Revert of Revert of Add a WorkerScheduler and a WebThreadImplForWorker

content/child/scheduler/worker_scheduler_impl_unittest.cc

Index: content/child/scheduler/worker_scheduler_impl_unittest.cc
diff --git a/content/child/scheduler/worker_scheduler_impl_unittest.cc b/content/child/scheduler/worker_scheduler_impl_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..eed8f55b3d523a1763a847c993616074643b965a
--- /dev/null
+++ b/content/child/scheduler/worker_scheduler_impl_unittest.cc
@@ -0,0 +1,420 @@
+// Copyright 2015 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 "content/child/scheduler/worker_scheduler_impl.h"
+
+#include "base/callback.h"
+#include "base/strings/stringprintf.h"
+#include "cc/test/ordered_simple_task_runner.h"
+#include "content/child/scheduler/nestable_task_runner_for_test.h"
+#include "content/child/scheduler/scheduler_message_loop_delegate.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+using testing::ElementsAreArray;
+
+namespace content {
+
+namespace {
+void NopTask() {
+}
+
+int TimeTicksToIntMs(const base::TimeTicks& time) {
+  return static_cast<int>((time - base::TimeTicks()).InMilliseconds());
+}
+
+void WakeUpTask(std::vector<std::string>* timeline, cc::TestNowSource* clock) {
+  if (timeline) {
+    timeline->push_back(base::StringPrintf(
+        "run WakeUpTask @ %d", TimeTicksToIntMs(clock->Now())));
+  }
+}
+
+void RecordTimelineTask(std::vector<std::string>* timeline,
+                        cc::TestNowSource* clock) {
+  timeline->push_back(base::StringPrintf(
+      "run RecordTimelineTask @ %d", TimeTicksToIntMs(clock->Now())));
+}
+
+void AppendToVectorTestTask(std::vector<std::string>* vector,
+                            std::string value) {
+  vector->push_back(value);
+}
+
+void AppendToVectorIdleTestTask(std::vector<std::string>* vector,
+                                std::string value,
+                                base::TimeTicks deadline) {
+  AppendToVectorTestTask(vector, value);
+}
+
+void TimelineIdleTestTask(std::vector<std::string>* timeline,
+                          base::TimeTicks deadline) {
+  timeline->push_back(base::StringPrintf("run TimelineIdleTestTask deadline %d",
+                                         TimeTicksToIntMs(deadline)));
+}
+
+};  // namespace
+
+class WorkerSchedulerImplForTest : public WorkerSchedulerImpl {
+ public:
+  WorkerSchedulerImplForTest(
+      scoped_refptr<NestableSingleThreadTaskRunner> main_task_runner,
+      scoped_refptr<cc::TestNowSource> clock_)
+      : WorkerSchedulerImpl(main_task_runner),
+        clock_(clock_),
+        timeline_(nullptr) {}
+
+  void RecordTimelineEvents(std::vector<std::string>* timeline) {
+    timeline_ = timeline;
+  }
+
+ private:
+  bool CanEnterLongIdlePeriod(
+      base::TimeTicks now,
+      base::TimeDelta* next_long_idle_period_delay_out) override {
+    if (timeline_) {
+      timeline_->push_back(base::StringPrintf("CanEnterLongIdlePeriod @ %d",
+                                              TimeTicksToIntMs(now)));
+    }
+    return WorkerSchedulerImpl::CanEnterLongIdlePeriod(
+        now, next_long_idle_period_delay_out);
+  }
+
+  void IsNotQuiescent() override {
+    if (timeline_) {
+      timeline_->push_back(base::StringPrintf("IsNotQuiescent @ %d",
+                                              TimeTicksToIntMs(clock_->Now())));
+    }
+    WorkerSchedulerImpl::IsNotQuiescent();
+  }
+
+  scoped_refptr<cc::TestNowSource> clock_;
+  std::vector<std::string>* timeline_;  // NOT OWNED
+};
+
+class WorkerSchedulerImplTest : public testing::Test {
+ public:
+  WorkerSchedulerImplTest()
+      : clock_(cc::TestNowSource::Create(5000)),
+        mock_task_runner_(new cc::OrderedSimpleTaskRunner(clock_, true)),
+        nestable_task_runner_(
+            NestableTaskRunnerForTest::Create(mock_task_runner_)),
+        scheduler_(
+            new WorkerSchedulerImplForTest(nestable_task_runner_, clock_)),
+        timeline_(nullptr) {
+    scheduler_->SetTimeSourceForTesting(clock_);
+  }
+
+  ~WorkerSchedulerImplTest() override {}
+
+  void TearDown() override {
+    // Check that all tests stop posting tasks.
+    while (mock_task_runner_->RunUntilIdle()) {
+    }
+  }
+
+  void Init() {
+    scheduler_->Init();
+    default_task_runner_ = scheduler_->DefaultTaskRunner();
+    idle_task_runner_ = scheduler_->IdleTaskRunner();
+    timeline_ = nullptr;
+  }
+
+  void RecordTimelineEvents(std::vector<std::string>* timeline) {
+    timeline_ = timeline;
+    scheduler_->RecordTimelineEvents(timeline);
+  }
+
+  void RunUntilIdle() {
+    if (timeline_) {
+      timeline_->push_back(base::StringPrintf("RunUntilIdle begin @ %d",
+                                              TimeTicksToIntMs(clock_->Now())));
+    }
+    mock_task_runner_->RunUntilIdle();
+    if (timeline_) {
+      timeline_->push_back(base::StringPrintf("RunUntilIdle end @ %d",
+                                              TimeTicksToIntMs(clock_->Now())));
+    }
+  }
+
+  void InitAndPostDelayedWakeupTask() {
+    Init();
+    // WorkerSchedulerImpl::Init causes a delayed task to be posted on the
+    // after wakeup control runner.  We need a task to wake the system up
+    // AFTER the delay for this has expired.
+    default_task_runner_->PostDelayedTask(
+        FROM_HERE, base::Bind(&WakeUpTask, base::Unretained(timeline_),
+                              base::Unretained(clock_.get())),
+        base::TimeDelta::FromMilliseconds(100));
+  }
+
+  // Helper for posting several tasks of specific types. |task_descriptor| is a
+  // string with space delimited task identifiers. The first letter of each
+  // task identifier specifies the task type:
+  // - 'D': Default task
+  // - 'I': Idle task
+  void PostTestTasks(std::vector<std::string>* run_order,
+                     const std::string& task_descriptor) {
+    std::istringstream stream(task_descriptor);
+    while (!stream.eof()) {
+      std::string task;
+      stream >> task;
+      switch (task[0]) {
+        case 'D':
+          default_task_runner_->PostTask(
+              FROM_HERE, base::Bind(&AppendToVectorTestTask, run_order, task));
+          break;
+        case 'I':
+          idle_task_runner_->PostIdleTask(
+              FROM_HERE,
+              base::Bind(&AppendToVectorIdleTestTask, run_order, task));
+          break;
+        default:
+          NOTREACHED();
+      }
+    }
+  }
+
+  static base::TimeDelta maximum_idle_period_duration() {
+    return base::TimeDelta::FromMilliseconds(
+        SchedulerHelper::kMaximumIdlePeriodMillis);
+  }
+
+ protected:
+  scoped_refptr<cc::TestNowSource> clock_;
+  // Only one of mock_task_runner_ or message_loop_ will be set.
+  scoped_refptr<cc::OrderedSimpleTaskRunner> mock_task_runner_;
+
+  scoped_refptr<NestableSingleThreadTaskRunner> nestable_task_runner_;
+  scoped_ptr<WorkerSchedulerImplForTest> scheduler_;
+  scoped_refptr<base::SingleThreadTaskRunner> default_task_runner_;
+  scoped_refptr<SingleThreadIdleTaskRunner> idle_task_runner_;
+  std::vector<std::string>* timeline_;  // NOT OWNED
+
+  DISALLOW_COPY_AND_ASSIGN(WorkerSchedulerImplTest);
+};
+
+TEST_F(WorkerSchedulerImplTest, TestPostDefaultTask) {
+  InitAndPostDelayedWakeupTask();
+
+  std::vector<std::string> run_order;
+  PostTestTasks(&run_order, "D1 D2 D3 D4");
+
+  RunUntilIdle();
+  EXPECT_THAT(run_order,
+              testing::ElementsAre(std::string("D1"), std::string("D2"),
+                                   std::string("D3"), std::string("D4")));
+}
+
+TEST_F(WorkerSchedulerImplTest, TestPostIdleTask) {
+  InitAndPostDelayedWakeupTask();
+
+  std::vector<std::string> run_order;
+  PostTestTasks(&run_order, "I1");
+
+  RunUntilIdle();
+  EXPECT_THAT(run_order, testing::ElementsAre(std::string("I1")));
+}
+
+TEST_F(WorkerSchedulerImplTest, TestPostIdleTask_NoWakeup) {
+  Init();
+  std::vector<std::string> run_order;
+  PostTestTasks(&run_order, "I1");
+
+  RunUntilIdle();
+  EXPECT_TRUE(run_order.empty());
+}
+
+TEST_F(WorkerSchedulerImplTest, TestPostDefaultAndIdleTasks) {
+  InitAndPostDelayedWakeupTask();
+
+  std::vector<std::string> run_order;
+  PostTestTasks(&run_order, "I1 D2 D3 D4");
+
+  RunUntilIdle();
+  EXPECT_THAT(run_order,
+              testing::ElementsAre(std::string("D2"), std::string("D3"),
+                                   std::string("D4"), std::string("I1")));
+}
+
+TEST_F(WorkerSchedulerImplTest, TestPostIdleTaskWithWakeupNeeded_NoWakeup) {
+  InitAndPostDelayedWakeupTask();
+
+  RunUntilIdle();
+  // The delayed call to EnableLongIdlePeriod happened and it posted a call to
+  // EnableLongIdlePeriod on the after wakeup control queue.
+
+  std::vector<std::string> run_order;
+  PostTestTasks(&run_order, "I1");
+
+  RunUntilIdle();
+  EXPECT_TRUE(run_order.empty());
+}
+
+TEST_F(WorkerSchedulerImplTest, TestPostDefaultDelayedAndIdleTasks) {
+  InitAndPostDelayedWakeupTask();
+
+  std::vector<std::string> run_order;
+  PostTestTasks(&run_order, "I1 D2 D3 D4");
+
+  default_task_runner_->PostDelayedTask(
+      FROM_HERE, base::Bind(&AppendToVectorTestTask, &run_order, "DELAYED"),
+      base::TimeDelta::FromMilliseconds(1000));
+
+  RunUntilIdle();
+  EXPECT_THAT(run_order,
+              testing::ElementsAre(std::string("D2"), std::string("D3"),
+                                   std::string("D4"), std::string("I1"),
+                                   std::string("DELAYED")));
+}
+
+TEST_F(WorkerSchedulerImplTest, TestIdleDeadlineWithPendingDelayedTask) {
+  std::vector<std::string> timeline;
+  RecordTimelineEvents(&timeline);
+  InitAndPostDelayedWakeupTask();
+
+  timeline.push_back("Post delayed and idle tasks");
+  // Post a delayed task timed to occur mid way during the long idle period.
+  default_task_runner_->PostDelayedTask(
+      FROM_HERE, base::Bind(&RecordTimelineTask, base::Unretained(&timeline),
+                            base::Unretained(clock_.get())),
+      base::TimeDelta::FromMilliseconds(420));
+  idle_task_runner_->PostIdleTask(FROM_HERE,
+                                  base::Bind(&TimelineIdleTestTask, &timeline));
+
+  RunUntilIdle();
+
+  std::string expected_timeline[] = {
+      "CanEnterLongIdlePeriod @ 5",
+      "Post delayed and idle tasks",
+      "IsNotQuiescent @ 105",
+      "CanEnterLongIdlePeriod @ 405",
+      "run TimelineIdleTestTask deadline 425",  // Note the short 20ms deadline.
+      "CanEnterLongIdlePeriod @ 425",
+      "run RecordTimelineTask @ 425"};
+
+  EXPECT_THAT(timeline, ElementsAreArray(expected_timeline));
+}
+
+TEST_F(WorkerSchedulerImplTest,
+       TestIdleDeadlineWithPendingDelayedTaskFarInTheFuture) {
+  std::vector<std::string> timeline;
+  RecordTimelineEvents(&timeline);
+  InitAndPostDelayedWakeupTask();
+
+  timeline.push_back("Post delayed and idle tasks");
+  // Post a delayed task timed to occur well after the long idle period.
+  default_task_runner_->PostDelayedTask(
+      FROM_HERE, base::Bind(&RecordTimelineTask, base::Unretained(&timeline),
+                            base::Unretained(clock_.get())),
+      base::TimeDelta::FromMilliseconds(1000));
+  idle_task_runner_->PostIdleTask(FROM_HERE,
+                                  base::Bind(&TimelineIdleTestTask, &timeline));
+
+  RunUntilIdle();
+
+  std::string expected_timeline[] = {
+      "CanEnterLongIdlePeriod @ 5",
+      "Post delayed and idle tasks",
+      "IsNotQuiescent @ 105",
+      "CanEnterLongIdlePeriod @ 405",
+      "run TimelineIdleTestTask deadline 455",  // Note the full 50ms deadline.
+      "CanEnterLongIdlePeriod @ 455",
+      "run RecordTimelineTask @ 1005"};
+
+  EXPECT_THAT(timeline, ElementsAreArray(expected_timeline));
+}
+
+TEST_F(WorkerSchedulerImplTest,
+       TestPostIdleTaskAfterRunningUntilIdle_NoWakeUp) {
+  InitAndPostDelayedWakeupTask();
+
+  default_task_runner_->PostDelayedTask(
+      FROM_HERE, base::Bind(&NopTask), base::TimeDelta::FromMilliseconds(1000));
+  RunUntilIdle();
+
+  // The delayed call to EnableLongIdlePeriod happened and it posted a call to
+  // EnableLongIdlePeriod on the after wakeup control queue. Without an other
+  // non-idle task posted, the idle tasks won't run.
+  std::vector<std::string> run_order;
+  PostTestTasks(&run_order, "I1 I2");
+
+  RunUntilIdle();
+  EXPECT_TRUE(run_order.empty());
+}
+
+TEST_F(WorkerSchedulerImplTest,
+       TestPostIdleTaskAfterRunningUntilIdle_WithWakeUp) {
+  InitAndPostDelayedWakeupTask();
+
+  default_task_runner_->PostDelayedTask(
+      FROM_HERE, base::Bind(&NopTask), base::TimeDelta::FromMilliseconds(1000));
+  RunUntilIdle();
+  // The delayed call to EnableLongIdlePeriod happened and it posted a call to
+  // EnableLongIdlePeriod on the after wakeup control queue. Without an other
+  // non-idle task posted, the idle tasks won't run.
+
+  std::vector<std::string> run_order;
+  PostTestTasks(&run_order, "I1 I2 D3");
+
+  RunUntilIdle();
+  EXPECT_THAT(run_order,
+              testing::ElementsAre(std::string("D3"), std::string("I1"),
+                                   std::string("I2")));
+}
+
+TEST_F(WorkerSchedulerImplTest, TestLongIdlePeriodTimeline) {
+  Init();
+
+  std::vector<std::string> timeline;
+  RecordTimelineEvents(&timeline);
+
+  // The scheduler should not run the initiate_next_long_idle_period task if
+  // there are no idle tasks and no other task woke up the scheduler, thus
+  // the idle period deadline shouldn't update at the end of the current long
+  // idle period.
+  base::TimeTicks idle_period_deadline =
+      scheduler_->CurrentIdleTaskDeadlineForTesting();
+  clock_->AdvanceNow(maximum_idle_period_duration());
+  RunUntilIdle();
+
+  base::TimeTicks new_idle_period_deadline =
+      scheduler_->CurrentIdleTaskDeadlineForTesting();
+  EXPECT_EQ(idle_period_deadline, new_idle_period_deadline);
+
+  // Posting a after-wakeup idle task also shouldn't wake the scheduler or
+  // initiate the next long idle period.
+  timeline.push_back("PostIdleTaskAfterWakeup");
+  idle_task_runner_->PostIdleTaskAfterWakeup(
+      FROM_HERE, base::Bind(&TimelineIdleTestTask, &timeline));
+  RunUntilIdle();
+  new_idle_period_deadline = scheduler_->CurrentIdleTaskDeadlineForTesting();
+
+  // Running a normal task should initiate a new long idle period after waiting
+  // 300ms for quiescence.
+  timeline.push_back("Post RecordTimelineTask");
+  default_task_runner_->PostTask(
+      FROM_HERE, base::Bind(&RecordTimelineTask, base::Unretained(&timeline),
+                            base::Unretained(clock_.get())));
+  RunUntilIdle();
+
+  std::string expected_timeline[] = {
+      "RunUntilIdle begin @ 55",
+      "RunUntilIdle end @ 55",
+      "PostIdleTaskAfterWakeup",
+      "RunUntilIdle begin @ 55",  // NOTE idle task doesn't run till later.
+      "RunUntilIdle end @ 55",
+      "Post RecordTimelineTask",
+      "RunUntilIdle begin @ 55",
+      "run RecordTimelineTask @ 55",
+      "IsNotQuiescent @ 55",  // NOTE we have to wait for quiescence.
+      "CanEnterLongIdlePeriod @ 355",
+      "run TimelineIdleTestTask deadline 405",
+      "CanEnterLongIdlePeriod @ 405",
+      "RunUntilIdle end @ 455"};
+
+  EXPECT_THAT(timeline, ElementsAreArray(expected_timeline));
+}
+
+}  // namespace content