1// Copyright (c) 2012 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 BASE_SINGLE_THREAD_TASK_RUNNER_H_
6#define BASE_SINGLE_THREAD_TASK_RUNNER_H_
7
8#include "base/base_export.h"
9#include "base/sequenced_task_runner.h"
10
11namespace base {
12
13// A SingleThreadTaskRunner is a SequencedTaskRunner with one more
14// guarantee; namely, that all tasks are run on a single dedicated
15// thread.  Most use cases require only a SequencedTaskRunner, unless
16// there is a specific need to run tasks on only a single thread.
17//
18// SingleThreadTaskRunner implementations might:
19//   - Post tasks to an existing thread's MessageLoop (see MessageLoopProxy).
20//   - Create their own worker thread and MessageLoop to post tasks to.
21//   - Add tasks to a FIFO and signal to a non-MessageLoop thread for them to
22//     be processed. This allows TaskRunner-oriented code run on threads
23//     running other kinds of message loop, e.g. Jingle threads.
24class BASE_EXPORT SingleThreadTaskRunner : public SequencedTaskRunner {
25 public:
26  // A more explicit alias to RunsTasksOnCurrentThread().
27  bool BelongsToCurrentThread() const {
28    return RunsTasksOnCurrentThread();
29  }
30
31 protected:
32  virtual ~SingleThreadTaskRunner() {}
33};
34
35}  // namespace base
36
37#endif  // BASE_SINGLE_THREAD_TASK_RUNNER_H_
38