base/synchronization/waitable_event_watcher_win.cc

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/synchronization/waitable_event_watcher.h"
   6
   7 #include "base/compiler_specific.h"
   8 #include "base/profiler/scoped_tracker.h"
   9 #include "base/synchronization/waitable_event.h"
  10 #include "base/win/object_watcher.h"
  11
  12 namespace base {
  13
  14 WaitableEventWatcher::WaitableEventWatcher()
  15     : event_(NULL) {
  16 }
  17
  18 WaitableEventWatcher::~WaitableEventWatcher() {
  19 }
  20
  21 bool WaitableEventWatcher::StartWatching(
  22     WaitableEvent* event,
  23     const EventCallback& callback) {
  24   callback_ = callback;
  25   event_ = event;
  26   return watcher_.StartWatching(event->handle(), this);
  27 }
  28
  29 void WaitableEventWatcher::StopWatching() {
  30   callback_.Reset();
  31   event_ = NULL;
  32   watcher_.StopWatching();
  33 }
  34
  35 WaitableEvent* WaitableEventWatcher::GetWatchedEvent() {
  36   return event_;
  37 }
  38
  39 void WaitableEventWatcher::OnObjectSignaled(HANDLE h) {
  40   // TODO(vadimt): Remove ScopedTracker below once crbug.com/418183 is fixed.
  41   tracked_objects::ScopedTracker tracking_profile(
  42       FROM_HERE_WITH_EXPLICIT_FUNCTION("WaitableEventWatche_OnObjectSignaled"));
  43
  44   WaitableEvent* event = event_;
  45   EventCallback callback = callback_;
  46   event_ = NULL;
  47   callback_.Reset();
  48   DCHECK(event);
  49
  50   callback.Run(event);
  51 }
  52
  53 }  // namespace base