Fix Java indentation issues.
[chromium-blink-merge.git] / base / deferred_sequenced_task_runner.h
blob3220ac1992cbcf8e707cf48c3f11d633b96809bd
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.
5 #ifndef BASE_DEFERRED_SEQUENCED_TASKRUNNER_H_
6 #define BASE_DEFERRED_SEQUENCED_TASKRUNNER_H_
8 #include <vector>
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"
15 #include "base/sequenced_task_runner.h"
16 #include "base/synchronization/lock.h"
17 #include "base/time/time.h"
18 #include "base/tracked_objects.h"
20 namespace base {
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);
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;
35 // SequencedTaskRunner implementation
36 virtual bool PostNonNestableDelayedTask(
37 const tracked_objects::Location& from_here,
38 const Closure& task,
39 TimeDelta delay) override;
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();
47 private:
48 struct DeferredTask {
49 DeferredTask();
50 ~DeferredTask();
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;
59 virtual ~DeferredSequencedTaskRunner();
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);
67 // // Protects |started_| and |deferred_tasks_queue_|.
68 mutable Lock lock_;
70 bool started_;
71 const scoped_refptr<SequencedTaskRunner> target_task_runner_;
72 std::vector<DeferredTask> deferred_tasks_queue_;
74 DISALLOW_COPY_AND_ASSIGN(DeferredSequencedTaskRunner);
77 } // namespace base
79 #endif // BASE_DEFERRED_SEQUENCED_TASKRUNNER_H_