Revert "Delete CC."

cc/scheduler/delay_based_time_source_unittest.cc

+// Copyright 2011 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 "cc/scheduler/delay_based_time_source.h"
+
+#include "base/basictypes.h"
+#include "base/test/test_simple_task_runner.h"
+#include "cc/test/scheduler_test_common.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace cc {
+namespace {
+
+base::TimeDelta Interval() {
+  return base::TimeDelta::FromMicroseconds(base::Time::kMicrosecondsPerSecond /
+                                           60);
+}
+
+TEST(DelayBasedTimeSourceTest, TaskPostedAndTickCalled) {
+  scoped_refptr<base::TestSimpleTaskRunner> task_runner =
+      new base::TestSimpleTaskRunner;
+  FakeTimeSourceClient client;
+  scoped_refptr<FakeDelayBasedTimeSource> timer =
+      FakeDelayBasedTimeSource::Create(Interval(), task_runner.get());
+  timer->SetClient(&client);
+
+  timer->SetActive(true);
+  EXPECT_TRUE(timer->Active());
+  EXPECT_TRUE(task_runner->HasPendingTask());
+
+  timer->SetNow(timer->Now() + base::TimeDelta::FromMilliseconds(16));
+  task_runner->RunPendingTasks();
+  EXPECT_TRUE(timer->Active());
+  EXPECT_TRUE(client.TickCalled());
+}
+
+TEST(DelayBasedTimeSourceTest, TickNotCalledWithTaskPosted) {
+  scoped_refptr<base::TestSimpleTaskRunner> task_runner =
+      new base::TestSimpleTaskRunner;
+  FakeTimeSourceClient client;
+  scoped_refptr<FakeDelayBasedTimeSource> timer =
+      FakeDelayBasedTimeSource::Create(Interval(), task_runner.get());
+  timer->SetClient(&client);
+  timer->SetActive(true);
+  EXPECT_TRUE(task_runner->HasPendingTask());
+  timer->SetActive(false);
+  task_runner->RunPendingTasks();
+  EXPECT_FALSE(client.TickCalled());
+}
+
+TEST(DelayBasedTimeSourceTest, StartTwiceEnqueuesOneTask) {
+  scoped_refptr<base::TestSimpleTaskRunner> task_runner =
+      new base::TestSimpleTaskRunner;
+  FakeTimeSourceClient client;
+  scoped_refptr<FakeDelayBasedTimeSource> timer =
+      FakeDelayBasedTimeSource::Create(Interval(), task_runner.get());
+  timer->SetClient(&client);
+  timer->SetActive(true);
+  EXPECT_TRUE(task_runner->HasPendingTask());
+  task_runner->ClearPendingTasks();
+  timer->SetActive(true);
+  EXPECT_FALSE(task_runner->HasPendingTask());
+}
+
+TEST(DelayBasedTimeSourceTest, StartWhenRunningDoesntTick) {
+  scoped_refptr<base::TestSimpleTaskRunner> task_runner =
+      new base::TestSimpleTaskRunner;
+  FakeTimeSourceClient client;
+  scoped_refptr<FakeDelayBasedTimeSource> timer =
+      FakeDelayBasedTimeSource::Create(Interval(), task_runner.get());
+  timer->SetClient(&client);
+  timer->SetActive(true);
+  EXPECT_TRUE(task_runner->HasPendingTask());
+  task_runner->RunPendingTasks();
+  task_runner->ClearPendingTasks();
+  timer->SetActive(true);
+  EXPECT_FALSE(task_runner->HasPendingTask());
+}
+
+// At 60Hz, when the tick returns at exactly the requested next time, make sure
+// a 16ms next delay is posted.
+TEST(DelayBasedTimeSourceTest, NextDelaySaneWhenExactlyOnRequestedTime) {
+  scoped_refptr<base::TestSimpleTaskRunner> task_runner =
+      new base::TestSimpleTaskRunner;
+  FakeTimeSourceClient client;
+  scoped_refptr<FakeDelayBasedTimeSource> timer =
+      FakeDelayBasedTimeSource::Create(Interval(), task_runner.get());
+  timer->SetClient(&client);
+  timer->SetActive(true);
+  // Run the first tick.
+  task_runner->RunPendingTasks();
+
+  EXPECT_EQ(16, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  timer->SetNow(timer->Now() + Interval());
+  task_runner->RunPendingTasks();
+
+  EXPECT_EQ(16, task_runner->NextPendingTaskDelay().InMilliseconds());
+}
+
+// At 60Hz, when the tick returns at slightly after the requested next time,
+// make sure a 16ms next delay is posted.
+TEST(DelayBasedTimeSourceTest, NextDelaySaneWhenSlightlyAfterRequestedTime) {
+  scoped_refptr<base::TestSimpleTaskRunner> task_runner =
+      new base::TestSimpleTaskRunner;
+  FakeTimeSourceClient client;
+  scoped_refptr<FakeDelayBasedTimeSource> timer =
+      FakeDelayBasedTimeSource::Create(Interval(), task_runner.get());
+  timer->SetClient(&client);
+  timer->SetActive(true);
+  // Run the first tick.
+  task_runner->RunPendingTasks();
+
+  EXPECT_EQ(16, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  timer->SetNow(timer->Now() + Interval() +
+                base::TimeDelta::FromMicroseconds(1));
+  task_runner->RunPendingTasks();
+
+  EXPECT_EQ(16, task_runner->NextPendingTaskDelay().InMilliseconds());
+}
+
+// At 60Hz, when the tick returns at exactly 2*interval after the requested next
+// time, make sure a 0ms next delay is posted.
+TEST(DelayBasedTimeSourceTest,
+     NextDelaySaneWhenExactlyTwiceAfterRequestedTime) {
+  scoped_refptr<base::TestSimpleTaskRunner> task_runner =
+      new base::TestSimpleTaskRunner;
+  FakeTimeSourceClient client;
+  scoped_refptr<FakeDelayBasedTimeSource> timer =
+      FakeDelayBasedTimeSource::Create(Interval(), task_runner.get());
+  timer->SetClient(&client);
+  timer->SetActive(true);
+  // Run the first tick.
+  task_runner->RunPendingTasks();
+
+  EXPECT_EQ(16, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  timer->SetNow(timer->Now() + 2 * Interval());
+  task_runner->RunPendingTasks();
+
+  EXPECT_EQ(0, task_runner->NextPendingTaskDelay().InMilliseconds());
+}
+
+// At 60Hz, when the tick returns at 2*interval and a bit after the requested
+// next time, make sure a 16ms next delay is posted.
+TEST(DelayBasedTimeSourceTest,
+     NextDelaySaneWhenSlightlyAfterTwiceRequestedTime) {
+  scoped_refptr<base::TestSimpleTaskRunner> task_runner =
+      new base::TestSimpleTaskRunner;
+  FakeTimeSourceClient client;
+  scoped_refptr<FakeDelayBasedTimeSource> timer =
+      FakeDelayBasedTimeSource::Create(Interval(), task_runner.get());
+  timer->SetClient(&client);
+  timer->SetActive(true);
+  // Run the first tick.
+  task_runner->RunPendingTasks();
+
+  EXPECT_EQ(16, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  timer->SetNow(timer->Now() + 2 * Interval() +
+                base::TimeDelta::FromMicroseconds(1));
+  task_runner->RunPendingTasks();
+
+  EXPECT_EQ(16, task_runner->NextPendingTaskDelay().InMilliseconds());
+}
+
+// At 60Hz, when the tick returns halfway to the next frame time, make sure
+// a correct next delay value is posted.
+TEST(DelayBasedTimeSourceTest, NextDelaySaneWhenHalfAfterRequestedTime) {
+  scoped_refptr<base::TestSimpleTaskRunner> task_runner =
+      new base::TestSimpleTaskRunner;
+  FakeTimeSourceClient client;
+  scoped_refptr<FakeDelayBasedTimeSource> timer =
+      FakeDelayBasedTimeSource::Create(Interval(), task_runner.get());
+  timer->SetClient(&client);
+  timer->SetActive(true);
+  // Run the first tick.
+  task_runner->RunPendingTasks();
+
+  EXPECT_EQ(16, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  timer->SetNow(timer->Now() + Interval() +
+                base::TimeDelta::FromMilliseconds(8));
+  task_runner->RunPendingTasks();
+
+  EXPECT_EQ(8, task_runner->NextPendingTaskDelay().InMilliseconds());
+}
+
+// If the timebase and interval are updated with a jittery source, we want to
+// make sure we do not double tick.
+TEST(DelayBasedTimeSourceTest, SaneHandlingOfJitteryTimebase) {
+  scoped_refptr<base::TestSimpleTaskRunner> task_runner =
+      new base::TestSimpleTaskRunner;
+  FakeTimeSourceClient client;
+  scoped_refptr<FakeDelayBasedTimeSource> timer =
+      FakeDelayBasedTimeSource::Create(Interval(), task_runner.get());
+  timer->SetClient(&client);
+  timer->SetActive(true);
+  // Run the first tick.
+  task_runner->RunPendingTasks();
+
+  EXPECT_EQ(16, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  // Jitter timebase ~1ms late
+  timer->SetNow(timer->Now() + Interval());
+  timer->SetTimebaseAndInterval(
+      timer->Now() + base::TimeDelta::FromMilliseconds(1), Interval());
+  task_runner->RunPendingTasks();
+
+  // Without double tick prevention, NextPendingTaskDelay would be 1.
+  EXPECT_EQ(17, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  // Jitter timebase ~1ms early
+  timer->SetNow(timer->Now() + Interval());
+  timer->SetTimebaseAndInterval(
+      timer->Now() - base::TimeDelta::FromMilliseconds(1), Interval());
+  task_runner->RunPendingTasks();
+
+  EXPECT_EQ(15, task_runner->NextPendingTaskDelay().InMilliseconds());
+}
+
+TEST(DelayBasedTimeSourceTest, HandlesSignificantTimebaseChangesImmediately) {
+  scoped_refptr<base::TestSimpleTaskRunner> task_runner =
+      new base::TestSimpleTaskRunner;
+  FakeTimeSourceClient client;
+  scoped_refptr<FakeDelayBasedTimeSource> timer =
+      FakeDelayBasedTimeSource::Create(Interval(), task_runner.get());
+  timer->SetClient(&client);
+  timer->SetActive(true);
+  // Run the first tick.
+  task_runner->RunPendingTasks();
+
+  EXPECT_EQ(16, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  // Tick, then shift timebase by +7ms.
+  timer->SetNow(timer->Now() + Interval());
+  task_runner->RunPendingTasks();
+
+  EXPECT_EQ(16, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  client.Reset();
+  task_runner->ClearPendingTasks();
+  task_runner->RunPendingTasks();
+  base::TimeDelta jitter = base::TimeDelta::FromMilliseconds(7) +
+                           base::TimeDelta::FromMicroseconds(1);
+  timer->SetTimebaseAndInterval(timer->Now() + jitter, Interval());
+
+  EXPECT_FALSE(client.TickCalled());  // Make sure pending tasks were canceled.
+  EXPECT_EQ(16 + 7, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  // Tick, then shift timebase by -7ms.
+  timer->SetNow(timer->Now() + Interval() + jitter);
+  task_runner->RunPendingTasks();
+
+  EXPECT_EQ(16, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  client.Reset();
+  task_runner->ClearPendingTasks();
+  task_runner->RunPendingTasks();
+  timer->SetTimebaseAndInterval(base::TimeTicks() + Interval(), Interval());
+
+  EXPECT_FALSE(client.TickCalled());  // Make sure pending tasks were canceled.
+  EXPECT_EQ(16 - 7, task_runner->NextPendingTaskDelay().InMilliseconds());
+}
+
+TEST(DelayBasedTimeSourceTest, HanldlesSignificantIntervalChangesImmediately) {
+  scoped_refptr<base::TestSimpleTaskRunner> task_runner =
+      new base::TestSimpleTaskRunner;
+  FakeTimeSourceClient client;
+  scoped_refptr<FakeDelayBasedTimeSource> timer =
+      FakeDelayBasedTimeSource::Create(Interval(), task_runner.get());
+  timer->SetClient(&client);
+  timer->SetActive(true);
+  // Run the first tick.
+  task_runner->RunPendingTasks();
+
+  EXPECT_EQ(16, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  // Tick, then double the interval.
+  timer->SetNow(timer->Now() + Interval());
+  task_runner->RunPendingTasks();
+
+  EXPECT_EQ(16, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  client.Reset();
+  task_runner->ClearPendingTasks();
+  task_runner->RunPendingTasks();
+  timer->SetTimebaseAndInterval(base::TimeTicks() + Interval(), Interval() * 2);
+
+  EXPECT_FALSE(client.TickCalled());  // Make sure pending tasks were canceled.
+  EXPECT_EQ(33, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  // Tick, then halve the interval.
+  timer->SetNow(timer->Now() + Interval() * 2);
+  task_runner->RunPendingTasks();
+
+  EXPECT_EQ(33, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  client.Reset();
+  task_runner->ClearPendingTasks();
+  task_runner->RunPendingTasks();
+  timer->SetTimebaseAndInterval(base::TimeTicks() + Interval() * 3, Interval());
+
+  EXPECT_FALSE(client.TickCalled());  // Make sure pending tasks were canceled.
+  EXPECT_EQ(16, task_runner->NextPendingTaskDelay().InMilliseconds());
+}
+
+TEST(DelayBasedTimeSourceTest, JitteryRuntimeWithFutureTimebases) {
+  scoped_refptr<base::TestSimpleTaskRunner> task_runner =
+      new base::TestSimpleTaskRunner;
+  FakeTimeSourceClient client;
+  scoped_refptr<FakeDelayBasedTimeSource> timer =
+      FakeDelayBasedTimeSource::Create(Interval(), task_runner.get());
+  timer->SetClient(&client);
+  timer->SetActive(true);
+
+  // Run the first tick.
+  task_runner->RunPendingTasks();
+  EXPECT_EQ(16, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  base::TimeTicks future_timebase = timer->Now() + Interval() * 10;
+
+  // 1ms jitter
+  base::TimeDelta jitter1 = base::TimeDelta::FromMilliseconds(1);
+
+  // Tick with +1ms of jitter
+  future_timebase += Interval();
+  timer->SetTimebaseAndInterval(future_timebase, Interval());
+  timer->SetNow(timer->Now() + Interval() + jitter1);
+  task_runner->RunPendingTasks();
+  EXPECT_EQ(15, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  // Tick with 0ms of jitter
+  future_timebase += Interval();
+  timer->SetTimebaseAndInterval(future_timebase, Interval());
+  timer->SetNow(timer->Now() + Interval() - jitter1);
+  task_runner->RunPendingTasks();
+  EXPECT_EQ(16, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  // Tick with -1ms of jitter
+  future_timebase += Interval();
+  timer->SetTimebaseAndInterval(future_timebase, Interval());
+  timer->SetNow(timer->Now() + Interval() - jitter1);
+  task_runner->RunPendingTasks();
+  EXPECT_EQ(17, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  // Tick with 0ms of jitter
+  future_timebase += Interval();
+  timer->SetTimebaseAndInterval(future_timebase, Interval());
+  timer->SetNow(timer->Now() + Interval() + jitter1);
+  task_runner->RunPendingTasks();
+  EXPECT_EQ(16, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  // 8 ms jitter
+  base::TimeDelta jitter8 = base::TimeDelta::FromMilliseconds(8);
+
+  // Tick with +8ms of jitter
+  future_timebase += Interval();
+  timer->SetTimebaseAndInterval(future_timebase, Interval());
+  timer->SetNow(timer->Now() + Interval() + jitter8);
+  task_runner->RunPendingTasks();
+  EXPECT_EQ(8, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  // Tick with 0ms of jitter
+  future_timebase += Interval();
+  timer->SetTimebaseAndInterval(future_timebase, Interval());
+  timer->SetNow(timer->Now() + Interval() - jitter8);
+  task_runner->RunPendingTasks();
+  EXPECT_EQ(16, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  // Tick with -8ms of jitter
+  future_timebase += Interval();
+  timer->SetTimebaseAndInterval(future_timebase, Interval());
+  timer->SetNow(timer->Now() + Interval() - jitter8);
+  task_runner->RunPendingTasks();
+  EXPECT_EQ(24, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  // Tick with 0ms of jitter
+  future_timebase += Interval();
+  timer->SetTimebaseAndInterval(future_timebase, Interval());
+  timer->SetNow(timer->Now() + Interval() + jitter8);
+  task_runner->RunPendingTasks();
+  EXPECT_EQ(16, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  // 15 ms jitter
+  base::TimeDelta jitter15  = base::TimeDelta::FromMilliseconds(15);
+
+  // Tick with +15ms jitter
+  future_timebase += Interval();
+  timer->SetTimebaseAndInterval(future_timebase, Interval());
+  timer->SetNow(timer->Now() + Interval() + jitter15);
+  task_runner->RunPendingTasks();
+  EXPECT_EQ(1, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  // Tick with 0ms of jitter
+  future_timebase += Interval();
+  timer->SetTimebaseAndInterval(future_timebase, Interval());
+  timer->SetNow(timer->Now() + Interval() - jitter15);
+  task_runner->RunPendingTasks();
+  EXPECT_EQ(16, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  // Tick with -15ms of jitter
+  future_timebase += Interval();
+  timer->SetTimebaseAndInterval(future_timebase, Interval());
+  timer->SetNow(timer->Now() + Interval() - jitter15);
+  task_runner->RunPendingTasks();
+  EXPECT_EQ(31, task_runner->NextPendingTaskDelay().InMilliseconds());
+
+  // Tick with 0ms of jitter
+  future_timebase += Interval();
+  timer->SetTimebaseAndInterval(future_timebase, Interval());
+  timer->SetNow(timer->Now() + Interval() + jitter15);
+  task_runner->RunPendingTasks();
+  EXPECT_EQ(16, task_runner->NextPendingTaskDelay().InMilliseconds());
+}
+
+TEST(DelayBasedTimeSourceTest, AchievesTargetRateWithNoNoise) {
+  int num_iterations = 10;
+
+  scoped_refptr<base::TestSimpleTaskRunner> task_runner =
+      new base::TestSimpleTaskRunner;
+  FakeTimeSourceClient client;
+  scoped_refptr<FakeDelayBasedTimeSource> timer =
+      FakeDelayBasedTimeSource::Create(Interval(), task_runner.get());
+  timer->SetClient(&client);
+  timer->SetActive(true);
+
+  double total_frame_time = 0.0;
+  for (int i = 0; i < num_iterations; ++i) {
+    int64 delay_ms = task_runner->NextPendingTaskDelay().InMilliseconds();
+
+    // accumulate the "delay"
+    total_frame_time += delay_ms / 1000.0;
+
+    // Run the callback exactly when asked
+    timer->SetNow(timer->Now() + base::TimeDelta::FromMilliseconds(delay_ms));
+    task_runner->RunPendingTasks();
+  }
+  double average_interval =
+      total_frame_time / static_cast<double>(num_iterations);
+  EXPECT_NEAR(1.0 / 60.0, average_interval, 0.1);
+}
+
+TEST(DelayBasedTimeSourceTest, TestDeactivateWhilePending) {
+  scoped_refptr<base::TestSimpleTaskRunner> task_runner =
+      new base::TestSimpleTaskRunner;
+  FakeTimeSourceClient client;
+  scoped_refptr<FakeDelayBasedTimeSource> timer =
+      FakeDelayBasedTimeSource::Create(Interval(), task_runner.get());
+  timer->SetClient(&client);
+  timer->SetActive(true);  // Should post a task.
+  timer->SetActive(false);
+  timer = NULL;
+  // Should run the posted task without crashing.
+  EXPECT_TRUE(task_runner->HasPendingTask());
+  task_runner->RunPendingTasks();
+}
+
+TEST(DelayBasedTimeSourceTest, TestDeactivateAndReactivateBeforeNextTickTime) {
+  scoped_refptr<base::TestSimpleTaskRunner> task_runner =
+      new base::TestSimpleTaskRunner;
+  FakeTimeSourceClient client;
+  scoped_refptr<FakeDelayBasedTimeSource> timer =
+      FakeDelayBasedTimeSource::Create(Interval(), task_runner.get());
+  timer->SetClient(&client);
+
+  // Should run the activate task, and pick up a new timebase.
+  timer->SetActive(true);
+  task_runner->RunPendingTasks();
+
+  // Stop the timer
+  timer->SetActive(false);
+
+  // Task will be pending anyway, run it
+  task_runner->RunPendingTasks();
+
+  // Start the timer again, but before the next tick time the timer previously
+  // planned on using. That same tick time should still be targeted.
+  timer->SetNow(timer->Now() + base::TimeDelta::FromMilliseconds(4));
+  timer->SetActive(true);
+  EXPECT_EQ(12, task_runner->NextPendingTaskDelay().InMilliseconds());
+}
+
+TEST(DelayBasedTimeSourceTest, TestDeactivateAndReactivateAfterNextTickTime) {
+  scoped_refptr<base::TestSimpleTaskRunner> task_runner =
+      new base::TestSimpleTaskRunner;
+  FakeTimeSourceClient client;
+  scoped_refptr<FakeDelayBasedTimeSource> timer =
+      FakeDelayBasedTimeSource::Create(Interval(), task_runner.get());
+  timer->SetClient(&client);
+
+  // Should run the activate task, and pick up a new timebase.
+  timer->SetActive(true);
+  task_runner->RunPendingTasks();
+
+  // Stop the timer.
+  timer->SetActive(false);
+
+  // Task will be pending anyway, run it.
+  task_runner->RunPendingTasks();
+
+  // Start the timer again, but before the next tick time the timer previously
+  // planned on using. That same tick time should still be targeted.
+  timer->SetNow(timer->Now() + base::TimeDelta::FromMilliseconds(20));
+  timer->SetActive(true);
+  EXPECT_EQ(13, task_runner->NextPendingTaskDelay().InMilliseconds());
+}
+
+TEST(DelayBasedTimeSourceTest, TestReturnValueWhenTimerIsDeActivated) {
+  scoped_refptr<base::TestSimpleTaskRunner> task_runner =
+      new base::TestSimpleTaskRunner;
+  FakeTimeSourceClient client;
+  scoped_refptr<FakeDelayBasedTimeSource> timer =
+      FakeDelayBasedTimeSource::Create(Interval(), task_runner.get());
+  timer->SetClient(&client);
+
+  timer->SetActive(true);
+  task_runner->RunPendingTasks();
+
+  // SetActive should return empty TimeTicks when the timer is deactivated.
+  base::TimeTicks missed_tick_time = timer->SetActive(false);
+  EXPECT_TRUE(missed_tick_time.is_null());
+}
+
+}  // namespace
+}  // namespace cc