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// Copyright 2015 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/macros.h"
#include "base/memory/scoped_refptr.h"
#include "base/sequenced_task_runner.h"
namespace base {
class ThreadTaskRunnerHandle;
class BASE_EXPORT SequencedTaskRunnerHandle {
// Returns a SequencedTaskRunner which guarantees that posted tasks will only
// run after the current task is finished and will satisfy a SequenceChecker.
// It should only be called if IsSet() returns true (see the comment there for
// the requirements).
static const scoped_refptr<SequencedTaskRunner>& Get() WARN_UNUSED_RESULT;
// Returns true if one of the following conditions is fulfilled:
// a) A SequencedTaskRunner has been assigned to the current thread by
// instantiating a SequencedTaskRunnerHandle.
// b) The current thread has a ThreadTaskRunnerHandle (which includes any
// thread that has a MessageLoop associated with it).
static bool IsSet() WARN_UNUSED_RESULT;
// Binds |task_runner| to the current thread.
explicit SequencedTaskRunnerHandle(
scoped_refptr<SequencedTaskRunner> task_runner);
// Friend needed for ThreadTaskRunnerHandle::OverrideForTesting().
friend class ThreadTaskRunnerHandle;
scoped_refptr<SequencedTaskRunner> task_runner_;
} // namespace base