scheduler: Ensure consistent delayed task ordering between task queues

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

Index: third_party/WebKit/Source/platform/scheduler/base/time_domain_unittest.cc
diff --git a/third_party/WebKit/Source/platform/scheduler/base/time_domain_unittest.cc b/third_party/WebKit/Source/platform/scheduler/base/time_domain_unittest.cc
index c8b6acb109dd3a8c69641a95dda2ffb7d4cbbcc4..0c837b6785a2156861b454f475acaa33651c721f 100644
--- a/third_party/WebKit/Source/platform/scheduler/base/time_domain_unittest.cc
+++ b/third_party/WebKit/Source/platform/scheduler/base/time_domain_unittest.cc
@@ -94,7 +94,7 @@ TEST_F(TimeDomainTest, ScheduleDelayedWork) {
   base::TimeTicks delayed_runtime = time_domain_->Now() + delay;
   EXPECT_CALL(*time_domain_.get(), RequestWakeupAt(_, delayed_runtime));
   base::TimeTicks now = time_domain_->Now();
-  time_domain_->ScheduleDelayedWork(task_queue_.get(), now + delay, now);
+  time_domain_->ScheduleDelayedWork(task_queue_.get(), now + delay, 0, now);
 
   base::TimeTicks next_scheduled_runtime;
   EXPECT_TRUE(time_domain_->NextScheduledRunTime(&next_scheduled_runtime));
@@ -115,7 +115,8 @@ TEST_F(TimeDomainTest, ScheduleDelayedWorkSupersedesPreviousWakeup) {
   base::TimeTicks delayed_runtime2 = time_domain_->Now() + delay2;
   EXPECT_CALL(*time_domain_.get(), RequestWakeupAt(_, delayed_runtime1));
   base::TimeTicks now = time_domain_->Now();
-  time_domain_->ScheduleDelayedWork(task_queue_.get(), delayed_runtime1, now);
+  time_domain_->ScheduleDelayedWork(task_queue_.get(), delayed_runtime1, 0,
+                                    now);
 
   base::TimeTicks next_scheduled_runtime;
   EXPECT_TRUE(time_domain_->NextScheduledRunTime(&next_scheduled_runtime));
@@ -126,7 +127,8 @@ TEST_F(TimeDomainTest, ScheduleDelayedWorkSupersedesPreviousWakeup) {
   // Now scheduler a later wakeup, which should replace the previously requested
   // one.
   EXPECT_CALL(*time_domain_.get(), RequestWakeupAt(_, delayed_runtime2));
-  time_domain_->ScheduleDelayedWork(task_queue_.get(), delayed_runtime2, now);
+  time_domain_->ScheduleDelayedWork(task_queue_.get(), delayed_runtime2, 0,
+                                    now);
 
   EXPECT_TRUE(time_domain_->NextScheduledRunTime(&next_scheduled_runtime));
   EXPECT_EQ(delayed_runtime2, next_scheduled_runtime);
@@ -159,19 +161,19 @@ TEST_F(TimeDomainTest, RequestWakeupAt_OnlyCalledForEarlierTasks) {
   // RequestWakeupAt should always be called if there are no other wakeups.
   base::TimeTicks now = time_domain_->Now();
   EXPECT_CALL(*time_domain_.get(), RequestWakeupAt(_, now + delay1));
-  time_domain_->ScheduleDelayedWork(task_queue_.get(), now + delay1, now);
+  time_domain_->ScheduleDelayedWork(task_queue_.get(), now + delay1, 0, now);
 
   Mock::VerifyAndClearExpectations(time_domain_.get());
 
   // RequestWakeupAt should not be called when scheduling later tasks.
   EXPECT_CALL(*time_domain_.get(), RequestWakeupAt(_, _)).Times(0);
-  time_domain_->ScheduleDelayedWork(task_queue2.get(), now + delay2, now);
-  time_domain_->ScheduleDelayedWork(task_queue3.get(), now + delay3, now);
+  time_domain_->ScheduleDelayedWork(task_queue2.get(), now + delay2, 0, now);
+  time_domain_->ScheduleDelayedWork(task_queue3.get(), now + delay3, 0, now);
 
   // RequestWakeupAt should be called when scheduling earlier tasks.
   Mock::VerifyAndClearExpectations(time_domain_.get());
   EXPECT_CALL(*time_domain_.get(), RequestWakeupAt(_, now + delay4));
-  time_domain_->ScheduleDelayedWork(task_queue4.get(), now + delay4, now);
+  time_domain_->ScheduleDelayedWork(task_queue4.get(), now + delay4, 0, now);
 
   Mock::VerifyAndClearExpectations(time_domain_.get());
 
@@ -191,9 +193,9 @@ TEST_F(TimeDomainTest, UnregisterQueue) {
   base::TimeTicks now = time_domain_->Now();
   base::TimeTicks wakeup1 = now + base::TimeDelta::FromMilliseconds(10);
   EXPECT_CALL(*time_domain_.get(), RequestWakeupAt(_, wakeup1)).Times(1);
-  time_domain_->ScheduleDelayedWork(task_queue_.get(), wakeup1, now);
+  time_domain_->ScheduleDelayedWork(task_queue_.get(), wakeup1, 0, now);
   base::TimeTicks wakeup2 = now + base::TimeDelta::FromMilliseconds(100);
-  time_domain_->ScheduleDelayedWork(task_queue2_.get(), wakeup2, now);
+  time_domain_->ScheduleDelayedWork(task_queue2_.get(), wakeup2, 0, now);
 
   TaskQueue* next_task_queue;
   EXPECT_TRUE(time_domain_->NextScheduledTaskQueue(&next_task_queue));
@@ -222,7 +224,7 @@ TEST_F(TimeDomainTest, WakeupReadyDelayedQueues) {
   base::TimeTicks now = time_domain_->Now();
   base::TimeTicks delayed_runtime = now + delay;
   EXPECT_CALL(*time_domain_.get(), RequestWakeupAt(_, delayed_runtime));
-  time_domain_->ScheduleDelayedWork(task_queue_.get(), delayed_runtime, now);
+  time_domain_->ScheduleDelayedWork(task_queue_.get(), delayed_runtime, 0, now);
 
   base::TimeTicks next_run_time;
   ASSERT_TRUE(time_domain_->NextScheduledRunTime(&next_run_time));
@@ -239,12 +241,42 @@ TEST_F(TimeDomainTest, WakeupReadyDelayedQueues) {
   ASSERT_FALSE(time_domain_->NextScheduledRunTime(&next_run_time));
 }
 
+TEST_F(TimeDomainTest, WakeupReadyDelayedQueuesWithIdenticalRuntimes) {

[altimin, 2017/03/01 11:23:17]

Nit: I'm slightly worried that we do something wrong, this test may flake
instead of failing consistently. Can we do better? For example, running this
test 10 times in a loop should help.

[Sami, 2017/03/01 12:17:42]

Hmm, this should now be completely deterministic (unlike before) because we are
no longer looking at queue memory addresses when deciding how to schedule
wake-ups. Were you thinking of some other source of flake?

[alex clarke (OOO till 29th), 2017/03/01 13:38:51]

I believe this is deterministic.

+  int sequence_num = 0;
+  base::TimeDelta delay = base::TimeDelta::FromMilliseconds(50);
+  base::TimeTicks now = time_domain_->Now();
+  base::TimeTicks delayed_runtime = now + delay;
+  EXPECT_CALL(*time_domain_.get(), RequestWakeupAt(_, delayed_runtime));
+  EXPECT_CALL(*time_domain_.get(), CancelWakeupAt(delayed_runtime));
+
+  scoped_refptr<internal::TaskQueueImpl> task_queue2 = make_scoped_refptr(
+      new internal::TaskQueueImpl(nullptr, time_domain_.get(),
+                                  TaskQueue::Spec(TaskQueue::QueueType::TEST),
+                                  "test.category", "test.category"));
+
+  time_domain_->ScheduleDelayedWork(task_queue2.get(), delayed_runtime,
+                                    ++sequence_num, now);
+  time_domain_->ScheduleDelayedWork(task_queue_.get(), delayed_runtime,
+                                    ++sequence_num, now);
+
+  LazyNow lazy_now = time_domain_->CreateLazyNow();
+  time_domain_->WakeupReadyDelayedQueues(&lazy_now);
+
+  // The second task queue should wake up first since it has a lower sequence
+  // number.
+  TaskQueue* next_task_queue;
+  EXPECT_TRUE(time_domain_->NextScheduledTaskQueue(&next_task_queue));
+  EXPECT_EQ(task_queue2.get(), next_task_queue);
+
+  task_queue2->UnregisterTaskQueue();
+}
+
 TEST_F(TimeDomainTest, CancelDelayedWork) {
   base::TimeTicks now = time_domain_->Now();
   base::TimeTicks run_time = now + base::TimeDelta::FromMilliseconds(20);
 
   EXPECT_CALL(*time_domain_.get(), RequestWakeupAt(_, run_time));
-  time_domain_->ScheduleDelayedWork(task_queue_.get(), run_time, now);
+  time_domain_->ScheduleDelayedWork(task_queue_.get(), run_time, 0, now);
 
   TaskQueue* next_task_queue;
   EXPECT_TRUE(time_domain_->NextScheduledTaskQueue(&next_task_queue));
@@ -265,11 +297,11 @@ TEST_F(TimeDomainTest, CancelDelayedWork_TwoQueues) {
   base::TimeTicks run_time1 = now + base::TimeDelta::FromMilliseconds(20);
   base::TimeTicks run_time2 = now + base::TimeDelta::FromMilliseconds(40);
   EXPECT_CALL(*time_domain_.get(), RequestWakeupAt(_, run_time1));
-  time_domain_->ScheduleDelayedWork(task_queue_.get(), run_time1, now);
+  time_domain_->ScheduleDelayedWork(task_queue_.get(), run_time1, 0, now);
   Mock::VerifyAndClearExpectations(time_domain_.get());
 
   EXPECT_CALL(*time_domain_.get(), RequestWakeupAt(_, _)).Times(0);
-  time_domain_->ScheduleDelayedWork(task_queue2.get(), run_time2, now);
+  time_domain_->ScheduleDelayedWork(task_queue2.get(), run_time2, 0, now);
   Mock::VerifyAndClearExpectations(time_domain_.get());
 
   TaskQueue* next_task_queue;
@@ -327,7 +359,7 @@ TEST_F(TimeDomainWithObserverTest, OnTimeDomainHasDelayedWork) {
   EXPECT_CALL(*time_domain_.get(), RequestWakeupAt(_, _));
   base::TimeTicks now = time_domain_->Now();
   time_domain_->ScheduleDelayedWork(
-      task_queue_.get(), now + base::TimeDelta::FromMilliseconds(10), now);
+      task_queue_.get(), now + base::TimeDelta::FromMilliseconds(10), 0, now);
 }
 
 }  // namespace scheduler