blob: 83378f065283ffa8a1742fc0f59d65b5965e50dd [file] [log] [blame]
// 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.
#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 {
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();
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 ThreadPool
// tasks that happen to run on the same thread but weren't posted to the same
// SingleThreadTaskRunner.
mutable SequenceToken sequence_token_;
} // namespace base