Mojo: Remove MessagePipeEndpoint::EnqueueMessage()'s return value.

The new semantics are that it must succeed. (Next, pending another CL that moves
the Dispatchers into the MessageInTransit itself: move the attaching of
dispatchers "up" the stack into message_pipe.cc.)

R=davemoore@chromium.org

Review URL: https://codereview.chromium.org/180133004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@253252 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 12 insertions, 12 deletions

diff --git a/mojo/system/local_message_pipe_endpoint.cc b/mojo/system/local_message_pipe_endpoint.cc
index 723f05b..3ed73d7 100644
--- a/mojo/system/local_message_pipe_endpoint.cc
+++ b/mojo/system/local_message_pipe_endpoint.cc
@@ -48,7 +48,7 @@ void LocalMessagePipeEndpoint::OnPeerClose() {
   }
 }
 
-MojoResult LocalMessagePipeEndpoint::EnqueueMessage(
+void LocalMessagePipeEndpoint::EnqueueMessage(
     scoped_ptr<MessageInTransit> message,
     std::vector<DispatcherTransport>* transports) {
   DCHECK(is_open_);
@@ -78,8 +78,6 @@ MojoResult LocalMessagePipeEndpoint::EnqueueMessage(
     waiter_list_.AwakeWaitersForStateChange(SatisfiedFlags(),
                                             SatisfiableFlags());
   }
-
-  return MOJO_RESULT_OK;
 }
 
 void LocalMessagePipeEndpoint::CancelAllWaiters() {
diff --git a/mojo/system/local_message_pipe_endpoint.h b/mojo/system/local_message_pipe_endpoint.h
index 45dbe2a..d5c7203 100644
--- a/mojo/system/local_message_pipe_endpoint.h
+++ b/mojo/system/local_message_pipe_endpoint.h
@@ -27,7 +27,7 @@ class MOJO_SYSTEM_IMPL_EXPORT LocalMessagePipeEndpoint
   // |MessagePipeEndpoint| implementation:
   virtual void Close() OVERRIDE;
   virtual void OnPeerClose() OVERRIDE;
-  virtual MojoResult EnqueueMessage(
+  virtual void EnqueueMessage(
       scoped_ptr<MessageInTransit> message,
       std::vector<DispatcherTransport>* transports) OVERRIDE;
 
diff --git a/mojo/system/message_pipe.cc b/mojo/system/message_pipe.cc
index ed5b4ca..76c0fae 100644
--- a/mojo/system/message_pipe.cc
+++ b/mojo/system/message_pipe.cc
@@ -159,7 +159,9 @@ MojoResult MessagePipe::EnqueueMessage(
     }
   }
 
-  return endpoints_[port]->EnqueueMessage(message.Pass(), transports);
+  // The endpoint's |EnqueueMessage()| may not report failure.
+  endpoints_[port]->EnqueueMessage(message.Pass(), transports);
+  return MOJO_RESULT_OK;
 }
 
 void MessagePipe::Attach(unsigned port,
diff --git a/mojo/system/message_pipe_endpoint.h b/mojo/system/message_pipe_endpoint.h
index 5cad2e6..d4a002d 100644
--- a/mojo/system/message_pipe_endpoint.h
+++ b/mojo/system/message_pipe_endpoint.h
@@ -39,10 +39,11 @@ class MOJO_SYSTEM_IMPL_EXPORT MessagePipeEndpoint {
   virtual void Close() = 0;
   virtual void OnPeerClose() = 0;
   // Implements |MessagePipe::EnqueueMessage()| (see its description for
-  // details).
-  virtual MojoResult EnqueueMessage(
-      scoped_ptr<MessageInTransit> message,
-      std::vector<DispatcherTransport>* transports) = 0;
+  // details). A major difference is that this |EnqueueMessage()| cannot report
+  // failure (if, e.g., a channel is torn down at this point, it should silently
+  // swallow the message).
+  virtual void EnqueueMessage(scoped_ptr<MessageInTransit> message,
+                              std::vector<DispatcherTransport>* transports) = 0;
 
   // Implementations must override these if they represent a local endpoint,
   // i.e., one for which there's a |MessagePipeDispatcher| (and thus a handle).
diff --git a/mojo/system/proxy_message_pipe_endpoint.cc b/mojo/system/proxy_message_pipe_endpoint.cc
index 28abe9e..ddea878 100644
--- a/mojo/system/proxy_message_pipe_endpoint.cc
+++ b/mojo/system/proxy_message_pipe_endpoint.cc
@@ -53,7 +53,7 @@ void ProxyMessagePipeEndpoint::OnPeerClose() {
                            0, 0, NULL)));
 }
 
-MojoResult ProxyMessagePipeEndpoint::EnqueueMessage(
+void ProxyMessagePipeEndpoint::EnqueueMessage(
     scoped_ptr<MessageInTransit> message,
     std::vector<DispatcherTransport>* transports) {
   DCHECK(!transports || !transports->empty());
@@ -62,7 +62,6 @@ MojoResult ProxyMessagePipeEndpoint::EnqueueMessage(
     AttachAndCloseDispatchers(message.get(), transports);
 
   EnqueueMessageInternal(message.Pass());
-  return MOJO_RESULT_OK;
 }
 
 void ProxyMessagePipeEndpoint::Attach(scoped_refptr<Channel> channel,
diff --git a/mojo/system/proxy_message_pipe_endpoint.h b/mojo/system/proxy_message_pipe_endpoint.h
index c99a60a..f395f03 100644
--- a/mojo/system/proxy_message_pipe_endpoint.h
+++ b/mojo/system/proxy_message_pipe_endpoint.h
@@ -47,7 +47,7 @@ class MOJO_SYSTEM_IMPL_EXPORT ProxyMessagePipeEndpoint
   // |MessagePipeEndpoint| implementation:
   virtual void Close() OVERRIDE;
   virtual void OnPeerClose() OVERRIDE;
-  virtual MojoResult EnqueueMessage(
+  virtual void EnqueueMessage(
       scoped_ptr<MessageInTransit> message,
       std::vector<DispatcherTransport>* transports) OVERRIDE;
   virtual void Attach(scoped_refptr<Channel> channel,