[mojo-edk] Add MojoWatch and MojoCancelWatch APIs

mojo/edk/system/message_pipe_dispatcher.cc

 // Copyright 2015 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/system/message_pipe_dispatcher.h"
 
 #include <limits>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
@@ skipping 79 matching lines @@
   return Type::MESSAGE_PIPE;
 }
 
 MojoResult MessagePipeDispatcher::Close() {
   base::AutoLock lock(signal_lock_);
   DVLOG(1) << "Closing message pipe " << pipe_id_ << " endpoint " << endpoint_
            << " [port=" << port_.name() << "]";
   return CloseNoLock();
 }
 
+MojoResult MessagePipeDispatcher::Watch(MojoHandleSignals signals,
+                                        const Watcher::WatchCallback& callback,
+                                        uintptr_t context) {
+  base::AutoLock lock(signal_lock_);
+
+  if (port_closed_ || in_transit_)
+    return MOJO_RESULT_INVALID_ARGUMENT;
+
+  return awakables_.AddWatcher(
+      signals, callback, context, GetHandleSignalsStateNoLock());
+}
+
+MojoResult MessagePipeDispatcher::CancelWatch(uintptr_t context) {
+  base::AutoLock lock(signal_lock_);
+
+  if (port_closed_ || in_transit_)
+    return MOJO_RESULT_INVALID_ARGUMENT;
+
+  return awakables_.RemoveWatcher(context);
+}
+
 MojoResult MessagePipeDispatcher::WriteMessage(
     const void* bytes,
     uint32_t num_bytes,
     const DispatcherInTransit* dispatchers,
     uint32_t num_dispatchers,
     MojoWriteMessageFlags flags) {
 
   {
     base::AutoLock lock(signal_lock_);
     if (port_closed_ || in_transit_)
@@ skipping 496 matching lines @@
     DVLOG(1) << "Peer closure detected on message pipe " << pipe_id_
              << " endpoint " << endpoint_ << " [port=" << port_.name() << "]";
   }
 #endif
 
   awakables_.AwakeForStateChange(GetHandleSignalsStateNoLock());
 }
 
 }  // namespace edk
 }  // namespace mojo