53 lines
1.7 KiB
C
53 lines
1.7 KiB
C
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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#ifndef BASE_SEQUENCE_CHECKER_IMPL_H_
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#define BASE_SEQUENCE_CHECKER_IMPL_H_
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#include "base/base_export.h"
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#include "base/basictypes.h"
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#include "base/synchronization/lock.h"
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#include "base/threading/sequenced_worker_pool.h"
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#include "base/threading/thread_checker_impl.h"
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namespace base {
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// SequenceCheckerImpl is used to help verify that some methods of a
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// class are called in sequence -- that is, called from the same
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// SequencedTaskRunner. It is a generalization of ThreadChecker; in
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// particular, it behaves exactly like ThreadChecker if constructed
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// on a thread that is not part of a SequencedWorkerPool.
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class BASE_EXPORT SequenceCheckerImpl {
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public:
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SequenceCheckerImpl();
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~SequenceCheckerImpl();
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// Returns whether the we are being called on the same sequence token
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// as previous calls. If there is no associated sequence, then returns
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// whether we are being called on the underlying ThreadChecker's thread.
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bool CalledOnValidSequencedThread() const;
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// Unbinds the checker from the currently associated sequence. The
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// checker will be re-bound on the next call to CalledOnValidSequence().
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void DetachFromSequence();
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private:
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void EnsureSequenceTokenAssigned() const;
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// Guards all variables below.
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mutable Lock lock_;
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// Used if |sequence_token_| is not valid.
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ThreadCheckerImpl thread_checker_;
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mutable bool sequence_token_assigned_;
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mutable SequencedWorkerPool::SequenceToken sequence_token_;
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DISALLOW_COPY_AND_ASSIGN(SequenceCheckerImpl);
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};
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} // namespace base
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#endif // BASE_SEQUENCE_CHECKER_IMPL_H_
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