msarda@chromium.org | 59491bb | 2013-04-19 02:17:33 +0900 | [diff] [blame] | 1 | // Copyright (c) 2013 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_DEFERRED_SEQUENCED_TASKRUNNER_H_ |
| 6 | #define BASE_DEFERRED_SEQUENCED_TASKRUNNER_H_ |
| 7 | |
| 8 | #include <vector> |
| 9 | |
| 10 | #include "base/base_export.h" |
| 11 | #include "base/basictypes.h" |
| 12 | #include "base/callback.h" |
| 13 | #include "base/compiler_specific.h" |
| 14 | #include "base/memory/ref_counted.h" |
dbeam@chromium.org | 36f6040 | 2013-05-08 14:35:24 +0900 | [diff] [blame] | 15 | #include "base/sequenced_task_runner.h" |
msarda@chromium.org | 59491bb | 2013-04-19 02:17:33 +0900 | [diff] [blame] | 16 | #include "base/synchronization/lock.h" |
avi@chromium.org | b039e8b | 2013-06-28 09:49:07 +0900 | [diff] [blame] | 17 | #include "base/time/time.h" |
msarda@chromium.org | 59491bb | 2013-04-19 02:17:33 +0900 | [diff] [blame] | 18 | #include "base/tracked_objects.h" |
| 19 | |
| 20 | namespace base { |
| 21 | |
| 22 | // A DeferredSequencedTaskRunner is a subclass of SequencedTaskRunner that |
| 23 | // queues up all requests until the first call to Start() is issued. |
| 24 | class BASE_EXPORT DeferredSequencedTaskRunner : public SequencedTaskRunner { |
| 25 | public: |
| 26 | explicit DeferredSequencedTaskRunner( |
| 27 | const scoped_refptr<SequencedTaskRunner>& target_runner); |
| 28 | |
| 29 | // TaskRunner implementation |
| 30 | virtual bool PostDelayedTask(const tracked_objects::Location& from_here, |
| 31 | const Closure& task, |
| 32 | TimeDelta delay) OVERRIDE; |
| 33 | virtual bool RunsTasksOnCurrentThread() const OVERRIDE; |
| 34 | |
| 35 | // SequencedTaskRunner implementation |
| 36 | virtual bool PostNonNestableDelayedTask( |
| 37 | const tracked_objects::Location& from_here, |
| 38 | const Closure& task, |
| 39 | TimeDelta delay) OVERRIDE; |
| 40 | |
| 41 | // Start the execution - posts all queued tasks to the target executor. The |
| 42 | // deferred tasks are posted with their initial delay, meaning that the task |
| 43 | // execution delay is actually measured from Start. |
| 44 | // Fails when called a second time. |
| 45 | void Start(); |
| 46 | |
| 47 | private: |
| 48 | struct DeferredTask { |
| 49 | DeferredTask(); |
| 50 | ~DeferredTask(); |
| 51 | |
| 52 | tracked_objects::Location posted_from; |
| 53 | Closure task; |
| 54 | // The delay this task was initially posted with. |
| 55 | TimeDelta delay; |
| 56 | bool is_non_nestable; |
| 57 | }; |
| 58 | |
| 59 | virtual ~DeferredSequencedTaskRunner(); |
| 60 | |
| 61 | // Creates a |Task| object and adds it to |deferred_tasks_queue_|. |
| 62 | void QueueDeferredTask(const tracked_objects::Location& from_here, |
| 63 | const Closure& task, |
| 64 | TimeDelta delay, |
| 65 | bool is_non_nestable); |
| 66 | |
| 67 | // // Protects |started_| and |deferred_tasks_queue_|. |
| 68 | mutable Lock lock_; |
| 69 | |
| 70 | bool started_; |
| 71 | const scoped_refptr<SequencedTaskRunner> target_task_runner_; |
| 72 | std::vector<DeferredTask> deferred_tasks_queue_; |
| 73 | |
| 74 | DISALLOW_COPY_AND_ASSIGN(DeferredSequencedTaskRunner); |
| 75 | }; |
| 76 | |
| 77 | } // namespace base |
| 78 | |
| 79 | #endif // BASE_DEFERRED_SEQUENCED_TASKRUNNER_H_ |