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// Copyright (c) 2012 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_SEQUENCE_CHECKER_IMPL_H_
#define BASE_SEQUENCE_CHECKER_IMPL_H_
#include "base/base_export.h"
#include "base/compiler_specific.h"
#include "base/macros.h"
#include "base/sequence_token.h"
#include "base/synchronization/lock.h"
#include "base/threading/sequenced_worker_pool.h"
#include "base/threading/thread_checker_impl.h"
namespace base {
// Real implementation of SequenceChecker 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 SequenceChecker class to get the right
// version for your build configuration.
class BASE_EXPORT SequenceCheckerImpl {
public:
SequenceCheckerImpl();
~SequenceCheckerImpl();
// Returns true if called in sequence with previous calls to this method and
// the constructor.
bool CalledOnValidSequence() const WARN_UNUSED_RESULT;
// Unbinds the checker from the currently associated sequence. The checker
// will be re-bound on the next call to CalledOnValidSequence().
void DetachFromSequence();
private:
void EnsureSequenceTokenAssigned() const;
// Guards all variables below.
mutable Lock lock_;
// True when the SequenceChecker is bound to a sequence or a thread.
mutable bool is_assigned_ = false;
mutable SequenceToken sequence_token_;
// TODO(gab): Remove this when SequencedWorkerPool is deprecated in favor of
// TaskScheduler. crbug.com/622400
mutable SequencedWorkerPool::SequenceToken sequenced_worker_pool_token_;
// Used when |sequenced_worker_pool_token_| and |sequence_token_| are invalid.
ThreadCheckerImpl thread_checker_;
DISALLOW_COPY_AND_ASSIGN(SequenceCheckerImpl);
};
} // namespace base
#endif // BASE_SEQUENCE_CHECKER_IMPL_H_