| // Copyright (c) 2011 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_THREADING_THREAD_CHECKER_IMPL_H_ |
| #define BASE_THREADING_THREAD_CHECKER_IMPL_H_ |
| |
| #include "base/base_export.h" |
| #include "base/compiler_specific.h" |
| #include "base/sequence_token.h" |
| #include "base/synchronization/lock.h" |
| #include "base/threading/platform_thread.h" |
| |
| namespace base { |
| |
| // Real implementation of ThreadChecker, for use in debug mode, or for temporary |
| // use in release mode (e.g. to CHECK on a threading issue seen only in the |
| // wild). |
| // |
| // Note: You should almost always use the ThreadChecker class to get the right |
| // version for your build configuration. |
| class BASE_EXPORT ThreadCheckerImpl { |
| public: |
| ThreadCheckerImpl(); |
| ~ThreadCheckerImpl(); |
| |
| bool CalledOnValidThread() const WARN_UNUSED_RESULT; |
| |
| // Changes the thread that is checked for in CalledOnValidThread. This may |
| // be useful when an object may be created on one thread and then used |
| // exclusively on another thread. |
| void DetachFromThread(); |
| |
| private: |
| void EnsureAssigned() const; |
| |
| // Members are mutable so that CalledOnValidThread() can set them. |
| |
| // Synchronizes access to all members. |
| mutable base::Lock lock_; |
| |
| // Thread on which CalledOnValidThread() may return true. |
| mutable PlatformThreadRef thread_id_; |
| |
| // TaskToken for which CalledOnValidThread() always returns true. This allows |
| // CalledOnValidThread() to return true when called multiple times from the |
| // same task, even if it's not running in a single-threaded context itself |
| // (allowing usage of ThreadChecker objects on the stack in the scope of one- |
| // off tasks). Note: CalledOnValidThread() may return true even if the current |
| // TaskToken is not equal to this. |
| mutable TaskToken task_token_; |
| |
| // SequenceToken for which CalledOnValidThread() may return true. Used to |
| // ensure that CalledOnValidThread() doesn't return true for TaskScheduler |
| // tasks that happen to run on the same thread but weren't posted to the same |
| // SingleThreadTaskRunner. |
| mutable SequenceToken sequence_token_; |
| }; |
| |
| } // namespace base |
| |
| #endif // BASE_THREADING_THREAD_CHECKER_IMPL_H_ |