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1 // Copyright 2017 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/task_scheduler/scheduler_single_thread_task_runner_manager.h" | |
6 | |
7 #include <algorithm> | |
8 #include <memory> | |
9 | |
10 #include "base/bind.h" | |
11 #include "base/callback.h" | |
12 #include "base/memory/ptr_util.h" | |
13 #include "base/single_thread_task_runner.h" | |
14 #include "base/strings/stringprintf.h" | |
15 #include "base/synchronization/atomic_flag.h" | |
16 #include "base/task_scheduler/delayed_task_manager.h" | |
17 #include "base/task_scheduler/scheduler_worker.h" | |
18 #include "base/task_scheduler/sequence.h" | |
19 #include "base/task_scheduler/task.h" | |
20 #include "base/task_scheduler/task_tracker.h" | |
21 #include "base/task_scheduler/task_traits.h" | |
22 #include "base/threading/platform_thread.h" | |
23 #include "base/time/time.h" | |
24 | |
25 namespace base { | |
26 namespace internal { | |
27 | |
28 namespace { | |
29 | |
30 class SchedulerWorkerDelegate : public SchedulerWorker::Delegate { | |
31 public: | |
32 SchedulerWorkerDelegate(const std::string& thread_name) | |
fdoray
2017/02/22 17:40:40
#include <string>
robliao
2017/02/22 21:50:28
Done.
| |
33 : thread_name_(thread_name) {} | |
34 | |
35 // SchedulerWorker::Delegate: | |
36 void OnMainEntry(SchedulerWorker* worker) override { | |
37 PlatformThread::SetName(thread_name_); | |
38 } | |
39 | |
40 scoped_refptr<Sequence> GetWork(SchedulerWorker* worker) override { | |
41 AutoSchedulerLock auto_lock(sequence_lock_); | |
42 return std::move(sequence_); | |
43 } | |
44 | |
45 void DidRunTask() override {} | |
46 | |
47 void ReEnqueueSequence(scoped_refptr<Sequence> sequence) override { | |
48 AutoSchedulerLock auto_lock(sequence_lock_); | |
49 DCHECK(!sequence_); | |
50 sequence_ = std::move(sequence); | |
51 } | |
52 | |
53 TimeDelta GetSleepTimeout() override { return TimeDelta::Max(); } | |
54 | |
55 bool CanDetach(SchedulerWorker* worker) override { | |
56 return can_detach_.IsSet(); | |
57 } | |
58 | |
59 void OnDetach() override {} | |
60 | |
61 // SchedulerSingleThreadTaskRunnerManager::SchedulerWorkerDelegate: | |
62 void AllowDetach() { can_detach_.Set(); } | |
63 | |
64 private: | |
65 const std::string thread_name_; | |
66 | |
67 // Synchronizes access to |sequence_| and handles the fact that | |
68 // ReEnqueueSequence() is called on both on the worker thread for reenqueuing | |
gab
2017/02/22 18:18:21
s/on both on/both on/ ?
robliao
2017/02/22 21:50:28
... on both the worker thread ...
Done
| |
69 // the sequence and off of the worker thread to seed the sequence for | |
70 // GetWork(). | |
71 SchedulerLock sequence_lock_; | |
72 scoped_refptr<Sequence> sequence_; | |
73 | |
74 AtomicFlag can_detach_; | |
75 | |
76 DISALLOW_COPY_AND_ASSIGN(SchedulerWorkerDelegate); | |
77 }; | |
78 | |
79 } // namespace | |
80 | |
81 class SchedulerSingleThreadTaskRunnerManager::SchedulerSingleThreadTaskRunner | |
82 : public SingleThreadTaskRunner { | |
83 public: | |
84 // Constructs a SchedulerSingleThreadTaskRunner that indirectly controls the | |
85 // lifetime of a dedicated |worker| for |traits|. | |
86 SchedulerSingleThreadTaskRunner( | |
87 SchedulerSingleThreadTaskRunnerManager* const outer, | |
88 const TaskTraits& traits, | |
89 SchedulerWorker* worker) | |
90 : outer_(outer), traits_(traits), worker_(worker) { | |
91 DCHECK(outer_); | |
92 DCHECK(worker_); | |
93 } | |
94 | |
95 // SingleThreadTaskRunner: | |
96 bool PostDelayedTask(const tracked_objects::Location& from_here, | |
97 const Closure& closure, | |
98 TimeDelta delay) override; | |
99 | |
100 bool PostNonNestableDelayedTask(const tracked_objects::Location& from_here, | |
101 const Closure& closure, | |
102 base::TimeDelta delay) override { | |
103 // Tasks are never nested within the task scheduler. | |
104 return PostDelayedTask(from_here, closure, delay); | |
105 } | |
106 | |
107 bool RunsTasksOnCurrentThread() const override { | |
108 return sequence_->token() == SequenceToken::GetForCurrentThread(); | |
fdoray
2017/02/22 17:40:40
Should we check the thread id instead? That way, R
robliao
2017/02/22 21:50:28
Hrm... now that's tricky as SchedulerWorker doesn'
| |
109 } | |
110 | |
111 private: | |
112 ~SchedulerSingleThreadTaskRunner() override { | |
113 outer_->UnregisterSchedulerWorker(worker_); | |
114 } | |
115 | |
116 void PostTaskNow(std::unique_ptr<Task> task); | |
117 | |
118 // Sequence for all Tasks posted through this TaskRunner. | |
119 const scoped_refptr<Sequence> sequence_ = new Sequence; | |
120 | |
121 SchedulerSingleThreadTaskRunnerManager* const outer_; | |
122 const TaskTraits traits_; | |
123 SchedulerWorker* const worker_; | |
124 | |
125 DISALLOW_COPY_AND_ASSIGN(SchedulerSingleThreadTaskRunner); | |
126 }; | |
127 | |
128 bool SchedulerSingleThreadTaskRunnerManager::SchedulerSingleThreadTaskRunner:: | |
129 PostDelayedTask(const tracked_objects::Location& from_here, | |
130 const Closure& closure, | |
131 TimeDelta delay) { | |
132 auto task = MakeUnique<Task>(from_here, closure, traits_, delay); | |
133 task->single_thread_task_runner_ref = this; | |
134 | |
135 if (!outer_->task_tracker_->WillPostTask(task.get())) | |
136 return false; | |
137 | |
138 if (task->delayed_run_time.is_null()) { | |
139 PostTaskNow(std::move(task)); | |
140 } else { | |
141 outer_->delayed_task_manager_->AddDelayedTask( | |
142 std::move(task), | |
143 Bind(&SchedulerSingleThreadTaskRunner::PostTaskNow, Unretained(this))); | |
144 } | |
145 return true; | |
146 } | |
147 | |
148 void SchedulerSingleThreadTaskRunnerManager::SchedulerSingleThreadTaskRunner:: | |
149 PostTaskNow(std::unique_ptr<Task> task) { | |
150 const bool sequence_was_empty = sequence_->PushTask(std::move(task)); | |
151 if (sequence_was_empty) { | |
152 auto delegate = static_cast<SchedulerWorkerDelegate*>(worker_->delegate()); | |
153 delegate->ReEnqueueSequence(sequence_); | |
154 worker_->WakeUp(); | |
155 } | |
156 } | |
157 | |
158 SchedulerSingleThreadTaskRunnerManager::SchedulerSingleThreadTaskRunnerManager( | |
159 const std::vector<SchedulerWorkerPoolParams>& worker_pool_params_vector, | |
160 const TaskScheduler::WorkerPoolIndexForTraitsCallback& | |
161 worker_pool_index_for_traits_callback, | |
162 TaskTracker* task_tracker, | |
163 DelayedTaskManager* delayed_task_manager) | |
164 : worker_pool_params_vector_(worker_pool_params_vector), | |
165 worker_pool_index_for_traits_callback_( | |
166 worker_pool_index_for_traits_callback), | |
167 task_tracker_(task_tracker), | |
168 delayed_task_manager_(delayed_task_manager) { | |
169 DCHECK_GT(worker_pool_params_vector_.size(), 0U); | |
170 DCHECK(worker_pool_index_for_traits_callback_); | |
171 DCHECK(task_tracker_); | |
172 DCHECK(delayed_task_manager_); | |
173 } | |
174 | |
175 SchedulerSingleThreadTaskRunnerManager:: | |
176 ~SchedulerSingleThreadTaskRunnerManager() = default; | |
fdoray
2017/02/22 17:40:40
DCHECK(workers_.empty()) << "Deleting SchedulerSin
robliao
2017/02/22 21:50:28
Done.
| |
177 | |
178 scoped_refptr<SingleThreadTaskRunner> | |
179 SchedulerSingleThreadTaskRunnerManager::CreateSingleThreadTaskRunnerWithTraits( | |
180 const TaskTraits& traits) { | |
181 size_t index = worker_pool_index_for_traits_callback_.Run(traits); | |
182 DCHECK_LT(index, worker_pool_params_vector_.size()); | |
183 return new SchedulerSingleThreadTaskRunner( | |
184 this, traits, | |
185 CreateAndRegisterSchedulerWorker(worker_pool_params_vector_[index])); | |
186 } | |
187 | |
188 void SchedulerSingleThreadTaskRunnerManager::JoinForTesting() { | |
189 decltype(workers_) local_workers; | |
190 { | |
191 AutoSchedulerLock auto_lock(workers_lock_); | |
192 local_workers = std::move(workers_); | |
193 } | |
194 | |
195 for (const auto& worker : local_workers) | |
196 worker->JoinForTesting(); | |
197 | |
198 { | |
199 AutoSchedulerLock auto_lock(workers_lock_); | |
200 DCHECK(workers_.empty()) | |
201 << "New worker(s) unexpectedly registered during join."; | |
202 workers_ = std::move(local_workers); | |
203 } | |
204 } | |
205 | |
206 SchedulerWorker* | |
207 SchedulerSingleThreadTaskRunnerManager::CreateAndRegisterSchedulerWorker( | |
208 const SchedulerWorkerPoolParams& params) { | |
209 AutoSchedulerLock auto_lock(workers_lock_); | |
210 int id = next_worker_id_++; | |
211 auto delegate = MakeUnique<SchedulerWorkerDelegate>(base::StringPrintf( | |
212 "TaskSchedulerSingleThreadWorker%d%s", id, params.name().c_str())); | |
213 workers_.emplace_back(SchedulerWorker::Create( | |
214 params.priority_hint(), std::move(delegate), task_tracker_, | |
215 SchedulerWorker::InitialState::DETACHED)); | |
216 return workers_.back().get(); | |
217 } | |
218 | |
219 void SchedulerSingleThreadTaskRunnerManager::UnregisterSchedulerWorker( | |
220 SchedulerWorker* worker) { | |
221 // Cleanup uses a SchedulerLock, so call Cleanup() after releasing | |
222 // |workers_lock_|. | |
223 scoped_refptr<SchedulerWorker> worker_to_destroy; | |
224 { | |
225 AutoSchedulerLock auto_lock(workers_lock_); | |
226 | |
227 // We might be joining, so no-op this if |workers_| is empty. | |
228 if (workers_.empty()) | |
229 return; | |
230 | |
231 auto worker_iter = | |
232 std::find_if(workers_.begin(), workers_.end(), | |
233 [worker](const scoped_refptr<SchedulerWorker>& candidate) { | |
234 return candidate.get() == worker; | |
235 }); | |
236 DCHECK(worker_iter != workers_.end()); | |
fdoray
2017/02/22 17:40:40
DCHECK_NE? Maybe it doesn't work with iterators.
robliao
2017/02/22 21:50:28
That's right. The template for value types like th
| |
237 worker_to_destroy = std::move(*worker_iter); | |
238 workers_.erase(worker_iter); | |
239 } | |
240 worker_to_destroy->Cleanup(); | |
241 } | |
242 | |
243 } // namespace internal | |
244 } // namespace base | |
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