Add a thread-safe CreateChannel method to ChannelManager.

mojo/edk/embedder/embedder_unittest.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "mojo/edk/embedder/embedder.h"
 
 #include <string.h>
 
 #include "base/bind.h"
 #include "base/location.h"
@@ skipping 26 matching lines @@
   // Creates a channel that lives on a given I/O thread (determined by the given
   // |TaskRunner|) attached to the given |platform_handle|. After construction,
   // |bootstrap_message_pipe()| gives the Mojo handle for the bootstrap message
   // pipe on this channel; it is up to the caller to close this handle.
   // Note: The I/O thread must outlive this object (and its message loop must
   // continue pumping messages while this object is alive).
   ScopedTestChannel(scoped_refptr<base::TaskRunner> io_thread_task_runner,
                     ScopedPlatformHandle platform_handle)
       : io_thread_task_runner_(io_thread_task_runner),
         bootstrap_message_pipe_(MOJO_HANDLE_INVALID),
-        did_create_channel_event_(true, false),
+        did_create_channel_event_(true, false),  // Manual reset.
         channel_info_(nullptr) {
     bootstrap_message_pipe_ =
         CreateChannel(platform_handle.Pass(), io_thread_task_runner_,
                       base::Bind(&ScopedTestChannel::DidCreateChannel,
                                  base::Unretained(this)),
                       nullptr)
             .release()
             .value();
     CHECK_NE(bootstrap_message_pipe_, MOJO_HANDLE_INVALID);
   }
 
   // Destructor: Shuts down the channel. (As noted above, for this to happen,
   // the I/O thread must be alive and pumping messages.)
-  ~ScopedTestChannel() { DestroyChannel(channel_info_); }
+  ~ScopedTestChannel() {
+    // |WaitForChannelCreationCompletion()| must be called before destruction.
+    CHECK(did_create_channel_event_.IsSignaled());
+    DestroyChannel(channel_info_);
+  }
 
   // Waits for channel creation to be completed.
   void WaitForChannelCreationCompletion() { did_create_channel_event_.Wait(); }
 
   MojoHandle bootstrap_message_pipe() const { return bootstrap_message_pipe_; }
 
   // Call only after |WaitForChannelCreationCompletion()|. Use only to check
   // that it's not null.
   const ChannelInfo* channel_info() const { return channel_info_; }
 
@@ skipping 558 matching lines @@
 
   EXPECT_TRUE(test::Shutdown());
 }
 
 // TODO(vtl): Test immediate write & close.
 // TODO(vtl): Test broken-connection cases.
 
 }  // namespace
 }  // namespace embedder
 }  // namespace mojo