1// Copyright 2014 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#ifndef CC_BASE_UNIQUE_NOTIFIER_H_
6#define CC_BASE_UNIQUE_NOTIFIER_H_
7
8#include "base/callback.h"
9#include "base/memory/weak_ptr.h"
10#include "cc/base/cc_export.h"
11
12namespace base {
13class SequencedTaskRunner;
14}  // namespace base
15
16namespace cc {
17
18class CC_EXPORT UniqueNotifier {
19 public:
20  // Configure this notifier to issue the |closure| notification when scheduled.
21  UniqueNotifier(base::SequencedTaskRunner* task_runner,
22                 const base::Closure& closure);
23
24  // Destroying the notifier will ensure that no further notifications will
25  // happen from this class.
26  ~UniqueNotifier();
27
28  // Schedule a notification to be run. If another notification is already
29  // pending, then only one notification will take place.
30  void Schedule();
31
32 private:
33  void Notify();
34
35  // TODO(dcheng): How come this doesn't need to hold a ref to the task runner?
36  base::SequencedTaskRunner* task_runner_;
37  base::Closure closure_;
38  bool notification_pending_;
39
40  base::WeakPtrFactory<UniqueNotifier> weak_ptr_factory_;
41};
42
43}  // namespace cc
44
45#endif  // CC_BASE_UNIQUE_NOTIFIER_H_
46