Mojo: Add Channel::AttachEndpoint(), which takes a ChannelEndpoint.

mojo/system/channel_endpoint.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/system/channel_endpoint.h"
 
 #include "base/logging.h"
 #include "mojo/system/channel.h"
 #include "mojo/system/message_pipe.h"
 
 namespace mojo {
 namespace system {
 
 ChannelEndpoint::ChannelEndpoint(MessagePipe* message_pipe, unsigned port)
     : state_(STATE_NORMAL),
       message_pipe_(message_pipe),
       port_(port),
       channel_(),
       local_id_(MessageInTransit::kInvalidEndpointId),
       remote_id_(MessageInTransit::kInvalidEndpointId) {
   DCHECK(message_pipe_.get());
   DCHECK(port_ == 0 || port_ == 1);
 }
 
 bool ChannelEndpoint::EnqueueMessage(scoped_ptr<MessageInTransit> message) {
   DCHECK(message);
 
   base::AutoLock locker(lock_);
+
   if (!channel_) {
     // Generally, this should only happen if the channel is shut down for some
     // reason (with live message pipes on it).
     return false;
   }
-  DCHECK_NE(local_id_, MessageInTransit::kInvalidEndpointId);
-  // TODO(vtl): Currently, we only support enqueueing messages when we're
-  // "running".
+
+  // TODO(vtl): Currently, this only works in the "running" case.
   DCHECK_NE(remote_id_, MessageInTransit::kInvalidEndpointId);
 
-  message->SerializeAndCloseDispatchers(channel_);
-  message->set_source_id(local_id_);
-  message->set_destination_id(remote_id_);
-  return channel_->WriteMessage(message.Pass());
+  return WriteMessageNoLock(message.Pass());
 }
 
 void ChannelEndpoint::DetachFromMessagePipe() {
   // TODO(vtl): Once |message_pipe_| is under |lock_|, we should null it out
   // here. For now, get the channel to do so for us.
 
   scoped_refptr<Channel> channel;
   {
     base::AutoLock locker(lock_);
     if (!channel_)
@@ skipping 39 matching lines @@
   local_id_ = MessageInTransit::kInvalidEndpointId;
   remote_id_ = MessageInTransit::kInvalidEndpointId;
 }
 
 ChannelEndpoint::~ChannelEndpoint() {
   DCHECK(!channel_);
   DCHECK_EQ(local_id_, MessageInTransit::kInvalidEndpointId);
   DCHECK_EQ(remote_id_, MessageInTransit::kInvalidEndpointId);
 }
 
+bool ChannelEndpoint::WriteMessageNoLock(scoped_ptr<MessageInTransit> message) {
+  DCHECK(message);
+
+  lock_.AssertAcquired();
+
+  DCHECK(channel_);
+  DCHECK_NE(local_id_, MessageInTransit::kInvalidEndpointId);
+  DCHECK_NE(remote_id_, MessageInTransit::kInvalidEndpointId);
+
+  message->SerializeAndCloseDispatchers(channel_);
+  message->set_source_id(local_id_);
+  message->set_destination_id(remote_id_);
+  return channel_->WriteMessage(message.Pass());
+}
+
 }  // namespace system
 }  // namespace mojo