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 #include "base/threading/worker_pool.h"
6
7 #include "base/bind.h"
8 #include "base/compiler_specific.h"
9 #include "base/lazy_instance.h"
10 #include "base/macros.h"
11 #include "base/task_runner.h"
12 #include "base/threading/post_task_and_reply_impl.h"
13 #include "base/tracked_objects.h"
14
15 namespace base {
16
17 namespace {
18
19 class PostTaskAndReplyWorkerPool : public internal::PostTaskAndReplyImpl {
20 public:
PostTaskAndReplyWorkerPool(bool task_is_slow)21 explicit PostTaskAndReplyWorkerPool(bool task_is_slow)
22 : task_is_slow_(task_is_slow) {
23 }
24 ~PostTaskAndReplyWorkerPool() override = default;
25
26 private:
PostTask(const tracked_objects::Location & from_here,const Closure & task)27 bool PostTask(const tracked_objects::Location& from_here,
28 const Closure& task) override {
29 return WorkerPool::PostTask(from_here, task, task_is_slow_);
30 }
31
32 bool task_is_slow_;
33 };
34
35 // WorkerPoolTaskRunner ---------------------------------------------
36 // A TaskRunner which posts tasks to a WorkerPool with a
37 // fixed ShutdownBehavior.
38 //
39 // Note that this class is RefCountedThreadSafe (inherited from TaskRunner).
40 class WorkerPoolTaskRunner : public TaskRunner {
41 public:
42 explicit WorkerPoolTaskRunner(bool tasks_are_slow);
43
44 // TaskRunner implementation
45 bool PostDelayedTask(const tracked_objects::Location& from_here,
46 const Closure& task,
47 TimeDelta delay) override;
48 bool RunsTasksOnCurrentThread() const override;
49
50 private:
51 ~WorkerPoolTaskRunner() override;
52
53 // Helper function for posting a delayed task. Asserts that the delay is
54 // zero because non-zero delays are not supported.
55 bool PostDelayedTaskAssertZeroDelay(
56 const tracked_objects::Location& from_here,
57 const Closure& task,
58 base::TimeDelta delay);
59
60 const bool tasks_are_slow_;
61
62 DISALLOW_COPY_AND_ASSIGN(WorkerPoolTaskRunner);
63 };
64
WorkerPoolTaskRunner(bool tasks_are_slow)65 WorkerPoolTaskRunner::WorkerPoolTaskRunner(bool tasks_are_slow)
66 : tasks_are_slow_(tasks_are_slow) {
67 }
68
~WorkerPoolTaskRunner()69 WorkerPoolTaskRunner::~WorkerPoolTaskRunner() {
70 }
71
PostDelayedTask(const tracked_objects::Location & from_here,const Closure & task,TimeDelta delay)72 bool WorkerPoolTaskRunner::PostDelayedTask(
73 const tracked_objects::Location& from_here,
74 const Closure& task,
75 TimeDelta delay) {
76 return PostDelayedTaskAssertZeroDelay(from_here, task, delay);
77 }
78
RunsTasksOnCurrentThread() const79 bool WorkerPoolTaskRunner::RunsTasksOnCurrentThread() const {
80 return WorkerPool::RunsTasksOnCurrentThread();
81 }
82
PostDelayedTaskAssertZeroDelay(const tracked_objects::Location & from_here,const Closure & task,base::TimeDelta delay)83 bool WorkerPoolTaskRunner::PostDelayedTaskAssertZeroDelay(
84 const tracked_objects::Location& from_here,
85 const Closure& task,
86 base::TimeDelta delay) {
87 DCHECK_EQ(delay.InMillisecondsRoundedUp(), 0)
88 << "WorkerPoolTaskRunner does not support non-zero delays";
89 return WorkerPool::PostTask(from_here, task, tasks_are_slow_);
90 }
91
92 struct TaskRunnerHolder {
TaskRunnerHolderbase::__anon1ecfa8f00111::TaskRunnerHolder93 TaskRunnerHolder() {
94 taskrunners_[0] = new WorkerPoolTaskRunner(false);
95 taskrunners_[1] = new WorkerPoolTaskRunner(true);
96 }
97 scoped_refptr<TaskRunner> taskrunners_[2];
98 };
99
100 base::LazyInstance<TaskRunnerHolder>::Leaky
101 g_taskrunners = LAZY_INSTANCE_INITIALIZER;
102
103 } // namespace
104
PostTaskAndReply(const tracked_objects::Location & from_here,const Closure & task,const Closure & reply,bool task_is_slow)105 bool WorkerPool::PostTaskAndReply(const tracked_objects::Location& from_here,
106 const Closure& task,
107 const Closure& reply,
108 bool task_is_slow) {
109 // Do not report PostTaskAndReplyRelay leaks in tests. There's nothing we can
110 // do about them because WorkerPool doesn't have a flushing API.
111 // http://crbug.com/248513
112 // http://crbug.com/290897
113 return PostTaskAndReplyWorkerPool(task_is_slow).PostTaskAndReply(
114 from_here, task, reply);
115 }
116
117 // static
118 const scoped_refptr<TaskRunner>&
GetTaskRunner(bool tasks_are_slow)119 WorkerPool::GetTaskRunner(bool tasks_are_slow) {
120 return g_taskrunners.Get().taskrunners_[tasks_are_slow];
121 }
122
123 } // namespace base
124