thread_checker.h revision dc0f95d653279beabeb9817299e2902918ba123e 
1// Copyright (c) 2010 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_THREADING_THREAD_CHECKER_H_
6#define BASE_THREADING_THREAD_CHECKER_H_
7#pragma once
8
9#ifndef NDEBUG
10#include "base/threading/thread_checker_impl.h"
11#endif
12
13namespace base {
14
15// Do nothing implementation, for use in release mode.
16//
17// Note: You should almost always use the ThreadChecker class to get the
18// right version for your build configuration.
19class ThreadCheckerDoNothing {
20 public:
21  bool CalledOnValidThread() const {
22    return true;
23  }
24
25  void DetachFromThread() {}
26};
27
28// Before using this class, please consider using NonThreadSafe as it
29// makes it much easier to determine the nature of your class.
30//
31// ThreadChecker is a helper class used to help verify that some methods of a
32// class are called from the same thread.  One can inherit from this class and
33// use CalledOnValidThread() to verify.
34//
35// Inheriting from class indicates that one must be careful when using the
36// class with multiple threads. However, it is up to the class document to
37// indicate how it can be used with threads.
38//
39// Example:
40// class MyClass : public ThreadChecker {
41//  public:
42//   void Foo() {
43//     DCHECK(CalledOnValidThread());
44//     ... (do stuff) ...
45//   }
46// }
47//
48// In Release mode, CalledOnValidThread will always return true.
49#ifndef NDEBUG
50class ThreadChecker : public ThreadCheckerImpl {
51};
52#else
53class ThreadChecker : public ThreadCheckerDoNothing {
54};
55#endif  // NDEBUG
56
57}  // namespace base
58
59#endif  // BASE_THREADING_THREAD_CHECKER_H_
60