Move throttling of background timers into the renderer scheduler

components/scheduler/renderer/throttling_helper_unittest.cc

Index: components/scheduler/renderer/throttling_helper_unittest.cc
diff --git a/components/scheduler/renderer/throttling_helper_unittest.cc b/components/scheduler/renderer/throttling_helper_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..9526f06fbea11fef9a383acb6acbdaab77a9b2c9
--- /dev/null
+++ b/components/scheduler/renderer/throttling_helper_unittest.cc
@@ -0,0 +1,203 @@
+// 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 "components/scheduler/renderer/throttling_helper.h"
+
+#include "base/callback.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/test/simple_test_tick_clock.h"
+#include "cc/test/ordered_simple_task_runner.h"
+#include "components/scheduler/base/test_time_source.h"
+#include "components/scheduler/child/scheduler_tqm_delegate_for_test.h"
+#include "components/scheduler/renderer/renderer_scheduler_impl.h"
+#include "components/scheduler/renderer/web_frame_scheduler_impl.h"
+#include "components/scheduler/renderer/web_view_scheduler_impl.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+using testing::ElementsAre;
+
+namespace scheduler {
+
+class ThrottlingHelperTest : public testing::Test {
+ public:
+  ThrottlingHelperTest() {}
+  ~ThrottlingHelperTest() override {}
+
+  void SetUp() override {
+    clock_.reset(new base::SimpleTestTickClock());
+    clock_->Advance(base::TimeDelta::FromMicroseconds(5000));
+    mock_task_runner_ =
+        make_scoped_refptr(new cc::OrderedSimpleTaskRunner(clock_.get(), true));
+    delegate_ = SchedulerTqmDelegateForTest::Create(
+        mock_task_runner_, make_scoped_ptr(new TestTimeSource(clock_.get())));
+    scheduler_.reset(new RendererSchedulerImpl(delegate_));
+    throttling_helper_ = scheduler_->throttling_helper();
+    timer_queue_ = scheduler_->NewTimerTaskRunner("test_queue");
+  }
+
+  void TearDown() override {
+    scheduler_->Shutdown();
+    scheduler_.reset();
+  }
+
+ protected:
+  scoped_ptr<base::SimpleTestTickClock> clock_;
+  scoped_refptr<cc::OrderedSimpleTaskRunner> mock_task_runner_;
+  scoped_refptr<SchedulerTqmDelegate> delegate_;
+  scoped_ptr<RendererSchedulerImpl> scheduler_;
+  scoped_refptr<TaskQueue> timer_queue_;
+  ThrottlingHelper* throttling_helper_;  // NOT OWNED
+
+  DISALLOW_COPY_AND_ASSIGN(ThrottlingHelperTest);
+};
+
+TEST_F(ThrottlingHelperTest, DelayToNextRunTimeInSeconds) {
+  EXPECT_EQ(base::TimeDelta::FromSecondsD(1.0),
+            ThrottlingHelper::DelayToNextRunTimeInSeconds(
+                base::TimeTicks() + base::TimeDelta::FromSecondsD(0.0)));
+
+  EXPECT_EQ(base::TimeDelta::FromSecondsD(0.9),
+            ThrottlingHelper::DelayToNextRunTimeInSeconds(
+                base::TimeTicks() + base::TimeDelta::FromSecondsD(0.1)));
+
+  EXPECT_EQ(base::TimeDelta::FromSecondsD(0.8),
+            ThrottlingHelper::DelayToNextRunTimeInSeconds(
+                base::TimeTicks() + base::TimeDelta::FromSecondsD(0.2)));
+
+  EXPECT_EQ(base::TimeDelta::FromSecondsD(0.5),
+            ThrottlingHelper::DelayToNextRunTimeInSeconds(
+                base::TimeTicks() + base::TimeDelta::FromSecondsD(0.5)));
+
+  EXPECT_EQ(base::TimeDelta::FromSecondsD(0.2),
+            ThrottlingHelper::DelayToNextRunTimeInSeconds(
+                base::TimeTicks() + base::TimeDelta::FromSecondsD(0.8)));
+
+  EXPECT_EQ(base::TimeDelta::FromSecondsD(0.1),
+            ThrottlingHelper::DelayToNextRunTimeInSeconds(
+                base::TimeTicks() + base::TimeDelta::FromSecondsD(0.9)));
+
+  EXPECT_EQ(base::TimeDelta::FromSecondsD(1.0),
+            ThrottlingHelper::DelayToNextRunTimeInSeconds(
+                base::TimeTicks() + base::TimeDelta::FromSecondsD(1.0)));
+
+  EXPECT_EQ(base::TimeDelta::FromSecondsD(0.9),
+            ThrottlingHelper::DelayToNextRunTimeInSeconds(
+                base::TimeTicks() + base::TimeDelta::FromSecondsD(1.1)));
+
+  EXPECT_EQ(base::TimeDelta::FromSecondsD(1.0),
+            ThrottlingHelper::DelayToNextRunTimeInSeconds(
+                base::TimeTicks() + base::TimeDelta::FromSecondsD(8.0)));
+
+  EXPECT_EQ(base::TimeDelta::FromSecondsD(0.9),
+            ThrottlingHelper::DelayToNextRunTimeInSeconds(
+                base::TimeTicks() + base::TimeDelta::FromSecondsD(8.1)));
+}
+
+namespace {
+void TestTask(std::vector<base::TimeTicks>* run_times,
+              base::SimpleTestTickClock* clock) {
+  run_times->push_back(clock->NowTicks());
+}
+}  // namespace
+
+TEST_F(ThrottlingHelperTest, TimerAlignment) {
+  std::vector<base::TimeTicks> run_times;
+  timer_queue_->PostDelayedTask(FROM_HERE,
+                                base::Bind(&TestTask, &run_times, clock_.get()),
+                                base::TimeDelta::FromMilliseconds(200.0));
+
+  timer_queue_->PostDelayedTask(FROM_HERE,
+                                base::Bind(&TestTask, &run_times, clock_.get()),
+                                base::TimeDelta::FromMilliseconds(800.0));
+
+  timer_queue_->PostDelayedTask(FROM_HERE,
+                                base::Bind(&TestTask, &run_times, clock_.get()),
+                                base::TimeDelta::FromMilliseconds(1200.0));
+
+  timer_queue_->PostDelayedTask(FROM_HERE,
+                                base::Bind(&TestTask, &run_times, clock_.get()),
+                                base::TimeDelta::FromMilliseconds(8300.0));
+
+  throttling_helper_->Throttle(timer_queue_.get());
+
+  mock_task_runner_->RunUntilIdle();
+
+  // Times are aligned to a multipple of 1000 milliseconds.
+  EXPECT_THAT(
+      run_times,
+      ElementsAre(
+          base::TimeTicks() + base::TimeDelta::FromMilliseconds(1000.0),
+          base::TimeTicks() + base::TimeDelta::FromMilliseconds(1000.0),
+          base::TimeTicks() + base::TimeDelta::FromMilliseconds(2000.0),
+          base::TimeTicks() + base::TimeDelta::FromMilliseconds(9000.0)));
+}
+
+TEST_F(ThrottlingHelperTest, TimerAlignment_Unthrottled) {
+  std::vector<base::TimeTicks> run_times;
+  base::TimeTicks start_time = clock_->NowTicks();
+  timer_queue_->PostDelayedTask(FROM_HERE,
+                                base::Bind(&TestTask, &run_times, clock_.get()),
+                                base::TimeDelta::FromMilliseconds(200.0));
+
+  timer_queue_->PostDelayedTask(FROM_HERE,
+                                base::Bind(&TestTask, &run_times, clock_.get()),
+                                base::TimeDelta::FromMilliseconds(800.0));
+
+  timer_queue_->PostDelayedTask(FROM_HERE,
+                                base::Bind(&TestTask, &run_times, clock_.get()),
+                                base::TimeDelta::FromMilliseconds(1200.0));
+
+  timer_queue_->PostDelayedTask(FROM_HERE,
+                                base::Bind(&TestTask, &run_times, clock_.get()),
+                                base::TimeDelta::FromMilliseconds(8300.0));
+
+  throttling_helper_->Throttle(timer_queue_.get());
+  throttling_helper_->Unthrottle(timer_queue_.get());
+
+  mock_task_runner_->RunUntilIdle();
+
+  // Times are not aligned.
+  EXPECT_THAT(
+      run_times,
+      ElementsAre(start_time + base::TimeDelta::FromMilliseconds(200.0),
+                  start_time + base::TimeDelta::FromMilliseconds(800.0),
+                  start_time + base::TimeDelta::FromMilliseconds(1200.0),
+                  start_time + base::TimeDelta::FromMilliseconds(8300.0)));
+}
+
+TEST_F(ThrottlingHelperTest, WakeUpForNonDelayedTask) {
+  std::vector<base::TimeTicks> run_times;
+
+  // Nothing is posted on timer_queue_ so PumpThrottledTasks will not tick.
+  throttling_helper_->Throttle(timer_queue_.get());
+
+  // Posting a task should trigger the pump.
+  timer_queue_->PostTask(FROM_HERE,
+                         base::Bind(&TestTask, &run_times, clock_.get()));
+
+  mock_task_runner_->RunUntilIdle();
+  EXPECT_THAT(run_times,
+              ElementsAre(base::TimeTicks() +
+                          base::TimeDelta::FromMilliseconds(1000.0)));
+}
+
+TEST_F(ThrottlingHelperTest, WakeUpForDelayedTask) {
+  std::vector<base::TimeTicks> run_times;
+
+  // Nothing is posted on timer_queue_ so PumpThrottledTasks will not tick.
+  throttling_helper_->Throttle(timer_queue_.get());
+
+  // Posting a task should trigger the pump.
+  timer_queue_->PostDelayedTask(FROM_HERE,
+                                base::Bind(&TestTask, &run_times, clock_.get()),
+                                base::TimeDelta::FromMilliseconds(1200.0));
+
+  mock_task_runner_->RunUntilIdle();
+  EXPECT_THAT(run_times,
+              ElementsAre(base::TimeTicks() +
+                          base::TimeDelta::FromMilliseconds(2000.0)));
+}
+
+}  // namespace scheduler