Implementation of SequencedTaskRunner based on SequencedWorkerPool.

base/sequenced_task_runner_impl.h

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.

[akalin, 2012/03/13 07:27:11]

This file should probably be live in threading/ side-by-side with
SequencedWorkerPool.

[Francois, 2012/03/14 15:43:31]

Done.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef BASE_SEQUENCED_TASK_RUNNER_IMPL_H_

[akalin, 2012/03/13 07:27:11]

Conceptually, this class is essentially an inner class of SWP, although it's
unwieldy to have it actually be such.  I'm not a big fan of the name but I can't
think of a better one just yet.

[Francois, 2012/03/14 15:43:31]

Yeah, I agree, the name could use some work. I will also think about it.

+#define BASE_SEQUENCED_TASK_RUNNER_IMPL_H_
+#pragma once
+
+#include "base/memory/scoped_ptr.h"
+#include "base/sequenced_task_runner.h"
+
+namespace base {
+
+class SequencedWorkerPool;
+
+// Note that this class is RefCountedThreadSafe (inherited from TaskRunner).
+class BASE_EXPORT SequencedTaskRunnerImpl : public base::SequencedTaskRunner {
+ public:
+  explicit SequencedTaskRunnerImpl(scoped_refptr<SequencedWorkerPool> pool);

[akalin, 2012/03/13 07:27:11]

I think you should make the token a parameter of the constructor, just in case
the client has a named one he wants to provide.

I was thinking that SWP would have a method:

scoped_refptr<SequencedTaskRunner> GetSequencedTaskRunner(SequenceToken token);

that would return an instance of this class

[Francois, 2012/03/14 15:43:31]

Done.

+
+  // TaskRunner implementation
+  virtual bool PostDelayedTask(const tracked_objects::Location& from_here,
+                               const Closure& task,
+                               int64 delay_ms) OVERRIDE;

[akalin, 2012/03/13 07:27:11]

#include compiler_specific.h for OVERRIDE

[Francois, 2012/03/14 15:43:31]

Done.

+  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,
+      base::TimeDelta delay) OVERRIDE;
+
+ private:
+  ~SequencedTaskRunnerImpl();
+
+  scoped_refptr<SequencedWorkerPool> pool_;
+
+  class SequenceToken;

[akalin, 2012/03/13 07:27:11]

No need to have another class just to avoid including sequenced_task_runner.h,
especially if you make a SequenceToken a parameter

[Francois, 2012/03/14 15:43:31]

Done.

+  scoped_ptr<SequenceToken> token_;
+
+  DISALLOW_COPY_AND_ASSIGN(SequencedTaskRunnerImpl);
+};
+
+}  // namespace base
+
+#endif  // BASE_SEQUENCED_TASK_RUNNER_IMPL_H_