * 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/client_config/resolvers/zookeeper_resolver.h"
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/string_util.h>
+
+#include <grpc/grpc_zookeeper.h>
+#include <zookeeper/zookeeper.h>
+
+#include "src/core/client_config/lb_policies/pick_first.h"
+#include "src/core/client_config/resolver_registry.h"
+#include "src/core/iomgr/resolve_address.h"
+#include "src/core/support/string.h"
+#include "src/core/json/json.h"
+
+/** Zookeeper session expiration time in milliseconds */
+#define GRPC_ZOOKEEPER_SESSION_TIMEOUT 15000
+
+typedef struct {
+  /** base class: must be first */
+  grpc_resolver base;
+  /** refcount */
+  gpr_refcount refs;
+  /** name to resolve */
+  char *name;
+  /** subchannel factory */
+  grpc_subchannel_factory *subchannel_factory;
+  /** load balancing policy factory */
+  grpc_lb_policy *(*lb_policy_factory)(grpc_subchannel **subchannels,
+                                       size_t num_subchannels);
+
+  /** mutex guarding the rest of the state */
+  gpr_mu mu;
+  /** are we currently resolving? */
+  int resolving;
+  /** which version of resolved_config have we published? */
+  int published_version;
+  /** which version of resolved_config is current? */
+  int resolved_version;
+  /** pending next completion, or NULL */
+  grpc_iomgr_closure *next_completion;
+  /** target config address for next completion */
+  grpc_client_config **target_config;
+  /** current (fully resolved) config */
+  grpc_client_config *resolved_config;
+
+  /** zookeeper handle */
+  zhandle_t *zookeeper_handle;
+  /** zookeeper resolved addresses */
+  grpc_resolved_addresses *resolved_addrs;
+  /** total number of addresses to be resolved */
+  int resolved_total;
+  /** number of addresses resolved */
+  int resolved_num;
+} zookeeper_resolver;
+
+static void zookeeper_destroy(grpc_resolver *r);
+
+static void zookeeper_start_resolving_locked(zookeeper_resolver *r);
+static void zookeeper_maybe_finish_next_locked(zookeeper_resolver *r);
+
+static void zookeeper_shutdown(grpc_resolver *r);
+static void zookeeper_channel_saw_error(grpc_resolver *r,
+                                        struct sockaddr *failing_address,
+                                        int failing_address_len);
+static void zookeeper_next(grpc_resolver *r, grpc_client_config **target_config,
+                           grpc_iomgr_closure *on_complete);
+
+static const grpc_resolver_vtable zookeeper_resolver_vtable = {
+    zookeeper_destroy, zookeeper_shutdown, zookeeper_channel_saw_error,
+    zookeeper_next};
+
+static void zookeeper_shutdown(grpc_resolver *resolver) {
+  zookeeper_resolver *r = (zookeeper_resolver *)resolver;
+  gpr_mu_lock(&r->mu);
+  if (r->next_completion != NULL) {
+    *r->target_config = NULL;
+    grpc_iomgr_add_callback(r->next_completion);
+    r->next_completion = NULL;
+  }
+  zookeeper_close(r->zookeeper_handle);
+  gpr_mu_unlock(&r->mu);
+}
+
+static void zookeeper_channel_saw_error(grpc_resolver *resolver,
+                                        struct sockaddr *sa, int len) {
+  zookeeper_resolver *r = (zookeeper_resolver *)resolver;
+  gpr_mu_lock(&r->mu);
+  if (r->resolving == 0) {
+    zookeeper_start_resolving_locked(r);
+  }
+  gpr_mu_unlock(&r->mu);
+}
+
+static void zookeeper_next(grpc_resolver *resolver,
+                           grpc_client_config **target_config,
+                           grpc_iomgr_closure *on_complete) {
+  zookeeper_resolver *r = (zookeeper_resolver *)resolver;
+  gpr_mu_lock(&r->mu);
+  GPR_ASSERT(r->next_completion == NULL);
+  r->next_completion = on_complete;
+  r->target_config = target_config;
+  if (r->resolved_version == 0 && r->resolving == 0) {
+    zookeeper_start_resolving_locked(r);
+  } else {
+    zookeeper_maybe_finish_next_locked(r);
+  }
+  gpr_mu_unlock(&r->mu);
+}
+
+/** Zookeeper global watcher for connection management 
+    TODO: better connection management besides logs */
+static void zookeeper_global_watcher(zhandle_t *zookeeper_handle, int type,
+                                     int state, const char *path,
+                                     void *watcher_ctx) {
+  if (type == ZOO_SESSION_EVENT) {
+    if (state == ZOO_EXPIRED_SESSION_STATE) {
+      gpr_log(GPR_ERROR, "Zookeeper session expired");
+    } else if (state == ZOO_AUTH_FAILED_STATE) {
+      gpr_log(GPR_ERROR, "Zookeeper authentication failed");
+    }
+  }
+}
+
+/** Zookeeper watcher triggered by changes to watched nodes
+    Once triggered, it tries to resolve again to get updated addresses */
+static void zookeeper_watcher(zhandle_t *zookeeper_handle, int type, int state,
+                              const char *path, void *watcher_ctx) {
+  if (watcher_ctx != NULL) {
+    zookeeper_resolver *r = (zookeeper_resolver *)watcher_ctx;
+    if (state == ZOO_CONNECTED_STATE) {
+      gpr_mu_lock(&r->mu);
+      if (r->resolving == 0) {
+        zookeeper_start_resolving_locked(r);
+      }
+      gpr_mu_unlock(&r->mu);
+    }
+  }
+}
+
+/** Callback function after getting all resolved addresses  
+    Creates a subchannel for each address */
+static void zookeeper_on_resolved(void *arg,
+                                  grpc_resolved_addresses *addresses) {
+  zookeeper_resolver *r = arg;
+  grpc_client_config *config = NULL;
+  grpc_subchannel **subchannels;
+  grpc_subchannel_args args;
+  grpc_lb_policy *lb_policy;
+  size_t i;
+  if (addresses != NULL) {
+    config = grpc_client_config_create();
+    subchannels = gpr_malloc(sizeof(grpc_subchannel *) * addresses->naddrs);
+    for (i = 0; i < addresses->naddrs; i++) {
+      memset(&args, 0, sizeof(args));
+      args.addr = (struct sockaddr *)(addresses->addrs[i].addr);
+      args.addr_len = addresses->addrs[i].len;
+      subchannels[i] = grpc_subchannel_factory_create_subchannel(
+          r->subchannel_factory, &args);
+    }
+    lb_policy = r->lb_policy_factory(subchannels, addresses->naddrs);
+    grpc_client_config_set_lb_policy(config, lb_policy);
+    GRPC_LB_POLICY_UNREF(lb_policy, "construction");
+    grpc_resolved_addresses_destroy(addresses);
+    gpr_free(subchannels);
+  }
+  gpr_mu_lock(&r->mu);
+  GPR_ASSERT(r->resolving == 1);
+  r->resolving = 0;
+  if (r->resolved_config != NULL) {
+    grpc_client_config_unref(r->resolved_config);
+  }
+  r->resolved_config = config;
+  r->resolved_version++;
+  zookeeper_maybe_finish_next_locked(r);
+  gpr_mu_unlock(&r->mu);
+
+  GRPC_RESOLVER_UNREF(&r->base, "zookeeper-resolving");
+}
+
+/** Callback function for each DNS resolved address */
+static void zookeeper_dns_resolved(void *arg,
+                                   grpc_resolved_addresses *addresses) {
+  size_t i;
+  zookeeper_resolver *r = arg;
+  int resolve_done = 0;
+
+  gpr_mu_lock(&r->mu);
+  r->resolved_num++;
+  r->resolved_addrs->addrs =
+      gpr_realloc(r->resolved_addrs->addrs,
+                  sizeof(grpc_resolved_address) *
+                      (r->resolved_addrs->naddrs + addresses->naddrs));
+  for (i = 0; i < addresses->naddrs; i++) {
+    memcpy(r->resolved_addrs->addrs[i + r->resolved_addrs->naddrs].addr,
+           addresses->addrs[i].addr, addresses->addrs[i].len);
+    r->resolved_addrs->addrs[i + r->resolved_addrs->naddrs].len =
+        addresses->addrs[i].len;
+  }
+
+  r->resolved_addrs->naddrs += addresses->naddrs;
+  grpc_resolved_addresses_destroy(addresses);
+
+  /** Wait for all addresses to be resolved */
+  resolve_done = (r->resolved_num == r->resolved_total);
+  gpr_mu_unlock(&r->mu);
+  if (resolve_done) {
+    zookeeper_on_resolved(r, r->resolved_addrs);
+  }
+}
+
+/** Parses JSON format address of a zookeeper node */
+static char *zookeeper_parse_address(const char *value, int value_len) {
+  grpc_json *json;
+  grpc_json *cur;
+  const char *host;
+  const char *port;
+  char* buffer;
+  char *address = NULL;
+
+  buffer = gpr_malloc(value_len);
+  memcpy(buffer, value, value_len);
+  json = grpc_json_parse_string_with_len(buffer, value_len);
+  if (json != NULL) {
+    host = NULL;
+    port = NULL;
+    for (cur = json->child; cur != NULL; cur = cur->next) {
+      if (!strcmp(cur->key, "host")) {
+        host = cur->value;
+        if (port != NULL) {
+          break;
+        }
+      } else if (!strcmp(cur->key, "port")) {
+        port = cur->value;
+        if (host != NULL) {
+          break;
+        }
+      }
+    }
+    if (host != NULL && port != NULL) {
+      gpr_asprintf(&address, "%s:%s", host, port);
+    }
+    grpc_json_destroy(json);
+  }
+  gpr_free(buffer);
+
+  return address;
+}
+
+static void zookeeper_get_children_node_completion(int rc, const char *value,
+                                                   int value_len,
+                                                   const struct Stat *stat,
+                                                   const void *arg) {
+  char *address = NULL;
+  zookeeper_resolver *r = (zookeeper_resolver *)arg;
+  int resolve_done = 0;
+
+  if (rc != 0) {
+    gpr_log(GPR_ERROR, "Error in getting a child node of %s", r->name);
+    return;
+  }
+
+  address = zookeeper_parse_address(value, value_len);
+  if (address != NULL) {
+    /** Further resolves address by DNS */
+    grpc_resolve_address(address, NULL, zookeeper_dns_resolved, r);
+    gpr_free(address);
+  } else {
+    gpr_log(GPR_ERROR, "Error in resolving a child node of %s", r->name);
+    gpr_mu_lock(&r->mu);
+    r->resolved_total--;
+    resolve_done = (r->resolved_num == r->resolved_total);
+    gpr_mu_unlock(&r->mu);
+    if (resolve_done) {
+      zookeeper_on_resolved(r, r->resolved_addrs);
+    }
+  }
+}
+
+static void zookeeper_get_children_completion(
+    int rc, const struct String_vector *children, const void *arg) {
+  char *path;
+  int status;
+  int i;
+  zookeeper_resolver *r = (zookeeper_resolver *)arg;
+
+  if (rc != 0) {
+    gpr_log(GPR_ERROR, "Error in getting zookeeper children of %s", r->name);
+    return;
+  }
+
+  if (children->count == 0) {
+    gpr_log(GPR_ERROR, "Error in resolving zookeeper address %s", r->name);
+    return;
+  }
+
+  r->resolved_addrs = gpr_malloc(sizeof(grpc_resolved_addresses));
+  r->resolved_addrs->addrs = NULL;
+  r->resolved_addrs->naddrs = 0;
+  r->resolved_total = children->count;
+
+  /** TODO: Replace expensive heap allocation with stack
+      if we can get maximum length of zookeeper path */
+  for (i = 0; i < children->count; i++) {
+    gpr_asprintf(&path, "%s/%s", r->name, children->data[i]);
+    status = zoo_awget(r->zookeeper_handle, path, zookeeper_watcher, r,
+                       zookeeper_get_children_node_completion, r);
+    gpr_free(path);
+    if (status != 0) {
+      gpr_log(GPR_ERROR, "Error in getting zookeeper node %s", path);
+    }
+  }
+}
+
+static void zookeeper_get_node_completion(int rc, const char *value,
+                                          int value_len,
+                                          const struct Stat *stat,
+                                          const void *arg) {
+  int status;
+  char *address = NULL;
+  zookeeper_resolver *r = (zookeeper_resolver *)arg;
+  r->resolved_addrs = NULL;
+  r->resolved_total = 0;
+  r->resolved_num = 0;
+
+  if (rc != 0) {
+    gpr_log(GPR_ERROR, "Error in getting zookeeper node %s", r->name);
+    return;
+  }
+
+  /** If zookeeper node of path r->name does not have address
+      (i.e. service node), get its children */
+  address = zookeeper_parse_address(value, value_len);
+  if (address != NULL) {
+    r->resolved_addrs = gpr_malloc(sizeof(grpc_resolved_addresses));
+    r->resolved_addrs->addrs = NULL;
+    r->resolved_addrs->naddrs = 0;
+    r->resolved_total = 1;
+    /** Further resolves address by DNS */
+    grpc_resolve_address(address, NULL, zookeeper_dns_resolved, r);
+    gpr_free(address);
+    return;
+  }
+
+  status = zoo_awget_children(r->zookeeper_handle, r->name, zookeeper_watcher,
+                              r, zookeeper_get_children_completion, r);
+  if (status != 0) {
+    gpr_log(GPR_ERROR, "Error in getting zookeeper children of %s", r->name);
+  }
+}
+
+static void zookeeper_resolve_address(zookeeper_resolver *r) {
+  int status;
+  status = zoo_awget(r->zookeeper_handle, r->name, zookeeper_watcher, r,
+                     zookeeper_get_node_completion, r);
+  if (status != 0) {
+    gpr_log(GPR_ERROR, "Error in getting zookeeper node %s", r->name);
+  }
+}
+
+static void zookeeper_start_resolving_locked(zookeeper_resolver *r) {
+  GRPC_RESOLVER_REF(&r->base, "zookeeper-resolving");
+  GPR_ASSERT(r->resolving == 0);
+  r->resolving = 1;
+  zookeeper_resolve_address(r);
+}
+
+static void zookeeper_maybe_finish_next_locked(zookeeper_resolver *r) {
+  if (r->next_completion != NULL &&
+      r->resolved_version != r->published_version) {
+    *r->target_config = r->resolved_config;
+    if (r->resolved_config != NULL) {
+      grpc_client_config_ref(r->resolved_config);
+    }
+    grpc_iomgr_add_callback(r->next_completion);
+    r->next_completion = NULL;
+    r->published_version = r->resolved_version;
+  }
+}
+
+static void zookeeper_destroy(grpc_resolver *gr) {
+  zookeeper_resolver *r = (zookeeper_resolver *)gr;
+  gpr_mu_destroy(&r->mu);
+  if (r->resolved_config != NULL) {
+    grpc_client_config_unref(r->resolved_config);
+  }
+  grpc_subchannel_factory_unref(r->subchannel_factory);
+  gpr_free(r->name);
+  gpr_free(r);
+}
+
+static grpc_resolver *zookeeper_create(
+    grpc_uri *uri,
+    grpc_lb_policy *(*lb_policy_factory)(grpc_subchannel **subchannels,
+                                         size_t num_subchannels),
+    grpc_subchannel_factory *subchannel_factory) {
+  zookeeper_resolver *r;
+  size_t length;
+  char *path = uri->path;
+
+  if (0 == strcmp(uri->authority, "")) {
+    gpr_log(GPR_ERROR, "No authority specified in zookeeper uri");
+    return NULL;
+  }
+
+  /** Removes the trailing slash if exists */
+  length = strlen(path);
+  if (length > 1 && path[length - 1] == '/') {
+    path[length - 1] = 0;
+  }
+
+  r = gpr_malloc(sizeof(zookeeper_resolver));
+  memset(r, 0, sizeof(*r));
+  gpr_ref_init(&r->refs, 1);
+  gpr_mu_init(&r->mu);
+  grpc_resolver_init(&r->base, &zookeeper_resolver_vtable);
+  r->name = gpr_strdup(path);
+  
+  r->subchannel_factory = subchannel_factory;
+  r->lb_policy_factory = lb_policy_factory;
+  grpc_subchannel_factory_ref(subchannel_factory);
+
+  /** Initializes zookeeper client */
+  zoo_set_debug_level(ZOO_LOG_LEVEL_WARN);
+  r->zookeeper_handle = zookeeper_init(uri->authority, zookeeper_global_watcher,
+                                       GRPC_ZOOKEEPER_SESSION_TIMEOUT, 0, 0, 0);
+  if (r->zookeeper_handle == NULL) {
+    gpr_log(GPR_ERROR, "Unable to connect to zookeeper server");
+    return NULL;
+  }
+
+  return &r->base;
+}
+
+static void zookeeper_plugin_init() {
+  grpc_register_resolver_type("zookeeper",
+                              grpc_zookeeper_resolver_factory_create());
+}
+
+void grpc_zookeeper_register() {
+  grpc_register_plugin(zookeeper_plugin_init, NULL);
+}
+
+/*
+ * FACTORY
+ */
+
+static void zookeeper_factory_ref(grpc_resolver_factory *factory) {}
+
+static void zookeeper_factory_unref(grpc_resolver_factory *factory) {}
+
+static grpc_resolver *zookeeper_factory_create_resolver(
+    grpc_resolver_factory *factory, grpc_uri *uri,
+    grpc_subchannel_factory *subchannel_factory) {
+  return zookeeper_create(uri, grpc_create_pick_first_lb_policy,
+                          subchannel_factory);
+}
+
+static const grpc_resolver_factory_vtable zookeeper_factory_vtable = {
+    zookeeper_factory_ref, zookeeper_factory_unref,
+    zookeeper_factory_create_resolver};
+static grpc_resolver_factory zookeeper_resolver_factory = {
+    &zookeeper_factory_vtable};
+
+grpc_resolver_factory *grpc_zookeeper_resolver_factory_create() {
+  return &zookeeper_resolver_factory;
+}

src/core/client_config/resolvers/zookeeper_resolver.h

@@ -0,0 +1,42 @@
+/*
+ *
+ * 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.
+ *
+ */
+
+#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVERS_ZOOKEEPER_RESOLVER_H
+#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVERS_ZOOKEEPER_RESOLVER_H
+
+#include "src/core/client_config/resolver_factory.h"
+
+/** Create a zookeeper resolver factory */
+grpc_resolver_factory *grpc_zookeeper_resolver_factory_create(void);
+
+#endif /* GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVERS_ZOOKEEPER_RESOLVER_H */

src/core/compression/algorithm.c

@@ -37,7 +37,7 @@
 
 int grpc_compression_algorithm_parse(const char* name,
                                      grpc_compression_algorithm *algorithm) {
-  if (strcmp(name, "none") == 0) {
+  if (strcmp(name, "identity") == 0) {
     *algorithm = GRPC_COMPRESS_NONE;
   } else if (strcmp(name, "gzip") == 0) {
     *algorithm = GRPC_COMPRESS_GZIP;
@@ -53,7 +53,7 @@ int grpc_compression_algorithm_name(grpc_compression_algorithm algorithm,
                                     char **name) {
   switch (algorithm) {
     case GRPC_COMPRESS_NONE:
-      *name = "none";
+      *name = "identity";
       break;
     case GRPC_COMPRESS_DEFLATE:
       *name = "deflate";

src/core/iomgr/udp_server.c

@@ -0,0 +1,438 @@
+/*
+ *
+ * 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.
+ *
+ */
+
+/* FIXME: "posix" files shouldn't be depending on _GNU_SOURCE */
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include <grpc/support/port_platform.h>
+
+#ifdef GPR_POSIX_SOCKET
+
+#include "src/core/iomgr/udp_server.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/un.h>
+#include <unistd.h>
+
+#include "src/core/iomgr/fd_posix.h"
+#include "src/core/iomgr/pollset_posix.h"
+#include "src/core/iomgr/resolve_address.h"
+#include "src/core/iomgr/sockaddr_utils.h"
+#include "src/core/iomgr/socket_utils_posix.h"
+#include "src/core/support/string.h"
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/sync.h>
+#include <grpc/support/string_util.h>
+#include <grpc/support/time.h>
+
+#define INIT_PORT_CAP 2
+
+/* one listening port */
+typedef struct {
+  int fd;
+  grpc_fd *emfd;
+  grpc_udp_server *server;
+  union {
+    gpr_uint8 untyped[GRPC_MAX_SOCKADDR_SIZE];
+    struct sockaddr sockaddr;
+    struct sockaddr_un un;
+  } addr;
+  int addr_len;
+  grpc_iomgr_closure read_closure;
+  grpc_iomgr_closure destroyed_closure;
+  grpc_udp_server_read_cb read_cb;
+} server_port;
+
+static void unlink_if_unix_domain_socket(const struct sockaddr_un *un) {
+  struct stat st;
+
+  if (stat(un->sun_path, &st) == 0 && (st.st_mode & S_IFMT) == S_IFSOCK) {
+    unlink(un->sun_path);
+  }
+}
+
+/* the overall server */
+struct grpc_udp_server {
+  grpc_udp_server_cb cb;
+  void *cb_arg;
+
+  gpr_mu mu;
+  gpr_cv cv;
+
+  /* active port count: how many ports are actually still listening */
+  size_t active_ports;
+  /* destroyed port count: how many ports are completely destroyed */
+  size_t destroyed_ports;
+
+  /* is this server shutting down? (boolean) */
+  int shutdown;
+
+  /* all listening ports */
+  server_port *ports;
+  size_t nports;
+  size_t port_capacity;
+
+  /* shutdown callback */
+  void (*shutdown_complete)(void *);
+  void *shutdown_complete_arg;
+
+  /* all pollsets interested in new connections */
+  grpc_pollset **pollsets;
+  /* number of pollsets in the pollsets array */
+  size_t pollset_count;
+};
+
+grpc_udp_server *grpc_udp_server_create(void) {
+  grpc_udp_server *s = gpr_malloc(sizeof(grpc_udp_server));
+  gpr_mu_init(&s->mu);
+  gpr_cv_init(&s->cv);
+  s->active_ports = 0;
+  s->destroyed_ports = 0;
+  s->shutdown = 0;
+  s->cb = NULL;
+  s->cb_arg = NULL;
+  s->ports = gpr_malloc(sizeof(server_port) * INIT_PORT_CAP);
+  s->nports = 0;
+  s->port_capacity = INIT_PORT_CAP;
+
+  return s;
+}
+
+static void finish_shutdown(grpc_udp_server *s) {
+  s->shutdown_complete(s->shutdown_complete_arg);
+
+  gpr_mu_destroy(&s->mu);
+  gpr_cv_destroy(&s->cv);
+
+  gpr_free(s->ports);
+  gpr_free(s);
+}
+
+static void destroyed_port(void *server, int success) {
+  grpc_udp_server *s = server;
+  gpr_mu_lock(&s->mu);
+  s->destroyed_ports++;
+  if (s->destroyed_ports == s->nports) {
+    gpr_mu_unlock(&s->mu);
+    finish_shutdown(s);
+  } else {
+    gpr_mu_unlock(&s->mu);
+  }
+}
+
+static void dont_care_about_shutdown_completion(void *ignored) {}
+
+/* called when all listening endpoints have been shutdown, so no further
+   events will be received on them - at this point it's safe to destroy
+   things */
+static void deactivated_all_ports(grpc_udp_server *s) {
+  size_t i;
+
+  /* delete ALL the things */
+  gpr_mu_lock(&s->mu);
+
+  if (!s->shutdown) {
+    gpr_mu_unlock(&s->mu);
+    return;
+  }
+
+  if (s->nports) {
+    for (i = 0; i < s->nports; i++) {
+      server_port *sp = &s->ports[i];
+      if (sp->addr.sockaddr.sa_family == AF_UNIX) {
+        unlink_if_unix_domain_socket(&sp->addr.un);
+      }
+      sp->destroyed_closure.cb = destroyed_port;
+      sp->destroyed_closure.cb_arg = s;
+      grpc_fd_orphan(sp->emfd, &sp->destroyed_closure, "udp_listener_shutdown");
+    }
+    gpr_mu_unlock(&s->mu);
+  } else {
+    gpr_mu_unlock(&s->mu);
+    finish_shutdown(s);
+  }
+}
+
+void grpc_udp_server_destroy(
+    grpc_udp_server *s, void (*shutdown_complete)(void *shutdown_complete_arg),
+    void *shutdown_complete_arg) {
+  size_t i;
+  gpr_mu_lock(&s->mu);
+
+  GPR_ASSERT(!s->shutdown);
+  s->shutdown = 1;
+
+  s->shutdown_complete = shutdown_complete
+                             ? shutdown_complete
+                             : dont_care_about_shutdown_completion;
+  s->shutdown_complete_arg = shutdown_complete_arg;
+
+  /* shutdown all fd's */
+  if (s->active_ports) {
+    for (i = 0; i < s->nports; i++) {
+      grpc_fd_shutdown(s->ports[i].emfd);
+    }
+    gpr_mu_unlock(&s->mu);
+  } else {
+    gpr_mu_unlock(&s->mu);
+    deactivated_all_ports(s);
+  }
+}
+
+/* Prepare a recently-created socket for listening. */
+static int prepare_socket(int fd, const struct sockaddr *addr, int addr_len) {
+  struct sockaddr_storage sockname_temp;
+  socklen_t sockname_len;
+  int get_local_ip;
+  int rc;
+
+  if (fd < 0) {
+    goto error;
+  }
+
+  get_local_ip = 1;
+  rc = setsockopt(fd, IPPROTO_IP, IP_PKTINFO,
+                      &get_local_ip, sizeof(get_local_ip));
+  if (rc == 0 && addr->sa_family == AF_INET6) {
+    rc = setsockopt(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO,
+                    &get_local_ip, sizeof(get_local_ip));
+  }
+
+  if (bind(fd, addr, addr_len) < 0) {
+    char *addr_str;
+    grpc_sockaddr_to_string(&addr_str, addr, 0);
+    gpr_log(GPR_ERROR, "bind addr=%s: %s", addr_str, strerror(errno));
+    gpr_free(addr_str);
+    goto error;
+  }
+
+  sockname_len = sizeof(sockname_temp);
+  if (getsockname(fd, (struct sockaddr *)&sockname_temp, &sockname_len) < 0) {
+    goto error;
+  }
+
+  return grpc_sockaddr_get_port((struct sockaddr *)&sockname_temp);
+
+error:
+  if (fd >= 0) {
+    close(fd);
+  }
+  return -1;
+}
+
+/* event manager callback when reads are ready */
+static void on_read(void *arg, int success) {
+  server_port *sp = arg;
+
+  if (success == 0) {
+    gpr_mu_lock(&sp->server->mu);
+    if (0 == --sp->server->active_ports) {
+      gpr_mu_unlock(&sp->server->mu);
+      deactivated_all_ports(sp->server);
+    } else {
+      gpr_mu_unlock(&sp->server->mu);
+    }
+    return;
+  }
+
+  /* Tell the registered callback that data is available to read. */
+  GPR_ASSERT(sp->read_cb);
+  sp->read_cb(sp->fd, sp->server->cb, sp->server->cb_arg);
+
+  /* Re-arm the notification event so we get another chance to read. */
+  grpc_fd_notify_on_read(sp->emfd, &sp->read_closure);
+}
+
+static int add_socket_to_server(grpc_udp_server *s, int fd,
+                                const struct sockaddr *addr, int addr_len,
+                                grpc_udp_server_read_cb read_cb) {
+  server_port *sp;
+  int port;
+  char *addr_str;
+  char *name;
+
+  port = prepare_socket(fd, addr, addr_len);
+  if (port >= 0) {
+    grpc_sockaddr_to_string(&addr_str, (struct sockaddr *)&addr, 1);
+    gpr_asprintf(&name, "udp-server-listener:%s", addr_str);
+    gpr_mu_lock(&s->mu);
+    GPR_ASSERT(!s->cb && "must add ports before starting server");
+    /* append it to the list under a lock */
+    if (s->nports == s->port_capacity) {
+      s->port_capacity *= 2;
+      s->ports = gpr_realloc(s->ports, sizeof(server_port) * s->port_capacity);
+    }
+    sp = &s->ports[s->nports++];
+    sp->server = s;
+    sp->fd = fd;
+    sp->emfd = grpc_fd_create(fd, name);
+    memcpy(sp->addr.untyped, addr, addr_len);
+    sp->addr_len = addr_len;
+    sp->read_cb = read_cb;
+    GPR_ASSERT(sp->emfd);
+    gpr_mu_unlock(&s->mu);
+  }
+
+  return port;
+}
+
+int grpc_udp_server_add_port(grpc_udp_server *s, const void *addr,
+                             int addr_len, grpc_udp_server_read_cb read_cb) {
+  int allocated_port1 = -1;
+  int allocated_port2 = -1;
+  unsigned i;
+  int fd;
+  grpc_dualstack_mode dsmode;
+  struct sockaddr_in6 addr6_v4mapped;
+  struct sockaddr_in wild4;
+  struct sockaddr_in6 wild6;
+  struct sockaddr_in addr4_copy;
+  struct sockaddr *allocated_addr = NULL;
+  struct sockaddr_storage sockname_temp;
+  socklen_t sockname_len;
+  int port;
+
+  if (((struct sockaddr *)addr)->sa_family == AF_UNIX) {
+    unlink_if_unix_domain_socket(addr);
+  }
+
+  /* Check if this is a wildcard port, and if so, try to keep the port the same
+     as some previously created listener. */
+  if (grpc_sockaddr_get_port(addr) == 0) {
+    for (i = 0; i < s->nports; i++) {
+      sockname_len = sizeof(sockname_temp);
+      if (0 == getsockname(s->ports[i].fd, (struct sockaddr *)&sockname_temp,
+                           &sockname_len)) {
+        port = grpc_sockaddr_get_port((struct sockaddr *)&sockname_temp);
+        if (port > 0) {
+          allocated_addr = malloc(addr_len);
+          memcpy(allocated_addr, addr, addr_len);
+          grpc_sockaddr_set_port(allocated_addr, port);
+          addr = allocated_addr;
+          break;
+        }
+      }
+    }
+  }
+
+  if (grpc_sockaddr_to_v4mapped(addr, &addr6_v4mapped)) {
+    addr = (const struct sockaddr *)&addr6_v4mapped;
+    addr_len = sizeof(addr6_v4mapped);
+  }
+
+  /* Treat :: or 0.0.0.0 as a family-agnostic wildcard. */
+  if (grpc_sockaddr_is_wildcard(addr, &port)) {
+    grpc_sockaddr_make_wildcards(port, &wild4, &wild6);
+
+    /* Try listening on IPv6 first. */
+    addr = (struct sockaddr *)&wild6;
+    addr_len = sizeof(wild6);
+    fd = grpc_create_dualstack_socket(addr, SOCK_DGRAM, IPPROTO_UDP, &dsmode);
+    allocated_port1 = add_socket_to_server(s, fd, addr, addr_len, read_cb);
+    if (fd >= 0 && dsmode == GRPC_DSMODE_DUALSTACK) {
+      goto done;
+    }
+
+    /* If we didn't get a dualstack socket, also listen on 0.0.0.0. */
+    if (port == 0 && allocated_port1 > 0) {
+      grpc_sockaddr_set_port((struct sockaddr *)&wild4, allocated_port1);
+    }
+    addr = (struct sockaddr *)&wild4;
+    addr_len = sizeof(wild4);
+  }
+
+  fd = grpc_create_dualstack_socket(addr, SOCK_DGRAM, IPPROTO_UDP, &dsmode);
+  if (fd < 0) {
+    gpr_log(GPR_ERROR, "Unable to create socket: %s", strerror(errno));
+  }
+  if (dsmode == GRPC_DSMODE_IPV4 &&
+      grpc_sockaddr_is_v4mapped(addr, &addr4_copy)) {
+    addr = (struct sockaddr *)&addr4_copy;
+    addr_len = sizeof(addr4_copy);
+  }
+  allocated_port2 = add_socket_to_server(s, fd, addr, addr_len, read_cb);
+
+done:
+  gpr_free(allocated_addr);
+  return allocated_port1 >= 0 ? allocated_port1 : allocated_port2;
+}
+
+int grpc_udp_server_get_fd(grpc_udp_server *s, unsigned index) {
+  return (index < s->nports) ? s->ports[index].fd : -1;
+}
+
+void grpc_udp_server_start(grpc_udp_server *s, grpc_pollset **pollsets,
+                           size_t pollset_count,
+                           grpc_udp_server_cb new_transport_cb, void *cb_arg) {
+  size_t i, j;
+  GPR_ASSERT(new_transport_cb);
+  gpr_mu_lock(&s->mu);
+  GPR_ASSERT(!s->cb);
+  GPR_ASSERT(s->active_ports == 0);
+  s->cb = new_transport_cb;
+  s->cb_arg = cb_arg;
+  s->pollsets = pollsets;
+  for (i = 0; i < s->nports; i++) {
+    for (j = 0; j < pollset_count; j++) {
+      grpc_pollset_add_fd(pollsets[j], s->ports[i].emfd);
+    }
+    s->ports[i].read_closure.cb = on_read;
+    s->ports[i].read_closure.cb_arg = &s->ports[i];
+    grpc_fd_notify_on_read(s->ports[i].emfd, &s->ports[i].read_closure);
+    s->active_ports++;
+  }
+  gpr_mu_unlock(&s->mu);
+}
+
+/* TODO(rjshade): Add a test for this method. */
+void grpc_udp_server_write(server_port *sp, const char *buffer, size_t buf_len,
+                           const struct sockaddr *peer_address) {
+  int rc;
+  rc = sendto(sp->fd, buffer, buf_len, 0, peer_address, sizeof(peer_address));
+  if (rc < 0) {
+    gpr_log(GPR_ERROR, "Unable to send data: %s", strerror(errno));
+  }
+}
+
+#endif

src/core/iomgr/udp_server.h

@@ -0,0 +1,85 @@
+/*
+ *
+ * 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.
+ *
+ */
+
+#ifndef GRPC_INTERNAL_CORE_IOMGR_UDP_SERVER_H
+#define GRPC_INTERNAL_CORE_IOMGR_UDP_SERVER_H
+
+#include "src/core/iomgr/endpoint.h"
+
+/* Forward decl of grpc_udp_server */
+typedef struct grpc_udp_server grpc_udp_server;
+
+/* New server callback: ep is the newly connected connection */
+typedef void (*grpc_udp_server_cb)(void *arg, grpc_endpoint *ep);
+
+/* Called when data is available to read from the socket. */
+typedef void (*grpc_udp_server_read_cb)(int fd,
+                                        grpc_udp_server_cb new_transport_cb,
+                                        void *cb_arg);
+
+/* Create a server, initially not bound to any ports */
+grpc_udp_server *grpc_udp_server_create(void);
+
+/* Start listening to bound ports */
+void grpc_udp_server_start(grpc_udp_server *server, grpc_pollset **pollsets,
+                           size_t pollset_count, grpc_udp_server_cb cb,
+                           void *cb_arg);
+
+int grpc_udp_server_get_fd(grpc_udp_server *s, unsigned index);
+
+/* Add a port to the server, returning port number on success, or negative
+   on failure.
+
+   The :: and 0.0.0.0 wildcard addresses are treated identically, accepting
+   both IPv4 and IPv6 connections, but :: is the preferred style.  This usually
+   creates one socket, but possibly two on systems which support IPv6,
+   but not dualstack sockets. */
+
+/* TODO(ctiller): deprecate this, and make grpc_udp_server_add_ports to handle
+                  all of the multiple socket port matching logic in one place */
+int grpc_udp_server_add_port(grpc_udp_server *s, const void *addr, int addr_len,
+                             grpc_udp_server_read_cb read_cb);
+
+void grpc_udp_server_destroy(grpc_udp_server *server,
+                             void (*shutdown_done)(void *shutdown_done_arg),
+                             void *shutdown_done_arg);
+
+/* Write the contents of buffer to the underlying UDP socket. */
+/*
+void grpc_udp_server_write(grpc_udp_server *s,
+                           const char *buffer,
+                           int buf_len,
+                           const struct sockaddr* to);
+                           */
+
+#endif /* GRPC_INTERNAL_CORE_IOMGR_UDP_SERVER_H */

src/core/security/client_auth_filter.c

@@ -75,11 +75,11 @@ typedef struct {
   grpc_mdstr *status_key;
 } channel_data;
 
-static void bubble_up_error(grpc_call_element *elem, const char *error_msg) {
+static void bubble_up_error(grpc_call_element *elem, grpc_status_code status,
+                            const char *error_msg) {
   call_data *calld = elem->call_data;
   gpr_log(GPR_ERROR, "Client side authentication failure: %s", error_msg);
-  grpc_transport_stream_op_add_cancellation(&calld->op,
-                                            GRPC_STATUS_UNAUTHENTICATED);
+  grpc_transport_stream_op_add_cancellation(&calld->op, status);
   grpc_call_next_op(elem, &calld->op);
 }
 
@@ -94,7 +94,8 @@ static void on_credentials_metadata(void *user_data,
   grpc_metadata_batch *mdb;
   size_t i;
   if (status != GRPC_CREDENTIALS_OK) {
-    bubble_up_error(elem, "Credentials failed to get metadata.");
+    bubble_up_error(elem, GRPC_STATUS_UNAUTHENTICATED,
+                    "Credentials failed to get metadata.");
     return;
   }
   GPR_ASSERT(num_md <= MAX_CREDENTIALS_METADATA_COUNT);
@@ -154,7 +155,7 @@ static void send_security_metadata(grpc_call_element *elem,
   if (channel_creds_has_md && call_creds_has_md) {
     calld->creds = grpc_composite_credentials_create(channel_creds, ctx->creds);
     if (calld->creds == NULL) {
-      bubble_up_error(elem,
+      bubble_up_error(elem, GRPC_STATUS_INVALID_ARGUMENT,
                       "Incompatible credentials set on channel and call.");
       return;
     }
@@ -182,7 +183,7 @@ static void on_host_checked(void *user_data, grpc_security_status status) {
     char *error_msg;
     gpr_asprintf(&error_msg, "Invalid host %s set in :authority metadata.",
                  grpc_mdstr_as_c_string(calld->host));
-    bubble_up_error(elem, error_msg);
+    bubble_up_error(elem, GRPC_STATUS_INVALID_ARGUMENT, error_msg);
     gpr_free(error_msg);
   }
 }
@@ -252,7 +253,7 @@ static void auth_start_transport_op(grpc_call_element *elem,
             gpr_asprintf(&error_msg,
                          "Invalid host %s set in :authority metadata.",
                          call_host);
-            bubble_up_error(elem, error_msg);
+            bubble_up_error(elem, GRPC_STATUS_INVALID_ARGUMENT, error_msg);
             gpr_free(error_msg);
           }
           return; /* early exit */

src/core/support/cancellable.c

@@ -1,157 +0,0 @@
-/*
- *
- * 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.
- *
- */
-
-/* Implementation for gpr_cancellable */
-
-#include <grpc/support/atm.h>
-#include <grpc/support/sync.h>
-#include <grpc/support/time.h>
-
-void gpr_cancellable_init(gpr_cancellable *c) {
-  gpr_mu_init(&c->mu);
-  c->cancelled = 0;
-  c->waiters.next = &c->waiters;
-  c->waiters.prev = &c->waiters;
-  c->waiters.mu = NULL;
-  c->waiters.cv = NULL;
-}
-
-void gpr_cancellable_destroy(gpr_cancellable *c) { gpr_mu_destroy(&c->mu); }
-
-int gpr_cancellable_is_cancelled(gpr_cancellable *c) {
-  return gpr_atm_acq_load(&c->cancelled) != 0;
-}
-
-/* Threads in gpr_cv_cancellable_wait(cv, mu, ..., c) place themselves on a
-   linked list c->waiters of gpr_cancellable_list_ before waiting on their
-   condition variables.  They check for cancellation while holding *mu.  Thus,
-   to wake a thread from gpr_cv_cancellable_wait(), it suffices to:
-      - set c->cancelled
-      - acquire and release *mu
-      - gpr_cv_broadcast(cv)
-
-   However, gpr_cancellable_cancel() may not use gpr_mu_lock(mu), since the
-   caller may already hold *mu---a possible deadlock.  (If we knew the caller
-   did not hold *mu, care would still be needed, because c->mu follows *mu in
-   the locking order, so *mu could not be acquired while holding c->mu---which
-   is needed to iterate over c->waiters.)
-
-   Therefore, gpr_cancellable_cancel() uses gpr_mu_trylock() rather than
-   gpr_mu_lock(), and retries until either gpr_mu_trylock() succeeds or the
-   thread leaves gpr_cv_cancellable_wait() for other reasons.  In the first
-   case, gpr_cancellable_cancel() removes the entry from the waiters list; in
-   the second, the waiting thread removes itself from the list.
-
-   A one-entry cache of mutexes and condition variables processed is kept to
-   avoid doing the same work again and again if many threads are blocked in the
-   same place.  However, it's important to broadcast on a condition variable if
-   the corresponding mutex has been locked successfully, even if the condition
-   variable has been signalled before.  */
-
-void gpr_cancellable_cancel(gpr_cancellable *c) {
-  if (!gpr_cancellable_is_cancelled(c)) {
-    int failures;
-    int backoff = 1;
-    do {
-      struct gpr_cancellable_list_ *l;
-      struct gpr_cancellable_list_ *nl;
-      gpr_mu *omu = 0; /* one-element cache of a processed gpr_mu */
-      gpr_cv *ocv = 0; /* one-element cache of a processd gpr_cv */
-      gpr_mu_lock(&c->mu);
-      gpr_atm_rel_store(&c->cancelled, 1);
-      failures = 0;
-      for (l = c->waiters.next; l != &c->waiters; l = nl) {
-        nl = l->next;
-        if (omu != l->mu) {
-          omu = l->mu;
-          if (gpr_mu_trylock(l->mu)) {
-            gpr_mu_unlock(l->mu);
-            l->next->prev = l->prev; /* remove *l from list */
-            l->prev->next = l->next;
-            /* allow unconditional dequeue in gpr_cv_cancellable_wait() */
-            l->next = l;
-            l->prev = l;
-            ocv = 0; /* force broadcast */
-          } else {
-            failures++;
-          }
-        }
-        if (ocv != l->cv) {
-          ocv = l->cv;
-          gpr_cv_broadcast(l->cv);
-        }
-      }
-      gpr_mu_unlock(&c->mu);
-      if (failures != 0) {
-        if (backoff < 10) {
-          volatile int i;
-          for (i = 0; i != (1 << backoff); i++) {
-          }
-          backoff++;
-        } else {
-          gpr_event ev;
-          gpr_event_init(&ev);
-          gpr_event_wait(
-              &ev, gpr_time_add(gpr_now(GPR_CLOCK_REALTIME),
-                                gpr_time_from_micros(1000, GPR_TIMESPAN)));
-        }
-      }
-    } while (failures != 0);
-  }
-}
-
-int gpr_cv_cancellable_wait(gpr_cv *cv, gpr_mu *mu, gpr_timespec abs_deadline,
-                            gpr_cancellable *c) {
-  gpr_int32 timeout;
-  gpr_mu_lock(&c->mu);
-  timeout = gpr_cancellable_is_cancelled(c);
-  if (!timeout) {
-    struct gpr_cancellable_list_ le;
-    le.mu = mu;
-    le.cv = cv;
-    le.next = c->waiters.next;
-    le.prev = &c->waiters;
-    le.next->prev = &le;
-    le.prev->next = &le;
-    gpr_mu_unlock(&c->mu);
-    timeout = gpr_cv_wait(cv, mu, abs_deadline);
-    gpr_mu_lock(&c->mu);
-    le.next->prev = le.prev;
-    le.prev->next = le.next;
-    if (!timeout) {
-      timeout = gpr_cancellable_is_cancelled(c);
-    }
-  }
-  gpr_mu_unlock(&c->mu);
-  return timeout;
-}

src/core/support/sync.c

@@ -94,21 +94,6 @@ void *gpr_event_wait(gpr_event *ev, gpr_timespec abs_deadline) {
   return result;
 }
 
-void *gpr_event_cancellable_wait(gpr_event *ev, gpr_timespec abs_deadline,
-                                 gpr_cancellable *c) {
-  void *result = (void *)gpr_atm_acq_load(&ev->state);
-  if (result == NULL) {
-    struct sync_array_s *s = hash(ev);
-    gpr_mu_lock(&s->mu);
-    do {
-      result = (void *)gpr_atm_acq_load(&ev->state);
-    } while (result == NULL &&
-             !gpr_cv_cancellable_wait(&s->cv, &s->mu, abs_deadline, c));
-    gpr_mu_unlock(&s->mu);
-  }
-  return result;
-}
-
 void gpr_ref_init(gpr_refcount *r, int n) { gpr_atm_rel_store(&r->count, n); }
 
 void gpr_ref(gpr_refcount *r) { gpr_atm_no_barrier_fetch_add(&r->count, 1); }

src/core/surface/call.c

@@ -964,7 +964,7 @@ static void call_on_done_recv(void *pc, int success) {
           next_child_call = child_call->sibling_next;
           if (child_call->cancellation_is_inherited) {
             GRPC_CALL_INTERNAL_REF(child_call, "propagate_cancel");
-            grpc_call_cancel(child_call);
+            grpc_call_cancel(child_call, NULL);
             GRPC_CALL_INTERNAL_UNREF(child_call, "propagate_cancel", 0);
           }
           child_call = next_child_call;
@@ -1265,18 +1265,22 @@ void grpc_call_destroy(grpc_call *c) {
   c->cancel_alarm |= c->have_alarm;
   cancel = c->read_state != READ_STATE_STREAM_CLOSED;
   unlock(c);
-  if (cancel) grpc_call_cancel(c);
+  if (cancel) grpc_call_cancel(c, NULL);
   GRPC_CALL_INTERNAL_UNREF(c, "destroy", 1);
 }
 
-grpc_call_error grpc_call_cancel(grpc_call *call) {
-  return grpc_call_cancel_with_status(call, GRPC_STATUS_CANCELLED, "Cancelled");
+grpc_call_error grpc_call_cancel(grpc_call *call, void *reserved) {
+  GPR_ASSERT(!reserved);
+  return grpc_call_cancel_with_status(call, GRPC_STATUS_CANCELLED, "Cancelled",
+                                      NULL);
 }
 
 grpc_call_error grpc_call_cancel_with_status(grpc_call *c,
                                              grpc_status_code status,
-                                             const char *description) {
+                                             const char *description,
+                                             void *reserved) {
   grpc_call_error r;
+  (void) reserved;
   lock(c);
   r = cancel_with_status(c, status, description);
   unlock(c);
@@ -1513,13 +1517,14 @@ static int are_write_flags_valid(gpr_uint32 flags) {
 }
 
 grpc_call_error grpc_call_start_batch(grpc_call *call, const grpc_op *ops,
-                                      size_t nops, void *tag) {
+                                      size_t nops, void *tag, void *reserved) {
   grpc_ioreq reqs[GRPC_IOREQ_OP_COUNT];
   size_t in;
   size_t out;
   const grpc_op *op;
   grpc_ioreq *req;
   void (*finish_func)(grpc_call *, int, void *) = finish_batch;
+  GPR_ASSERT(!reserved);
 
   GRPC_CALL_LOG_BATCH(GPR_INFO, call, ops, nops, tag);
 

src/core/surface/channel.c

@@ -168,7 +168,8 @@ grpc_call *grpc_channel_create_call(grpc_channel *channel,
                                     gpr_uint32 propagation_mask,
                                     grpc_completion_queue *cq,
                                     const char *method, const char *host,
-                                    gpr_timespec deadline) {
+                                    gpr_timespec deadline, void *reserved) {
+  GPR_ASSERT(!reserved);
   return grpc_channel_create_call_internal(
       channel, parent_call, propagation_mask, cq,
       grpc_mdelem_from_metadata_strings(
@@ -182,8 +183,9 @@ grpc_call *grpc_channel_create_call(grpc_channel *channel,
 }
 
 void *grpc_channel_register_call(grpc_channel *channel, const char *method,
-                                 const char *host) {
+                                 const char *host, void *reserved) {
   registered_call *rc = gpr_malloc(sizeof(registered_call));
+  GPR_ASSERT(!reserved);
   rc->path = grpc_mdelem_from_metadata_strings(
       channel->metadata_context, GRPC_MDSTR_REF(channel->path_string),
       grpc_mdstr_from_string(channel->metadata_context, method, 0));
@@ -200,8 +202,9 @@ void *grpc_channel_register_call(grpc_channel *channel, const char *method,
 grpc_call *grpc_channel_create_registered_call(
     grpc_channel *channel, grpc_call *parent_call, gpr_uint32 propagation_mask,
     grpc_completion_queue *completion_queue, void *registered_call_handle,
-    gpr_timespec deadline) {
+    gpr_timespec deadline, void *reserved) {
   registered_call *rc = registered_call_handle;
+  GPR_ASSERT(!reserved);
   return grpc_channel_create_call_internal(
       channel, parent_call, propagation_mask, completion_queue, 
       GRPC_MDELEM_REF(rc->path), 

src/core/surface/channel_create.c

@@ -155,7 +155,8 @@ static const grpc_subchannel_factory_vtable subchannel_factory_vtable = {
                    - connect to it (trying alternatives as presented)
                    - perform handshakes */
 grpc_channel *grpc_insecure_channel_create(const char *target,
-                                           const grpc_channel_args *args) {
+                                           const grpc_channel_args *args,
+                                           void *reserved) {
   grpc_channel *channel = NULL;
 #define MAX_FILTERS 3
   const grpc_channel_filter *filters[MAX_FILTERS];
@@ -163,6 +164,7 @@ grpc_channel *grpc_insecure_channel_create(const char *target,
   subchannel_factory *f;
   grpc_mdctx *mdctx = grpc_mdctx_create();
   int n = 0;
+  GPR_ASSERT(!reserved);
   /* TODO(census)
   if (grpc_channel_args_is_census_enabled(args)) {
     filters[n++] = &grpc_client_census_filter;

src/core/surface/completion_queue.c

@@ -69,8 +69,9 @@ struct grpc_completion_queue {
   plucker pluckers[GRPC_MAX_COMPLETION_QUEUE_PLUCKERS];
 };
 
-grpc_completion_queue *grpc_completion_queue_create(void) {
+grpc_completion_queue *grpc_completion_queue_create(void *reserved) {
   grpc_completion_queue *cc = gpr_malloc(sizeof(grpc_completion_queue));
+  GPR_ASSERT(!reserved);
   memset(cc, 0, sizeof(*cc));
   /* Initial ref is dropped by grpc_completion_queue_shutdown */
   gpr_ref_init(&cc->pending_events, 1);
@@ -166,9 +167,11 @@ void grpc_cq_end_op(grpc_completion_queue *cc, void *tag, int success,
 }
 
 grpc_event grpc_completion_queue_next(grpc_completion_queue *cc,
-                                      gpr_timespec deadline) {
+                                      gpr_timespec deadline,
+                                      void *reserved) {
   grpc_event ret;
   grpc_pollset_worker worker;
+  GPR_ASSERT(!reserved);
 
   deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC);
 
@@ -232,11 +235,12 @@ static void del_plucker(grpc_completion_queue *cc, void *tag,
 }
 
 grpc_event grpc_completion_queue_pluck(grpc_completion_queue *cc, void *tag,
-                                       gpr_timespec deadline) {
+                                       gpr_timespec deadline, void *reserved) {
   grpc_event ret;
   grpc_cq_completion *c;
   grpc_cq_completion *prev;
   grpc_pollset_worker worker;
+  GPR_ASSERT(!reserved);
 
   deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC);
 

src/core/surface/init.c

@@ -33,8 +33,11 @@
 
 #include <grpc/support/port_platform.h>
 
+#include <memory.h>
+
 #include <grpc/census.h>
 #include <grpc/grpc.h>
+#include <grpc/support/alloc.h>
 #include <grpc/support/time.h>
 #include "src/core/channel/channel_stack.h"
 #include "src/core/client_config/resolver_registry.h"
@@ -49,6 +52,8 @@
 #include "src/core/transport/chttp2_transport.h"
 #include "src/core/transport/connectivity_state.h"
 
+#define MAX_PLUGINS 128
+
 static gpr_once g_basic_init = GPR_ONCE_INIT;
 static gpr_mu g_init_mu;
 static int g_initializations;
@@ -58,7 +63,23 @@ static void do_basic_init(void) {
   g_initializations = 0;
 }
 
+typedef struct grpc_plugin {
+  void (*init)();
+  void (*destroy)();
+} grpc_plugin;
+
+static grpc_plugin g_all_of_the_plugins[MAX_PLUGINS];
+static int g_number_of_plugins = 0;
+
+void grpc_register_plugin(void (*init)(void), void (*destroy)(void)) {
+  GPR_ASSERT(g_number_of_plugins != MAX_PLUGINS);
+  g_all_of_the_plugins[g_number_of_plugins].init = init;
+  g_all_of_the_plugins[g_number_of_plugins].destroy = destroy;
+  g_number_of_plugins++;
+}
+
 void grpc_init(void) {
+  int i;
   gpr_once_init(&g_basic_init, do_basic_init);
 
   gpr_mu_lock(&g_init_mu);
@@ -87,11 +108,17 @@ void grpc_init(void) {
       }
     }
     grpc_timers_global_init();
+    for (i = 0; i < g_number_of_plugins; i++) {
+      if (g_all_of_the_plugins[i].init != NULL) {
+        g_all_of_the_plugins[i].init();
+      }
+    }
   }
   gpr_mu_unlock(&g_init_mu);
 }
 
 void grpc_shutdown(void) {
+  int i;
   gpr_mu_lock(&g_init_mu);
   if (--g_initializations == 0) {
     grpc_iomgr_shutdown();
@@ -99,6 +126,11 @@ void grpc_shutdown(void) {
     grpc_timers_global_destroy();
     grpc_tracer_shutdown();
     grpc_resolver_registry_shutdown();
+    for (i = 0; i < g_number_of_plugins; i++) {
+      if (g_all_of_the_plugins[i].destroy != NULL) {
+        g_all_of_the_plugins[i].destroy();
+      }
+    }
   }
   gpr_mu_unlock(&g_init_mu);
 }

src/core/surface/server.c

@@ -761,8 +761,10 @@ static const grpc_channel_filter server_surface_filter = {
 };
 
 void grpc_server_register_completion_queue(grpc_server *server,
-                                           grpc_completion_queue *cq) {
+                                           grpc_completion_queue *cq,
+                                           void *reserved) {
   size_t i, n;
+  GPR_ASSERT(!reserved);
   for (i = 0; i < server->cq_count; i++) {
     if (server->cqs[i] == cq) return;
   }

src/core/surface/server_create.c

@@ -36,8 +36,9 @@
 #include "src/core/surface/server.h"
 #include "src/core/channel/compress_filter.h"
 
-grpc_server *grpc_server_create(const grpc_channel_args *args) {
+grpc_server *grpc_server_create(const grpc_channel_args *args, void *reserved) {
   const grpc_channel_filter *filters[] = {&grpc_compress_filter};
+  (void) reserved;
   return grpc_server_create_from_filters(filters, GPR_ARRAY_SIZE(filters),
                                          args);
 }

src/core/transport/stream_op.c

@@ -258,6 +258,7 @@ static void link_tail(grpc_mdelem_list *list, grpc_linked_mdelem *storage) {
   GPR_ASSERT(storage->md);
   storage->prev = list->tail;
   storage->next = NULL;
+  storage->reserved = NULL;
   if (list->tail != NULL) {
     list->tail->next = storage;
   } else {

src/core/transport/stream_op.h

@@ -77,6 +77,7 @@ typedef struct grpc_linked_mdelem {
   grpc_mdelem *md;
   struct grpc_linked_mdelem *next;
   struct grpc_linked_mdelem *prev;
+  void *reserved;
 } grpc_linked_mdelem;
 
 typedef struct grpc_mdelem_list {

src/cpp/client/channel.cc

@@ -61,19 +61,25 @@ Channel::~Channel() { grpc_channel_destroy(c_channel_); }
 
 Call Channel::CreateCall(const RpcMethod& method, ClientContext* context,
                          CompletionQueue* cq) {
-  const char* host_str = host_.empty() ? NULL : host_.c_str();
-  auto c_call = method.channel_tag() && context->authority().empty()
-                    ? grpc_channel_create_registered_call(
-                          c_channel_, context->propagate_from_call_,
-                          context->propagation_options_.c_bitmask(), cq->cq(),
-                          method.channel_tag(), context->raw_deadline())
-                    : grpc_channel_create_call(
-                          c_channel_, context->propagate_from_call_,
-                          context->propagation_options_.c_bitmask(), cq->cq(),
-                          method.name(), context->authority().empty()
-                                             ? host_str
-                                             : context->authority().c_str(),
-                          context->raw_deadline());
+  const bool kRegistered = method.channel_tag() && context->authority().empty();
+  grpc_call* c_call = NULL;
+  if (kRegistered) {
+    c_call = grpc_channel_create_registered_call(
+        c_channel_, context->propagate_from_call_,
+        context->propagation_options_.c_bitmask(), cq->cq(),
+        method.channel_tag(), context->raw_deadline(), nullptr);
+  } else {
+    const char* host_str = NULL;
+    if (!context->authority().empty()) {
+      host_str = context->authority().c_str();
+    } else if (!host_.empty()) {
+      host_str = host_.c_str();
+    }
+    c_call = grpc_channel_create_call(c_channel_, context->propagate_from_call_,
+                                      context->propagation_options_.c_bitmask(),
+                                      cq->cq(), method.name(), host_str,
+                                      context->raw_deadline(), nullptr);
+  }
   grpc_census_call_set_context(c_call, context->census_context());
   GRPC_TIMER_MARK(GRPC_PTAG_CPP_CALL_CREATED, c_call);
   context->set_call(c_call, shared_from_this());
@@ -87,13 +93,14 @@ void Channel::PerformOpsOnCall(CallOpSetInterface* ops, Call* call) {
   GRPC_TIMER_BEGIN(GRPC_PTAG_CPP_PERFORM_OPS, call->call());
   ops->FillOps(cops, &nops);
   GPR_ASSERT(GRPC_CALL_OK ==
-             grpc_call_start_batch(call->call(), cops, nops, ops));
+             grpc_call_start_batch(call->call(), cops, nops, ops, nullptr));
   GRPC_TIMER_END(GRPC_PTAG_CPP_PERFORM_OPS, call->call());
 }
 
 void* Channel::RegisterMethod(const char* method) {
   return grpc_channel_register_call(c_channel_, method,
-                                    host_.empty() ? NULL : host_.c_str());
+                                    host_.empty() ? NULL : host_.c_str(),
+                                    nullptr);
 }
 
 grpc_connectivity_state Channel::GetState(bool try_to_connect) {

src/cpp/client/client_context.cc

@@ -48,7 +48,6 @@ namespace grpc {
 ClientContext::ClientContext()
     : initial_metadata_received_(false),
       call_(nullptr),
-      cq_(nullptr),
       deadline_(gpr_inf_future(GPR_CLOCK_REALTIME)),
       propagate_from_call_(nullptr) {}
 
@@ -56,14 +55,6 @@ ClientContext::~ClientContext() {
   if (call_) {
     grpc_call_destroy(call_);
   }
-  if (cq_) {
-    // Drain cq_.
-    grpc_completion_queue_shutdown(cq_);
-    while (grpc_completion_queue_next(cq_, gpr_inf_future(GPR_CLOCK_REALTIME))
-               .type != GRPC_QUEUE_SHUTDOWN)
-      ;
-    grpc_completion_queue_destroy(cq_);
-  }
 }
 
 std::unique_ptr<ClientContext> ClientContext::FromServerContext(
@@ -86,19 +77,19 @@ void ClientContext::set_call(grpc_call* call,
   channel_ = channel;
   if (creds_ && !creds_->ApplyToCall(call_)) {
     grpc_call_cancel_with_status(call, GRPC_STATUS_CANCELLED,
-                                 "Failed to set credentials to rpc.");
+                                 "Failed to set credentials to rpc.", nullptr);
   }
 }
 
 void ClientContext::set_compression_algorithm(
     grpc_compression_algorithm algorithm) {
-  char* algorithm_name = NULL;
+  char* algorithm_name = nullptr;
   if (!grpc_compression_algorithm_name(algorithm, &algorithm_name)) {
     gpr_log(GPR_ERROR, "Name for compression algorithm '%d' unknown.",
             algorithm);
     abort();
   }
-  GPR_ASSERT(algorithm_name != NULL);
+  GPR_ASSERT(algorithm_name != nullptr);
   AddMetadata(GRPC_COMPRESS_REQUEST_ALGORITHM_KEY, algorithm_name);
 }
 
@@ -111,7 +102,7 @@ std::shared_ptr<const AuthContext> ClientContext::auth_context() const {
 
 void ClientContext::TryCancel() {
   if (call_) {
-    grpc_call_cancel(call_);
+    grpc_call_cancel(call_, nullptr);
   }
 }
 

src/cpp/client/insecure_credentials.cc

@@ -49,7 +49,7 @@ class InsecureCredentialsImpl GRPC_FINAL : public Credentials {
     grpc_channel_args channel_args;
     args.SetChannelArgs(&channel_args);
     return std::shared_ptr<ChannelInterface>(new Channel(
-        grpc_insecure_channel_create(target.c_str(), &channel_args)));
+        grpc_insecure_channel_create(target.c_str(), &channel_args, nullptr)));
   }
 
   // InsecureCredentials should not be applied to a call.

src/cpp/common/completion_queue.cc

@@ -40,7 +40,9 @@
 
 namespace grpc {
 
-CompletionQueue::CompletionQueue() { cq_ = grpc_completion_queue_create(); }
+CompletionQueue::CompletionQueue() {
+  cq_ = grpc_completion_queue_create(nullptr);
+}
 
 CompletionQueue::CompletionQueue(grpc_completion_queue* take) : cq_(take) {}
 
@@ -51,7 +53,7 @@ void CompletionQueue::Shutdown() { grpc_completion_queue_shutdown(cq_); }
 CompletionQueue::NextStatus CompletionQueue::AsyncNextInternal(
     void** tag, bool* ok, gpr_timespec deadline) {
   for (;;) {
-    auto ev = grpc_completion_queue_next(cq_, deadline);
+    auto ev = grpc_completion_queue_next(cq_, deadline, nullptr);
     switch (ev.type) {
       case GRPC_QUEUE_TIMEOUT:
         return TIMEOUT;
@@ -70,8 +72,8 @@ CompletionQueue::NextStatus CompletionQueue::AsyncNextInternal(
 }
 
 bool CompletionQueue::Pluck(CompletionQueueTag* tag) {
-  auto ev =
-      grpc_completion_queue_pluck(cq_, tag, gpr_inf_future(GPR_CLOCK_REALTIME));
+  auto deadline = gpr_inf_future(GPR_CLOCK_REALTIME);
+  auto ev = grpc_completion_queue_pluck(cq_, tag, deadline, nullptr);
   bool ok = ev.success != 0;
   void* ignored = tag;
   GPR_ASSERT(tag->FinalizeResult(&ignored, &ok));
@@ -81,8 +83,8 @@ bool CompletionQueue::Pluck(CompletionQueueTag* tag) {
 }
 
 void CompletionQueue::TryPluck(CompletionQueueTag* tag) {
-  auto ev =
-      grpc_completion_queue_pluck(cq_, tag, gpr_time_0(GPR_CLOCK_REALTIME));
+  auto deadline = gpr_time_0(GPR_CLOCK_REALTIME);
+  auto ev = grpc_completion_queue_pluck(cq_, tag, deadline, nullptr);
   if (ev.type == GRPC_QUEUE_TIMEOUT) return;
   bool ok = ev.success != 0;
   void* ignored = tag;

src/cpp/server/server.cc

@@ -67,11 +67,17 @@ class Server::SyncRequest GRPC_FINAL : public CompletionQueueTag {
         has_request_payload_(method->method_type() == RpcMethod::NORMAL_RPC ||
                              method->method_type() ==
                                  RpcMethod::SERVER_STREAMING),
+        call_details_(nullptr),
         cq_(nullptr) {
     grpc_metadata_array_init(&request_metadata_);
   }
 
-  ~SyncRequest() { grpc_metadata_array_destroy(&request_metadata_); }
+  ~SyncRequest() {
+    if (call_details_) {
+      delete call_details_;
+    }
+    grpc_metadata_array_destroy(&request_metadata_);
+  }
 
   static SyncRequest* Wait(CompletionQueue* cq, bool* ok) {
     void* tag = nullptr;
@@ -84,7 +90,7 @@ class Server::SyncRequest GRPC_FINAL : public CompletionQueueTag {
     return mrd;
   }
 
-  void SetupRequest() { cq_ = grpc_completion_queue_create(); }
+  void SetupRequest() { cq_ = grpc_completion_queue_create(nullptr); }
 
   void TeardownRequest() {
     grpc_completion_queue_destroy(cq_);
@@ -94,17 +100,32 @@ class Server::SyncRequest GRPC_FINAL : public CompletionQueueTag {
   void Request(grpc_server* server, grpc_completion_queue* notify_cq) {
     GPR_ASSERT(cq_ && !in_flight_);
     in_flight_ = true;
-    GPR_ASSERT(GRPC_CALL_OK ==
-               grpc_server_request_registered_call(
-                   server, tag_, &call_, &deadline_, &request_metadata_,
-                   has_request_payload_ ? &request_payload_ : nullptr, cq_,
-                   notify_cq, this));
+    if (tag_) {
+      GPR_ASSERT(GRPC_CALL_OK ==
+                 grpc_server_request_registered_call(
+                     server, tag_, &call_, &deadline_, &request_metadata_,
+                     has_request_payload_ ? &request_payload_ : nullptr, cq_,
+                     notify_cq, this));
+    } else {
+      if (!call_details_) {
+        call_details_ = new grpc_call_details;
+        grpc_call_details_init(call_details_);
+      }
+      GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(
+                                     server, &call_, call_details_,
+                                     &request_metadata_, cq_, notify_cq, this));
+    }
   }
 
   bool FinalizeResult(void** tag, bool* status) GRPC_OVERRIDE {
     if (!*status) {
       grpc_completion_queue_destroy(cq_);
     }
+    if (call_details_) {
+      deadline_ = call_details_->deadline;
+      grpc_call_details_destroy(call_details_);
+      grpc_call_details_init(call_details_);
+    }
     return true;
   }
 
@@ -157,6 +178,7 @@ class Server::SyncRequest GRPC_FINAL : public CompletionQueueTag {
   bool in_flight_;
   const bool has_request_payload_;
   grpc_call* call_;
+  grpc_call_details* call_details_;
   gpr_timespec deadline_;
   grpc_metadata_array request_metadata_;
   grpc_byte_buffer* request_payload_;
@@ -170,9 +192,9 @@ static grpc_server* CreateServer(int max_message_size) {
     arg.key = const_cast<char*>(GRPC_ARG_MAX_MESSAGE_LENGTH);
     arg.value.integer = max_message_size;
     grpc_channel_args args = {1, &arg};
-    return grpc_server_create(&args);
+    return grpc_server_create(&args, nullptr);
   } else {
-    return grpc_server_create(nullptr);
+    return grpc_server_create(nullptr, nullptr);
   }
 }
 
@@ -183,10 +205,11 @@ Server::Server(ThreadPoolInterface* thread_pool, bool thread_pool_owned,
       shutdown_(false),
       num_running_cb_(0),
       sync_methods_(new std::list<SyncRequest>),
+      has_generic_service_(false),
       server_(CreateServer(max_message_size)),
       thread_pool_(thread_pool),
       thread_pool_owned_(thread_pool_owned) {
-  grpc_server_register_completion_queue(server_, cq_.cq());
+  grpc_server_register_completion_queue(server_, cq_.cq(), nullptr);
 }
 
 Server::~Server() {
@@ -223,7 +246,8 @@ bool Server::RegisterService(const grpc::string *host, RpcService* service) {
   return true;
 }
 
-bool Server::RegisterAsyncService(const grpc::string *host, AsynchronousService* service) {
+bool Server::RegisterAsyncService(const grpc::string* host,
+                                  AsynchronousService* service) {
   GPR_ASSERT(service->server_ == nullptr &&
              "Can only register an asynchronous service against one server.");
   service->server_ = this;
@@ -245,6 +269,7 @@ void Server::RegisterAsyncGenericService(AsyncGenericService* service) {
   GPR_ASSERT(service->server_ == nullptr &&
              "Can only register an async generic service against one server.");
   service->server_ = this;
+  has_generic_service_ = true;
 }
 
 int Server::AddListeningPort(const grpc::string& addr,
@@ -258,6 +283,11 @@ bool Server::Start() {
   started_ = true;
   grpc_server_start(server_);
 
+  if (!has_generic_service_) {
+    unknown_method_.reset(new RpcServiceMethod(
+        "unknown", RpcMethod::BIDI_STREAMING, new UnknownMethodHandler));
+    sync_methods_->emplace_back(unknown_method_.get(), nullptr);
+  }
   // Start processing rpcs.
   if (!sync_methods_->empty()) {
     for (auto m = sync_methods_->begin(); m != sync_methods_->end(); m++) {
@@ -297,8 +327,8 @@ void Server::PerformOpsOnCall(CallOpSetInterface* ops, Call* call) {
   size_t nops = 0;
   grpc_op cops[MAX_OPS];
   ops->FillOps(cops, &nops);
-  GPR_ASSERT(GRPC_CALL_OK ==
-             grpc_call_start_batch(call->call(), cops, nops, ops));
+  auto result = grpc_call_start_batch(call->call(), cops, nops, ops, nullptr);
+  GPR_ASSERT(GRPC_CALL_OK == result);
 }
 
 Server::BaseAsyncRequest::BaseAsyncRequest(

src/cpp/server/server_builder.cc

@@ -38,6 +38,7 @@
 #include <grpc++/impl/service_type.h>
 #include <grpc++/server.h>
 #include <grpc++/thread_pool_interface.h>
+#include <grpc++/fixed_size_thread_pool.h>
 
 namespace grpc {
 
@@ -100,10 +101,17 @@ std::unique_ptr<Server> ServerBuilder::BuildAndStart() {
     thread_pool_ = CreateDefaultThreadPool();
     thread_pool_owned = true;
   }
+  // Async services only, create a thread pool to handle requests to unknown
+  // services.
+  if (!thread_pool_ && !generic_service_ && !async_services_.empty()) {
+    thread_pool_ = new FixedSizeThreadPool(1);
+    thread_pool_owned = true;
+  }
   std::unique_ptr<Server> server(
       new Server(thread_pool_, thread_pool_owned, max_message_size_));
   for (auto cq = cqs_.begin(); cq != cqs_.end(); ++cq) {
-    grpc_server_register_completion_queue(server->server_, (*cq)->cq());
+    grpc_server_register_completion_queue(server->server_, (*cq)->cq(),
+                                          nullptr);
   }
   for (auto service = services_.begin(); service != services_.end();
        service++) {

src/cpp/server/server_context.cc

@@ -91,6 +91,7 @@ void ServerContext::CompletionOp::FillOps(grpc_op* ops, size_t* nops) {
   ops->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   ops->data.recv_close_on_server.cancelled = &cancelled_;
   ops->flags = 0;
+  ops->reserved = NULL;
   *nops = 1;
 }
 

src/csharp/Grpc.Core.Tests/ClientBaseTest.cs

@@ -0,0 +1,62 @@
+#region Copyright notice and license
+
+// 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.
+
+#endregion
+
+using System;
+using Grpc.Core;
+using Grpc.Core.Internal;
+using Grpc.Core.Utils;
+using NUnit.Framework;
+
+namespace Grpc.Core.Tests
+{
+    public class ClientBaseTest
+    {
+        [Test]
+        public void GetAuthUriBase_Valid()
+        {
+            Assert.AreEqual("https://some.googleapi.com/", ClientBase.GetAuthUriBase("some.googleapi.com"));
+            Assert.AreEqual("https://some.googleapi.com/", ClientBase.GetAuthUriBase("dns:///some.googleapi.com/"));
+            Assert.AreEqual("https://some.googleapi.com/", ClientBase.GetAuthUriBase("dns:///some.googleapi.com:443/"));
+            Assert.AreEqual("https://some.googleapi.com/", ClientBase.GetAuthUriBase("some.googleapi.com:443/"));
+        }
+
+        [Test]
+        public void GetAuthUriBase_Invalid()
+        {
+            Assert.IsNull(ClientBase.GetAuthUriBase("some.googleapi.com:"));
+            Assert.IsNull(ClientBase.GetAuthUriBase("https://some.googleapi.com/"));
+            Assert.IsNull(ClientBase.GetAuthUriBase("dns://some.googleapi.com:443"));  // just two slashes
+            Assert.IsNull(ClientBase.GetAuthUriBase(""));
+        }
+    }
+}

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

@@ -63,6 +63,7 @@
     <Compile Include="..\Grpc.Core\Version.cs">
       <Link>Version.cs</Link>
     </Compile>
+    <Compile Include="ClientBaseTest.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="ClientServerTest.cs" />
     <Compile Include="ServerTest.cs" />

src/csharp/Grpc.Core/ClientBase.cs

@@ -33,9 +33,10 @@
 
 using System;
 using System.Collections.Generic;
+using System.Text.RegularExpressions;
 
 using Grpc.Core.Internal;
-using System.Text.RegularExpressions;
+using Grpc.Core.Utils;
 
 namespace Grpc.Core
 {
@@ -46,15 +47,16 @@ namespace Grpc.Core
     /// </summary>
     public abstract class ClientBase
     {
-        static readonly Regex TrailingPortPattern = new Regex(":[0-9]+/?$");
+        // Regex for removal of the optional DNS scheme, trailing port, and trailing backslash
+        static readonly Regex ChannelTargetPattern = new Regex(@"^(dns:\/{3})?([^:\/]+)(:\d+)?\/?$");
+
         readonly Channel channel;
         readonly string authUriBase;
 
         public ClientBase(Channel channel)
         {
             this.channel = channel;
-            // TODO(jtattermush): we shouldn't need to hand-curate the channel.Target contents.
-            this.authUriBase = "https://" + TrailingPortPattern.Replace(channel.Target, "") + "/";
+            this.authUriBase = GetAuthUriBase(channel.Target);
         }
 
         /// <summary>
@@ -104,10 +106,23 @@ namespace Grpc.Core
                 {
                     options = options.WithHeaders(new Metadata());
                 }
-                var authUri = authUriBase + method.ServiceName;
+                var authUri = authUriBase != null ? authUriBase + method.ServiceName : null;
                 interceptor(authUri, options.Headers);
             }
             return new CallInvocationDetails<TRequest, TResponse>(channel, method, Host, options);
         }
+
+        /// <summary>
+        /// Creates Auth URI base from channel's target (the one passed at channel creation).
+        /// Fully-qualified service name is to be appended to this.
+        /// </summary>
+        internal static string GetAuthUriBase(string target)
+        {
+            var match = ChannelTargetPattern.Match(target);
+            if (!match.Success) {
+                return null;
+            }
+            return "https://" + match.Groups[2].Value + "/";
+        }
     }
 }

src/csharp/ext/grpc_csharp_ext.c

@@ -339,7 +339,7 @@ GPR_EXPORT void GPR_CALLTYPE grpcsharp_shutdown(void) { grpc_shutdown(); }
 
 GPR_EXPORT grpc_completion_queue *GPR_CALLTYPE
 grpcsharp_completion_queue_create(void) {
-  return grpc_completion_queue_create();
+  return grpc_completion_queue_create(NULL);
 }
 
 GPR_EXPORT void GPR_CALLTYPE
@@ -354,13 +354,14 @@ grpcsharp_completion_queue_destroy(grpc_completion_queue *cq) {
 
 GPR_EXPORT grpc_event GPR_CALLTYPE
 grpcsharp_completion_queue_next(grpc_completion_queue *cq) {
-  return grpc_completion_queue_next(cq, gpr_inf_future(GPR_CLOCK_REALTIME));
+  return grpc_completion_queue_next(cq, gpr_inf_future(GPR_CLOCK_REALTIME),
+                                    NULL);
 }
 
 GPR_EXPORT grpc_event GPR_CALLTYPE
 grpcsharp_completion_queue_pluck(grpc_completion_queue *cq, void *tag) {
   return grpc_completion_queue_pluck(cq, tag,
-                                     gpr_inf_future(GPR_CLOCK_REALTIME));
+                                     gpr_inf_future(GPR_CLOCK_REALTIME), NULL);
 }
 
 /* Channel */
@@ -368,7 +369,7 @@ grpcsharp_completion_queue_pluck(grpc_completion_queue *cq, void *tag) {
 GPR_EXPORT grpc_channel *GPR_CALLTYPE
 
 grpcsharp_insecure_channel_create(const char *target, const grpc_channel_args *args) {
-  return grpc_insecure_channel_create(target, args);
+  return grpc_insecure_channel_create(target, args, NULL);
 }
 
 GPR_EXPORT void GPR_CALLTYPE grpcsharp_channel_destroy(grpc_channel *channel) {
@@ -382,7 +383,7 @@ grpcsharp_channel_create_call(grpc_channel *channel, grpc_call *parent_call,
                               const char *method, const char *host,
                               gpr_timespec deadline) {
   return grpc_channel_create_call(channel, parent_call, propagation_mask, cq,
-                                  method, host, deadline);
+                                  method, host, deadline, NULL);
 }
 
 GPR_EXPORT grpc_connectivity_state GPR_CALLTYPE
@@ -475,13 +476,13 @@ GPR_EXPORT gpr_int32 GPR_CALLTYPE gprsharp_sizeof_timespec(void) {
 /* Call */
 
 GPR_EXPORT grpc_call_error GPR_CALLTYPE grpcsharp_call_cancel(grpc_call *call) {
-  return grpc_call_cancel(call);
+  return grpc_call_cancel(call, NULL);
 }
 
 GPR_EXPORT grpc_call_error GPR_CALLTYPE
 grpcsharp_call_cancel_with_status(grpc_call *call, grpc_status_code status,
                                   const char *description) {
-  return grpc_call_cancel_with_status(call, status, description);
+  return grpc_call_cancel_with_status(call, status, description, NULL);
 }
 
 GPR_EXPORT char *GPR_CALLTYPE grpcsharp_call_get_peer(grpc_call *call) {
@@ -538,7 +539,8 @@ grpcsharp_call_start_unary(grpc_call *call, grpcsharp_batch_context *ctx,
       &(ctx->recv_status_on_client.status_details_capacity);
   ops[5].flags = 0;
 
-  return grpc_call_start_batch(call, ops, sizeof(ops) / sizeof(ops[0]), ctx);
+  return grpc_call_start_batch(call, ops, sizeof(ops) / sizeof(ops[0]), ctx,
+                               NULL);
 }
 
 GPR_EXPORT grpc_call_error GPR_CALLTYPE
@@ -575,7 +577,8 @@ grpcsharp_call_start_client_streaming(grpc_call *call,
       &(ctx->recv_status_on_client.status_details_capacity);
   ops[3].flags = 0;
 
-  return grpc_call_start_batch(call, ops, sizeof(ops) / sizeof(ops[0]), ctx);
+  return grpc_call_start_batch(call, ops, sizeof(ops) / sizeof(ops[0]), ctx,
+                               NULL);
 }
 
 GPR_EXPORT grpc_call_error GPR_CALLTYPE grpcsharp_call_start_server_streaming(
@@ -615,7 +618,8 @@ GPR_EXPORT grpc_call_error GPR_CALLTYPE grpcsharp_call_start_server_streaming(
       &(ctx->recv_status_on_client.status_details_capacity);
   ops[4].flags = 0;
 
-  return grpc_call_start_batch(call, ops, sizeof(ops) / sizeof(ops[0]), ctx);
+  return grpc_call_start_batch(call, ops, sizeof(ops) / sizeof(ops[0]), ctx,
+                               NULL);
 }
 
 GPR_EXPORT grpc_call_error GPR_CALLTYPE
@@ -648,7 +652,8 @@ grpcsharp_call_start_duplex_streaming(grpc_call *call,
       &(ctx->recv_status_on_client.status_details_capacity);
   ops[2].flags = 0;
 
-  return grpc_call_start_batch(call, ops, sizeof(ops) / sizeof(ops[0]), ctx);
+  return grpc_call_start_batch(call, ops, sizeof(ops) / sizeof(ops[0]), ctx,
+                               NULL);
 }
 
 GPR_EXPORT grpc_call_error GPR_CALLTYPE
@@ -668,7 +673,7 @@ grpcsharp_call_send_message(grpc_call *call, grpcsharp_batch_context *ctx,
   ops[1].data.send_initial_metadata.metadata = NULL;
   ops[1].flags = 0;
 
-  return grpc_call_start_batch(call, ops, nops, ctx);
+  return grpc_call_start_batch(call, ops, nops, ctx, NULL);
 }
 
 GPR_EXPORT grpc_call_error GPR_CALLTYPE
@@ -679,7 +684,8 @@ grpcsharp_call_send_close_from_client(grpc_call *call,
   ops[0].op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   ops[0].flags = 0;
 
-  return grpc_call_start_batch(call, ops, sizeof(ops) / sizeof(ops[0]), ctx);
+  return grpc_call_start_batch(call, ops, sizeof(ops) / sizeof(ops[0]), ctx,
+                               NULL);
 }
 
 GPR_EXPORT grpc_call_error GPR_CALLTYPE grpcsharp_call_send_status_from_server(
@@ -705,7 +711,7 @@ GPR_EXPORT grpc_call_error GPR_CALLTYPE grpcsharp_call_send_status_from_server(
   ops[1].data.send_initial_metadata.metadata = NULL;
   ops[1].flags = 0;
 
-  return grpc_call_start_batch(call, ops, nops, ctx);
+  return grpc_call_start_batch(call, ops, nops, ctx, NULL);
 }
 
 GPR_EXPORT grpc_call_error GPR_CALLTYPE
@@ -715,7 +721,8 @@ grpcsharp_call_recv_message(grpc_call *call, grpcsharp_batch_context *ctx) {
   ops[0].op = GRPC_OP_RECV_MESSAGE;
   ops[0].data.recv_message = &(ctx->recv_message);
   ops[0].flags = 0;
-  return grpc_call_start_batch(call, ops, sizeof(ops) / sizeof(ops[0]), ctx);
+  return grpc_call_start_batch(call, ops, sizeof(ops) / sizeof(ops[0]), ctx,
+                               NULL);
 }
 
 GPR_EXPORT grpc_call_error GPR_CALLTYPE
@@ -727,7 +734,8 @@ grpcsharp_call_start_serverside(grpc_call *call, grpcsharp_batch_context *ctx) {
       (&ctx->recv_close_on_server_cancelled);
   ops[0].flags = 0;
 
-  return grpc_call_start_batch(call, ops, sizeof(ops) / sizeof(ops[0]), ctx);
+  return grpc_call_start_batch(call, ops, sizeof(ops) / sizeof(ops[0]), ctx,
+                               NULL);
 }
 
 GPR_EXPORT grpc_call_error GPR_CALLTYPE
@@ -744,7 +752,8 @@ grpcsharp_call_send_initial_metadata(grpc_call *call,
       ctx->send_initial_metadata.metadata;
   ops[0].flags = 0;
 
-  return grpc_call_start_batch(call, ops, sizeof(ops) / sizeof(ops[0]), ctx);
+  return grpc_call_start_batch(call, ops, sizeof(ops) / sizeof(ops[0]), ctx,
+                               NULL);
 }
 
 /* Server */
@@ -752,8 +761,8 @@ grpcsharp_call_send_initial_metadata(grpc_call *call,
 GPR_EXPORT grpc_server *GPR_CALLTYPE
 grpcsharp_server_create(grpc_completion_queue *cq,
                         const grpc_channel_args *args) {
-  grpc_server *server = grpc_server_create(args);
-  grpc_server_register_completion_queue(server, cq);
+  grpc_server *server = grpc_server_create(args, NULL);
+  grpc_server_register_completion_queue(server, cq, NULL);
   return server;
 }
 

src/node/examples/perf_test.js

@@ -40,7 +40,7 @@ var interop_server = require('../interop/interop_server.js');
 
 function runTest(iterations, callback) {
   var testServer = interop_server.getServer(0, false);
-  testServer.server.listen();
+  testServer.server.start();
   var client = new testProto.TestService('localhost:' + testServer.port,
                                          grpc.Credentials.createInsecure());
 

src/node/examples/qps_test.js

@@ -60,7 +60,7 @@ var interop_server = require('../interop/interop_server.js');
  */
 function runTest(concurrent_calls, seconds, callback) {
   var testServer = interop_server.getServer(0, false);
-  testServer.server.listen();
+  testServer.server.start();
   var client = new testProto.TestService('localhost:' + testServer.port,
                                          grpc.Credentials.createInsecure());
 

src/node/examples/route_guide_server.js

@@ -248,7 +248,7 @@ if (require.main === module) {
       throw err;
     }
     feature_list = JSON.parse(data);
-    routeServer.listen();
+    routeServer.start();
   });
 }
 

src/node/examples/stock_server.js

@@ -81,7 +81,7 @@ stockServer.addProtoService(examples.Stock.service, {
 
 if (require.main === module) {
   stockServer.bind('0.0.0.0:50051', grpc.ServerCredentials.createInsecure());
-  stockServer.listen();
+  stockServer.start();
 }
 
 module.exports = stockServer;

src/node/ext/call.cc

@@ -516,12 +516,12 @@ NAN_METHOD(Call::New) {
         wrapped_call = grpc_channel_create_call(
             wrapped_channel, NULL, GRPC_PROPAGATE_DEFAULTS,
             CompletionQueueAsyncWorker::GetQueue(), *method,
-            *host_override, MillisecondsToTimespec(deadline));
+            *host_override, MillisecondsToTimespec(deadline), NULL);
       } else if (args[3]->IsUndefined() || args[3]->IsNull()) {
         wrapped_call = grpc_channel_create_call(
             wrapped_channel, NULL, GRPC_PROPAGATE_DEFAULTS,
             CompletionQueueAsyncWorker::GetQueue(), *method,
-            NULL, MillisecondsToTimespec(deadline));
+            NULL, MillisecondsToTimespec(deadline), NULL);
       } else {
         return NanThrowTypeError("Call's fourth argument must be a string");
       }
@@ -601,7 +601,7 @@ NAN_METHOD(Call::StartBatch) {
   NanCallback *callback = new NanCallback(callback_func);
   grpc_call_error error = grpc_call_start_batch(
       call->wrapped_call, &ops[0], nops, new struct tag(
-          callback, op_vector.release(), resources));
+          callback, op_vector.release(), resources), NULL);
   if (error != GRPC_CALL_OK) {
     return NanThrowError("startBatch failed", error);
   }
@@ -615,7 +615,7 @@ NAN_METHOD(Call::Cancel) {
     return NanThrowTypeError("cancel can only be called on Call objects");
   }
   Call *call = ObjectWrap::Unwrap<Call>(args.This());
-  grpc_call_error error = grpc_call_cancel(call->wrapped_call);
+  grpc_call_error error = grpc_call_cancel(call->wrapped_call, NULL);
   if (error != GRPC_CALL_OK) {
     return NanThrowError("cancel failed", error);
   }

src/node/ext/channel.cc

@@ -33,12 +33,17 @@
 
 #include <vector>
 
+#include "grpc/support/log.h"
+
 #include <node.h>
 #include <nan.h>
 #include "grpc/grpc.h"
 #include "grpc/grpc_security.h"
+#include "call.h"
 #include "channel.h"
+#include "completion_queue_async_worker.h"
 #include "credentials.h"
+#include "timeval.h"
 
 namespace grpc {
 namespace node {
@@ -51,6 +56,7 @@ using v8::Handle;
 using v8::HandleScope;
 using v8::Integer;
 using v8::Local;
+using v8::Number;
 using v8::Object;
 using v8::Persistent;
 using v8::String;
@@ -76,6 +82,12 @@ void Channel::Init(Handle<Object> exports) {
                           NanNew<FunctionTemplate>(Close)->GetFunction());
   NanSetPrototypeTemplate(tpl, "getTarget",
                           NanNew<FunctionTemplate>(GetTarget)->GetFunction());
+  NanSetPrototypeTemplate(
+      tpl, "getConnectivityState",
+      NanNew<FunctionTemplate>(GetConnectivityState)->GetFunction());
+  NanSetPrototypeTemplate(
+      tpl, "watchConnectivityState",
+      NanNew<FunctionTemplate>(WatchConnectivityState)->GetFunction());
   NanAssignPersistent(fun_tpl, tpl);
   Handle<Function> ctr = tpl->GetFunction();
   constructor = new NanCallback(ctr);
@@ -111,7 +123,7 @@ NAN_METHOD(Channel::New) {
     grpc_channel_args *channel_args_ptr;
     if (args[2]->IsUndefined()) {
       channel_args_ptr = NULL;
-      wrapped_channel = grpc_insecure_channel_create(*host, NULL);
+      wrapped_channel = grpc_insecure_channel_create(*host, NULL, NULL);
     } else if (args[2]->IsObject()) {
       Handle<Object> args_hash(args[2]->ToObject()->Clone());
       Handle<Array> keys(args_hash->GetOwnPropertyNames());
@@ -145,7 +157,8 @@ NAN_METHOD(Channel::New) {
       return NanThrowTypeError("Channel expects a string and an object");
     }
     if (creds == NULL) {
-      wrapped_channel = grpc_insecure_channel_create(*host, channel_args_ptr);
+      wrapped_channel = grpc_insecure_channel_create(*host, channel_args_ptr,
+                                                     NULL);
     } else {
       wrapped_channel =
           grpc_secure_channel_create(creds, *host, channel_args_ptr);
@@ -185,5 +198,52 @@ NAN_METHOD(Channel::GetTarget) {
   NanReturnValue(NanNew(grpc_channel_get_target(channel->wrapped_channel)));
 }
 
+NAN_METHOD(Channel::GetConnectivityState) {
+  NanScope();
+  if (!HasInstance(args.This())) {
+    return NanThrowTypeError(
+        "getConnectivityState can only be called on Channel objects");
+  }
+  Channel *channel = ObjectWrap::Unwrap<Channel>(args.This());
+  int try_to_connect = (int)args[0]->Equals(NanTrue());
+  NanReturnValue(grpc_channel_check_connectivity_state(channel->wrapped_channel,
+                                                       try_to_connect));
+}
+
+NAN_METHOD(Channel::WatchConnectivityState) {
+  NanScope();
+  if (!HasInstance(args.This())) {
+    return NanThrowTypeError(
+        "watchConnectivityState can only be called on Channel objects");
+  }
+  if (!args[0]->IsUint32()) {
+    return NanThrowTypeError(
+        "watchConnectivityState's first argument must be a channel state");
+  }
+  if (!(args[1]->IsNumber() || args[1]->IsDate())) {
+    return NanThrowTypeError(
+        "watchConnectivityState's second argument must be a date or a number");
+  }
+  if (!args[2]->IsFunction()) {
+    return NanThrowTypeError(
+        "watchConnectivityState's third argument must be a callback");
+  }
+  grpc_connectivity_state last_state =
+      static_cast<grpc_connectivity_state>(args[0]->Uint32Value());
+  double deadline = args[1]->NumberValue();
+  Handle<Function> callback_func = args[2].As<Function>();
+  NanCallback *callback = new NanCallback(callback_func);
+  Channel *channel = ObjectWrap::Unwrap<Channel>(args.This());
+  unique_ptr<OpVec> ops(new OpVec());
+  grpc_channel_watch_connectivity_state(
+      channel->wrapped_channel, last_state, MillisecondsToTimespec(deadline),
+      CompletionQueueAsyncWorker::GetQueue(),
+      new struct tag(callback,
+                     ops.release(),
+                     shared_ptr<Resources>(nullptr)));
+  CompletionQueueAsyncWorker::Next();
+  NanReturnUndefined();
+}
+
 }  // namespace node
 }  // namespace grpc

src/node/ext/channel.h

@@ -64,6 +64,8 @@ class Channel : public ::node::ObjectWrap {
   static NAN_METHOD(New);
   static NAN_METHOD(Close);
   static NAN_METHOD(GetTarget);
+  static NAN_METHOD(GetConnectivityState);
+  static NAN_METHOD(WatchConnectivityState);
   static NanCallback *constructor;
   static v8::Persistent<v8::FunctionTemplate> fun_tpl;
 

src/node/ext/completion_queue_async_worker.cc

@@ -63,9 +63,9 @@ CompletionQueueAsyncWorker::~CompletionQueueAsyncWorker() {}
 
 void CompletionQueueAsyncWorker::Execute() {
   result =
-      grpc_completion_queue_next(queue, gpr_inf_future(GPR_CLOCK_REALTIME));
+      grpc_completion_queue_next(queue, gpr_inf_future(GPR_CLOCK_REALTIME), NULL);
   if (!result.success) {
-    SetErrorMessage("The batch encountered an error");
+    SetErrorMessage("The async function encountered an error");
   }
 }
 
@@ -85,7 +85,7 @@ void CompletionQueueAsyncWorker::Init(Handle<Object> exports) {
   NanScope();
   current_threads = 0;
   waiting_next_calls = 0;
-  queue = grpc_completion_queue_create();
+  queue = grpc_completion_queue_create(NULL);
 }
 
 void CompletionQueueAsyncWorker::HandleOKCallback() {

src/node/ext/node_grpc.cc

@@ -159,12 +159,31 @@ void InitOpTypeConstants(Handle<Object> exports) {
   op_type->Set(NanNew("RECV_CLOSE_ON_SERVER"), RECV_CLOSE_ON_SERVER);
 }
 
+void InitConnectivityStateConstants(Handle<Object> exports) {
+  NanScope();
+  Handle<Object> channel_state = NanNew<Object>();
+  exports->Set(NanNew("connectivityState"), channel_state);
+  Handle<Value> IDLE(NanNew<Uint32, uint32_t>(GRPC_CHANNEL_IDLE));
+  channel_state->Set(NanNew("IDLE"), IDLE);
+  Handle<Value> CONNECTING(NanNew<Uint32, uint32_t>(GRPC_CHANNEL_CONNECTING));
+  channel_state->Set(NanNew("CONNECTING"), CONNECTING);
+  Handle<Value> READY(NanNew<Uint32, uint32_t>(GRPC_CHANNEL_READY));
+  channel_state->Set(NanNew("READY"), READY);
+  Handle<Value> TRANSIENT_FAILURE(
+      NanNew<Uint32, uint32_t>(GRPC_CHANNEL_TRANSIENT_FAILURE));
+  channel_state->Set(NanNew("TRANSIENT_FAILURE"), TRANSIENT_FAILURE);
+  Handle<Value> FATAL_FAILURE(
+      NanNew<Uint32, uint32_t>(GRPC_CHANNEL_FATAL_FAILURE));
+  channel_state->Set(NanNew("FATAL_FAILURE"), FATAL_FAILURE);
+}
+
 void init(Handle<Object> exports) {
   NanScope();
   grpc_init();
   InitStatusConstants(exports);
   InitCallErrorConstants(exports);
   InitOpTypeConstants(exports);
+  InitConnectivityStateConstants(exports);
 
   grpc::node::Call::Init(exports);
   grpc::node::Channel::Init(exports);

src/node/ext/server.cc

@@ -113,8 +113,8 @@ class NewCallOp : public Op {
 };
 
 Server::Server(grpc_server *server) : wrapped_server(server) {
-  shutdown_queue = grpc_completion_queue_create();
-  grpc_server_register_completion_queue(server, shutdown_queue);
+  shutdown_queue = grpc_completion_queue_create(NULL);
+  grpc_server_register_completion_queue(server, shutdown_queue, NULL);
 }
 
 Server::~Server() {
@@ -158,7 +158,7 @@ void Server::ShutdownServer() {
                                     this->shutdown_queue,
                                     NULL);
     grpc_completion_queue_pluck(this->shutdown_queue, NULL,
-                                gpr_inf_future(GPR_CLOCK_REALTIME));
+                                gpr_inf_future(GPR_CLOCK_REALTIME), NULL);
     this->wrapped_server = NULL;
   }
 }
@@ -176,7 +176,7 @@ NAN_METHOD(Server::New) {
   grpc_server *wrapped_server;
   grpc_completion_queue *queue = CompletionQueueAsyncWorker::GetQueue();
   if (args[0]->IsUndefined()) {
-    wrapped_server = grpc_server_create(NULL);
+    wrapped_server = grpc_server_create(NULL, NULL);
   } else if (args[0]->IsObject()) {
     Handle<Object> args_hash(args[0]->ToObject());
     Handle<Array> keys(args_hash->GetOwnPropertyNames());
@@ -205,12 +205,12 @@ NAN_METHOD(Server::New) {
         return NanThrowTypeError("Arg values must be strings");
       }
     }
-    wrapped_server = grpc_server_create(&channel_args);
+    wrapped_server = grpc_server_create(&channel_args, NULL);
     free(channel_args.args);
   } else {
     return NanThrowTypeError("Server expects an object");
   }
-  grpc_server_register_completion_queue(wrapped_server, queue);
+  grpc_server_register_completion_queue(wrapped_server, queue, NULL);
   Server *server = new Server(wrapped_server);
   server->Wrap(args.This());
   NanReturnValue(args.This());

src/node/interop/interop_server.js

@@ -194,7 +194,7 @@ if (require.main === module) {
   });
   var server_obj = getServer(argv.port, argv.use_tls === 'true');
   console.log('Server attaching to port ' + argv.port);
-  server_obj.server.listen();
+  server_obj.server.start();
 }
 
 /**

src/node/src/client.js

@@ -558,6 +558,35 @@ exports.makeClientConstructor = function(methods, serviceName) {
     this.$updateMetadata = updateMetadata;
   }
 
+  /**
+   * Wait for the client to be ready. The callback will be called when the
+   * client has successfully connected to the server, and it will be called
+   * with an error if the attempt to connect to the server has unrecoverablly
+   * failed or if the deadline expires. This function will make the channel
+   * start connecting if it has not already done so.
+   * @param {(Date|Number)} deadline When to stop waiting for a connection. Pass
+   *     Infinity to wait forever.
+   * @param {function(Error)} callback The callback to call when done attempting
+   *     to connect.
+   */
+  Client.prototype.$waitForReady = function(deadline, callback) {
+    var self = this;
+    var checkState = function(err) {
+      if (err) {
+        callback(new Error('Failed to connect before the deadline'));
+      }
+      var new_state = self.$channel.getConnectivityState(true);
+      if (new_state === grpc.connectivityState.READY) {
+        callback();
+      } else if (new_state === grpc.connectivityState.FATAL_FAILURE) {
+        callback(new Error('Failed to connect to server'));
+      } else {
+        self.$channel.watchConnectivityState(new_state, deadline, checkState);
+      }
+    };
+    checkState();
+  };
+
   _.each(methods, function(attrs, name) {
     var method_type;
     if (_.startsWith(name, '$')) {

src/node/test/channel_test.js

@@ -36,6 +36,26 @@
 var assert = require('assert');
 var grpc = require('bindings')('grpc.node');
 
+/**
+ * This is used for testing functions with multiple asynchronous calls that
+ * can happen in different orders. This should be passed the number of async
+ * function invocations that can occur last, and each of those should call this
+ * function's return value
+ * @param {function()} done The function that should be called when a test is
+ *     complete.
+ * @param {number} count The number of calls to the resulting function if the
+ *     test passes.
+ * @return {function()} The function that should be called at the end of each
+ *     sequence of asynchronous functions.
+ */
+function multiDone(done, count) {
+  return function() {
+    count -= 1;
+    if (count <= 0) {
+      done();
+    }
+  };
+}
 var insecureCreds = grpc.Credentials.createInsecure();
 
 describe('channel', function() {
@@ -86,14 +106,16 @@ describe('channel', function() {
     });
   });
   describe('close', function() {
+    var channel;
+    beforeEach(function() {
+      channel = new grpc.Channel('hostname', insecureCreds, {});
+    });
     it('should succeed silently', function() {
-      var channel = new grpc.Channel('hostname', insecureCreds, {});
       assert.doesNotThrow(function() {
         channel.close();
       });
     });
     it('should be idempotent', function() {
-      var channel = new grpc.Channel('hostname', insecureCreds, {});
       assert.doesNotThrow(function() {
         channel.close();
         channel.close();
@@ -101,9 +123,68 @@ describe('channel', function() {
     });
   });
   describe('getTarget', function() {
+    var channel;
+    beforeEach(function() {
+      channel = new grpc.Channel('hostname', insecureCreds, {});
+    });
     it('should return a string', function() {
-      var channel = new grpc.Channel('localhost', insecureCreds, {});
       assert.strictEqual(typeof channel.getTarget(), 'string');
     });
   });
+  describe('getConnectivityState', function() {
+    var channel;
+    beforeEach(function() {
+      channel = new grpc.Channel('hostname', insecureCreds, {});
+    });
+    it('should return IDLE for a new channel', function() {
+      assert.strictEqual(channel.getConnectivityState(),
+                         grpc.connectivityState.IDLE);
+    });
+  });
+  describe('watchConnectivityState', function() {
+    var channel;
+    beforeEach(function() {
+      channel = new grpc.Channel('localhost', insecureCreds, {});
+    });
+    afterEach(function() {
+      channel.close();
+    });
+    it('should time out if called alone', function(done) {
+      var old_state = channel.getConnectivityState();
+      var deadline = new Date();
+      deadline.setSeconds(deadline.getSeconds() + 1);
+      channel.watchConnectivityState(old_state, deadline, function(err, value) {
+        assert(err);
+        done();
+      });
+    });
+    it('should complete if a connection attempt is forced', function(done) {
+      var old_state = channel.getConnectivityState();
+      var deadline = new Date();
+      deadline.setSeconds(deadline.getSeconds() + 1);
+      channel.watchConnectivityState(old_state, deadline, function(err, value) {
+        assert.ifError(err);
+        assert.notEqual(value.new_state, old_state);
+        done();
+      });
+      channel.getConnectivityState(true);
+    });
+    it('should complete twice if called twice', function(done) {
+      done = multiDone(done, 2);
+      var old_state = channel.getConnectivityState();
+      var deadline = new Date();
+      deadline.setSeconds(deadline.getSeconds() + 1);
+      channel.watchConnectivityState(old_state, deadline, function(err, value) {
+        assert.ifError(err);
+        assert.notEqual(value.new_state, old_state);
+        done();
+      });
+      channel.watchConnectivityState(old_state, deadline, function(err, value) {
+        assert.ifError(err);
+        assert.notEqual(value.new_state, old_state);
+        done();
+      });
+      channel.getConnectivityState(true);
+    });
+  });
 });

src/node/test/constant_test.js

@@ -78,6 +78,19 @@ var callErrorNames = [
   'INVALID_FLAGS'
 ];
 
+/**
+ * List of all connectivity state names
+ * @const
+ * @type {Array.<string>}
+ */
+var connectivityStateNames = [
+  'IDLE',
+  'CONNECTING',
+  'READY',
+  'TRANSIENT_FAILURE',
+  'FATAL_FAILURE'
+];
+
 describe('constants', function() {
   it('should have all of the status constants', function() {
     for (var i = 0; i < statusNames.length; i++) {
@@ -91,4 +104,10 @@ describe('constants', function() {
              'call error missing: ' + callErrorNames[i]);
     }
   });
+  it('should have all of the connectivity states', function() {
+    for (var i = 0; i < connectivityStateNames.length; i++) {
+      assert(grpc.connectivityState.hasOwnProperty(connectivityStateNames[i]),
+             'connectivity status missing: ' + connectivityStateNames[i]);
+    }
+  });
 });

src/node/test/server_test.js

@@ -83,7 +83,7 @@ describe('server', function() {
       server = new grpc.Server();
     });
   });
-  describe('listen', function() {
+  describe('start', function() {
     var server;
     before(function() {
       server = new grpc.Server();
@@ -92,7 +92,7 @@ describe('server', function() {
     after(function() {
       server.shutdown();
     });
-    it('should listen without error', function() {
+    it('should start without error', function() {
       assert.doesNotThrow(function() {
         server.start();
       });

src/node/test/surface_test.js

@@ -47,6 +47,26 @@ var mathService = math_proto.lookup('math.Math');
 
 var _ = require('lodash');
 
+/**
+ * This is used for testing functions with multiple asynchronous calls that
+ * can happen in different orders. This should be passed the number of async
+ * function invocations that can occur last, and each of those should call this
+ * function's return value
+ * @param {function()} done The function that should be called when a test is
+ *     complete.
+ * @param {number} count The number of calls to the resulting function if the
+ *     test passes.
+ * @return {function()} The function that should be called at the end of each
+ *     sequence of asynchronous functions.
+ */
+function multiDone(done, count) {
+  return function() {
+    count -= 1;
+    if (count <= 0) {
+      done();
+    }
+  };
+}
 var server_insecure_creds = grpc.ServerCredentials.createInsecure();
 
 describe('File loader', function() {
@@ -130,6 +150,58 @@ describe('Client constructor building', function() {
     }, /\$/);
   });
 });
+describe('Client#$waitForReady', function() {
+  var server;
+  var port;
+  var Client;
+  var client;
+  before(function() {
+    server = new grpc.Server();
+    port = server.bind('localhost:0', grpc.ServerCredentials.createInsecure());
+    server.start();
+    Client = surface_client.makeProtobufClientConstructor(mathService);
+  });
+  beforeEach(function() {
+    client = new Client('localhost:' + port, grpc.Credentials.createInsecure());
+  });
+  after(function() {
+    server.shutdown();
+  });
+  it('should complete when called alone', function(done) {
+    client.$waitForReady(Infinity, function(error) {
+      assert.ifError(error);
+      done();
+    });
+  });
+  it('should complete when a call is initiated', function(done) {
+    client.$waitForReady(Infinity, function(error) {
+      assert.ifError(error);
+      done();
+    });
+    var call = client.div({}, function(err, response) {});
+    call.cancel();
+  });
+  it('should complete if called more than once', function(done) {
+    done = multiDone(done, 2);
+    client.$waitForReady(Infinity, function(error) {
+      assert.ifError(error);
+      done();
+    });
+    client.$waitForReady(Infinity, function(error) {
+      assert.ifError(error);
+      done();
+    });
+  });
+  it('should complete if called when already ready', function(done) {
+    client.$waitForReady(Infinity, function(error) {
+      assert.ifError(error);
+      client.$waitForReady(Infinity, function(error) {
+        assert.ifError(error);
+        done();
+      });
+    });
+  });
+});
 describe('Echo service', function() {
   var server;
   var client;

src/objective-c/GRPCClient/GRPCCall+OAuth2.m

@@ -40,7 +40,7 @@ static NSString * const kChallengeHeader = @"www-authenticate";
 @implementation GRPCCall (OAuth2)
 
 - (NSString *)oauth2AccessToken {
-  NSString *headerValue = self.requestMetadata[kAuthorizationHeader];
+  NSString *headerValue = self.requestHeaders[kAuthorizationHeader];
   if ([headerValue hasPrefix:kBearerPrefix]) {
     return [headerValue substringFromIndex:kBearerPrefix.length];
   } else {
@@ -50,14 +50,14 @@ static NSString * const kChallengeHeader = @"www-authenticate";
 
 - (void)setOauth2AccessToken:(NSString *)token {
   if (token) {
-    self.requestMetadata[kAuthorizationHeader] = [kBearerPrefix stringByAppendingString:token];
+    self.requestHeaders[kAuthorizationHeader] = [kBearerPrefix stringByAppendingString:token];
   } else {
-    [self.requestMetadata removeObjectForKey:kAuthorizationHeader];
+    [self.requestHeaders removeObjectForKey:kAuthorizationHeader];
   }
 }
 
 - (NSString *)oauth2ChallengeHeader {
-  return self.responseMetadata[kChallengeHeader];
+  return self.responseHeaders[kChallengeHeader];
 }
 
 @end

src/objective-c/GRPCClient/GRPCCall.h

@@ -48,8 +48,10 @@
 #import <Foundation/Foundation.h>
 #import <RxLibrary/GRXWriter.h>
 
-// Key used in |NSError|'s |userInfo| dictionary to store the response metadata sent by the server.
-extern id const kGRPCStatusMetadataKey;
+// Keys used in |NSError|'s |userInfo| dictionary to store the response headers and trailers sent by
+// the server.
+extern id const kGRPCHeadersKey;
+extern id const kGRPCTrailersKey;
 
 // Represents a single gRPC remote call.
 @interface GRPCCall : GRXWriter
@@ -57,43 +59,49 @@ extern id const kGRPCStatusMetadataKey;
 // These HTTP headers will be passed to the server as part of this call. Each HTTP header is a
 // name-value pair with string names and either string or binary values.
 //
-// The passed dictionary has to use NSString keys, corresponding to the header names. The
-// value associated to each can be a NSString object or a NSData object. E.g.:
+// The passed dictionary has to use NSString keys, corresponding to the header names. The value
+// associated to each can be a NSString object or a NSData object. E.g.:
 //
-// call.requestMetadata = @{@"Authorization": @"Bearer ..."};
+// call.requestHeaders = @{@"authorization": @"Bearer ..."};
 //
-// call.requestMetadata[@"SomeBinaryHeader"] = someData;
+// call.requestHeaders[@"my-header-bin"] = someData;
 //
-// After the call is started, modifying this won't have any effect.
+// After the call is started, trying to modify this property is an error.
 //
 // For convenience, the property is initialized to an empty NSMutableDictionary, and the setter
 // accepts (and copies) both mutable and immutable dictionaries.
-- (NSMutableDictionary *)requestMetadata; // nonatomic
-- (void)setRequestMetadata:(NSDictionary *)requestMetadata; // nonatomic, copy
+- (NSMutableDictionary *)requestHeaders; // nonatomic
+- (void)setRequestHeaders:(NSDictionary *)requestHeaders; // nonatomic, copy
 
-// This dictionary is populated with the HTTP headers received from the server. When the RPC ends,
-// the HTTP trailers received are added to the dictionary too. It has the same structure as the
-// request metadata dictionary.
+// This dictionary is populated with the HTTP headers received from the server. This happens before
+// any response message is received from the server. It has the same structure as the request
+// headers dictionary: Keys are NSString header names; names ending with the suffix "-bin" have a
+// NSData value; the others have a NSString value.
 //
-// The first time this object calls |writeValue| on the writeable passed to |startWithWriteable|,
-// the |responseMetadata| dictionary already contains the response headers. When it calls
-// |writesFinishedWithError|, the dictionary contains both the response headers and trailers.
-@property(atomic, readonly) NSDictionary *responseMetadata;
+// The value of this property is nil until all response headers are received, and will change before
+// any of -writeValue: or -writesFinishedWithError: are sent to the writeable.
+@property(atomic, readonly) NSDictionary *responseHeaders;
+
+// Same as responseHeaders, but populated with the HTTP trailers received from the server before the
+// call finishes.
+//
+// The value of this property is nil until all response trailers are received, and will change
+// before -writesFinishedWithError: is sent to the writeable.
+@property(atomic, readonly) NSDictionary *responseTrailers;
 
 // The request writer has to write NSData objects into the provided Writeable. The server will
-// receive each of those separately and in order.
-// A gRPC call might not complete until the request writer finishes. On the other hand, the
-// request finishing doesn't necessarily make the call to finish, as the server might continue
-// sending messages to the response side of the call indefinitely (depending on the semantics of
-// the specific remote method called).
+// receive each of those separately and in order as distinct messages.
+// A gRPC call might not complete until the request writer finishes. On the other hand, the request
+// finishing doesn't necessarily make the call to finish, as the server might continue sending
+// messages to the response side of the call indefinitely (depending on the semantics of the
+// specific remote method called).
 // To finish a call right away, invoke cancel.
 - (instancetype)initWithHost:(NSString *)host
                         path:(NSString *)path
               requestsWriter:(GRXWriter *)requestsWriter NS_DESIGNATED_INITIALIZER;
 
-// Finishes the request side of this call, notifies the server that the RPC
-// should be cancelled, and finishes the response side of the call with an error
-// of code CANCELED.
+// Finishes the request side of this call, notifies the server that the RPC should be cancelled, and
+// finishes the response side of the call with an error of code CANCELED.
 - (void)cancel;
 
 // TODO(jcanizales): Let specify a deadline. As a category of GRXWriter?

src/objective-c/GRPCClient/GRPCCall.m

@@ -42,9 +42,13 @@
 #import "private/NSDictionary+GRPC.h"
 #import "private/NSError+GRPC.h"
 
-NSString * const kGRPCStatusMetadataKey = @"io.grpc.StatusMetadataKey";
+NSString * const kGRPCHeadersKey = @"io.grpc.HeadersKey";
+NSString * const kGRPCTrailersKey = @"io.grpc.TrailersKey";
 
 @interface GRPCCall () <GRXWriteable>
+// Make them read-write.
+@property(atomic, strong) NSDictionary *responseHeaders;
+@property(atomic, strong) NSDictionary *responseTrailers;
 @end
 
 // The following methods of a C gRPC call object aren't reentrant, and thus
@@ -89,8 +93,7 @@ NSString * const kGRPCStatusMetadataKey = @"io.grpc.StatusMetadataKey";
   // the response arrives.
   GRPCCall *_retainSelf;
 
-  NSMutableDictionary *_requestMetadata;
-  NSMutableDictionary *_responseMetadata;
+  NSMutableDictionary *_requestHeaders;
 }
 
 @synthesize state = _state;
@@ -121,24 +124,19 @@ NSString * const kGRPCStatusMetadataKey = @"io.grpc.StatusMetadataKey";
 
     _requestWriter = requestWriter;
 
-    _requestMetadata = [NSMutableDictionary dictionary];
-    _responseMetadata = [NSMutableDictionary dictionary];
+    _requestHeaders = [NSMutableDictionary dictionary];
   }
   return self;
 }
 
 #pragma mark Metadata
 
-- (NSMutableDictionary *)requestMetadata {
-  return _requestMetadata;
+- (NSMutableDictionary *)requestHeaders {
+  return _requestHeaders;
 }
 
-- (void)setRequestMetadata:(NSDictionary *)requestMetadata {
-  _requestMetadata = [NSMutableDictionary dictionaryWithDictionary:requestMetadata];
-}
-
-- (NSDictionary *)responseMetadata {
-  return _responseMetadata;
+- (void)setRequestHeaders:(NSDictionary *)requestHeaders {
+  _requestHeaders = [NSMutableDictionary dictionaryWithDictionary:requestHeaders];
 }
 
 #pragma mark Finish
@@ -232,11 +230,10 @@ NSString * const kGRPCStatusMetadataKey = @"io.grpc.StatusMetadataKey";
 
 #pragma mark Send headers
 
-// TODO(jcanizales): Rename to commitHeaders.
-- (void)sendHeaders:(NSDictionary *)metadata {
+- (void)sendHeaders:(NSDictionary *)headers {
   // TODO(jcanizales): Add error handlers for async failures
   [_wrappedCall startBatchWithOperations:@[[[GRPCOpSendMetadata alloc]
-                                            initWithMetadata:metadata ?: @{} handler:nil]]];
+                                            initWithMetadata:headers ?: @{} handler:nil]]];
 }
 
 #pragma mark GRXWriteable implementation
@@ -305,35 +302,45 @@ NSString * const kGRPCStatusMetadataKey = @"io.grpc.StatusMetadataKey";
 
 // Both handlers will eventually be called, from the network queue. Writes can start immediately
 // after this.
-// The first one (metadataHandler), when the response headers are received.
+// The first one (headersHandler), when the response headers are received.
 // The second one (completionHandler), whenever the RPC finishes for any reason.
-- (void)invokeCallWithMetadataHandler:(void(^)(NSDictionary *))metadataHandler
+- (void)invokeCallWithHeadersHandler:(void(^)(NSDictionary *))headersHandler
                     completionHandler:(void(^)(NSError *, NSDictionary *))completionHandler {
   // TODO(jcanizales): Add error handlers for async failures
   [_wrappedCall startBatchWithOperations:@[[[GRPCOpRecvMetadata alloc]
-                                            initWithHandler:metadataHandler]]];
+                                            initWithHandler:headersHandler]]];
   [_wrappedCall startBatchWithOperations:@[[[GRPCOpRecvStatus alloc]
                                             initWithHandler:completionHandler]]];
 }
 
 - (void)invokeCall {
   __weak GRPCCall *weakSelf = self;
-  [self invokeCallWithMetadataHandler:^(NSDictionary *headers) {
+  [self invokeCallWithHeadersHandler:^(NSDictionary *headers) {
     // Response headers received.
     GRPCCall *strongSelf = weakSelf;
     if (strongSelf) {
-      [strongSelf->_responseMetadata addEntriesFromDictionary:headers];
+      strongSelf.responseHeaders = headers;
       [strongSelf startNextRead];
     }
   } completionHandler:^(NSError *error, NSDictionary *trailers) {
     GRPCCall *strongSelf = weakSelf;
     if (strongSelf) {
-      [strongSelf->_responseMetadata addEntriesFromDictionary:trailers];
+      strongSelf.responseTrailers = trailers;
 
       if (error) {
-        NSMutableDictionary *userInfo =
-            [NSMutableDictionary dictionaryWithDictionary:error.userInfo];
-        userInfo[kGRPCStatusMetadataKey] = strongSelf->_responseMetadata;
+        NSMutableDictionary *userInfo = [NSMutableDictionary dictionary];
+        if (error.userInfo) {
+          [userInfo addEntriesFromDictionary:error.userInfo];
+        }
+        userInfo[kGRPCTrailersKey] = strongSelf.responseTrailers;
+        // TODO(jcanizales): The C gRPC library doesn't guarantee that the headers block will be
+        // called before this one, so an error might end up with trailers but no headers. We
+        // shouldn't call finishWithError until ater both blocks are called. It is also when this is
+        // done that we can provide a merged view of response headers and trailers in a thread-safe
+        // way.
+        if (strongSelf.responseHeaders) {
+          userInfo[kGRPCHeadersKey] = strongSelf.responseHeaders;
+        }
         error = [NSError errorWithDomain:error.domain code:error.code userInfo:userInfo];
       }
       [strongSelf finishWithError:error];
@@ -356,7 +363,7 @@ NSString * const kGRPCStatusMetadataKey = @"io.grpc.StatusMetadataKey";
   _retainSelf = self;
 
   _responseWriteable = [[GRXConcurrentWriteable alloc] initWithWriteable:writeable];
-  [self sendHeaders:_requestMetadata];
+  [self sendHeaders:_requestHeaders];
   [self invokeCall];
 }
 

src/objective-c/GRPCClient/private/GRPCCompletionQueue.m

@@ -43,7 +43,7 @@
 
 - (instancetype)init {
   if ((self = [super init])) {
-    _unmanagedQueue = grpc_completion_queue_create();
+    _unmanagedQueue = grpc_completion_queue_create(NULL);
 
     // This is for the following block to capture the pointer by value (instead
     // of retaining self and doing self->_unmanagedQueue). This is essential
@@ -64,7 +64,8 @@
       while (YES) {
         // The following call blocks until an event is available.
         grpc_event event = grpc_completion_queue_next(unmanagedQueue,
-                                                      gpr_inf_future(GPR_CLOCK_REALTIME));
+                                                      gpr_inf_future(GPR_CLOCK_REALTIME),
+                                                      NULL);
         GRPCQueueCompletionHandler handler;
         switch (event.type) {
           case GRPC_OP_COMPLETE:

src/objective-c/GRPCClient/private/GRPCHost.m

@@ -97,7 +97,7 @@
                                   queue.unmanagedQueue,
                                   path.UTF8String,
                                   self.hostName.UTF8String,
-                                  gpr_inf_future(GPR_CLOCK_REALTIME));
+                                  gpr_inf_future(GPR_CLOCK_REALTIME), NULL);
 }
 
 - (GRPCChannel *)channel {

src/objective-c/GRPCClient/private/GRPCUnsecuredChannel.m

@@ -38,7 +38,7 @@
 @implementation GRPCUnsecuredChannel
 
 - (instancetype)initWithHost:(NSString *)host {
-  return (self = [super initWithChannel:grpc_insecure_channel_create(host.UTF8String, NULL)]);
+  return (self = [super initWithChannel:grpc_insecure_channel_create(host.UTF8String, NULL, NULL)]);
 }
 
 // TODO(jcanizales): GRPCSecureChannel and GRPCUnsecuredChannel are just convenience initializers

src/objective-c/GRPCClient/private/GRPCWrappedCall.m

@@ -282,7 +282,7 @@
     for (GRPCOperation *operation in operations) {
       [operation finish];
     }
-  }));
+  }), NULL);
   gpr_free(ops_array);
 
   if (error != GRPC_CALL_OK) {
@@ -293,7 +293,7 @@
 }
 
 - (void)cancel {
-  grpc_call_cancel(_call);
+  grpc_call_cancel(_call, NULL);
 }
 
 - (void)dealloc {

src/objective-c/tests/GRPCClientTests.m

@@ -168,11 +168,13 @@ static ProtoMethod *kUnaryCallMethod;
   } completionHandler:^(NSError *errorOrNil) {
     XCTAssertNotNil(errorOrNil, @"Finished without error!");
     XCTAssertEqual(errorOrNil.code, 16, @"Finished with unexpected error: %@", errorOrNil);
-    XCTAssertEqualObjects(call.responseMetadata, errorOrNil.userInfo[kGRPCStatusMetadataKey],
-                          @"Metadata in the NSError object and call object differ.");
+    XCTAssertEqualObjects(call.responseHeaders, errorOrNil.userInfo[kGRPCHeadersKey],
+                          @"Headers in the NSError object and call object differ.");
+    XCTAssertEqualObjects(call.responseTrailers, errorOrNil.userInfo[kGRPCTrailersKey],
+                          @"Trailers in the NSError object and call object differ.");
     NSString *challengeHeader = call.oauth2ChallengeHeader;
     XCTAssertGreaterThan(challengeHeader.length, 0,
-                         @"No challenge in response headers %@", call.responseMetadata);
+                         @"No challenge in response headers %@", call.responseHeaders);
     [expectation fulfill];
   }];
 

src/php/ext/grpc/call.c

@@ -241,7 +241,7 @@ PHP_METHOD(Call, __construct) {
           deadline_obj TSRMLS_CC);
   call->wrapped = grpc_channel_create_call(
       channel->wrapped, NULL, GRPC_PROPAGATE_DEFAULTS, completion_queue, method,
-      channel->target, deadline->wrapped);
+      channel->target, deadline->wrapped, NULL);
 }
 
 /**
@@ -400,7 +400,8 @@ PHP_METHOD(Call, startBatch) {
     ops[op_num].flags = 0;
     op_num++;
   }
-  error = grpc_call_start_batch(call->wrapped, ops, op_num, call->wrapped);
+  error = grpc_call_start_batch(call->wrapped, ops, op_num, call->wrapped,
+                                NULL);
   if (error != GRPC_CALL_OK) {
     zend_throw_exception(spl_ce_LogicException,
                          "start_batch was called incorrectly",
@@ -408,7 +409,7 @@ PHP_METHOD(Call, startBatch) {
     goto cleanup;
   }
   event = grpc_completion_queue_pluck(completion_queue, call->wrapped,
-                                      gpr_inf_future(GPR_CLOCK_REALTIME));
+                                      gpr_inf_future(GPR_CLOCK_REALTIME), NULL);
   if (!event.success) {
     zend_throw_exception(spl_ce_LogicException,
                          "The batch failed for some reason",
@@ -489,7 +490,7 @@ PHP_METHOD(Call, getPeer) {
 PHP_METHOD(Call, cancel) {
   wrapped_grpc_call *call =
       (wrapped_grpc_call *)zend_object_store_get_object(getThis() TSRMLS_CC);
-  grpc_call_cancel(call->wrapped);
+  grpc_call_cancel(call->wrapped, NULL);
 }
 
 static zend_function_entry call_methods[] = {

src/php/ext/grpc/channel.c

@@ -51,8 +51,10 @@
 #include <grpc/support/log.h>
 #include <grpc/grpc_security.h>
 
-#include "server.h"
+#include "completion_queue.h"
 #include "credentials.h"
+#include "server.h"
+#include "timeval.h"
 
 zend_class_entry *grpc_ce_channel;
 
@@ -152,7 +154,7 @@ PHP_METHOD(Channel, __construct) {
   override = target;
   override_len = target_length;
   if (args_array == NULL) {
-    channel->wrapped = grpc_insecure_channel_create(target, NULL);
+    channel->wrapped = grpc_insecure_channel_create(target, NULL, NULL);
   } else {
     array_hash = Z_ARRVAL_P(args_array);
     if (zend_hash_find(array_hash, "credentials", sizeof("credentials"),
@@ -182,7 +184,7 @@ PHP_METHOD(Channel, __construct) {
     }
     php_grpc_read_args_array(args_array, &args);
     if (creds == NULL) {
-      channel->wrapped = grpc_insecure_channel_create(target, &args);
+      channel->wrapped = grpc_insecure_channel_create(target, &args, NULL);
     } else {
       gpr_log(GPR_DEBUG, "Initialized secure channel");
       channel->wrapped =
@@ -204,6 +206,59 @@ PHP_METHOD(Channel, getTarget) {
   RETURN_STRING(grpc_channel_get_target(channel->wrapped), 1);
 }
 
+/**
+ * Get the connectivity state of the channel
+ * @param bool (optional) try to connect on the channel
+ * @return long The grpc connectivity state
+ */
+PHP_METHOD(Channel, getConnectivityState) {
+  wrapped_grpc_channel *channel =
+      (wrapped_grpc_channel *)zend_object_store_get_object(getThis() TSRMLS_CC);
+  bool try_to_connect;
+  /* "|b" == 1 optional bool */
+  if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "|b", &try_to_connect) ==
+      FAILURE) {
+    zend_throw_exception(spl_ce_InvalidArgumentException,
+                         "getConnectivityState expects a bool", 1 TSRMLS_CC);
+    return;
+  }
+  RETURN_LONG(grpc_channel_check_connectivity_state(channel->wrapped,
+                                                    (int)try_to_connect));
+}
+
+/**
+ * Watch the connectivity state of the channel until it changed
+ * @param long The previous connectivity state of the channel
+ * @param Timeval The deadline this function should wait until
+ * @return bool If the connectivity state changes from last_state
+ *              before deadline
+ */
+PHP_METHOD(Channel, watchConnectivityState) {
+  wrapped_grpc_channel *channel =
+      (wrapped_grpc_channel *)zend_object_store_get_object(getThis() TSRMLS_CC);
+  long last_state;
+  zval *deadline_obj;
+  /* "lO" == 1 long 1 object */
+  if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "lO",
+          &last_state, &deadline_obj, grpc_ce_timeval) == FAILURE) {
+    zend_throw_exception(spl_ce_InvalidArgumentException,
+        "watchConnectivityState expects 1 long 1 timeval",
+        1 TSRMLS_CC);
+    return;
+  }
+
+  wrapped_grpc_timeval *deadline =
+      (wrapped_grpc_timeval *)zend_object_store_get_object(
+          deadline_obj TSRMLS_CC);
+  grpc_channel_watch_connectivity_state(
+      channel->wrapped, (grpc_connectivity_state)last_state,
+      deadline->wrapped, completion_queue, NULL);
+  grpc_event event = grpc_completion_queue_pluck(
+      completion_queue, NULL,
+      gpr_inf_future(GPR_CLOCK_REALTIME), NULL);
+  RETURN_BOOL(event.success);
+}
+
 /**
  * Close the channel
  */
@@ -219,6 +274,8 @@ PHP_METHOD(Channel, close) {
 static zend_function_entry channel_methods[] = {
     PHP_ME(Channel, __construct, NULL, ZEND_ACC_PUBLIC | ZEND_ACC_CTOR)
     PHP_ME(Channel, getTarget, NULL, ZEND_ACC_PUBLIC)
+    PHP_ME(Channel, getConnectivityState, NULL, ZEND_ACC_PUBLIC)
+    PHP_ME(Channel, watchConnectivityState, NULL, ZEND_ACC_PUBLIC)
     PHP_ME(Channel, close, NULL, ZEND_ACC_PUBLIC)
     PHP_FE_END};
 

src/php/ext/grpc/completion_queue.c

@@ -38,14 +38,13 @@
 grpc_completion_queue *completion_queue;
 
 void grpc_php_init_completion_queue(TSRMLS_D) {
-  completion_queue = grpc_completion_queue_create();
+  completion_queue = grpc_completion_queue_create(NULL);
 }
 
 void grpc_php_shutdown_completion_queue(TSRMLS_D) {
   grpc_completion_queue_shutdown(completion_queue);
   while (grpc_completion_queue_next(completion_queue,
-                                    gpr_inf_future(GPR_CLOCK_REALTIME))
-             .type != GRPC_QUEUE_SHUTDOWN)
-    ;
+                                    gpr_inf_future(GPR_CLOCK_REALTIME),
+                                    NULL).type != GRPC_QUEUE_SHUTDOWN);
   grpc_completion_queue_destroy(completion_queue);
 }

src/php/ext/grpc/php_grpc.c

@@ -183,6 +183,18 @@ PHP_MINIT_FUNCTION(grpc) {
   REGISTER_LONG_CONSTANT("Grpc\\OP_RECV_CLOSE_ON_SERVER",
                          GRPC_OP_RECV_CLOSE_ON_SERVER, CONST_CS);
 
+  /* Register connectivity state constants */
+  REGISTER_LONG_CONSTANT("Grpc\\CHANNEL_IDLE",
+                         GRPC_CHANNEL_IDLE, CONST_CS);
+  REGISTER_LONG_CONSTANT("Grpc\\CHANNEL_CONNECTING",
+                         GRPC_CHANNEL_CONNECTING, CONST_CS);
+  REGISTER_LONG_CONSTANT("Grpc\\CHANNEL_READY",
+                         GRPC_CHANNEL_READY, CONST_CS);
+  REGISTER_LONG_CONSTANT("Grpc\\CHANNEL_TRANSIENT_FAILURE",
+                         GRPC_CHANNEL_TRANSIENT_FAILURE, CONST_CS);
+  REGISTER_LONG_CONSTANT("Grpc\\CHANNEL_FATAL_FAILURE",
+                         GRPC_CHANNEL_FATAL_FAILURE, CONST_CS);
+
   grpc_init_call(TSRMLS_C);
   grpc_init_channel(TSRMLS_C);
   grpc_init_server(TSRMLS_C);

src/php/ext/grpc/server.c

@@ -66,7 +66,7 @@ void free_wrapped_grpc_server(void *object TSRMLS_DC) {
     grpc_server_shutdown_and_notify(server->wrapped, completion_queue, NULL);
     grpc_server_cancel_all_calls(server->wrapped);
     grpc_completion_queue_pluck(completion_queue, NULL,
-                                gpr_inf_future(GPR_CLOCK_REALTIME));
+                                gpr_inf_future(GPR_CLOCK_REALTIME), NULL);
     grpc_server_destroy(server->wrapped);
   }
   efree(server);
@@ -109,13 +109,14 @@ PHP_METHOD(Server, __construct) {
     return;
   }
   if (args_array == NULL) {
-    server->wrapped = grpc_server_create(NULL);
+    server->wrapped = grpc_server_create(NULL, NULL);
   } else {
     php_grpc_read_args_array(args_array, &args);
-    server->wrapped = grpc_server_create(&args);
+    server->wrapped = grpc_server_create(&args, NULL);
     efree(args.args);
   }
-  grpc_server_register_completion_queue(server->wrapped, completion_queue);
+  grpc_server_register_completion_queue(server->wrapped, completion_queue,
+                                        NULL);
 }
 
 /**
@@ -146,7 +147,7 @@ PHP_METHOD(Server, requestCall) {
     goto cleanup;
   }
   event = grpc_completion_queue_pluck(completion_queue, NULL,
-                                      gpr_inf_future(GPR_CLOCK_REALTIME));
+                                      gpr_inf_future(GPR_CLOCK_REALTIME), NULL);
   if (!event.success) {
     zend_throw_exception(spl_ce_LogicException,
                          "Failed to request a call for some reason",

src/php/lib/Grpc/BaseStub.php

@@ -74,6 +74,51 @@ class BaseStub {
     return $this->channel->getTarget();
   }
 
+  /**
+   * @param $try_to_connect bool
+   * @return int The grpc connectivity state
+   */
+  public function getConnectivityState($try_to_connect = false) {
+    return $this->channel->getConnectivityState($try_to_connect);
+  }
+
+  /**
+   * @param $timeout in microseconds
+   * @return bool true if channel is ready
+   * @throw Exception if channel is in FATAL_ERROR state
+   */
+  public function waitForReady($timeout) {
+    $new_state = $this->getConnectivityState(true);
+    if ($this->_checkConnectivityState($new_state)) {
+      return true;
+    }
+
+    $now = Timeval::now();
+    $delta = new Timeval($timeout);
+    $deadline = $now->add($delta);
+
+    while ($this->channel->watchConnectivityState($new_state, $deadline)) {
+      // state has changed before deadline
+      $new_state = $this->getConnectivityState();
+      if ($this->_checkConnectivityState($new_state)) {
+        return true;
+      }
+    }
+    // deadline has passed
+    $new_state = $this->getConnectivityState();
+    return $this->_checkConnectivityState($new_state);
+  }
+
+  private function _checkConnectivityState($new_state) {
+    if ($new_state == Grpc\CHANNEL_READY) {
+      return true;
+    }
+    if ($new_state == Grpc\CHANNEL_FATAL_ERROR) {
+      throw new Exception('Failed to connect to server');
+    }
+    return false;
+  }
+
   /**
    * Close the communication channel associated with this stub
    */

src/php/tests/unit_tests/EndToEndTest.php

@@ -153,4 +153,50 @@ class EndToEndTest extends PHPUnit_Framework_TestCase{
   public function testGetTarget() {
     $this->assertTrue(is_string($this->channel->getTarget()));
   }
+
+  public function testGetConnectivityState() {
+    $this->assertTrue($this->channel->getConnectivityState() == Grpc\CHANNEL_IDLE);
+  }
+
+  public function testWatchConnectivityStateFailed() {
+    $idle_state = $this->channel->getConnectivityState(true);
+    $this->assertTrue($idle_state == Grpc\CHANNEL_IDLE);
+
+    $now = Grpc\Timeval::now();
+    $delta = new Grpc\Timeval(1);
+    $deadline = $now->add($delta);
+
+    $this->assertFalse($this->channel->watchConnectivityState(
+        $idle_state, $deadline));
+  }
+
+  public function testWatchConnectivityStateSuccess() {
+    $idle_state = $this->channel->getConnectivityState(true);
+    $this->assertTrue($idle_state == Grpc\CHANNEL_IDLE);
+
+    $now = Grpc\Timeval::now();
+    $delta = new Grpc\Timeval(3000000); // should finish well before
+    $deadline = $now->add($delta);
+
+    $this->assertTrue($this->channel->watchConnectivityState(
+        $idle_state, $deadline));
+
+    $new_state = $this->channel->getConnectivityState();
+    $this->assertTrue($idle_state != $new_state);
+  }
+
+  public function testWatchConnectivityStateDoNothing() {
+    $idle_state = $this->channel->getConnectivityState();
+    $this->assertTrue($idle_state == Grpc\CHANNEL_IDLE);
+
+    $now = Grpc\Timeval::now();
+    $delta = new Grpc\Timeval(100000);
+    $deadline = $now->add($delta);
+
+    $this->assertFalse($this->channel->watchConnectivityState(
+        $idle_state, $deadline));
+
+    $new_state = $this->channel->getConnectivityState();
+    $this->assertTrue($new_state == Grpc\CHANNEL_IDLE);
+  }
 }

src/python/grpcio/grpc/_adapter/_c/types/call.c

@@ -132,7 +132,7 @@ PyObject *pygrpc_Call_start_batch(Call *self, PyObject *args, PyObject *kwargs)
     }
   }
   tag = pygrpc_produce_batch_tag(user_tag, self, ops, nops);
-  errcode = grpc_call_start_batch(self->c_call, tag->ops, tag->nops, tag);
+  errcode = grpc_call_start_batch(self->c_call, tag->ops, tag->nops, tag, NULL);
   gpr_free(ops);
   return PyInt_FromLong(errcode);
 }
@@ -152,13 +152,13 @@ PyObject *pygrpc_Call_cancel(Call *self, PyObject *args, PyObject *kwargs) {
       return NULL;
     }
     code = PyInt_AsLong(py_code);
-    errcode = grpc_call_cancel_with_status(self->c_call, code, details);
+    errcode = grpc_call_cancel_with_status(self->c_call, code, details, NULL);
   } else if (py_code != NULL || details != NULL) {
     PyErr_SetString(PyExc_ValueError,
                     "if `code` is specified, so must `details`");
     return NULL;
   } else {
-    errcode = grpc_call_cancel(self->c_call);
+    errcode = grpc_call_cancel(self->c_call, NULL);
   }
   return PyInt_FromLong(errcode);
 }

src/python/grpcio/grpc/_adapter/_c/types/channel.c

@@ -108,7 +108,7 @@ Channel *pygrpc_Channel_new(
   if (creds) {
     self->c_chan = grpc_secure_channel_create(creds->c_creds, target, &c_args);
   } else {
-    self->c_chan = grpc_insecure_channel_create(target, &c_args);
+    self->c_chan = grpc_insecure_channel_create(target, &c_args, NULL);
   }
   pygrpc_discard_channel_args(c_args);
   return self;
@@ -133,7 +133,7 @@ Call *pygrpc_Channel_create_call(
   call = pygrpc_Call_new_empty(cq);
   call->c_call = grpc_channel_create_call(
       self->c_chan, NULL, GRPC_PROPAGATE_DEFAULTS, cq->c_cq, method, host,
-      pygrpc_cast_double_to_gpr_timespec(deadline));
+      pygrpc_cast_double_to_gpr_timespec(deadline), NULL);
   return call;
 }
 

src/python/grpcio/grpc/_adapter/_c/types/completion_queue.c

@@ -90,7 +90,7 @@ PyTypeObject pygrpc_CompletionQueue_type = {
 CompletionQueue *pygrpc_CompletionQueue_new(
     PyTypeObject *type, PyObject *args, PyObject *kwargs) {
   CompletionQueue *self = (CompletionQueue *)type->tp_alloc(type, 0);
-  self->c_cq = grpc_completion_queue_create();
+  self->c_cq = grpc_completion_queue_create(NULL);
   return self;
 }
 
@@ -111,7 +111,7 @@ PyObject *pygrpc_CompletionQueue_next(
   }
   Py_BEGIN_ALLOW_THREADS;
   event = grpc_completion_queue_next(
-      self->c_cq, pygrpc_cast_double_to_gpr_timespec(deadline));
+      self->c_cq, pygrpc_cast_double_to_gpr_timespec(deadline), NULL);
   Py_END_ALLOW_THREADS;
   transliterated_event = pygrpc_consume_event(event);
   return transliterated_event;

src/python/grpcio/grpc/_adapter/_c/types/server.c

@@ -104,8 +104,8 @@ Server *pygrpc_Server_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
     return NULL;
   }
   self = (Server *)type->tp_alloc(type, 0);
-  self->c_serv = grpc_server_create(&c_args);
-  grpc_server_register_completion_queue(self->c_serv, cq->c_cq);
+  self->c_serv = grpc_server_create(&c_args, NULL);
+  grpc_server_register_completion_queue(self->c_serv, cq->c_cq, NULL);
   pygrpc_discard_channel_args(c_args);
   self->cq = cq;
   Py_INCREF(self->cq);

src/python/grpcio/grpc/_links/service.py

@@ -44,7 +44,10 @@ from grpc.framework.interfaces.links import links
 @enum.unique
 class _Read(enum.Enum):
   READING = 'reading'
-  AWAITING_ALLOWANCE = 'awaiting allowance'
+  # TODO(issue 2916): This state will again be necessary after eliminating the
+  # "early_read" field of _RPCState and going back to only reading when granted
+  # allowance to read.
+  # AWAITING_ALLOWANCE = 'awaiting allowance'
   CLOSED = 'closed'
 
 
@@ -67,12 +70,15 @@ class _RPCState(object):
 
   def __init__(
       self, request_deserializer, response_serializer, sequence_number, read,
-      allowance, high_write, low_write, premetadataed, terminal_metadata, code,
-      message):
+      early_read, allowance, high_write, low_write, premetadataed,
+      terminal_metadata, code, message):
     self.request_deserializer = request_deserializer
     self.response_serializer = response_serializer
     self.sequence_number = sequence_number
     self.read = read
+    # TODO(issue 2916): Eliminate this by eliminating the necessity of calling
+    # call.read just to advance the RPC.
+    self.early_read = early_read  # A raw (not deserialized) read.
     self.allowance = allowance
     self.high_write = high_write
     self.low_write = low_write
@@ -120,7 +126,7 @@ class _Kernel(object):
 
     call.read(call)
     self._rpc_states[call] = _RPCState(
-        request_deserializer, response_serializer, 1, _Read.READING, 0,
+        request_deserializer, response_serializer, 1, _Read.READING, None, 1,
         _HighWrite.OPEN, _LowWrite.OPEN, False, None, None, None)
     ticket = links.Ticket(
         call, 0, group, method, links.Ticket.Subscription.FULL,
@@ -140,12 +146,15 @@ class _Kernel(object):
       termination = links.Ticket.Termination.COMPLETION
     else:
       if 0 < rpc_state.allowance:
+        payload = rpc_state.request_deserializer(event.bytes)
+        termination = None
         rpc_state.allowance -= 1
         call.read(call)
       else:
-        rpc_state.read = _Read.AWAITING_ALLOWANCE
-      payload = rpc_state.request_deserializer(event.bytes)
-      termination = None
+        rpc_state.early_read = event.bytes
+        return
+        # TODO(issue 2916): Instead of returning:
+        # rpc_state.read = _Read.AWAITING_ALLOWANCE
     ticket = links.Ticket(
         call, rpc_state.sequence_number, None, None, None, None, None, None,
         payload, None, None, None, termination)
@@ -237,12 +246,22 @@ class _Kernel(object):
           rpc_state.premetadataed = True
 
       if ticket.allowance is not None:
-        if rpc_state.read is _Read.AWAITING_ALLOWANCE:
-          rpc_state.allowance += ticket.allowance - 1
-          call.read(call)
-          rpc_state.read = _Read.READING
-        else:
+        if rpc_state.early_read is None:
           rpc_state.allowance += ticket.allowance
+        else:
+          payload = rpc_state.request_deserializer(rpc_state.early_read)
+          rpc_state.allowance += ticket.allowance - 1
+          rpc_state.early_read = None
+          if rpc_state.read is _Read.READING:
+            call.read(call)
+            termination = None
+          else:
+            termination = links.Ticket.Termination.COMPLETION
+          ticket = links.Ticket(
+              call, rpc_state.sequence_number, None, None, None, None, None,
+              None, payload, None, None, None, termination)
+          rpc_state.sequence_number += 1
+          self._relay.add_value(ticket)
 
       if ticket.payload is not None:
         call.write(rpc_state.response_serializer(ticket.payload), call)

src/python/grpcio_health_checking/MANIFEST.in

@@ -0,0 +1,2 @@
+graft grpc
+include commands.py

src/python/grpcio_health_checking/README.rst

@@ -0,0 +1,9 @@
+gRPC Python Health Checking
+===========================
+
+Reference package for GRPC Python health checking.
+
+Dependencies
+------------
+
+Depends on the `grpcio` package, available from PyPI via `pip install grpcio`.

src/python/grpcio_health_checking/commands.py

@@ -0,0 +1,80 @@
+# 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.
+
+"""Provides distutils command classes for the GRPC Python setup process."""
+
+import distutils
+import glob
+import os
+import os.path
+import subprocess
+import sys
+
+import setuptools
+from setuptools.command import build_py
+
+
+class BuildProtoModules(setuptools.Command):
+  """Command to generate project *_pb2.py modules from proto files."""
+
+  description = ''
+  user_options = []
+
+  def initialize_options(self):
+    pass
+
+  def finalize_options(self):
+    self.protoc_command = 'protoc'
+    self.grpc_python_plugin_command = distutils.spawn.find_executable(
+        'grpc_python_plugin')
+
+  def run(self):
+    paths = []
+    root_directory = os.getcwd()
+    for walk_root, directories, filenames in os.walk(root_directory):
+      for filename in filenames:
+        if filename.endswith('.proto'):
+          paths.append(os.path.join(walk_root, filename))
+    command = [
+        self.protoc_command,
+        '--plugin=protoc-gen-python-grpc={}'.format(
+            self.grpc_python_plugin_command),
+        '-I {}'.format(root_directory),
+        '--python_out={}'.format(root_directory),
+        '--python-grpc_out={}'.format(root_directory),
+    ] + paths
+    subprocess.check_call(' '.join(command), cwd=root_directory, shell=True)
+
+
+class BuildPy(build_py.build_py):
+  """Custom project build command."""
+
+  def run(self):
+    self.run_command('build_proto_modules')
+    build_py.build_py.run(self)

src/python/grpcio_health_checking/grpc/__init__.py

@@ -0,0 +1,30 @@
+# 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.
+
+

src/python/grpcio_health_checking/grpc/health/__init__.py

@@ -0,0 +1,30 @@
+# 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.
+
+

src/python/grpcio_health_checking/grpc/health/v1alpha/__init__.py

@@ -0,0 +1,30 @@
+# 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.
+
+

src/python/grpcio_health_checking/grpc/health/v1alpha/health.proto

@@ -0,0 +1,49 @@
+// 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.
+
+syntax = "proto3";
+
+package grpc.health.v1alpha;
+
+message HealthCheckRequest {
+  string service = 1;
+}
+
+message HealthCheckResponse {
+  enum ServingStatus {
+    UNKNOWN = 0;
+    SERVING = 1;
+    NOT_SERVING = 2;
+  }
+  ServingStatus status = 1;
+}
+
+service Health {
+  rpc Check(HealthCheckRequest) returns (HealthCheckResponse);
+}

src/python/grpcio_health_checking/grpc/health/v1alpha/health.py

@@ -0,0 +1,129 @@
+# 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.
+
+"""Reference implementation for health checking in gRPC Python."""
+
+import abc
+import enum
+import threading
+
+from grpc.health.v1alpha import health_pb2
+
+
+@enum.unique
+class HealthStatus(enum.Enum):
+  """Statuses for a service mirroring the reference health.proto's values."""
+  UNKNOWN = health_pb2.HealthCheckResponse.UNKNOWN
+  SERVING = health_pb2.HealthCheckResponse.SERVING
+  NOT_SERVING = health_pb2.HealthCheckResponse.NOT_SERVING
+
+
+class _HealthServicer(health_pb2.EarlyAdopterHealthServicer):
+  """Servicer handling RPCs for service statuses."""
+
+  def __init__(self):
+    self._server_status_lock = threading.Lock()
+    self._server_status = {}
+
+  def Check(self, request, context):
+    with self._server_status_lock:
+      if request.service not in self._server_status:
+        # TODO(atash): once the Python API has a way of setting the server
+        # status, bring us into conformance with the health check spec by
+        # returning the NOT_FOUND status here.
+        raise NotImplementedError()
+      else:
+        return health_pb2.HealthCheckResponse(
+            status=self._server_status[request.service].value)
+
+  def set(service, status):
+    if not isinstance(status, HealthStatus):
+      raise TypeError('expected grpc.health.v1alpha.health.HealthStatus '
+                      'for argument `status` but got {}'.format(status))
+    with self._server_status_lock:
+      self._server_status[service] = status
+
+
+class HealthServer(health_pb2.EarlyAdopterHealthServer):
+  """Interface for the reference gRPC Python health server."""
+  __metaclass__ = abc.ABCMeta
+
+  @abc.abstractmethod
+  def start(self):
+    raise NotImplementedError()
+
+  @abc.abstractmethod
+  def stop(self):
+    raise NotImplementedError()
+
+  @abc.abstractmethod
+  def set(self, service, status):
+    """Set the status of the given service.
+
+    Args:
+      service (str): service name of the service to set the reported status of
+      status (HealthStatus): status to set for the specified service
+    """
+    raise NotImplementedError()
+
+
+class _HealthServerImplementation(HealthServer):
+  """Implementation for the reference gRPC Python health server."""
+
+  def __init__(self, server, servicer):
+    self._server = server
+    self._servicer = servicer
+
+  def start(self):
+    self._server.start()
+
+  def stop(self):
+    self._server.stop()
+
+  def set(self, service, status):
+    self._servicer.set(service, status)
+
+
+def create_Health_server(port, private_key=None, certificate_chain=None):
+  """Get a HealthServer instance.
+
+  Args:
+    port (int): port number passed through to health_pb2 server creation
+      routine.
+    private_key (str): to-be-created server's desired private key
+    certificate_chain (str): to-be-created server's desired certificate chain
+
+  Returns:
+    An instance of HealthServer (conforming thus to
+    EarlyAdopterHealthServer and providing a method to set server status)."""
+  servicer = _HealthServicer()
+  server = health_pb2.early_adopter_create_Health_server(
+      servicer, port=port, private_key=private_key,
+      certificate_chain=certificate_chain)
+  return _HealthServerImplementation(server, servicer)

src/python/grpcio_health_checking/setup.py

@@ -0,0 +1,72 @@
+# 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.
+
+"""Setup module for the GRPC Python package's optional health checking."""
+
+import os
+import os.path
+import sys
+
+from distutils import core as _core
+import setuptools
+
+# Ensure we're in the proper directory whether or not we're being used by pip.
+os.chdir(os.path.dirname(os.path.abspath(__file__)))
+
+# Break import-style to ensure we can actually find our commands module.
+import commands
+
+_PACKAGES = (
+    setuptools.find_packages('.')
+)
+
+_PACKAGE_DIRECTORIES = {
+    '': '.',
+}
+
+_INSTALL_REQUIRES = (
+    'grpcio>=0.10.0a0',
+)
+
+_SETUP_REQUIRES = _INSTALL_REQUIRES
+
+_COMMAND_CLASS = {
+    'build_proto_modules': commands.BuildProtoModules,
+    'build_py': commands.BuildPy,
+}
+
+setuptools.setup(
+    name='grpcio_health_checking',
+    version='0.10.0a0',
+    packages=list(_PACKAGES),
+    package_dir=_PACKAGE_DIRECTORIES,
+    install_requires=_INSTALL_REQUIRES,
+    setup_requires=_SETUP_REQUIRES,
+    cmdclass=_COMMAND_CLASS
+)

src/python/grpcio_test/grpc_test/framework/interfaces/links/test_cases.py

@@ -303,16 +303,9 @@ class TransmissionTest(object):
         invocation_message, links.Ticket.Termination.COMPLETION)
     self._invocation_link.accept_ticket(original_invocation_ticket)
 
-    # TODO(nathaniel): This shouldn't be necessary. Detecting the end of the
-    # invocation-side ticket sequence shouldn't require granting allowance for
-    # another payload.
     self._service_mate.block_until_tickets_satisfy(
         at_least_n_payloads_received_predicate(1))
     service_operation_id = self._service_mate.tickets()[0].operation_id
-    self._service_link.accept_ticket(
-        links.Ticket(
-            service_operation_id, 0, None, None, links.Ticket.Subscription.FULL,
-            None, 1, None, None, None, None, None, None))
 
     self._service_mate.block_until_tickets_satisfy(terminated)
     self._assert_is_valid_invocation_sequence(
@@ -321,7 +314,7 @@ class TransmissionTest(object):
         invocation_terminal_metadata, links.Ticket.Termination.COMPLETION)
 
     original_service_ticket = links.Ticket(
-        service_operation_id, 1, None, None, links.Ticket.Subscription.FULL,
+        service_operation_id, 0, None, None, links.Ticket.Subscription.FULL,
         timeout, 0, service_initial_metadata, service_payload,
         service_terminal_metadata, service_code, service_message,
         links.Ticket.Termination.COMPLETION)

src/ruby/bin/interop/interop_client.rb

@@ -110,6 +110,14 @@ def create_stub(opts)
       end
     end
 
+    if opts.test_case == 'oauth2_auth_token'
+      auth_creds = Google::Auth.get_application_default(opts.oauth_scope)
+      kw = auth_creds.updater_proc.call({})  # gives as an auth token
+
+      # use a metadata update proc that just adds the auth token.
+      stub_opts[:update_metadata] = proc { |md| md.merge(kw) }
+    end
+
     if opts.test_case == 'jwt_token_creds'  # don't use a scope
       auth_creds = Google::Auth.get_application_default
       stub_opts[:update_metadata] = auth_creds.updater_proc
@@ -228,6 +236,33 @@ class NamedTests
     p 'OK: compute_engine_creds'
   end
 
+  def oauth2_auth_token
+    resp = perform_large_unary(fill_username: true,
+                               fill_oauth_scope: true)
+    json_key = File.read(ENV[AUTH_ENV])
+    wanted_email = MultiJson.load(json_key)['client_email']
+    assert_equal(wanted_email, resp.username,
+                 "#{__callee__}: incorrect username")
+    assert(@args.oauth_scope.include?(resp.oauth_scope),
+           "#{__callee__}: incorrect oauth_scope")
+    p "OK: #{__callee__}"
+  end
+
+  def per_rpc_creds
+    auth_creds = Google::Auth.get_application_default(@args.oauth_scope)
+    kw = auth_creds.updater_proc.call({})
+    resp = perform_large_unary(fill_username: true,
+                               fill_oauth_scope: true,
+                               **kw)
+    json_key = File.read(ENV[AUTH_ENV])
+    wanted_email = MultiJson.load(json_key)['client_email']
+    assert_equal(wanted_email, resp.username,
+                 "#{__callee__}: incorrect username")
+    assert(@args.oauth_scope.include?(resp.oauth_scope),
+           "#{__callee__}: incorrect oauth_scope")
+    p "OK: #{__callee__}"
+  end
+
   def client_streaming
     msg_sizes = [27_182, 8, 1828, 45_904]
     wanted_aggregate_size = 74_922
@@ -265,6 +300,29 @@ class NamedTests
     p 'OK: ping_pong'
   end
 
+  def timeout_on_sleeping_server
+    msg_sizes = [[27_182, 31_415]]
+    ppp = PingPongPlayer.new(msg_sizes)
+    resps = @stub.full_duplex_call(ppp.each_item, timeout: 0.001)
+    resps.each { |r| ppp.queue.push(r) }
+    fail 'Should have raised GRPC::BadStatus(DEADLINE_EXCEEDED)'
+  rescue GRPC::BadStatus => e
+    assert_equal(e.code, GRPC::Core::StatusCodes::DEADLINE_EXCEEDED)
+    p "OK: #{__callee__}"
+  end
+
+  def empty_stream
+    ppp = PingPongPlayer.new([])
+    resps = @stub.full_duplex_call(ppp.each_item)
+    count = 0
+    resps.each do
+      |r| ppp.queue.push(r)
+      count += 1
+    end
+    assert_equal(0, count, 'too many responses, expect 0')
+    p 'OK: empty_stream'
+  end
+
   def cancel_after_begin
     msg_sizes = [27_182, 8, 1828, 45_904]
     reqs = msg_sizes.map do |x|
@@ -283,7 +341,7 @@ class NamedTests
     ppp = PingPongPlayer.new(msg_sizes)
     op = @stub.full_duplex_call(ppp.each_item, return_op: true)
     ppp.canceller_op = op  # causes ppp to cancel after the 1st message
-    op.execute.each { |r| ppp.queue.push(r) }
+    assert_raises(GRPC::Cancelled) { op.execute.each { |r| ppp.queue.push(r) } }
     op.wait
     assert(op.cancelled, 'call operation was not CANCELLED')
     p 'OK: cancel_after_first_response'
@@ -300,7 +358,7 @@ class NamedTests
 
   private
 
-  def perform_large_unary(fill_username: false, fill_oauth_scope: false)
+  def perform_large_unary(fill_username: false, fill_oauth_scope: false, **kw)
     req_size, wanted_response_size = 271_828, 314_159
     payload = Payload.new(type: :COMPRESSABLE, body: nulls(req_size))
     req = SimpleRequest.new(response_type: :COMPRESSABLE,
@@ -308,7 +366,7 @@ class NamedTests
                             payload: payload)
     req.fill_username = fill_username
     req.fill_oauth_scope = fill_oauth_scope
-    resp = @stub.unary_call(req)
+    resp = @stub.unary_call(req, **kw)
     assert_equal(:COMPRESSABLE, resp.payload.type,
                  'large_unary: payload had the wrong type')
     assert_equal(wanted_response_size, resp.payload.body.length,

src/ruby/ext/grpc/rb_call.c

@@ -170,7 +170,7 @@ static VALUE grpc_rb_call_cancel(VALUE self) {
   grpc_call *call = NULL;
   grpc_call_error err;
   TypedData_Get_Struct(self, grpc_call, &grpc_call_data_type, call);
-  err = grpc_call_cancel(call);
+  err = grpc_call_cancel(call, NULL);
   if (err != GRPC_CALL_OK) {
     rb_raise(grpc_rb_eCallError, "cancel failed: %s (code=%d)",
              grpc_call_error_detail_of(err), err);
@@ -615,7 +615,7 @@ static VALUE grpc_rb_call_run_batch(VALUE self, VALUE cqueue, VALUE tag,
 
   /* call grpc_call_start_batch, then wait for it to complete using
    * pluck_event */
-  err = grpc_call_start_batch(call, st.ops, st.op_num, ROBJECT(tag));
+  err = grpc_call_start_batch(call, st.ops, st.op_num, ROBJECT(tag), NULL);
   if (err != GRPC_CALL_OK) {
     grpc_run_batch_stack_cleanup(&st);
     rb_raise(grpc_rb_eCallError,
@@ -629,13 +629,9 @@ static VALUE grpc_rb_call_run_batch(VALUE self, VALUE cqueue, VALUE tag,
     rb_raise(grpc_rb_eOutOfTime, "grpc_call_start_batch timed out");
     return Qnil;
   }
-  if (!ev.success) {
-    grpc_run_batch_stack_cleanup(&st);
-    rb_raise(grpc_rb_eCallError, "start_batch completion failed");
-    return Qnil;
-  }
 
-  /* Build and return the BatchResult struct result */
+  /* Build and return the BatchResult struct result,
+     if there is an error, it's reflected in the status */
   result = grpc_run_batch_stack_build_result(&st);
   grpc_run_batch_stack_cleanup(&st);
   return result;

src/ruby/ext/grpc/rb_channel.c

@@ -147,7 +147,7 @@ static VALUE grpc_rb_channel_init(int argc, VALUE *argv, VALUE self) {
   target_chars = StringValueCStr(target);
   grpc_rb_hash_convert_to_channel_args(channel_args, &args);
   if (credentials == Qnil) {
-    ch = grpc_insecure_channel_create(target_chars, &args);
+    ch = grpc_insecure_channel_create(target_chars, &args, NULL);
   } else {
     creds = grpc_rb_get_wrapped_credentials(credentials);
     ch = grpc_secure_channel_create(creds, target_chars, &args);
@@ -165,6 +165,65 @@ static VALUE grpc_rb_channel_init(int argc, VALUE *argv, VALUE self) {
   return self;
 }
 
+/*
+  call-seq:
+    insecure_channel = Channel:new("myhost:8080", {'arg1': 'value1'})
+    creds = ...
+    secure_channel = Channel:new("myhost:443", {'arg1': 'value1'}, creds)
+
+  Creates channel instances. */
+static VALUE grpc_rb_channel_get_connectivity_state(int argc, VALUE *argv,
+                                                    VALUE self) {
+  VALUE try_to_connect = Qfalse;
+  grpc_rb_channel *wrapper = NULL;
+  grpc_channel *ch = NULL;
+
+  /* "01" == 0 mandatory args, 1 (try_to_connect) is optional */
+  rb_scan_args(argc, argv, "01", try_to_connect);
+
+  TypedData_Get_Struct(self, grpc_rb_channel, &grpc_channel_data_type, wrapper);
+  ch = wrapper->wrapped;
+  if (ch == NULL) {
+    rb_raise(rb_eRuntimeError, "closed!");
+    return Qnil;
+  }
+  return NUM2LONG(
+      grpc_channel_check_connectivity_state(ch, (int)try_to_connect));
+}
+
+/* Watch for a change in connectivity state.
+
+   Once the channel connectivity state is different from the last observed
+   state, tag will be enqueued on cq with success=1
+
+   If deadline expires BEFORE the state is changed, tag will be enqueued on
+   the completion queue with success=0 */
+static VALUE grpc_rb_channel_watch_connectivity_state(VALUE self,
+                                                      VALUE last_state,
+                                                      VALUE cqueue,
+                                                      VALUE deadline,
+                                                      VALUE tag) {
+  grpc_rb_channel *wrapper = NULL;
+  grpc_channel *ch = NULL;
+  grpc_completion_queue *cq = NULL;
+
+  cq = grpc_rb_get_wrapped_completion_queue(cqueue);
+  TypedData_Get_Struct(self, grpc_rb_channel, &grpc_channel_data_type, wrapper);
+  ch = wrapper->wrapped;
+  if (ch == NULL) {
+    rb_raise(rb_eRuntimeError, "closed!");
+    return Qnil;
+  }
+  grpc_channel_watch_connectivity_state(
+      ch,
+      NUM2LONG(last_state),
+      grpc_rb_time_timeval(deadline, /* absolute time */ 0),
+      cq,
+      ROBJECT(tag));
+
+  return Qnil;
+}
+
 /* Clones Channel instances.
 
    Gives Channel a consistent implementation of Ruby's object copy/dup
@@ -195,18 +254,28 @@ static VALUE grpc_rb_channel_init_copy(VALUE copy, VALUE orig) {
 
 /* Create a call given a grpc_channel, in order to call method. The request
    is not sent until grpc_call_invoke is called. */
-static VALUE grpc_rb_channel_create_call(VALUE self, VALUE cqueue, VALUE method,
-                                         VALUE host, VALUE deadline) {
+static VALUE grpc_rb_channel_create_call(VALUE self, VALUE cqueue,
+                                         VALUE parent, VALUE mask,
+                                         VALUE method, VALUE host,
+                                         VALUE deadline) {
   VALUE res = Qnil;
   grpc_rb_channel *wrapper = NULL;
   grpc_call *call = NULL;
+  grpc_call *parent_call = NULL;
   grpc_channel *ch = NULL;
   grpc_completion_queue *cq = NULL;
+  int flags = GRPC_PROPAGATE_DEFAULTS;
   char *method_chars = StringValueCStr(method);
   char *host_chars = NULL;
   if (host != Qnil) {
     host_chars = StringValueCStr(host);
   }
+  if (mask != Qnil) {
+    flags = NUM2UINT(mask);
+  }
+  if (parent != Qnil) {
+    parent_call = grpc_rb_get_wrapped_call(parent);
+  }
 
   cq = grpc_rb_get_wrapped_completion_queue(cqueue);
   TypedData_Get_Struct(self, grpc_rb_channel, &grpc_channel_data_type, wrapper);
@@ -216,10 +285,10 @@ static VALUE grpc_rb_channel_create_call(VALUE self, VALUE cqueue, VALUE method,
     return Qnil;
   }
 
-  call = grpc_channel_create_call(ch, NULL, GRPC_PROPAGATE_DEFAULTS, cq,
-                                  method_chars, host_chars,
-                                  grpc_rb_time_timeval(deadline,
-                                                       /* absolute time */ 0));
+  call = grpc_channel_create_call(ch, parent_call, flags, cq, method_chars,
+                                  host_chars, grpc_rb_time_timeval(
+                                      deadline,
+                                      /* absolute time */ 0), NULL);
   if (call == NULL) {
     rb_raise(rb_eRuntimeError, "cannot create call with method %s",
              method_chars);
@@ -237,6 +306,7 @@ static VALUE grpc_rb_channel_create_call(VALUE self, VALUE cqueue, VALUE method,
   return res;
 }
 
+
 /* Closes the channel, calling it's destroy method */
 static VALUE grpc_rb_channel_destroy(VALUE self) {
   grpc_rb_channel *wrapper = NULL;
@@ -268,6 +338,38 @@ static VALUE grpc_rb_channel_get_target(VALUE self) {
   return res;
 }
 
+static void Init_grpc_propagate_masks() {
+  /* Constants representing call propagation masks in grpc.h */
+  VALUE grpc_rb_mPropagateMasks = rb_define_module_under(
+      grpc_rb_mGrpcCore, "PropagateMasks");
+  rb_define_const(grpc_rb_mPropagateMasks, "DEADLINE",
+                  UINT2NUM(GRPC_PROPAGATE_DEADLINE));
+  rb_define_const(grpc_rb_mPropagateMasks, "CENSUS_STATS_CONTEXT",
+                  UINT2NUM(GRPC_PROPAGATE_CENSUS_STATS_CONTEXT));
+  rb_define_const(grpc_rb_mPropagateMasks, "CENSUS_TRACING_CONTEXT",
+                  UINT2NUM(GRPC_PROPAGATE_CENSUS_TRACING_CONTEXT));
+  rb_define_const(grpc_rb_mPropagateMasks, "CANCELLATION",
+                  UINT2NUM(GRPC_PROPAGATE_CANCELLATION));
+  rb_define_const(grpc_rb_mPropagateMasks, "DEFAULTS",
+                  UINT2NUM(GRPC_PROPAGATE_DEFAULTS));
+}
+
+static void Init_grpc_connectivity_states() {
+  /* Constants representing call propagation masks in grpc.h */
+  VALUE grpc_rb_mConnectivityStates = rb_define_module_under(
+      grpc_rb_mGrpcCore, "ConnectivityStates");
+  rb_define_const(grpc_rb_mConnectivityStates, "IDLE",
+                  LONG2NUM(GRPC_CHANNEL_IDLE));
+  rb_define_const(grpc_rb_mConnectivityStates, "CONNECTING",
+                  LONG2NUM(GRPC_CHANNEL_CONNECTING));
+  rb_define_const(grpc_rb_mConnectivityStates, "READY",
+                  LONG2NUM(GRPC_CHANNEL_READY));
+  rb_define_const(grpc_rb_mConnectivityStates, "TRANSIENT_FAILURE",
+                  LONG2NUM(GRPC_CHANNEL_TRANSIENT_FAILURE));
+  rb_define_const(grpc_rb_mConnectivityStates, "FATAL_FAILURE",
+                  LONG2NUM(GRPC_CHANNEL_FATAL_FAILURE));
+}
+
 void Init_grpc_channel() {
   grpc_rb_cChannelArgs = rb_define_class("TmpChannelArgs", rb_cObject);
   grpc_rb_cChannel =
@@ -282,8 +384,13 @@ void Init_grpc_channel() {
                    grpc_rb_channel_init_copy, 1);
 
   /* Add ruby analogues of the Channel methods. */
+  rb_define_method(grpc_rb_cChannel, "connectivity_state",
+                   grpc_rb_channel_get_connectivity_state,
+                   -1);
+  rb_define_method(grpc_rb_cChannel, "watch_connectivity_state",
+                   grpc_rb_channel_watch_connectivity_state, 4);
   rb_define_method(grpc_rb_cChannel, "create_call",
-                   grpc_rb_channel_create_call, 4);
+                   grpc_rb_channel_create_call, 6);
   rb_define_method(grpc_rb_cChannel, "target", grpc_rb_channel_get_target, 0);
   rb_define_method(grpc_rb_cChannel, "destroy", grpc_rb_channel_destroy, 0);
   rb_define_alias(grpc_rb_cChannel, "close", "destroy");
@@ -299,6 +406,8 @@ void Init_grpc_channel() {
                   ID2SYM(rb_intern(GRPC_ARG_MAX_CONCURRENT_STREAMS)));
   rb_define_const(grpc_rb_cChannel, "MAX_MESSAGE_LENGTH",
                   ID2SYM(rb_intern(GRPC_ARG_MAX_MESSAGE_LENGTH)));
+  Init_grpc_propagate_masks();
+  Init_grpc_connectivity_states();
 }
 
 /* Gets the wrapped channel from the ruby wrapper */

src/ruby/ext/grpc/rb_completion_queue.c

@@ -56,7 +56,7 @@ typedef struct next_call_stack {
 static void *grpc_rb_completion_queue_next_no_gil(void *param) {
   next_call_stack *const next_call = (next_call_stack*)param;
   next_call->event =
-      grpc_completion_queue_next(next_call->cq, next_call->timeout);
+      grpc_completion_queue_next(next_call->cq, next_call->timeout, NULL);
   return NULL;
 }
 
@@ -64,7 +64,7 @@ static void *grpc_rb_completion_queue_next_no_gil(void *param) {
 static void *grpc_rb_completion_queue_pluck_no_gil(void *param) {
   next_call_stack *const next_call = (next_call_stack*)param;
   next_call->event = grpc_completion_queue_pluck(next_call->cq, next_call->tag,
-                                                 next_call->timeout);
+                                                 next_call->timeout, NULL);
   return NULL;
 }
 
@@ -128,7 +128,7 @@ static rb_data_type_t grpc_rb_completion_queue_data_type = {
 
 /* Allocates a completion queue. */
 static VALUE grpc_rb_completion_queue_alloc(VALUE cls) {
-  grpc_completion_queue *cq = grpc_completion_queue_create();
+  grpc_completion_queue *cq = grpc_completion_queue_create(NULL);
   if (cq == NULL) {
     rb_raise(rb_eArgError, "could not create a completion queue: not sure why");
   }

src/ruby/ext/grpc/rb_server.c

@@ -128,7 +128,7 @@ static VALUE grpc_rb_server_init(VALUE self, VALUE cqueue, VALUE channel_args) {
   TypedData_Get_Struct(self, grpc_rb_server, &grpc_rb_server_data_type,
                        wrapper);
   grpc_rb_hash_convert_to_channel_args(channel_args, &args);
-  srv = grpc_server_create(&args);
+  srv = grpc_server_create(&args, NULL);
 
   if (args.args != NULL) {
     xfree(args.args); /* Allocated by grpc_rb_hash_convert_to_channel_args */
@@ -136,7 +136,7 @@ static VALUE grpc_rb_server_init(VALUE self, VALUE cqueue, VALUE channel_args) {
   if (srv == NULL) {
     rb_raise(rb_eRuntimeError, "could not create a gRPC server, not sure why");
   }
-  grpc_server_register_completion_queue(srv, cq);
+  grpc_server_register_completion_queue(srv, cq, NULL);
   wrapper->wrapped = srv;
 
   /* Add the cq as the server's mark object. This ensures the ruby cq can't be