Implementation of SequencedTaskRunner based on SequencedWorkerPool.

base/threading/sequenced_worker_pool_task_runner.h

+// 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_THREADING_SEQUENCED_WORKER_POOL_TASK_RUNNER_H_
+#define BASE_THREADING_SEQUENCED_WORKER_POOL_TASK_RUNNER_H_
+#pragma once
+
+#include "base/basictypes.h"
+#include "base/callback.h"

[akalin, 2012/03/26 18:44:08]

no need for callback.h include (you could include callback_forward.h, but all
uses come from inheriting from SequencedTaskRunner, so you can assume it's
included in sequenced_task_runner.h)

[Francois, 2012/03/28 14:32:42]

Done.

+#include "base/compiler_specific.h"
+#include "base/memory/ref_counted.h"
+#include "base/sequenced_task_runner.h"
+#include "base/threading/sequenced_worker_pool.h"
+#include "base/time.h"

[akalin, 2012/03/26 18:44:08]

no need for time.h include (since you're pulling it in via
sequenced_task_runner.h)

[Francois, 2012/03/28 14:32:42]

Yeah but the Google style guide says not to rely on other headers to pull in
definitions. Is this situation different because SWPTR derives from STR?

+
+namespace tracked_objects {
+class Location;

[akalin, 2012/03/26 18:44:08]

no need for this forward-declaration (since you're pulling it in via
SequencedTaskRunner)

[Francois, 2012/03/28 14:32:42]

Please see my comment above.

+}  // namespace tracked_objects
+
+namespace base {
+
+// Note that this class is RefCountedThreadSafe (inherited from TaskRunner).

[akalin, 2012/03/26 18:44:08]

Add a comment explaining what the class does.  Something like:

// SequencedWorkerPoolTaskRunner is a SequencedTaskRunner that posts tasks to a
SequencedWorkerPool with a fixed sequence token>

[Francois, 2012/03/28 14:32:42]

Done.

+class BASE_EXPORT SequencedWorkerPoolTaskRunner : public SequencedTaskRunner {
+ public:
+  SequencedWorkerPoolTaskRunner(const scoped_refptr<SequencedWorkerPool>& pool,
+                          SequencedWorkerPool::SequenceToken token);

[akalin, 2012/03/26 18:44:08]

fix indent

[Francois, 2012/03/28 14:32:42]

Done.

+
+  // TaskRunner implementation
+  virtual bool PostDelayedTask(const tracked_objects::Location& from_here,
+                               const Closure& task,
+                               int64 delay_ms) OVERRIDE;
+  virtual bool PostDelayedTask(const tracked_objects::Location& from_here,
+                               const Closure& task,
+                               TimeDelta delay) OVERRIDE;
+  virtual bool RunsTasksOnCurrentThread() const OVERRIDE;
+
+  // SequencedTaskRunner implementation
+  virtual bool PostNonNestableDelayedTask(
+      const tracked_objects::Location& from_here,
+      const Closure& task,
+      int64 delay_ms) OVERRIDE;
+  virtual bool PostNonNestableDelayedTask(
+      const tracked_objects::Location& from_here,
+      const Closure& task,
+      TimeDelta delay) OVERRIDE;
+
+ private:
+  virtual ~SequencedWorkerPoolTaskRunner();
+
+  const scoped_refptr<SequencedWorkerPool> pool_;
+
+  const SequencedWorkerPool::SequenceToken token_;
+
+  DISALLOW_COPY_AND_ASSIGN(SequencedWorkerPoolTaskRunner);
+};
+
+}  // namespace base
+
+#endif  // BASE_THREADING_SEQUENCED_TASK_RUNNER_IMPL_H_