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1 // Copyright 2014 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 "content/child/scheduler/task_queue_manager.h" | |
6 | |
7 #include <queue> | |
8 #include <set> | |
9 | |
10 #include "base/bind.h" | |
11 #include "base/trace_event/trace_event.h" | |
12 #include "base/trace_event/trace_event_argument.h" | |
13 #include "content/child/scheduler/nestable_single_thread_task_runner.h" | |
14 #include "content/child/scheduler/task_queue_selector.h" | |
15 #include "content/child/scheduler/time_source.h" | |
16 | |
17 namespace { | |
18 const int64_t kMaxTimeTicks = std::numeric_limits<int64>::max(); | |
19 } | |
20 | |
21 namespace content { | |
22 namespace internal { | |
23 | |
24 // Now() is somewhat expensive so it makes sense not to call Now() unless we | |
25 // really need to. | |
26 class LazyNow { | |
27 public: | |
28 explicit LazyNow(base::TimeTicks now) | |
29 : task_queue_manager_(nullptr), now_(now) { | |
30 DCHECK(!now.is_null()); | |
31 } | |
32 | |
33 explicit LazyNow(TaskQueueManager* task_queue_manager) | |
34 : task_queue_manager_(task_queue_manager) {} | |
35 | |
36 base::TimeTicks Now() { | |
37 if (now_.is_null()) | |
38 now_ = task_queue_manager_->Now(); | |
39 return now_; | |
40 } | |
41 | |
42 private: | |
43 TaskQueueManager* task_queue_manager_; // NOT OWNED | |
44 base::TimeTicks now_; | |
45 }; | |
46 | |
47 class TaskQueue : public base::SingleThreadTaskRunner { | |
48 public: | |
49 TaskQueue(TaskQueueManager* task_queue_manager, | |
50 const char* disabled_by_default_tracing_category); | |
51 | |
52 // base::SingleThreadTaskRunner implementation. | |
53 bool RunsTasksOnCurrentThread() const override; | |
54 bool PostDelayedTask(const tracked_objects::Location& from_here, | |
55 const base::Closure& task, | |
56 base::TimeDelta delay) override { | |
57 return PostDelayedTaskImpl(from_here, task, delay, TaskType::NORMAL); | |
58 } | |
59 | |
60 bool PostNonNestableDelayedTask(const tracked_objects::Location& from_here, | |
61 const base::Closure& task, | |
62 base::TimeDelta delay) override { | |
63 return PostDelayedTaskImpl(from_here, task, delay, TaskType::NON_NESTABLE); | |
64 } | |
65 | |
66 bool IsQueueEmpty() const; | |
67 | |
68 void SetPumpPolicy(TaskQueueManager::PumpPolicy pump_policy); | |
69 void PumpQueue(); | |
70 | |
71 bool NextPendingDelayedTaskRunTime( | |
72 base::TimeTicks* next_pending_delayed_task); | |
73 | |
74 bool UpdateWorkQueue(LazyNow* lazy_now, | |
75 const base::PendingTask* previous_task); | |
76 base::PendingTask TakeTaskFromWorkQueue(); | |
77 | |
78 void WillDeleteTaskQueueManager(); | |
79 | |
80 base::TaskQueue& work_queue() { return work_queue_; } | |
81 | |
82 void set_name(const char* name) { name_ = name; } | |
83 | |
84 void AsValueInto(base::trace_event::TracedValue* state) const; | |
85 | |
86 private: | |
87 enum class TaskType { | |
88 NORMAL, | |
89 NON_NESTABLE, | |
90 }; | |
91 | |
92 ~TaskQueue() override; | |
93 | |
94 bool PostDelayedTaskImpl(const tracked_objects::Location& from_here, | |
95 const base::Closure& task, | |
96 base::TimeDelta delay, | |
97 TaskType task_type); | |
98 | |
99 // Delayed task posted to the underlying run loop, which locks |lock_| and | |
100 // calls MoveReadyDelayedTasksToIncomingQueueLocked to process dealyed tasks | |
101 // that need to be run now. | |
102 void MoveReadyDelayedTasksToIncomingQueue(); | |
103 | |
104 // Enqueues any delayed tasks which should be run now on the incoming_queue_ | |
105 // and calls ScheduleDelayedWorkLocked to ensure future tasks are scheduled. | |
106 // Must be called with |lock_| locked. | |
107 void MoveReadyDelayedTasksToIncomingQueueLocked(LazyNow* lazy_now); | |
108 | |
109 // Posts MoveReadyDelayedTasksToIncomingQueue if there isn't already a task | |
110 // posted on the underlying runloop for the next task's scheduled run time. | |
111 void ScheduleDelayedWorkLocked(LazyNow* lazy_now); | |
112 | |
113 void PumpQueueLocked(); | |
114 bool TaskIsOlderThanQueuedTasks(const base::PendingTask* task); | |
115 bool ShouldAutoPumpQueueLocked(const base::PendingTask* previous_task); | |
116 void EnqueueTaskLocked(const base::PendingTask& pending_task); | |
117 | |
118 void TraceQueueSize(bool is_locked) const; | |
119 static const char* PumpPolicyToString( | |
120 TaskQueueManager::PumpPolicy pump_policy); | |
121 static void QueueAsValueInto(const base::TaskQueue& queue, | |
122 base::trace_event::TracedValue* state); | |
123 static void QueueAsValueInto(const base::DelayedTaskQueue& queue, | |
124 base::trace_event::TracedValue* state); | |
125 static void TaskAsValueInto(const base::PendingTask& task, | |
126 base::trace_event::TracedValue* state); | |
127 | |
128 // This lock protects all members except the work queue and the | |
129 // main_thread_checker_. | |
130 mutable base::Lock lock_; | |
131 base::PlatformThreadId thread_id_; | |
132 TaskQueueManager* task_queue_manager_; | |
133 base::TaskQueue incoming_queue_; | |
134 TaskQueueManager::PumpPolicy pump_policy_; | |
135 const char* name_; | |
136 const char* disabled_by_default_tracing_category_; | |
137 base::DelayedTaskQueue delayed_task_queue_; | |
138 std::set<base::TimeTicks> in_flight_kick_delayed_tasks_; | |
139 | |
140 base::ThreadChecker main_thread_checker_; | |
141 base::TaskQueue work_queue_; | |
142 | |
143 DISALLOW_COPY_AND_ASSIGN(TaskQueue); | |
144 }; | |
145 | |
146 TaskQueue::TaskQueue(TaskQueueManager* task_queue_manager, | |
147 const char* disabled_by_default_tracing_category) | |
148 : thread_id_(base::PlatformThread::CurrentId()), | |
149 task_queue_manager_(task_queue_manager), | |
150 pump_policy_(TaskQueueManager::PumpPolicy::AUTO), | |
151 name_(nullptr), | |
152 disabled_by_default_tracing_category_( | |
153 disabled_by_default_tracing_category) { | |
154 } | |
155 | |
156 TaskQueue::~TaskQueue() { | |
157 } | |
158 | |
159 void TaskQueue::WillDeleteTaskQueueManager() { | |
160 base::AutoLock lock(lock_); | |
161 task_queue_manager_ = nullptr; | |
162 delayed_task_queue_ = base::DelayedTaskQueue(); | |
163 incoming_queue_ = base::TaskQueue(); | |
164 work_queue_ = base::TaskQueue(); | |
165 } | |
166 | |
167 bool TaskQueue::RunsTasksOnCurrentThread() const { | |
168 base::AutoLock lock(lock_); | |
169 return base::PlatformThread::CurrentId() == thread_id_; | |
170 } | |
171 | |
172 bool TaskQueue::PostDelayedTaskImpl(const tracked_objects::Location& from_here, | |
173 const base::Closure& task, | |
174 base::TimeDelta delay, | |
175 TaskType task_type) { | |
176 base::AutoLock lock(lock_); | |
177 if (!task_queue_manager_) | |
178 return false; | |
179 | |
180 base::PendingTask pending_task(from_here, task, base::TimeTicks(), | |
181 task_type != TaskType::NON_NESTABLE); | |
182 task_queue_manager_->DidQueueTask(&pending_task); | |
183 | |
184 if (delay > base::TimeDelta()) { | |
185 base::TimeTicks now = task_queue_manager_->Now(); | |
186 pending_task.delayed_run_time = now + delay; | |
187 delayed_task_queue_.push(pending_task); | |
188 TraceQueueSize(true); | |
189 // If we changed the topmost task, then it is time to reschedule. | |
190 if (delayed_task_queue_.top().task.Equals(pending_task.task)) { | |
191 LazyNow lazy_now(now); | |
192 ScheduleDelayedWorkLocked(&lazy_now); | |
193 } | |
194 return true; | |
195 } | |
196 EnqueueTaskLocked(pending_task); | |
197 return true; | |
198 } | |
199 | |
200 void TaskQueue::MoveReadyDelayedTasksToIncomingQueue() { | |
201 DCHECK(main_thread_checker_.CalledOnValidThread()); | |
202 base::AutoLock lock(lock_); | |
203 if (!task_queue_manager_) | |
204 return; | |
205 | |
206 LazyNow lazy_now(task_queue_manager_); | |
207 MoveReadyDelayedTasksToIncomingQueueLocked(&lazy_now); | |
208 } | |
209 | |
210 void TaskQueue::MoveReadyDelayedTasksToIncomingQueueLocked(LazyNow* lazy_now) { | |
211 lock_.AssertAcquired(); | |
212 // Enqueue all delayed tasks that should be running now. | |
213 while (!delayed_task_queue_.empty() && | |
214 delayed_task_queue_.top().delayed_run_time <= lazy_now->Now()) { | |
215 in_flight_kick_delayed_tasks_.erase( | |
216 delayed_task_queue_.top().delayed_run_time); | |
217 EnqueueTaskLocked(delayed_task_queue_.top()); | |
218 delayed_task_queue_.pop(); | |
219 } | |
220 TraceQueueSize(true); | |
221 ScheduleDelayedWorkLocked(lazy_now); | |
222 } | |
223 | |
224 void TaskQueue::ScheduleDelayedWorkLocked(LazyNow* lazy_now) { | |
225 lock_.AssertAcquired(); | |
226 // Any remaining tasks are in the future, so queue a task to kick them. | |
227 if (!delayed_task_queue_.empty()) { | |
228 base::TimeTicks next_run_time = delayed_task_queue_.top().delayed_run_time; | |
229 DCHECK_GT(next_run_time, lazy_now->Now()); | |
230 // Make sure we don't have more than one | |
231 // MoveReadyDelayedTasksToIncomingQueue posted for a particular scheduled | |
232 // run time (note it's fine to have multiple ones in flight for distinct | |
233 // run times). | |
234 if (in_flight_kick_delayed_tasks_.find(next_run_time) == | |
235 in_flight_kick_delayed_tasks_.end()) { | |
236 in_flight_kick_delayed_tasks_.insert(next_run_time); | |
237 base::TimeDelta delay = next_run_time - lazy_now->Now(); | |
238 task_queue_manager_->PostDelayedTask( | |
239 FROM_HERE, | |
240 Bind(&TaskQueue::MoveReadyDelayedTasksToIncomingQueue, this), delay); | |
241 } | |
242 } | |
243 } | |
244 | |
245 bool TaskQueue::IsQueueEmpty() const { | |
246 if (!work_queue_.empty()) | |
247 return false; | |
248 | |
249 { | |
250 base::AutoLock lock(lock_); | |
251 return incoming_queue_.empty(); | |
252 } | |
253 } | |
254 | |
255 bool TaskQueue::TaskIsOlderThanQueuedTasks(const base::PendingTask* task) { | |
256 lock_.AssertAcquired(); | |
257 // A null task is passed when UpdateQueue is called before any task is run. | |
258 // In this case we don't want to pump an after_wakeup queue, so return true | |
259 // here. | |
260 if (!task) | |
261 return true; | |
262 | |
263 // Return false if there are no task in the incoming queue. | |
264 if (incoming_queue_.empty()) | |
265 return false; | |
266 | |
267 base::PendingTask oldest_queued_task = incoming_queue_.front(); | |
268 DCHECK(oldest_queued_task.delayed_run_time.is_null()); | |
269 DCHECK(task->delayed_run_time.is_null()); | |
270 | |
271 // Note: the comparison is correct due to the fact that the PendingTask | |
272 // operator inverts its comparison operation in order to work well in a heap | |
273 // based priority queue. | |
274 return oldest_queued_task < *task; | |
275 } | |
276 | |
277 bool TaskQueue::ShouldAutoPumpQueueLocked( | |
278 const base::PendingTask* previous_task) { | |
279 lock_.AssertAcquired(); | |
280 if (pump_policy_ == TaskQueueManager::PumpPolicy::MANUAL) | |
281 return false; | |
282 if (pump_policy_ == TaskQueueManager::PumpPolicy::AFTER_WAKEUP && | |
283 TaskIsOlderThanQueuedTasks(previous_task)) | |
284 return false; | |
285 if (incoming_queue_.empty()) | |
286 return false; | |
287 return true; | |
288 } | |
289 | |
290 bool TaskQueue::NextPendingDelayedTaskRunTime( | |
291 base::TimeTicks* next_pending_delayed_task) { | |
292 base::AutoLock lock(lock_); | |
293 if (delayed_task_queue_.empty()) | |
294 return false; | |
295 *next_pending_delayed_task = delayed_task_queue_.top().delayed_run_time; | |
296 return true; | |
297 } | |
298 | |
299 bool TaskQueue::UpdateWorkQueue(LazyNow* lazy_now, | |
300 const base::PendingTask* previous_task) { | |
301 if (!work_queue_.empty()) | |
302 return true; | |
303 | |
304 { | |
305 base::AutoLock lock(lock_); | |
306 if (!ShouldAutoPumpQueueLocked(previous_task)) | |
307 return false; | |
308 MoveReadyDelayedTasksToIncomingQueueLocked(lazy_now); | |
309 work_queue_.Swap(&incoming_queue_); | |
310 TraceQueueSize(true); | |
311 return true; | |
312 } | |
313 } | |
314 | |
315 base::PendingTask TaskQueue::TakeTaskFromWorkQueue() { | |
316 base::PendingTask pending_task = work_queue_.front(); | |
317 work_queue_.pop(); | |
318 TraceQueueSize(false); | |
319 return pending_task; | |
320 } | |
321 | |
322 void TaskQueue::TraceQueueSize(bool is_locked) const { | |
323 bool is_tracing; | |
324 TRACE_EVENT_CATEGORY_GROUP_ENABLED(disabled_by_default_tracing_category_, | |
325 &is_tracing); | |
326 if (!is_tracing || !name_) | |
327 return; | |
328 if (!is_locked) | |
329 lock_.Acquire(); | |
330 else | |
331 lock_.AssertAcquired(); | |
332 TRACE_COUNTER1( | |
333 disabled_by_default_tracing_category_, name_, | |
334 incoming_queue_.size() + work_queue_.size() + delayed_task_queue_.size()); | |
335 if (!is_locked) | |
336 lock_.Release(); | |
337 } | |
338 | |
339 void TaskQueue::EnqueueTaskLocked(const base::PendingTask& pending_task) { | |
340 lock_.AssertAcquired(); | |
341 if (!task_queue_manager_) | |
342 return; | |
343 if (pump_policy_ == TaskQueueManager::PumpPolicy::AUTO && | |
344 incoming_queue_.empty()) | |
345 task_queue_manager_->MaybePostDoWorkOnMainRunner(); | |
346 incoming_queue_.push(pending_task); | |
347 | |
348 if (!pending_task.delayed_run_time.is_null()) { | |
349 // Clear the delayed run time because we've already applied the delay | |
350 // before getting here. | |
351 incoming_queue_.back().delayed_run_time = base::TimeTicks(); | |
352 } | |
353 TraceQueueSize(true); | |
354 } | |
355 | |
356 void TaskQueue::SetPumpPolicy(TaskQueueManager::PumpPolicy pump_policy) { | |
357 base::AutoLock lock(lock_); | |
358 if (pump_policy == TaskQueueManager::PumpPolicy::AUTO && | |
359 pump_policy_ != TaskQueueManager::PumpPolicy::AUTO) { | |
360 PumpQueueLocked(); | |
361 } | |
362 pump_policy_ = pump_policy; | |
363 } | |
364 | |
365 void TaskQueue::PumpQueueLocked() { | |
366 lock_.AssertAcquired(); | |
367 if (task_queue_manager_) { | |
368 LazyNow lazy_now(task_queue_manager_); | |
369 MoveReadyDelayedTasksToIncomingQueueLocked(&lazy_now); | |
370 } | |
371 while (!incoming_queue_.empty()) { | |
372 work_queue_.push(incoming_queue_.front()); | |
373 incoming_queue_.pop(); | |
374 } | |
375 if (!work_queue_.empty()) | |
376 task_queue_manager_->MaybePostDoWorkOnMainRunner(); | |
377 } | |
378 | |
379 void TaskQueue::PumpQueue() { | |
380 base::AutoLock lock(lock_); | |
381 PumpQueueLocked(); | |
382 } | |
383 | |
384 void TaskQueue::AsValueInto(base::trace_event::TracedValue* state) const { | |
385 base::AutoLock lock(lock_); | |
386 state->BeginDictionary(); | |
387 if (name_) | |
388 state->SetString("name", name_); | |
389 state->SetString("pump_policy", PumpPolicyToString(pump_policy_)); | |
390 state->BeginArray("incoming_queue"); | |
391 QueueAsValueInto(incoming_queue_, state); | |
392 state->EndArray(); | |
393 state->BeginArray("work_queue"); | |
394 QueueAsValueInto(work_queue_, state); | |
395 state->EndArray(); | |
396 state->BeginArray("delayed_task_queue"); | |
397 QueueAsValueInto(delayed_task_queue_, state); | |
398 state->EndArray(); | |
399 state->EndDictionary(); | |
400 } | |
401 | |
402 // static | |
403 const char* TaskQueue::PumpPolicyToString( | |
404 TaskQueueManager::PumpPolicy pump_policy) { | |
405 switch (pump_policy) { | |
406 case TaskQueueManager::PumpPolicy::AUTO: | |
407 return "auto"; | |
408 case TaskQueueManager::PumpPolicy::AFTER_WAKEUP: | |
409 return "after_wakeup"; | |
410 case TaskQueueManager::PumpPolicy::MANUAL: | |
411 return "manual"; | |
412 default: | |
413 NOTREACHED(); | |
414 return nullptr; | |
415 } | |
416 } | |
417 | |
418 // static | |
419 void TaskQueue::QueueAsValueInto(const base::TaskQueue& queue, | |
420 base::trace_event::TracedValue* state) { | |
421 base::TaskQueue queue_copy(queue); | |
422 while (!queue_copy.empty()) { | |
423 TaskAsValueInto(queue_copy.front(), state); | |
424 queue_copy.pop(); | |
425 } | |
426 } | |
427 | |
428 // static | |
429 void TaskQueue::QueueAsValueInto(const base::DelayedTaskQueue& queue, | |
430 base::trace_event::TracedValue* state) { | |
431 base::DelayedTaskQueue queue_copy(queue); | |
432 while (!queue_copy.empty()) { | |
433 TaskAsValueInto(queue_copy.top(), state); | |
434 queue_copy.pop(); | |
435 } | |
436 } | |
437 | |
438 // static | |
439 void TaskQueue::TaskAsValueInto(const base::PendingTask& task, | |
440 base::trace_event::TracedValue* state) { | |
441 state->BeginDictionary(); | |
442 state->SetString("posted_from", task.posted_from.ToString()); | |
443 state->SetInteger("sequence_num", task.sequence_num); | |
444 state->SetBoolean("nestable", task.nestable); | |
445 state->SetBoolean("is_high_res", task.is_high_res); | |
446 state->SetDouble( | |
447 "delayed_run_time", | |
448 (task.delayed_run_time - base::TimeTicks()).InMicroseconds() / 1000.0L); | |
449 state->EndDictionary(); | |
450 } | |
451 | |
452 } // namespace internal | |
453 | |
454 TaskQueueManager::TaskQueueManager( | |
455 size_t task_queue_count, | |
456 scoped_refptr<NestableSingleThreadTaskRunner> main_task_runner, | |
457 TaskQueueSelector* selector, | |
458 const char* disabled_by_default_tracing_category) | |
459 : main_task_runner_(main_task_runner), | |
460 selector_(selector), | |
461 task_was_run_bitmap_(0), | |
462 pending_dowork_count_(0), | |
463 work_batch_size_(1), | |
464 time_source_(new TimeSource), | |
465 disabled_by_default_tracing_category_( | |
466 disabled_by_default_tracing_category), | |
467 deletion_sentinel_(new DeletionSentinel()), | |
468 weak_factory_(this) { | |
469 DCHECK(main_task_runner->RunsTasksOnCurrentThread()); | |
470 DCHECK_LE(task_queue_count, sizeof(task_was_run_bitmap_) * CHAR_BIT) | |
471 << "You need a bigger int for task_was_run_bitmap_"; | |
472 TRACE_EVENT_OBJECT_CREATED_WITH_ID(disabled_by_default_tracing_category, | |
473 "TaskQueueManager", this); | |
474 | |
475 for (size_t i = 0; i < task_queue_count; i++) { | |
476 scoped_refptr<internal::TaskQueue> queue(make_scoped_refptr( | |
477 new internal::TaskQueue(this, disabled_by_default_tracing_category))); | |
478 queues_.push_back(queue); | |
479 } | |
480 | |
481 std::vector<const base::TaskQueue*> work_queues; | |
482 for (const auto& queue : queues_) | |
483 work_queues.push_back(&queue->work_queue()); | |
484 selector_->RegisterWorkQueues(work_queues); | |
485 selector_->SetTaskQueueSelectorObserver(this); | |
486 | |
487 do_work_from_main_thread_closure_ = | |
488 base::Bind(&TaskQueueManager::DoWork, weak_factory_.GetWeakPtr(), true); | |
489 do_work_from_other_thread_closure_ = | |
490 base::Bind(&TaskQueueManager::DoWork, weak_factory_.GetWeakPtr(), false); | |
491 } | |
492 | |
493 TaskQueueManager::~TaskQueueManager() { | |
494 TRACE_EVENT_OBJECT_DELETED_WITH_ID(disabled_by_default_tracing_category_, | |
495 "TaskQueueManager", this); | |
496 for (auto& queue : queues_) | |
497 queue->WillDeleteTaskQueueManager(); | |
498 selector_->SetTaskQueueSelectorObserver(nullptr); | |
499 } | |
500 | |
501 internal::TaskQueue* TaskQueueManager::Queue(size_t queue_index) const { | |
502 DCHECK_LT(queue_index, queues_.size()); | |
503 return queues_[queue_index].get(); | |
504 } | |
505 | |
506 scoped_refptr<base::SingleThreadTaskRunner> | |
507 TaskQueueManager::TaskRunnerForQueue(size_t queue_index) const { | |
508 return Queue(queue_index); | |
509 } | |
510 | |
511 bool TaskQueueManager::IsQueueEmpty(size_t queue_index) const { | |
512 internal::TaskQueue* queue = Queue(queue_index); | |
513 return queue->IsQueueEmpty(); | |
514 } | |
515 | |
516 base::TimeTicks TaskQueueManager::NextPendingDelayedTaskRunTime() { | |
517 DCHECK(main_thread_checker_.CalledOnValidThread()); | |
518 bool found_pending_task = false; | |
519 base::TimeTicks next_pending_delayed_task( | |
520 base::TimeTicks::FromInternalValue(kMaxTimeTicks)); | |
521 for (auto& queue : queues_) { | |
522 base::TimeTicks queues_next_pending_delayed_task; | |
523 if (queue->NextPendingDelayedTaskRunTime( | |
524 &queues_next_pending_delayed_task)) { | |
525 found_pending_task = true; | |
526 next_pending_delayed_task = | |
527 std::min(next_pending_delayed_task, queues_next_pending_delayed_task); | |
528 } | |
529 } | |
530 | |
531 if (!found_pending_task) | |
532 return base::TimeTicks(); | |
533 | |
534 DCHECK_NE(next_pending_delayed_task, | |
535 base::TimeTicks::FromInternalValue(kMaxTimeTicks)); | |
536 return next_pending_delayed_task; | |
537 } | |
538 | |
539 void TaskQueueManager::SetPumpPolicy(size_t queue_index, | |
540 PumpPolicy pump_policy) { | |
541 DCHECK(main_thread_checker_.CalledOnValidThread()); | |
542 internal::TaskQueue* queue = Queue(queue_index); | |
543 queue->SetPumpPolicy(pump_policy); | |
544 } | |
545 | |
546 void TaskQueueManager::PumpQueue(size_t queue_index) { | |
547 DCHECK(main_thread_checker_.CalledOnValidThread()); | |
548 internal::TaskQueue* queue = Queue(queue_index); | |
549 queue->PumpQueue(); | |
550 } | |
551 | |
552 bool TaskQueueManager::UpdateWorkQueues( | |
553 const base::PendingTask* previous_task) { | |
554 // TODO(skyostil): This is not efficient when the number of queues grows very | |
555 // large due to the number of locks taken. Consider optimizing when we get | |
556 // there. | |
557 DCHECK(main_thread_checker_.CalledOnValidThread()); | |
558 internal::LazyNow lazy_now(this); | |
559 bool has_work = false; | |
560 for (auto& queue : queues_) { | |
561 has_work |= queue->UpdateWorkQueue(&lazy_now, previous_task); | |
562 if (!queue->work_queue().empty()) { | |
563 // Currently we should not be getting tasks with delayed run times in any | |
564 // of the work queues. | |
565 DCHECK(queue->work_queue().front().delayed_run_time.is_null()); | |
566 } | |
567 } | |
568 return has_work; | |
569 } | |
570 | |
571 void TaskQueueManager::MaybePostDoWorkOnMainRunner() { | |
572 bool on_main_thread = main_task_runner_->BelongsToCurrentThread(); | |
573 if (on_main_thread) { | |
574 // We only want one pending DoWork posted from the main thread, or we risk | |
575 // an explosion of pending DoWorks which could starve out everything else. | |
576 if (pending_dowork_count_ > 0) { | |
577 return; | |
578 } | |
579 pending_dowork_count_++; | |
580 main_task_runner_->PostTask(FROM_HERE, do_work_from_main_thread_closure_); | |
581 } else { | |
582 main_task_runner_->PostTask(FROM_HERE, do_work_from_other_thread_closure_); | |
583 } | |
584 } | |
585 | |
586 void TaskQueueManager::DoWork(bool posted_from_main_thread) { | |
587 if (posted_from_main_thread) { | |
588 pending_dowork_count_--; | |
589 DCHECK_GE(pending_dowork_count_, 0); | |
590 } | |
591 DCHECK(main_thread_checker_.CalledOnValidThread()); | |
592 | |
593 // Pass nullptr to UpdateWorkQueues here to prevent waking up a | |
594 // pump-after-wakeup queue. | |
595 if (!UpdateWorkQueues(nullptr)) | |
596 return; | |
597 | |
598 base::PendingTask previous_task((tracked_objects::Location()), | |
599 (base::Closure())); | |
600 for (int i = 0; i < work_batch_size_; i++) { | |
601 size_t queue_index; | |
602 if (!SelectWorkQueueToService(&queue_index)) | |
603 return; | |
604 // Note that this function won't post another call to DoWork if one is | |
605 // already pending, so it is safe to call it in a loop. | |
606 MaybePostDoWorkOnMainRunner(); | |
607 | |
608 if (ProcessTaskFromWorkQueue(queue_index, i > 0, &previous_task)) | |
609 return; // The TaskQueueManager got deleted, we must bail out. | |
610 | |
611 if (!UpdateWorkQueues(&previous_task)) | |
612 return; | |
613 } | |
614 } | |
615 | |
616 bool TaskQueueManager::SelectWorkQueueToService(size_t* out_queue_index) { | |
617 bool should_run = selector_->SelectWorkQueueToService(out_queue_index); | |
618 TRACE_EVENT_OBJECT_SNAPSHOT_WITH_ID( | |
619 disabled_by_default_tracing_category_, "TaskQueueManager", this, | |
620 AsValueWithSelectorResult(should_run, *out_queue_index)); | |
621 return should_run; | |
622 } | |
623 | |
624 void TaskQueueManager::DidQueueTask(base::PendingTask* pending_task) { | |
625 pending_task->sequence_num = task_sequence_num_.GetNext(); | |
626 task_annotator_.DidQueueTask("TaskQueueManager::PostTask", *pending_task); | |
627 } | |
628 | |
629 bool TaskQueueManager::ProcessTaskFromWorkQueue( | |
630 size_t queue_index, | |
631 bool has_previous_task, | |
632 base::PendingTask* previous_task) { | |
633 DCHECK(main_thread_checker_.CalledOnValidThread()); | |
634 scoped_refptr<DeletionSentinel> protect(deletion_sentinel_); | |
635 internal::TaskQueue* queue = Queue(queue_index); | |
636 base::PendingTask pending_task = queue->TakeTaskFromWorkQueue(); | |
637 task_was_run_bitmap_ |= UINT64_C(1) << queue_index; | |
638 if (!pending_task.nestable && main_task_runner_->IsNested()) { | |
639 // Defer non-nestable work to the main task runner. NOTE these tasks can be | |
640 // arbitrarily delayed so the additional delay should not be a problem. | |
641 main_task_runner_->PostNonNestableTask(pending_task.posted_from, | |
642 pending_task.task); | |
643 } else { | |
644 // Suppress "will" task observer notifications for the first and "did" | |
645 // notifications for the last task in the batch to avoid duplicate | |
646 // notifications. | |
647 if (has_previous_task) { | |
648 FOR_EACH_OBSERVER(base::MessageLoop::TaskObserver, task_observers_, | |
649 DidProcessTask(*previous_task)); | |
650 FOR_EACH_OBSERVER(base::MessageLoop::TaskObserver, task_observers_, | |
651 WillProcessTask(pending_task)); | |
652 } | |
653 task_annotator_.RunTask("TaskQueueManager::PostTask", | |
654 "TaskQueueManager::RunTask", pending_task); | |
655 | |
656 // Detect if the TaskQueueManager just got deleted. If this happens we must | |
657 // not access any member variables after this point. | |
658 if (protect->HasOneRef()) | |
659 return true; | |
660 | |
661 pending_task.task.Reset(); | |
662 *previous_task = pending_task; | |
663 } | |
664 return false; | |
665 } | |
666 | |
667 bool TaskQueueManager::RunsTasksOnCurrentThread() const { | |
668 return main_task_runner_->RunsTasksOnCurrentThread(); | |
669 } | |
670 | |
671 bool TaskQueueManager::PostDelayedTask( | |
672 const tracked_objects::Location& from_here, | |
673 const base::Closure& task, | |
674 base::TimeDelta delay) { | |
675 DCHECK(delay > base::TimeDelta()); | |
676 return main_task_runner_->PostDelayedTask(from_here, task, delay); | |
677 } | |
678 | |
679 void TaskQueueManager::SetQueueName(size_t queue_index, const char* name) { | |
680 DCHECK(main_thread_checker_.CalledOnValidThread()); | |
681 internal::TaskQueue* queue = Queue(queue_index); | |
682 queue->set_name(name); | |
683 } | |
684 | |
685 void TaskQueueManager::SetWorkBatchSize(int work_batch_size) { | |
686 DCHECK(main_thread_checker_.CalledOnValidThread()); | |
687 DCHECK_GE(work_batch_size, 1); | |
688 work_batch_size_ = work_batch_size; | |
689 } | |
690 | |
691 void TaskQueueManager::AddTaskObserver( | |
692 base::MessageLoop::TaskObserver* task_observer) { | |
693 DCHECK(main_thread_checker_.CalledOnValidThread()); | |
694 base::MessageLoop::current()->AddTaskObserver(task_observer); | |
695 task_observers_.AddObserver(task_observer); | |
696 } | |
697 | |
698 void TaskQueueManager::RemoveTaskObserver( | |
699 base::MessageLoop::TaskObserver* task_observer) { | |
700 DCHECK(main_thread_checker_.CalledOnValidThread()); | |
701 base::MessageLoop::current()->RemoveTaskObserver(task_observer); | |
702 task_observers_.RemoveObserver(task_observer); | |
703 } | |
704 | |
705 void TaskQueueManager::SetTimeSourceForTesting( | |
706 scoped_ptr<TimeSource> time_source) { | |
707 DCHECK(main_thread_checker_.CalledOnValidThread()); | |
708 time_source_ = time_source.Pass(); | |
709 } | |
710 | |
711 uint64 TaskQueueManager::GetAndClearTaskWasRunOnQueueBitmap() { | |
712 uint64 bitmap = task_was_run_bitmap_; | |
713 task_was_run_bitmap_ = 0; | |
714 return bitmap; | |
715 } | |
716 | |
717 base::TimeTicks TaskQueueManager::Now() const { | |
718 return time_source_->Now(); | |
719 } | |
720 | |
721 scoped_refptr<base::trace_event::ConvertableToTraceFormat> | |
722 TaskQueueManager::AsValueWithSelectorResult(bool should_run, | |
723 size_t selected_queue) const { | |
724 DCHECK(main_thread_checker_.CalledOnValidThread()); | |
725 scoped_refptr<base::trace_event::TracedValue> state = | |
726 new base::trace_event::TracedValue(); | |
727 state->BeginArray("queues"); | |
728 for (auto& queue : queues_) | |
729 queue->AsValueInto(state.get()); | |
730 state->EndArray(); | |
731 state->BeginDictionary("selector"); | |
732 selector_->AsValueInto(state.get()); | |
733 state->EndDictionary(); | |
734 if (should_run) | |
735 state->SetInteger("selected_queue", selected_queue); | |
736 return state; | |
737 } | |
738 | |
739 void TaskQueueManager::OnTaskQueueEnabled() { | |
740 DCHECK(main_thread_checker_.CalledOnValidThread()); | |
741 MaybePostDoWorkOnMainRunner(); | |
742 } | |
743 | |
744 } // namespace content | |
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