Mojo: Make some attempts towards fixing remote message pipe closure.

mojo/system/local_message_pipe_endpoint.cc

 // Copyright 2013 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/local_message_pipe_endpoint.h"
 
 #include <string.h>
 
 #include "base/logging.h"
 #include "mojo/system/dispatcher.h"
 #include "mojo/system/message_in_transit.h"
 
 namespace mojo {
 namespace system {
 
 LocalMessagePipeEndpoint::LocalMessagePipeEndpoint()
     : is_open_(true),
       is_peer_open_(true) {
 }
 
 LocalMessagePipeEndpoint::~LocalMessagePipeEndpoint() {
   DCHECK(!is_open_);
   DCHECK(message_queue_.IsEmpty());  // Should be implied by not being open.
 }
 
 MessagePipeEndpoint::Type LocalMessagePipeEndpoint::GetType() const {
   return kTypeLocal;
 }
 
-void LocalMessagePipeEndpoint::Close() {
-  DCHECK(is_open_);
-  is_open_ = false;
-  message_queue_.Clear();
-}
-
-void LocalMessagePipeEndpoint::OnPeerClose() {
+bool LocalMessagePipeEndpoint::OnPeerClose() {
   DCHECK(is_open_);
   DCHECK(is_peer_open_);
 
   MojoWaitFlags old_satisfied_flags = SatisfiedFlags();
   MojoWaitFlags old_satisfiable_flags = SatisfiableFlags();
   is_peer_open_ = false;
   MojoWaitFlags new_satisfied_flags = SatisfiedFlags();
   MojoWaitFlags new_satisfiable_flags = SatisfiableFlags();
 
   if (new_satisfied_flags != old_satisfied_flags ||
       new_satisfiable_flags != old_satisfiable_flags) {
     waiter_list_.AwakeWaitersForStateChange(new_satisfied_flags,
                                             new_satisfiable_flags);
   }
+
+  return true;
 }
 
 void LocalMessagePipeEndpoint::EnqueueMessage(
     scoped_ptr<MessageInTransit> message) {
   DCHECK(is_open_);
   DCHECK(is_peer_open_);
 
   bool was_empty = message_queue_.IsEmpty();
   message_queue_.AddMessage(message.Pass());
   if (was_empty) {
     waiter_list_.AwakeWaitersForStateChange(SatisfiedFlags(),
                                             SatisfiableFlags());
   }
 }
 
+void LocalMessagePipeEndpoint::Close() {
+  DCHECK(is_open_);
+  is_open_ = false;
+  message_queue_.Clear();
+}
+
 void LocalMessagePipeEndpoint::CancelAllWaiters() {
   DCHECK(is_open_);
   waiter_list_.CancelAllWaiters();
 }
 
 MojoResult LocalMessagePipeEndpoint::ReadMessage(
     void* bytes, uint32_t* num_bytes,
     std::vector<scoped_refptr<Dispatcher> >* dispatchers,
     uint32_t* num_dispatchers,
     MojoReadMessageFlags flags) {
@@ skipping 90 matching lines @@
   MojoWaitFlags satisfiable_flags = 0;
   if (!message_queue_.IsEmpty() || is_peer_open_)
     satisfiable_flags |= MOJO_WAIT_FLAG_READABLE;
   if (is_peer_open_)
     satisfiable_flags |= MOJO_WAIT_FLAG_WRITABLE;
   return satisfiable_flags;
 }
 
 }  // namespace system
 }  // namespace mojo