Merge branch 'v1.7.x' of https://github.com/grpc/grpc

39 files changed, 626 insertions, 106 deletions

diff --git a/src/compiler/objective_c_generator.cc b/src/compiler/objective_c_generator.cc
index 349f1dc281..583ed6d105 100644
--- a/src/compiler/objective_c_generator.cc
+++ b/src/compiler/objective_c_generator.cc
@@ -31,6 +31,7 @@ using ::grpc::protobuf::FileDescriptor;
 using ::grpc::protobuf::MethodDescriptor;
 using ::grpc::protobuf::ServiceDescriptor;
 using ::grpc::protobuf::io::Printer;
+using ::grpc::protobuf::FileDescriptor;
 using ::std::map;
 using ::std::set;
 
diff --git a/src/compiler/objective_c_generator.h b/src/compiler/objective_c_generator.h
index 2337abaf6a..700c9c496e 100644
--- a/src/compiler/objective_c_generator.h
+++ b/src/compiler/objective_c_generator.h
@@ -25,6 +25,7 @@ namespace grpc_objective_c_generator {
 
 using ::grpc::protobuf::FileDescriptor;
 using ::grpc::protobuf::ServiceDescriptor;
+using ::grpc::protobuf::FileDescriptor;
 using ::grpc::string;
 
 // Returns forward declaration of classes in the generated header file.
diff --git a/src/core/lib/iomgr/fork_posix.cc b/src/core/lib/iomgr/fork_posix.cc
new file mode 100644
index 0000000000..a55b3a349a
--- /dev/null
+++ b/src/core/lib/iomgr/fork_posix.cc
@@ -0,0 +1,88 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include "src/core/lib/iomgr/port.h"
+
+#ifdef GRPC_POSIX_FORK
+
+#include <string.h>
+
+#include <grpc/fork.h>
+#include <grpc/support/log.h>
+#include <grpc/support/thd.h>
+#include <grpc/support/useful.h>
+
+#include "src/core/lib/iomgr/ev_posix.h"
+#include "src/core/lib/iomgr/executor.h"
+#include "src/core/lib/iomgr/timer_manager.h"
+#include "src/core/lib/iomgr/wakeup_fd_posix.h"
+#include "src/core/lib/support/env.h"
+#include "src/core/lib/support/fork.h"
+#include "src/core/lib/support/thd_internal.h"
+#include "src/core/lib/surface/init.h"
+
+/*
+ * NOTE: FORKING IS NOT GENERALLY SUPPORTED, THIS IS ONLY INTENDED TO WORK
+ *       AROUND VERY SPECIFIC USE CASES.
+ */
+
+void grpc_prefork() {
+  if (!grpc_fork_support_enabled()) {
+    gpr_log(GPR_ERROR,
+            "Fork support not enabled; try running with the "
+            "environment variable GRPC_ENABLE_FORK_SUPPORT=1");
+    return;
+  }
+  if (grpc_is_initialized()) {
+    grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+    grpc_timer_manager_set_threading(false);
+    grpc_executor_set_threading(&exec_ctx, false);
+    grpc_exec_ctx_finish(&exec_ctx);
+    if (!gpr_await_threads(
+            gpr_time_add(gpr_now(GPR_CLOCK_REALTIME),
+                         gpr_time_from_seconds(3, GPR_TIMESPAN)))) {
+      gpr_log(GPR_ERROR, "gRPC thread still active! Cannot fork!");
+    }
+  }
+}
+
+void grpc_postfork_parent() {
+  if (grpc_is_initialized()) {
+    grpc_timer_manager_set_threading(true);
+    grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+    grpc_executor_set_threading(&exec_ctx, true);
+    grpc_exec_ctx_finish(&exec_ctx);
+  }
+}
+
+void grpc_postfork_child() {
+  if (grpc_is_initialized()) {
+    grpc_timer_manager_set_threading(true);
+    grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+    grpc_executor_set_threading(&exec_ctx, true);
+    grpc_exec_ctx_finish(&exec_ctx);
+  }
+}
+
+void grpc_fork_handlers_auto_register() {
+  if (grpc_fork_support_enabled()) {
+    pthread_atfork(grpc_prefork, grpc_postfork_parent, grpc_postfork_child);
+  }
+}
+
+#endif  // GRPC_POSIX_FORK
diff --git a/src/core/lib/iomgr/fork_windows.cc b/src/core/lib/iomgr/fork_windows.cc
new file mode 100644
index 0000000000..f9986f33c7
--- /dev/null
+++ b/src/core/lib/iomgr/fork_windows.cc
@@ -0,0 +1,39 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include "src/core/lib/iomgr/port.h"
+
+#ifndef GRPC_POSIX_FORK
+
+#include <grpc/fork.h>
+#include <grpc/support/log.h>
+
+/*
+ * NOTE: FORKING IS NOT GENERALLY SUPPORTED, THIS IS ONLY INTENDED TO WORK
+ *       AROUND VERY SPECIFIC USE CASES.
+ */
+
+void grpc_prefork() { gpr_log(GPR_ERROR, "Forking not supported on Windows"); }
+
+void grpc_postfork_parent() {}
+
+void grpc_postfork_child() {}
+
+void grpc_fork_handlers_auto_register() {}
+
+#endif  // GRPC_POSIX_FORK
diff --git a/src/core/lib/iomgr/port.h b/src/core/lib/iomgr/port.h
index 1cc6d98491..9fae8c0052 100644
--- a/src/core/lib/iomgr/port.h
+++ b/src/core/lib/iomgr/port.h
@@ -30,6 +30,7 @@
 #define GRPC_HAVE_IP_PKTINFO 1
 #define GRPC_HAVE_MSG_NOSIGNAL 1
 #define GRPC_HAVE_UNIX_SOCKET 1
+#define GRPC_POSIX_FORK 1
 #define GRPC_POSIX_NO_SPECIAL_WAKEUP_FD 1
 #define GRPC_POSIX_SOCKET 1
 #define GRPC_POSIX_SOCKETADDR 1
@@ -59,6 +60,7 @@
 #define GRPC_HAVE_MSG_NOSIGNAL 1
 #define GRPC_HAVE_UNIX_SOCKET 1
 #define GRPC_LINUX_MULTIPOLL_WITH_EPOLL 1
+#define GRPC_POSIX_FORK 1
 #define GRPC_POSIX_HOST_NAME_MAX 1
 #define GRPC_POSIX_SOCKET 1
 #define GRPC_POSIX_SOCKETADDR 1
@@ -90,6 +92,7 @@
 #define GRPC_HAVE_SO_NOSIGPIPE 1
 #define GRPC_HAVE_UNIX_SOCKET 1
 #define GRPC_MSG_IOVLEN_TYPE int
+#define GRPC_POSIX_FORK 1
 #define GRPC_POSIX_NO_SPECIAL_WAKEUP_FD 1
 #define GRPC_POSIX_SOCKET 1
 #define GRPC_POSIX_SOCKETADDR 1
@@ -103,6 +106,7 @@
 #define GRPC_HAVE_IPV6_RECVPKTINFO 1
 #define GRPC_HAVE_SO_NOSIGPIPE 1
 #define GRPC_HAVE_UNIX_SOCKET 1
+#define GRPC_POSIX_FORK 1
 #define GRPC_POSIX_NO_SPECIAL_WAKEUP_FD 1
 #define GRPC_POSIX_SOCKET 1
 #define GRPC_POSIX_SOCKETADDR 1
diff --git a/src/core/lib/support/fork.cc b/src/core/lib/support/fork.cc
new file mode 100644
index 0000000000..2f29af899d
--- /dev/null
+++ b/src/core/lib/support/fork.cc
@@ -0,0 +1,62 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include "src/core/lib/support/fork.h"
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/useful.h>
+
+#include "src/core/lib/support/env.h"
+
+/*
+ * NOTE: FORKING IS NOT GENERALLY SUPPORTED, THIS IS ONLY INTENDED TO WORK
+ *       AROUND VERY SPECIFIC USE CASES.
+ */
+
+static int override_fork_support_enabled = -1;
+static int fork_support_enabled;
+
+void grpc_fork_support_init() {
+#ifdef GRPC_ENABLE_FORK_SUPPORT
+  fork_support_enabled = 1;
+#else
+  fork_support_enabled = 0;
+  char *env = gpr_getenv("GRPC_ENABLE_FORK_SUPPORT");
+  if (env != NULL) {
+    static const char *truthy[] = {"yes",  "Yes",  "YES", "true",
+                                   "True", "TRUE", "1"};
+    for (size_t i = 0; i < GPR_ARRAY_SIZE(truthy); i++) {
+      if (0 == strcmp(env, truthy[i])) {
+        fork_support_enabled = 1;
+      }
+    }
+    gpr_free(env);
+  }
+#endif
+  if (override_fork_support_enabled != -1) {
+    fork_support_enabled = override_fork_support_enabled;
+  }
+}
+
+int grpc_fork_support_enabled() { return fork_support_enabled; }
+
+void grpc_enable_fork_support(int enable) {
+  override_fork_support_enabled = enable;
+}
diff --git a/src/core/lib/support/fork.h b/src/core/lib/support/fork.h
new file mode 100644
index 0000000000..215d4214a6
--- /dev/null
+++ b/src/core/lib/support/fork.h
@@ -0,0 +1,35 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_SUPPORT_FORK_H
+#define GRPC_CORE_LIB_SUPPORT_FORK_H
+
+/*
+ * NOTE: FORKING IS NOT GENERALLY SUPPORTED, THIS IS ONLY INTENDED TO WORK
+ *       AROUND VERY SPECIFIC USE CASES.
+ */
+
+void grpc_fork_support_init(void);
+
+int grpc_fork_support_enabled(void);
+
+// Test only:  Must be called before grpc_init(), and overrides
+// environment variables/compile flags
+void grpc_enable_fork_support(int enable);
+
+#endif /* GRPC_CORE_LIB_SUPPORT_FORK_H */
diff --git a/src/core/lib/support/thd_internal.h b/src/core/lib/support/thd_internal.h
new file mode 100644
index 0000000000..38bffc847d
--- /dev/null
+++ b/src/core/lib/support/thd_internal.h
@@ -0,0 +1,30 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_SUPPORT_THD_INTERNAL_H
+#define GRPC_CORE_LIB_SUPPORT_THD_INTERNAL_H
+
+#include <grpc/support/time.h>
+
+/* Internal interfaces between modules within the gpr support library.  */
+void gpr_thd_init();
+
+/* Wait for all outstanding threads to finish, up to deadline */
+int gpr_await_threads(gpr_timespec deadline);
+
+#endif /* GRPC_CORE_LIB_SUPPORT_THD_INTERNAL_H */
diff --git a/src/core/lib/support/thd_posix.cc b/src/core/lib/support/thd_posix.cc
index 02e3846be1..c2a4f4198f 100644
--- a/src/core/lib/support/thd_posix.cc
+++ b/src/core/lib/support/thd_posix.cc
@@ -24,22 +24,34 @@
 
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
+#include <grpc/support/sync.h>
 #include <grpc/support/thd.h>
 #include <grpc/support/useful.h>
 #include <pthread.h>
 #include <stdlib.h>
 #include <string.h>
 
+#include "src/core/lib/support/fork.h"
+
+static gpr_mu g_mu;
+static gpr_cv g_cv;
+static int g_thread_count;
+static int g_awaiting_threads;
+
 struct thd_arg {
   void (*body)(void* arg); /* body of a thread */
   void* arg;               /* argument to a thread */
 };
 
+static void inc_thd_count();
+static void dec_thd_count();
+
 /* Body of every thread started via gpr_thd_new. */
 static void* thread_body(void* v) {
   struct thd_arg a = *(struct thd_arg*)v;
   free(v);
   (*a.body)(a.arg);
+  dec_thd_count();
   return nullptr;
 }
 
@@ -54,6 +66,7 @@ int gpr_thd_new(gpr_thd_id* t, void (*thd_body)(void* arg), void* arg,
   GPR_ASSERT(a != nullptr);
   a->body = thd_body;
   a->arg = arg;
+  inc_thd_count();
 
   GPR_ASSERT(pthread_attr_init(&attr) == 0);
   if (gpr_thd_options_is_detached(options)) {
@@ -68,6 +81,7 @@ int gpr_thd_new(gpr_thd_id* t, void (*thd_body)(void* arg), void* arg,
   if (!thread_started) {
     /* don't use gpr_free, as this was allocated using malloc (see above) */
     free(a);
+    dec_thd_count();
   }
   *t = (gpr_thd_id)p;
   return thread_started;
@@ -77,4 +91,46 @@ gpr_thd_id gpr_thd_currentid(void) { return (gpr_thd_id)pthread_self(); }
 
 void gpr_thd_join(gpr_thd_id t) { pthread_join((pthread_t)t, nullptr); }
 
+/*****************************************
+ * Only used when fork support is enabled
+ */
+
+static void inc_thd_count() {
+  if (grpc_fork_support_enabled()) {
+    gpr_mu_lock(&g_mu);
+    g_thread_count++;
+    gpr_mu_unlock(&g_mu);
+  }
+}
+
+static void dec_thd_count() {
+  if (grpc_fork_support_enabled()) {
+    gpr_mu_lock(&g_mu);
+    g_thread_count--;
+    if (g_awaiting_threads && g_thread_count == 0) {
+      gpr_cv_signal(&g_cv);
+    }
+    gpr_mu_unlock(&g_mu);
+  }
+}
+
+void gpr_thd_init() {
+  gpr_mu_init(&g_mu);
+  gpr_cv_init(&g_cv);
+  g_thread_count = 0;
+  g_awaiting_threads = 0;
+}
+
+int gpr_await_threads(gpr_timespec deadline) {
+  gpr_mu_lock(&g_mu);
+  g_awaiting_threads = 1;
+  int res = 0;
+  if (g_thread_count > 0) {
+    res = gpr_cv_wait(&g_cv, &g_mu, deadline);
+  }
+  g_awaiting_threads = 0;
+  gpr_mu_unlock(&g_mu);
+  return res == 0;
+}
+
 #endif /* GPR_POSIX_SYNC */
diff --git a/src/core/lib/support/thd_windows.cc b/src/core/lib/support/thd_windows.cc
index 5bda7f440c..0875c2f03e 100644
--- a/src/core/lib/support/thd_windows.cc
+++ b/src/core/lib/support/thd_windows.cc
@@ -50,6 +50,8 @@ static void destroy_thread(struct thd_info* t) {
   gpr_free(t);
 }
 
+void gpr_thd_init(void) {}
+
 /* Body of every thread started via gpr_thd_new. */
 static DWORD WINAPI thread_body(void* v) {
   g_thd_info = (struct thd_info*)v;
diff --git a/src/core/lib/surface/init.cc b/src/core/lib/surface/init.cc
index c6d2f0a192..8ee1383fb8 100644
--- a/src/core/lib/surface/init.cc
+++ b/src/core/lib/surface/init.cc
@@ -21,6 +21,7 @@
 #include <limits.h>
 #include <memory.h>
 
+#include <grpc/fork.h>
 #include <grpc/grpc.h>
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
@@ -39,6 +40,8 @@
 #include "src/core/lib/iomgr/timer_manager.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/slice/slice_internal.h"
+#include "src/core/lib/support/fork.h"
+#include "src/core/lib/support/thd_internal.h"
 #include "src/core/lib/surface/alarm_internal.h"
 #include "src/core/lib/surface/api_trace.h"
 #include "src/core/lib/surface/call.h"
@@ -62,10 +65,12 @@ static int g_initializations;
 
 static void do_basic_init(void) {
   gpr_log_verbosity_init();
+  grpc_fork_support_init();
   gpr_mu_init(&g_init_mu);
   grpc_register_built_in_plugins();
   grpc_cq_global_init();
   g_initializations = 0;
+  grpc_fork_handlers_auto_register();
 }
 
 static bool append_filter(grpc_exec_ctx* exec_ctx,
@@ -122,6 +127,7 @@ void grpc_init(void) {
   gpr_mu_lock(&g_init_mu);
   if (++g_initializations == 1) {
     gpr_time_init();
+    gpr_thd_init();
     grpc_stats_init();
     grpc_slice_intern_init();
     grpc_mdctx_global_init();
diff --git a/src/core/lib/surface/version.cc b/src/core/lib/surface/version.cc
index f4feadc640..5c06c66d0c 100644
--- a/src/core/lib/surface/version.cc
+++ b/src/core/lib/surface/version.cc
@@ -21,6 +21,6 @@
 
 #include <grpc/grpc.h>
 
-const char* grpc_version_string(void) { return "5.0.0-dev"; }
+const char* grpc_version_string(void) { return "5.0.0"; }
 
-const char* grpc_g_stands_for(void) { return "generous"; }
+const char* grpc_g_stands_for(void) { return "gambit"; }
diff --git a/src/cpp/common/version_cc.cc b/src/cpp/common/version_cc.cc
index e1e5e895f6..49de8ba98c 100644
--- a/src/cpp/common/version_cc.cc
+++ b/src/cpp/common/version_cc.cc
@@ -22,5 +22,5 @@
 #include <grpc++/grpc++.h>
 
 namespace grpc {
-grpc::string Version() { return "1.8.0-dev"; }
+grpc::string Version() { return "1.7.2"; }
 }  // namespace grpc
diff --git a/src/csharp/Grpc.Core.Tests/CallCancellationTest.cs b/src/csharp/Grpc.Core.Tests/CallCancellationTest.cs
new file mode 100644
index 0000000000..e040f52380
--- /dev/null
+++ b/src/csharp/Grpc.Core.Tests/CallCancellationTest.cs
@@ -0,0 +1,182 @@
+#region Copyright notice and license
+
+// Copyright 2015 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#endregion
+
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Grpc.Core;
+using Grpc.Core.Internal;
+using Grpc.Core.Profiling;
+using Grpc.Core.Utils;
+using NUnit.Framework;
+
+namespace Grpc.Core.Tests
+{
+    public class CallCancellationTest
+    {
+        const string Host = "127.0.0.1";
+
+        MockServiceHelper helper;
+        Server server;
+        Channel channel;
+
+        [SetUp]
+        public void Init()
+        {
+            helper = new MockServiceHelper(Host);
+            server = helper.GetServer();
+            server.Start();
+            channel = helper.GetChannel();
+        }
+
+        [TearDown]
+        public void Cleanup()
+        {
+            channel.ShutdownAsync().Wait();
+            server.ShutdownAsync().Wait();
+        }
+
+        [Test]
+        public async Task ClientStreamingCall_CancelAfterBegin()
+        {
+            var barrier = new TaskCompletionSource<object>();
+
+            helper.ClientStreamingHandler = new ClientStreamingServerMethod<string, string>(async (requestStream, context) =>
+            {
+                barrier.SetResult(null);
+                await requestStream.ToListAsync();
+                return "";
+            });
+
+            var cts = new CancellationTokenSource();
+            var call = Calls.AsyncClientStreamingCall(helper.CreateClientStreamingCall(new CallOptions(cancellationToken: cts.Token)));
+
+            await barrier.Task;  // make sure the handler has started.
+            cts.Cancel();
+
+            try
+            {
+                // cannot use Assert.ThrowsAsync because it uses Task.Wait and would deadlock.
+                await call.ResponseAsync;
+                Assert.Fail();
+            }
+            catch (RpcException ex)
+            {
+                Assert.AreEqual(StatusCode.Cancelled, ex.Status.StatusCode);
+            }
+        }
+
+        [Test]
+        public async Task ClientStreamingCall_ServerSideReadAfterCancelNotificationReturnsNull()
+        {
+            var handlerStartedBarrier = new TaskCompletionSource<object>();
+            var cancelNotificationReceivedBarrier = new TaskCompletionSource<object>();
+            var successTcs = new TaskCompletionSource<string>();
+
+            helper.ClientStreamingHandler = new ClientStreamingServerMethod<string, string>(async (requestStream, context) =>
+            {
+                handlerStartedBarrier.SetResult(null);
+
+                // wait for cancellation to be delivered.
+                context.CancellationToken.Register(() => cancelNotificationReceivedBarrier.SetResult(null));
+                await cancelNotificationReceivedBarrier.Task;
+
+                var moveNextResult = await requestStream.MoveNext();
+                successTcs.SetResult(!moveNextResult ? "SUCCESS" : "FAIL");
+                return "";
+            });
+
+            var cts = new CancellationTokenSource();
+            var call = Calls.AsyncClientStreamingCall(helper.CreateClientStreamingCall(new CallOptions(cancellationToken: cts.Token)));
+
+            await handlerStartedBarrier.Task;
+            cts.Cancel();
+
+            try
+            {
+                await call.ResponseAsync;
+                Assert.Fail();
+            }
+            catch (RpcException ex)
+            {
+                Assert.AreEqual(StatusCode.Cancelled, ex.Status.StatusCode);
+            }
+            Assert.AreEqual("SUCCESS", await successTcs.Task);
+        }
+
+        [Test]
+        public async Task ClientStreamingCall_CancelServerSideRead()
+        {
+            helper.ClientStreamingHandler = new ClientStreamingServerMethod<string, string>(async (requestStream, context) =>
+            {
+                var cts = new CancellationTokenSource();
+                var moveNextTask = requestStream.MoveNext(cts.Token);
+                cts.Cancel();
+                await moveNextTask;
+                return "";
+            });
+
+            var call = Calls.AsyncClientStreamingCall(helper.CreateClientStreamingCall());
+            try
+            {
+                // cannot use Assert.ThrowsAsync because it uses Task.Wait and would deadlock.
+                await call.ResponseAsync;
+                Assert.Fail();
+            }
+            catch (RpcException ex)
+            {
+                Assert.AreEqual(StatusCode.Cancelled, ex.Status.StatusCode);
+            }
+        }
+
+        [Test]
+        public async Task ServerStreamingCall_CancelClientSideRead()
+        {
+            helper.ServerStreamingHandler = new ServerStreamingServerMethod<string, string>(async (request, responseStream, context) =>
+            {
+                await responseStream.WriteAsync("abc");
+                while (!context.CancellationToken.IsCancellationRequested)
+                {
+                    await Task.Delay(10);
+                }
+            });
+
+            var call = Calls.AsyncServerStreamingCall(helper.CreateServerStreamingCall(), "");
+            await call.ResponseStream.MoveNext();
+            Assert.AreEqual("abc", call.ResponseStream.Current);
+
+            var cts = new CancellationTokenSource();
+            var moveNextTask = call.ResponseStream.MoveNext(cts.Token);
+            cts.Cancel();
+
+            try
+            {
+                // cannot use Assert.ThrowsAsync because it uses Task.Wait and would deadlock.
+                await moveNextTask;
+                Assert.Fail();
+            }
+            catch (RpcException ex)
+            {
+                Assert.AreEqual(StatusCode.Cancelled, ex.Status.StatusCode);
+            }
+        }
+    }
+}
diff --git a/src/csharp/Grpc.Core.Tests/ClientServerTest.cs b/src/csharp/Grpc.Core.Tests/ClientServerTest.cs
index 72d9035a6f..90dd365b07 100644
--- a/src/csharp/Grpc.Core.Tests/ClientServerTest.cs
+++ b/src/csharp/Grpc.Core.Tests/ClientServerTest.cs
@@ -273,74 +273,6 @@ namespace Grpc.Core.Tests
         }
 
         [Test]
-        public async Task ClientStreamingCall_CancelAfterBegin()
-        {
-            var barrier = new TaskCompletionSource<object>();
-
-            helper.ClientStreamingHandler = new ClientStreamingServerMethod<string, string>(async (requestStream, context) =>
-            {
-                barrier.SetResult(null);
-                await requestStream.ToListAsync();
-                return "";
-            });
-
-            var cts = new CancellationTokenSource();
-            var call = Calls.AsyncClientStreamingCall(helper.CreateClientStreamingCall(new CallOptions(cancellationToken: cts.Token)));
-
-            await barrier.Task;  // make sure the handler has started.
-            cts.Cancel();
-
-            try
-            {
-                // cannot use Assert.ThrowsAsync because it uses Task.Wait and would deadlock.
-                await call.ResponseAsync;
-                Assert.Fail();
-            }
-            catch (RpcException ex)
-            {
-                Assert.AreEqual(StatusCode.Cancelled, ex.Status.StatusCode);
-            }
-        }
-
-        [Test]
-        public async Task ClientStreamingCall_ServerSideReadAfterCancelNotificationReturnsNull()
-        {
-            var handlerStartedBarrier = new TaskCompletionSource<object>();
-            var cancelNotificationReceivedBarrier = new TaskCompletionSource<object>();
-            var successTcs = new TaskCompletionSource<string>();
-
-            helper.ClientStreamingHandler = new ClientStreamingServerMethod<string, string>(async (requestStream, context) =>
-            {
-                handlerStartedBarrier.SetResult(null);
-
-                // wait for cancellation to be delivered.
-                context.CancellationToken.Register(() => cancelNotificationReceivedBarrier.SetResult(null));
-                await cancelNotificationReceivedBarrier.Task;
-
-                var moveNextResult = await requestStream.MoveNext();
-                successTcs.SetResult(!moveNextResult ? "SUCCESS" : "FAIL");
-                return "";
-            });
-
-            var cts = new CancellationTokenSource();
-            var call = Calls.AsyncClientStreamingCall(helper.CreateClientStreamingCall(new CallOptions(cancellationToken: cts.Token)));
-
-            await handlerStartedBarrier.Task;
-            cts.Cancel();
-
-            try
-            {
-                await call.ResponseAsync;
-                Assert.Fail();
-            }
-            catch (RpcException ex)
-            {
-                Assert.AreEqual(StatusCode.Cancelled, ex.Status.StatusCode);
-            }
-            Assert.AreEqual("SUCCESS", await successTcs.Task);
-        }
-
-        [Test]
         public async Task AsyncUnaryCall_EchoMetadata()
         {
             helper.UnaryHandler = new UnaryServerMethod<string, string>((request, context) =>
diff --git a/src/csharp/Grpc.Core/IAsyncStreamReader.cs b/src/csharp/Grpc.Core/IAsyncStreamReader.cs
index 42bfbb87e0..3751d549e3 100644
--- a/src/csharp/Grpc.Core/IAsyncStreamReader.cs
+++ b/src/csharp/Grpc.Core/IAsyncStreamReader.cs
@@ -41,6 +41,13 @@ namespace Grpc.Core
     /// (<c>MoveNext</c> will return <c>false</c>) and the <c>CancellationToken</c>
     /// associated with the call will be cancelled to signal the failure.
     /// </para>
+    /// <para>
+    /// <c>MoveNext()</c> operations can be cancelled via a cancellation token. Cancelling
+    /// an individual read operation has the same effect as cancelling the entire call
+    /// (which will also result in the read operation returning prematurely), but the per-read cancellation
+    /// tokens passed to MoveNext() only result in cancelling the call if the read operation haven't finished
+    /// yet.
+    /// </para>
     /// </summary>
     /// <typeparam name="T">The message type.</typeparam>
     public interface IAsyncStreamReader<T> : IAsyncEnumerator<T>
diff --git a/src/csharp/Grpc.Core/Internal/ClientResponseStream.cs b/src/csharp/Grpc.Core/Internal/ClientResponseStream.cs
index 851b6ca213..ab649ee766 100644
--- a/src/csharp/Grpc.Core/Internal/ClientResponseStream.cs
+++ b/src/csharp/Grpc.Core/Internal/ClientResponseStream.cs
@@ -49,19 +49,19 @@ namespace Grpc.Core.Internal
 
         public async Task<bool> MoveNext(CancellationToken token)
         {
-            if (token != CancellationToken.None)
+            var cancellationTokenRegistration = token.CanBeCanceled ? token.Register(() => call.Cancel()) : (IDisposable) null;
+            using (cancellationTokenRegistration)
             {
-                throw new InvalidOperationException("Cancellation of individual reads is not supported.");
-            }
-            var result = await call.ReadMessageAsync().ConfigureAwait(false);
-            this.current = result;
+                var result = await call.ReadMessageAsync().ConfigureAwait(false);
+                this.current = result;
 
-            if (result == null)
-            {
-                await call.StreamingResponseCallFinishedTask.ConfigureAwait(false);
-                return false;
+                if (result == null)
+                {
+                    await call.StreamingResponseCallFinishedTask.ConfigureAwait(false);
+                    return false;
+                }
+                return true;
             }
-            return true;
         }
 
         public void Dispose()
diff --git a/src/csharp/Grpc.Core/Internal/ServerRequestStream.cs b/src/csharp/Grpc.Core/Internal/ServerRequestStream.cs
index c65b960afb..058dddb7eb 100644
--- a/src/csharp/Grpc.Core/Internal/ServerRequestStream.cs
+++ b/src/csharp/Grpc.Core/Internal/ServerRequestStream.cs
@@ -49,13 +49,14 @@ namespace Grpc.Core.Internal
 
         public async Task<bool> MoveNext(CancellationToken token)
         {
-            if (token != CancellationToken.None)
+            
+            var cancellationTokenRegistration = token.CanBeCanceled ? token.Register(() => call.Cancel()) : (IDisposable) null;
+            using (cancellationTokenRegistration)
             {
-                throw new InvalidOperationException("Cancellation of individual reads is not supported.");
+                var result = await call.ReadMessageAsync().ConfigureAwait(false);
+                this.current = result;
+                return result != null;
             }
-            var result = await call.ReadMessageAsync().ConfigureAwait(false);
-            this.current = result;
-            return result != null;
         }
 
         public void Dispose()
diff --git a/src/csharp/Grpc.Core/Version.csproj.include b/src/csharp/Grpc.Core/Version.csproj.include
index b9ceaf8254..7cae4a55d4 100755
--- a/src/csharp/Grpc.Core/Version.csproj.include
+++ b/src/csharp/Grpc.Core/Version.csproj.include
@@ -1,7 +1,7 @@
 <!-- This file is generated -->
 <Project>
   <PropertyGroup>
-    <GrpcCsharpVersion>1.8.0-dev</GrpcCsharpVersion>
+    <GrpcCsharpVersion>1.7.2</GrpcCsharpVersion>
     <GoogleProtobufVersion>3.3.0</GoogleProtobufVersion>
   </PropertyGroup>
 </Project>
diff --git a/src/csharp/Grpc.Core/VersionInfo.cs b/src/csharp/Grpc.Core/VersionInfo.cs
index dab938821f..e4c97ffda7 100644
--- a/src/csharp/Grpc.Core/VersionInfo.cs
+++ b/src/csharp/Grpc.Core/VersionInfo.cs
@@ -33,11 +33,11 @@ namespace Grpc.Core
         /// <summary>
         /// Current <c>AssemblyFileVersion</c> of gRPC C# assemblies
         /// </summary>
-        public const string CurrentAssemblyFileVersion = "1.8.0.0";
+        public const string CurrentAssemblyFileVersion = "1.7.2.0";
 
         /// <summary>
         /// Current version of gRPC C#
         /// </summary>
-        public const string CurrentVersion = "1.8.0-dev";
+        public const string CurrentVersion = "1.7.2";
     }
 }
diff --git a/src/csharp/build_packages_dotnetcli.bat b/src/csharp/build_packages_dotnetcli.bat
index ff013d5680..3be049ae1d 100755
--- a/src/csharp/build_packages_dotnetcli.bat
+++ b/src/csharp/build_packages_dotnetcli.bat
@@ -13,7 +13,7 @@
 @rem limitations under the License.
 
 @rem Current package versions
-set VERSION=1.8.0-dev
+set VERSION=1.7.2
 
 @rem Adjust the location of nuget.exe
 set NUGET=C:\nuget\nuget.exe
diff --git a/src/csharp/build_packages_dotnetcli.sh b/src/csharp/build_packages_dotnetcli.sh
index 44a4791146..cf565b2e8d 100755
--- a/src/csharp/build_packages_dotnetcli.sh
+++ b/src/csharp/build_packages_dotnetcli.sh
@@ -39,7 +39,7 @@ dotnet pack --configuration Release Grpc.Auth --output ../../../artifacts
 dotnet pack --configuration Release Grpc.HealthCheck --output ../../../artifacts
 dotnet pack --configuration Release Grpc.Reflection --output ../../../artifacts
 
-nuget pack Grpc.nuspec -Version "1.8.0-dev" -OutputDirectory ../../artifacts
-nuget pack Grpc.Tools.nuspec -Version "1.8.0-dev" -OutputDirectory ../../artifacts
+nuget pack Grpc.nuspec -Version "1.7.2" -OutputDirectory ../../artifacts
+nuget pack Grpc.Tools.nuspec -Version "1.7.2" -OutputDirectory ../../artifacts
 
 (cd ../../artifacts && zip csharp_nugets_dotnetcli.zip *.nupkg)
diff --git a/src/csharp/tests.json b/src/csharp/tests.json
index 7841051052..65a0ed293f 100644
--- a/src/csharp/tests.json
+++ b/src/csharp/tests.json
@@ -10,6 +10,7 @@
     "Grpc.Core.Tests.AppDomainUnloadTest",
     "Grpc.Core.Tests.AuthContextTest",
     "Grpc.Core.Tests.AuthPropertyTest",
+    "Grpc.Core.Tests.CallCancellationTest",
     "Grpc.Core.Tests.CallCredentialsTest",
     "Grpc.Core.Tests.CallOptionsTest",
     "Grpc.Core.Tests.ChannelCredentialsTest",
diff --git a/src/node/health_check/package.json b/src/node/health_check/package.json
new file mode 100644
index 0000000000..fca3a2a7a6
--- /dev/null
+++ b/src/node/health_check/package.json
@@ -0,0 +1,29 @@
+{
+  "name": "grpc-health-check",
+  "version": "1.7.2",
+  "author": "Google Inc.",
+  "description": "Health check service for use with gRPC",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/grpc/grpc.git"
+  },
+  "bugs": "https://github.com/grpc/grpc/issues",
+  "contributors": [
+    {
+      "name": "Michael Lumish",
+      "email": "mlumish@google.com"
+    }
+  ],
+  "dependencies": {
+    "grpc": "^1.7.2",
+    "lodash": "^3.9.3",
+    "google-protobuf": "^3.0.0"
+  },
+  "files": [
+    "LICENSE",
+    "health.js",
+    "v1"
+  ],
+  "main": "src/node/index.js",
+  "license": "Apache-2.0"
+}
diff --git a/src/node/tools/package.json b/src/node/tools/package.json
new file mode 100644
index 0000000000..99fd854067
--- /dev/null
+++ b/src/node/tools/package.json
@@ -0,0 +1,41 @@
+{
+  "name": "grpc-tools",
+  "version": "1.7.2",
+  "author": "Google Inc.",
+  "description": "Tools for developing with gRPC on Node.js",
+  "homepage": "https://grpc.io/",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/grpc/grpc.git"
+  },
+  "bugs": "https://github.com/grpc/grpc/issues",
+  "contributors": [
+    {
+      "name": "Michael Lumish",
+      "email": "mlumish@google.com"
+    }
+  ],
+  "bin": {
+    "grpc_tools_node_protoc": "./bin/protoc.js",
+    "grpc_tools_node_protoc_plugin": "./bin/protoc_plugin.js"
+  },
+  "scripts": {
+    "install": "./node_modules/.bin/node-pre-gyp install"
+  },
+  "bundledDependencies": ["node-pre-gyp"],
+  "binary": {
+    "module_name": "grpc_tools",
+    "host": "https://storage.googleapis.com/",
+    "remote_path": "grpc-precompiled-binaries/node/{name}/v{version}",
+    "package_name": "{platform}-{arch}.tar.gz",
+    "module_path": "bin"
+  },
+  "files": [
+    "index.js",
+    "bin/protoc.js",
+    "bin/protoc_plugin.js",
+    "bin/google/protobuf",
+    "LICENSE"
+  ],
+  "main": "index.js"
+}
diff --git a/src/objective-c/!ProtoCompiler-gRPCPlugin.podspec b/src/objective-c/!ProtoCompiler-gRPCPlugin.podspec
index 9065ab9f73..616fa01957 100644
--- a/src/objective-c/!ProtoCompiler-gRPCPlugin.podspec
+++ b/src/objective-c/!ProtoCompiler-gRPCPlugin.podspec
@@ -42,7 +42,7 @@ Pod::Spec.new do |s|
   # exclamation mark ensures that other "regular" pods will be able to find it as it'll be installed
   # before them.
   s.name     = '!ProtoCompiler-gRPCPlugin'
-  v = '1.8.0-dev'
+  v = '1.7.2'
   s.version  = v
   s.summary  = 'The gRPC ProtoC plugin generates Objective-C files from .proto services.'
   s.description = <<-DESC
diff --git a/src/objective-c/GRPCClient/private/version.h b/src/objective-c/GRPCClient/private/version.h
index db589d12de..ace39f7e77 100644
--- a/src/objective-c/GRPCClient/private/version.h
+++ b/src/objective-c/GRPCClient/private/version.h
@@ -23,4 +23,4 @@
 // `tools/buildgen/generate_projects.sh`.
 
 
-#define GRPC_OBJC_VERSION_STRING @"1.8.0-dev"
+#define GRPC_OBJC_VERSION_STRING @"1.7.2"
diff --git a/src/objective-c/tests/version.h b/src/objective-c/tests/version.h
index 02515063fa..c3d5719745 100644
--- a/src/objective-c/tests/version.h
+++ b/src/objective-c/tests/version.h
@@ -23,5 +23,5 @@
 // `tools/buildgen/generate_projects.sh`.
 
 
-#define GRPC_OBJC_VERSION_STRING @"1.8.0-dev"
-#define GRPC_C_VERSION_STRING @"5.0.0-dev"
+#define GRPC_OBJC_VERSION_STRING @"1.7.2"
+#define GRPC_C_VERSION_STRING @"5.0.0"
diff --git a/src/php/composer.json b/src/php/composer.json
index 09471d23fe..ad448332f1 100644
--- a/src/php/composer.json
+++ b/src/php/composer.json
@@ -2,7 +2,7 @@
   "name": "grpc/grpc-dev",
   "description": "gRPC library for PHP - for Developement use only",
   "license": "Apache-2.0",
-  "version": "1.8.0",
+  "version": "1.7.2",
   "require": {
     "php": ">=5.5.0",
     "google/protobuf": "^v3.3.0"
diff --git a/src/php/ext/grpc/version.h b/src/php/ext/grpc/version.h
index 93dd563cff..1083c2c4f5 100644
--- a/src/php/ext/grpc/version.h
+++ b/src/php/ext/grpc/version.h
@@ -20,6 +20,6 @@
 #ifndef VERSION_H
 #define VERSION_H
 
-#define PHP_GRPC_VERSION "1.8.0dev"
+#define PHP_GRPC_VERSION "1.7.2"
 
 #endif /* VERSION_H */
diff --git a/src/python/grpcio/grpc/_grpcio_metadata.py b/src/python/grpcio/grpc/_grpcio_metadata.py
index 0887ac1722..500a253e54 100644
--- a/src/python/grpcio/grpc/_grpcio_metadata.py
+++ b/src/python/grpcio/grpc/_grpcio_metadata.py
@@ -14,4 +14,4 @@
 
 # AUTO-GENERATED FROM `$REPO_ROOT/templates/src/python/grpcio/grpc/_grpcio_metadata.py.template`!!!
 
-__version__ = """1.8.0.dev0"""
+__version__ = """1.7.2"""
diff --git a/src/python/grpcio/grpc_core_dependencies.py b/src/python/grpcio/grpc_core_dependencies.py
index 330c4185c6..665b2acbb4 100644
--- a/src/python/grpcio/grpc_core_dependencies.py
+++ b/src/python/grpcio/grpc_core_dependencies.py
@@ -29,6 +29,7 @@ CORE_SOURCE_FILES = [
   'src/core/lib/support/env_linux.cc',
   'src/core/lib/support/env_posix.cc',
   'src/core/lib/support/env_windows.cc',
+  'src/core/lib/support/fork.cc',
   'src/core/lib/support/histogram.cc',
   'src/core/lib/support/host_port.cc',
   'src/core/lib/support/log.cc',
@@ -94,6 +95,8 @@ CORE_SOURCE_FILES = [
   'src/core/lib/iomgr/ev_windows.cc',
   'src/core/lib/iomgr/exec_ctx.cc',
   'src/core/lib/iomgr/executor.cc',
+  'src/core/lib/iomgr/fork_posix.cc',
+  'src/core/lib/iomgr/fork_windows.cc',
   'src/core/lib/iomgr/gethostname_fallback.cc',
   'src/core/lib/iomgr/gethostname_host_name_max.cc',
   'src/core/lib/iomgr/gethostname_sysconf.cc',
diff --git a/src/python/grpcio/grpc_version.py b/src/python/grpcio/grpc_version.py
index 61c4157375..a5d4b2082b 100644
--- a/src/python/grpcio/grpc_version.py
+++ b/src/python/grpcio/grpc_version.py
@@ -14,4 +14,4 @@
 
 # AUTO-GENERATED FROM `$REPO_ROOT/templates/src/python/grpcio/grpc_version.py.template`!!!
 
-VERSION='1.8.0.dev0'
+VERSION='1.7.2'
diff --git a/src/python/grpcio_health_checking/grpc_version.py b/src/python/grpcio_health_checking/grpc_version.py
index 889297f020..dc1bc96503 100644
--- a/src/python/grpcio_health_checking/grpc_version.py
+++ b/src/python/grpcio_health_checking/grpc_version.py
@@ -14,4 +14,4 @@
 
 # AUTO-GENERATED FROM `$REPO_ROOT/templates/src/python/grpcio_health_checking/grpc_version.py.template`!!!
 
-VERSION='1.8.0.dev0'
+VERSION='1.7.2'
diff --git a/src/python/grpcio_reflection/grpc_version.py b/src/python/grpcio_reflection/grpc_version.py
index 192f4cc217..3744cb67dc 100644
--- a/src/python/grpcio_reflection/grpc_version.py
+++ b/src/python/grpcio_reflection/grpc_version.py
@@ -14,4 +14,4 @@
 
 # AUTO-GENERATED FROM `$REPO_ROOT/templates/src/python/grpcio_reflection/grpc_version.py.template`!!!
 
-VERSION='1.8.0.dev0'
+VERSION='1.7.2'
diff --git a/src/python/grpcio_testing/grpc_version.py b/src/python/grpcio_testing/grpc_version.py
index 83470c2825..fbf9f22ed4 100644
--- a/src/python/grpcio_testing/grpc_version.py
+++ b/src/python/grpcio_testing/grpc_version.py
@@ -14,4 +14,4 @@
 
 # AUTO-GENERATED FROM `$REPO_ROOT/templates/src/python/grpcio_testing/grpc_version.py.template`!!!
 
-VERSION='1.8.0.dev0'
+VERSION='1.7.2'
diff --git a/src/python/grpcio_tests/grpc_version.py b/src/python/grpcio_tests/grpc_version.py
index 7065edd3bf..abd6b50072 100644
--- a/src/python/grpcio_tests/grpc_version.py
+++ b/src/python/grpcio_tests/grpc_version.py
@@ -14,4 +14,4 @@
 
 # AUTO-GENERATED FROM `$REPO_ROOT/templates/src/python/grpcio_tests/grpc_version.py.template`!!!
 
-VERSION='1.8.0.dev0'
+VERSION='1.7.2'
diff --git a/src/ruby/lib/grpc/version.rb b/src/ruby/lib/grpc/version.rb
index 3001579ce7..9b9007c01f 100644
--- a/src/ruby/lib/grpc/version.rb
+++ b/src/ruby/lib/grpc/version.rb
@@ -14,5 +14,5 @@
 
 # GRPC contains the General RPC module.
 module GRPC
-  VERSION = '1.8.0.dev'
+  VERSION = '1.7.2'
 end
diff --git a/src/ruby/tools/version.rb b/src/ruby/tools/version.rb
index c584a7cf59..22fbc5b6de 100644
--- a/src/ruby/tools/version.rb
+++ b/src/ruby/tools/version.rb
@@ -14,6 +14,6 @@
 
 module GRPC
   module Tools
-    VERSION = '1.8.0.dev'
+    VERSION = '1.7.2'
   end
 end