Move CancellationFlag and WaitableEvent to the synchronization subdirectory....

base/waitable_event_watcher.h

Index: base/waitable_event_watcher.h
===================================================================
--- base/waitable_event_watcher.h	(revision 70364)
+++ base/waitable_event_watcher.h	(working copy)
@@ -1,162 +0,0 @@
-// Copyright (c) 2006-2008 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.
-
-#ifndef BASE_WAITABLE_EVENT_WATCHER_H_
-#define BASE_WAITABLE_EVENT_WATCHER_H_
-#pragma once
-
-#include "build/build_config.h"
-
-#if defined(OS_WIN)
-#include "base/win/object_watcher.h"
-#else
-#include "base/message_loop.h"
-#include "base/waitable_event.h"
-#endif
-
-namespace base {
-
-class Flag;
-class AsyncWaiter;
-class AsyncCallbackTask;
-class WaitableEvent;
-
-// -----------------------------------------------------------------------------
-// This class provides a way to wait on a WaitableEvent asynchronously.
-//
-// Each instance of this object can be waiting on a single WaitableEvent. When
-// the waitable event is signaled, a callback is made in the thread of a given
-// MessageLoop. This callback can be deleted by deleting the waiter.
-//
-// Typical usage:
-//
-//   class MyClass : public base::WaitableEventWatcher::Delegate {
-//    public:
-//     void DoStuffWhenSignaled(WaitableEvent *waitable_event) {
-//       watcher_.StartWatching(waitable_event, this);
-//     }
-//     virtual void OnWaitableEventSignaled(WaitableEvent* waitable_event) {
-//       // OK, time to do stuff!
-//     }
-//    private:
-//     base::WaitableEventWatcher watcher_;
-//   };
-//
-// In the above example, MyClass wants to "do stuff" when waitable_event
-// becomes signaled. WaitableEventWatcher makes this task easy. When MyClass
-// goes out of scope, the watcher_ will be destroyed, and there is no need to
-// worry about OnWaitableEventSignaled being called on a deleted MyClass
-// pointer.
-//
-// BEWARE: With automatically reset WaitableEvents, a signal may be lost if it
-// occurs just before a WaitableEventWatcher is deleted. There is currently no
-// safe way to stop watching an automatic reset WaitableEvent without possibly
-// missing a signal.
-//
-// NOTE: you /are/ allowed to delete the WaitableEvent while still waiting on
-// it with a Watcher. It will act as if the event was never signaled.
-// -----------------------------------------------------------------------------
-
-class WaitableEventWatcher
-#if defined(OS_POSIX)
-    : public MessageLoop::DestructionObserver
-#endif
-{
- public:
-
-  WaitableEventWatcher();
-  ~WaitableEventWatcher();
-
-  class Delegate {
-   public:
-    virtual ~Delegate() { }
-
-    // -------------------------------------------------------------------------
-    // This is called on the MessageLoop thread when WaitableEvent has been
-    // signaled.
-    //
-    // Note: the event may not be signaled by the time that this function is
-    // called. This indicates only that it has been signaled at some point in
-    // the past.
-    // -------------------------------------------------------------------------
-    virtual void OnWaitableEventSignaled(WaitableEvent* waitable_event) = 0;
-  };
-
-  // ---------------------------------------------------------------------------
-  // When @event is signaled, the given delegate is called on the thread of the
-  // current message loop when StartWatching is called. The delegate is not
-  // deleted.
-  // ---------------------------------------------------------------------------
-  bool StartWatching(WaitableEvent* event, Delegate* delegate);
-
-  // ---------------------------------------------------------------------------
-  // Cancel the current watch. Must be called from the same thread which
-  // started the watch.
-  //
-  // Does nothing if no event is being watched, nor if the watch has completed.
-  // The delegate will *not* be called for the current watch after this
-  // function returns. Since the delegate runs on the same thread as this
-  // function, it cannot be called during this function either.
-  // ---------------------------------------------------------------------------
-  void StopWatching();
-
-  // ---------------------------------------------------------------------------
-  // Return the currently watched event, or NULL if no object is currently being
-  // watched.
-  // ---------------------------------------------------------------------------
-  WaitableEvent* GetWatchedEvent();
-
-  // ---------------------------------------------------------------------------
-  // Return the delegate, or NULL if there is no delegate.
-  // ---------------------------------------------------------------------------
-  Delegate* delegate() {
-    return delegate_;
-  }
-
- private:
-  WaitableEvent* event_;
-
-#if defined(OS_WIN)
-  // ---------------------------------------------------------------------------
-  // The helper class exists because, if WaitableEventWatcher were to inherit
-  // from ObjectWatcher::Delegate, then it couldn't also have an inner class
-  // called Delegate (at least on Windows). Thus this object exists to proxy
-  // the callback function
-  // ---------------------------------------------------------------------------
-  class ObjectWatcherHelper : public win::ObjectWatcher::Delegate {
-   public:
-    ObjectWatcherHelper(WaitableEventWatcher* watcher);
-
-    // -------------------------------------------------------------------------
-    // Implementation of ObjectWatcher::Delegate
-    // -------------------------------------------------------------------------
-    void OnObjectSignaled(HANDLE h);
-
-   private:
-    WaitableEventWatcher *const watcher_;
-  };
-
-  void OnObjectSignaled();
-
-  ObjectWatcherHelper helper_;
-  win::ObjectWatcher watcher_;
-#else
-  // ---------------------------------------------------------------------------
-  // Implementation of MessageLoop::DestructionObserver
-  // ---------------------------------------------------------------------------
-  virtual void WillDestroyCurrentMessageLoop();
-
-  MessageLoop* message_loop_;
-  scoped_refptr<Flag> cancel_flag_;
-  AsyncWaiter* waiter_;
-  AsyncCallbackTask* callback_task_;
-  scoped_refptr<WaitableEvent::WaitableEventKernel> kernel_;
-#endif
-
-  Delegate* delegate_;
-};
-
-}  // namespace base
-
-#endif  // BASE_WAITABLE_EVENT_WATCHER_H_