remoting/base/auto_thread_task_runner.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef REMOTING_BASE_AUTO_THREAD_TASK_RUNNER_H_
   6 #define REMOTING_BASE_AUTO_THREAD_TASK_RUNNER_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/callback.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/message_loop/message_loop.h"
  12 #include "base/single_thread_task_runner.h"
  13
  14 namespace remoting {
  15
  16 // A wrapper around |SingleThreadTaskRunner| that provides automatic lifetime
  17 // management, by posting a caller-supplied task to the underlying task runner
  18 // when no more references remain.
  19 class AutoThreadTaskRunner : public base::SingleThreadTaskRunner {
  20  public:
  21   // Constructs an instance of |AutoThreadTaskRunner| wrapping |task_runner|.
  22   // |stop_task| is posted to |task_runner| when the last reference to
  23   // the AutoThreadTaskRunner is dropped.
  24   AutoThreadTaskRunner(scoped_refptr<base::SingleThreadTaskRunner> task_runner,
  25                        const base::Closure& stop_task);
  26
  27   // SingleThreadTaskRunner implementation
  28   virtual bool PostDelayedTask(
  29       const tracked_objects::Location& from_here,
  30       const base::Closure& task,
  31       base::TimeDelta delay) OVERRIDE;
  32   virtual bool PostNonNestableDelayedTask(
  33       const tracked_objects::Location& from_here,
  34       const base::Closure& task,
  35       base::TimeDelta delay) OVERRIDE;
  36   virtual bool RunsTasksOnCurrentThread() const OVERRIDE;
  37
  38  private:
  39   virtual ~AutoThreadTaskRunner();
  40
  41   // Task posted to |task_runner_| to notify the caller that it may be stopped.
  42   base::Closure stop_task_;
  43
  44   // The wrapped task runner.
  45   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
  46
  47   DISALLOW_COPY_AND_ASSIGN(AutoThreadTaskRunner);
  48 };
  49
  50 }  // namespace remoting
  51
  52 #endif  // REMOTING_BASE_AUTO_THREAD_TASK_RUNNER_H_