[Reland] Dont post delayed DoWork for disabled queues.

third_party/WebKit/Source/platform/scheduler/base/task_queue_manager.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "platform/scheduler/base/task_queue_manager.h"
 
 #include <queue>
 #include <set>
 
 #include "base/bind.h"
@@ skipping 212 matching lines @@
     any_thread().immediate_do_work_posted_count++;
   }
 
   TRACE_EVENT0(disabled_by_default_tracing_category_,
                "TaskQueueManager::MaybeScheduleImmediateWorkLocked::PostTask");
   delegate_->PostTask(from_here, immediate_do_work_closure_);
 }
 
 void TaskQueueManager::MaybeScheduleDelayedWork(
     const tracked_objects::Location& from_here,
-    base::TimeTicks now,
-    base::TimeDelta delay) {
+    TimeDomain* requesting_time_domain,
+    LazyNow* lazy_now,
+    base::TimeTicks run_time) {
   DCHECK(main_thread_checker_.CalledOnValidThread());

[Sami, 2017/02/01 07:30:05]

DCHECK(!next_delayed_do_work_ || next_delayed_do_work_.time_domain() ==
requesting_time_domain);

[alex clarke (OOO till 29th), 2017/02/01 14:50:11]

Done.

-  DCHECK_GE(delay, base::TimeDelta());
   {
     base::AutoLock lock(any_thread_lock_);
 
     // Unless we're nested, don't post a delayed DoWork if there's an immediate
     // DoWork in flight or we're inside a DoWork. We can rely on DoWork posting
     // a delayed continuation as needed.
     if (!any_thread().is_nested &&
         (any_thread().immediate_do_work_posted_count > 0 ||
          any_thread().do_work_running_count == 1)) {
       return;
     }
   }
 
   // De-duplicate DoWork posts.
-  base::TimeTicks run_time = now + delay;
-  if (next_scheduled_delayed_do_work_time_ <= run_time &&
-      !next_scheduled_delayed_do_work_time_.is_null())
+  if (next_delayed_do_work_ && next_delayed_do_work_.run_time() <= run_time)
     return;
 
+  cancelable_delayed_do_work_closure_.Reset(delayed_do_work_closure_);
+
+  base::TimeDelta delay =
+      std::max(base::TimeDelta(), run_time - lazy_now->Now());
+
   TRACE_EVENT1(disabled_by_default_tracing_category_,
                "TaskQueueManager::MaybeScheduleDelayedWork::PostDelayedTask",
                "delay_ms", delay.InMillisecondsF());
 
   cancelable_delayed_do_work_closure_.Reset(delayed_do_work_closure_);
-  next_scheduled_delayed_do_work_time_ = run_time;
+  next_delayed_do_work_ = NextDelayedDoWork(run_time, requesting_time_domain);
   delegate_->PostDelayedTask(
       from_here, cancelable_delayed_do_work_closure_.callback(), delay);
 }
 
+void TaskQueueManager::CancelDelayedWork(TimeDomain* requesting_time_domain,
+                                         base::TimeTicks run_time) {
+  DCHECK(main_thread_checker_.CalledOnValidThread());
+  if (next_delayed_do_work_.run_time() != run_time)
+    return;
+
+  DCHECK_EQ(next_delayed_do_work_.time_domain(), requesting_time_domain);
+  cancelable_delayed_do_work_closure_.Cancel();
+  next_delayed_do_work_.Clear();
+}
+
 void TaskQueueManager::DoWork(bool delayed) {
   DCHECK(main_thread_checker_.CalledOnValidThread());
   TRACE_EVENT1(tracing_category_, "TaskQueueManager::DoWork", "delayed",
                delayed);
 
   LazyNow lazy_now(real_time_domain()->CreateLazyNow());
   bool is_nested = delegate_->IsNested();
   if (!is_nested)
     queues_to_delete_.clear();
 
   // This must be done before running any tasks because they could invoke a
   // nested message loop and we risk having a stale
-  // |next_scheduled_delayed_do_work_time_|.
+  // |next_delayed_do_work_|.

[Sami, 2017/02/01 07:30:04]

nit: rewrap

[alex clarke (OOO till 29th), 2017/02/01 14:50:11]

Done.

   if (delayed)
-    next_scheduled_delayed_do_work_time_ = base::TimeTicks();
+    next_delayed_do_work_.Clear();
+  ;

[Sami, 2017/02/01 07:30:04]

Extra ';'?

[alex clarke (OOO till 29th), 2017/02/01 14:50:11]

Done.

 
   for (int i = 0; i < work_batch_size_; i++) {
     IncomingImmediateWorkMap queues_to_reload;
 
     {
       base::AutoLock lock(any_thread_lock_);
       if (i == 0) {
         any_thread().do_work_running_count++;
 
         if (!delayed) {
@@ skipping 41 matching lines @@
     if (is_nested)
       break;
   }
 
   // TODO(alexclarke): Consider refactoring the above loop to terminate only
   // when there's no more work left to be done, rather than posting a
   // continuation task.
 
   {
     MoveableAutoLock lock(any_thread_lock_);
-    base::Optional<base::TimeDelta> next_delay =
+    base::Optional<NextTaskDelay> next_delay =
         ComputeDelayTillNextTaskLocked(&lazy_now);
 
     any_thread().do_work_running_count--;
     DCHECK_GE(any_thread().do_work_running_count, 0);
 
     any_thread().is_nested = is_nested;
     DCHECK_EQ(any_thread().is_nested, delegate_->IsNested());
 
     PostDoWorkContinuationLocked(next_delay, &lazy_now, std::move(lock));
   }
 }
 
 void TaskQueueManager::PostDoWorkContinuationLocked(
-    base::Optional<base::TimeDelta> next_delay,
+    base::Optional<NextTaskDelay> next_delay,
     LazyNow* lazy_now,
     MoveableAutoLock&& lock) {
   DCHECK(main_thread_checker_.CalledOnValidThread());
   base::TimeDelta delay;
 
   {
     MoveableAutoLock auto_lock(std::move(lock));
 
     // If there are no tasks left then we don't need to post a continuation.
     if (!next_delay) {
       // If there's a pending delayed DoWork, cancel it because it's not needed.
-      if (!next_scheduled_delayed_do_work_time_.is_null()) {
-        next_scheduled_delayed_do_work_time_ = base::TimeTicks();
+      if (next_delayed_do_work_) {
+        next_delayed_do_work_.Clear();
         cancelable_delayed_do_work_closure_.Cancel();
       }
       return;
     }
 
     // If an immediate DoWork is posted, we don't need to post a continuation.
     if (any_thread().immediate_do_work_posted_count > 0)
       return;
 
-    delay = next_delay.value();
+    delay = next_delay->delay();
 
     // This isn't supposed to happen, but in case it does convert to
     // non-delayed.
     if (delay < base::TimeDelta())
       delay = base::TimeDelta();
 
     if (delay.is_zero()) {
       // If a delayed DoWork is pending then we don't need to post a
       // continuation because it should run immediately.
-      if (!next_scheduled_delayed_do_work_time_.is_null() &&
-          next_scheduled_delayed_do_work_time_ <= lazy_now->Now()) {
+      if (next_delayed_do_work_ &&
+          next_delayed_do_work_.run_time() <= lazy_now->Now()) {
         return;
       }
 
       any_thread().immediate_do_work_posted_count++;
-    } else {
-      base::TimeTicks run_time = lazy_now->Now() + delay;
-      if (next_scheduled_delayed_do_work_time_ == run_time)
-        return;
-
-      next_scheduled_delayed_do_work_time_ = run_time;
     }
   }
 
   // We avoid holding |any_thread_lock_| while posting the task.
   if (delay.is_zero()) {
     delegate_->PostTask(FROM_HERE, immediate_do_work_closure_);
   } else {
+    base::TimeTicks run_time = lazy_now->Now() + delay;
+    if (next_delayed_do_work_.run_time() == run_time)
+      return;
+
+    next_delayed_do_work_ =
+        NextDelayedDoWork(run_time, next_delay->time_domain());
     cancelable_delayed_do_work_closure_.Reset(delayed_do_work_closure_);
     delegate_->PostDelayedTask(
         FROM_HERE, cancelable_delayed_do_work_closure_.callback(), delay);
   }
 }
 
-base::Optional<base::TimeDelta>
+base::Optional<TaskQueueManager::NextTaskDelay>
 TaskQueueManager::ComputeDelayTillNextTaskLocked(LazyNow* lazy_now) {
   DCHECK(main_thread_checker_.CalledOnValidThread());
 
   // Unfortunately because |any_thread_lock_| is held it's not safe to call
   // ReloadEmptyWorkQueues here (possible lock order inversion), however this
   // check is equavalent to calling ReloadEmptyWorkQueues first.
   for (const auto& pair : any_thread().has_incoming_immediate_work) {
     if (pair.first->CouldTaskRun(pair.second))
-      return base::TimeDelta();
+      return NextTaskDelay();
   }
 
   // If the selector has non-empty queues we trivially know there is immediate
   // work to be done.
   if (!selector_.EnabledWorkQueuesEmpty())
-    return base::TimeDelta();
+    return NextTaskDelay();
 
   // Otherwise we need to find the shortest delay, if any.  NB we don't need to
   // call WakeupReadyDelayedQueues because it's assumed DelayTillNextTask will
   // return base::TimeDelta>() if the delayed task is due to run now.
-  base::Optional<base::TimeDelta> next_continuation;
+  base::Optional<NextTaskDelay> delay_till_next_task;
   for (TimeDomain* time_domain : time_domains_) {
-    base::Optional<base::TimeDelta> continuation =
+    base::Optional<base::TimeDelta> delay =
         time_domain->DelayTillNextTask(lazy_now);
-    if (!continuation)
+    if (!delay)
       continue;
-    if (!next_continuation || next_continuation.value() > continuation.value())
-      next_continuation = continuation;
+
+    NextTaskDelay task_delay = (delay.value() == base::TimeDelta())
+                                   ? NextTaskDelay()
+                                   : NextTaskDelay(delay.value(), time_domain);
+
+    if (!delay_till_next_task || task_delay < delay_till_next_task.value())
+      delay_till_next_task = task_delay;
   }
-  return next_continuation;
+  return delay_till_next_task;
 }
 
 bool TaskQueueManager::SelectWorkQueueToService(
     internal::WorkQueue** out_work_queue) {
   bool should_run = selector_.SelectWorkQueueToService(out_work_queue);
   TRACE_EVENT_OBJECT_SNAPSHOT_WITH_ID(
       disabled_by_default_tracing_category_, "TaskQueueManager", this,
       AsValueWithSelectorResult(should_run, *out_work_queue));
   return should_run;
 }
@@ skipping 237 matching lines @@
   for (const scoped_refptr<internal::TaskQueueImpl>& queue : queues_) {
     TimeDomain* time_domain = queue->GetTimeDomain();
     if (time_domain_now.find(time_domain) == time_domain_now.end())
       time_domain_now.insert(std::make_pair(time_domain, time_domain->Now()));
     queue->SweepCanceledDelayedTasks(time_domain_now[time_domain]);
   }
 }
 
 }  // namespace scheduler
 }  // namespace blink