base/single_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 BASE_SINGLE_THREAD_TASK_RUNNER_H_
   6 #define BASE_SINGLE_THREAD_TASK_RUNNER_H_
   7
   8 #include "base/base_export.h"
   9 #include "base/sequenced_task_runner.h"
  10
  11 namespace base {
  12
  13 // A SingleThreadTaskRunner is a SequencedTaskRunner with one more
  14 // guarantee; namely, that all tasks are run on a single dedicated
  15 // thread.  Most use cases require only a SequencedTaskRunner, unless
  16 // there is a specific need to run tasks on only a single dedicated.
  17 //
  18 // Some theoretical implementations of SingleThreadTaskRunner:
  19 //
  20 //   - A SingleThreadTaskRunner that uses a single worker thread to
  21 //     run posted tasks (i.e., a message loop).
  22 //
  23 //   - A SingleThreadTaskRunner that stores the list of posted tasks
  24 //     and has a method Run() that runs each runnable task in FIFO
  25 //     order that must be run only from the thread the
  26 //     SingleThreadTaskRunner was created on.
  27 class BASE_EXPORT SingleThreadTaskRunner : public SequencedTaskRunner {
  28  public:
  29   // A more explicit alias to RunsTasksOnCurrentThread().
  30   bool BelongsToCurrentThread() const {
  31     return RunsTasksOnCurrentThread();
  32   }
  33
  34  protected:
  35   virtual ~SingleThreadTaskRunner() {}
  36 };
  37
  38 }  // namespace base
  39
  40 #endif  // BASE_SINGLE_THREAD_TASK_RUNNER_H_