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/synchronization/waitable_event.h"
   9 #include "base/win/object_watcher.h"
  10
  11 namespace base {
  12
  13 WaitableEventWatcher::ObjectWatcherHelper::ObjectWatcherHelper(
  14     WaitableEventWatcher* watcher)
  15     : watcher_(watcher) {
  16 };
  17
  18 void WaitableEventWatcher::ObjectWatcherHelper::OnObjectSignaled(HANDLE h) {
  19   watcher_->OnObjectSignaled();
  20 }
  21
  22
  23 WaitableEventWatcher::WaitableEventWatcher()
  24     : ALLOW_THIS_IN_INITIALIZER_LIST(helper_(this)),
  25       event_(NULL),
  26       delegate_(NULL) {
  27 }
  28
  29 WaitableEventWatcher::~WaitableEventWatcher() {
  30 }
  31
  32 bool WaitableEventWatcher::StartWatching(WaitableEvent* event,
  33                                          Delegate* delegate) {
  34   delegate_ = delegate;
  35   event_ = event;
  36
  37   return watcher_.StartWatching(event->handle(), &helper_);
  38 }
  39
  40 void WaitableEventWatcher::StopWatching() {
  41   delegate_ = NULL;
  42   event_ = NULL;
  43   watcher_.StopWatching();
  44 }
  45
  46 WaitableEvent* WaitableEventWatcher::GetWatchedEvent() {
  47   return event_;
  48 }
  49
  50 void WaitableEventWatcher::OnObjectSignaled() {
  51   WaitableEvent* event = event_;
  52   Delegate* delegate = delegate_;
  53   event_ = NULL;
  54   delegate_ = NULL;
  55   DCHECK(event);
  56
  57   delegate->OnWaitableEventSignaled(event);
  58 }
  59
  60 }  // namespace base