Make IPC::SyncChannel not duplicate the underlying MessageLoop implementation...

chrome/common/ipc_channel_proxy.cc

 // Copyright (c) 2006-2008 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 "base/message_loop.h"
 #include "base/thread.h"
 #include "chrome/common/ipc_channel_proxy.h"
 #include "chrome/common/ipc_logging.h"
 #include "chrome/common/ipc_message_utils.h"
 
@@ skipping 34 matching lines @@
 #endif
       return true;
     }
   }
   return false;
 }
 
 // Called on the IPC::Channel thread
 void ChannelProxy::Context::OnMessageReceived(const Message& message) {
   // First give a chance to the filters to process this message.
-  if (TryFilters(message))
-    return;
+  if (!TryFilters(message))
+    OnMessageReceivedNoFilter(message);
+}
 
+// Called on the IPC::Channel thread
+void ChannelProxy::Context::OnMessageReceivedNoFilter(const Message& message) {
   // NOTE: This code relies on the listener's message loop not going away while
   // this thread is active.  That should be a reasonable assumption, but it
   // feels risky.  We may want to invent some more indirect way of referring to
   // a MessageLoop if this becomes a problem.
-
   listener_message_loop_->PostTask(FROM_HERE, NewRunnableMethod(
       this, &Context::OnDispatchMessage, message));
 }
 
 // Called on the IPC::Channel thread
 void ChannelProxy::Context::OnChannelConnected(int32 peer_pid) {
   for (size_t i = 0; i < filters_.size(); ++i)
     filters_[i]->OnChannelConnected(peer_pid);
 
   // See above comment about using listener_message_loop_ here.
   listener_message_loop_->PostTask(FROM_HERE, NewRunnableMethod(
       this, &Context::OnDispatchConnected, peer_pid));
 }
 
 // Called on the IPC::Channel thread
 void ChannelProxy::Context::OnChannelError() {
   // See above comment about using listener_message_loop_ here.
   listener_message_loop_->PostTask(FROM_HERE, NewRunnableMethod(
       this, &Context::OnDispatchError));
 }
 
 // Called on the IPC::Channel thread
-void ChannelProxy::Context::OnOpenChannel() {
+void ChannelProxy::Context::OnChannelOpened() {
   DCHECK(channel_ != NULL);
 
   // Assume a reference to ourselves on behalf of this thread.  This reference
   // will be released when we are closed.
   AddRef();
 
   if (!channel_->Connect()) {
     OnChannelError();
     return;
   }
 
   for (size_t i = 0; i < filters_.size(); ++i)
     filters_[i]->OnFilterAdded(channel_);
 }
 
 // Called on the IPC::Channel thread
-void ChannelProxy::Context::OnCloseChannel() {
+void ChannelProxy::Context::OnChannelClosed() {
   // It's okay for IPC::ChannelProxy::Close to be called more than once, which
   // would result in this branch being taken.
   if (!channel_)
     return;
 
   for (size_t i = 0; i < filters_.size(); ++i) {
     filters_[i]->OnChannelClosing();
     filters_[i]->OnFilterRemoved();
   }
 
@@ skipping 100 matching lines @@
     // the pipe immediately, it is possible for a listener to attempt
     // to connect and get an error since the pipe doesn't exist yet.
     context_->CreateChannel(channel_id, mode);
   } else {
     context_->ipc_message_loop()->PostTask(FROM_HERE, NewRunnableMethod(
         context_.get(), &Context::CreateChannel, channel_id, mode));
   }
 
   // complete initialization on the background thread
   context_->ipc_message_loop()->PostTask(FROM_HERE, NewRunnableMethod(
-      context_.get(), &Context::OnOpenChannel));
+      context_.get(), &Context::OnChannelOpened));
 }
 
 void ChannelProxy::Close() {
   // Clear the backpointer to the listener so that any pending calls to
   // Context::OnDispatchMessage or OnDispatchError will be ignored.  It is
   // possible that the channel could be closed while it is receiving messages!
-  context_->clear();
+  context_->Clear();
 
-  if (MessageLoop::current() == context_->ipc_message_loop()) {
-    // We're being destructed on the IPC thread, so no need to use the message
-    // loop as it might go away.
-    context_->OnCloseChannel();
-  } else {
+  if (context_->ipc_message_loop()) {
     context_->ipc_message_loop()->PostTask(FROM_HERE, NewRunnableMethod(
-        context_.get(), &Context::OnCloseChannel));
+        context_.get(), &Context::OnChannelClosed));
   }
 }
 
 bool ChannelProxy::Send(Message* message) {
 #ifdef IPC_MESSAGE_LOG_ENABLED
   Logging::current()->OnSendMessage(message, context_->channel_id());
 #endif
 
   context_->ipc_message_loop()->PostTask(FROM_HERE, NewRunnableMethod(
       context_.get(), &Context::OnSendMessage, message));
@@ skipping 10 matching lines @@
 
 void ChannelProxy::RemoveFilter(MessageFilter* filter) {
   context_->ipc_message_loop()->PostTask(FROM_HERE, NewRunnableMethod(
       context_.get(), &Context::OnRemoveFilter, filter));
 }
 
 //-----------------------------------------------------------------------------
 
 }  // namespace IPC