michael@0: // Copyright (c) 2012 The Chromium Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: 
michael@0: #ifndef BASE_SINGLE_THREAD_TASK_RUNNER_H_
michael@0: #define BASE_SINGLE_THREAD_TASK_RUNNER_H_
michael@0: 
michael@0: #include "base/base_export.h"
michael@0: #include "base/sequenced_task_runner.h"
michael@0: 
michael@0: namespace base {
michael@0: 
michael@0: // A SingleThreadTaskRunner is a SequencedTaskRunner with one more
michael@0: // guarantee; namely, that all tasks are run on a single dedicated
michael@0: // thread.  Most use cases require only a SequencedTaskRunner, unless
michael@0: // there is a specific need to run tasks on only a single thread.
michael@0: //
michael@0: // SingleThreadTaskRunner implementations might:
michael@0: //   - Post tasks to an existing thread's MessageLoop (see MessageLoopProxy).
michael@0: //   - Create their own worker thread and MessageLoop to post tasks to.
michael@0: //   - Add tasks to a FIFO and signal to a non-MessageLoop thread for them to
michael@0: //     be processed. This allows TaskRunner-oriented code run on threads
michael@0: //     running other kinds of message loop, e.g. Jingle threads.
michael@0: class BASE_EXPORT SingleThreadTaskRunner : public SequencedTaskRunner {
michael@0:  public:
michael@0:   // A more explicit alias to RunsTasksOnCurrentThread().
michael@0:   bool BelongsToCurrentThread() const {
michael@0:     return RunsTasksOnCurrentThread();
michael@0:   }
michael@0: 
michael@0:  protected:
michael@0:   virtual ~SingleThreadTaskRunner() {}
michael@0: };
michael@0: 
michael@0: }  // namespace base
michael@0: 
michael@0: #endif  // BASE_SINGLE_THREAD_TASK_RUNNER_H_