Add a WorkerScheduler and a WebThreadImplForWorker

content/child/scheduler/worker_scheduler_impl_unittest.cc

+// 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 "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"
+
+namespace content {
+
+namespace {
+void NopTask() {
+}
+
+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 IdleTestTask(base::TimeTicks* deadline_out, base::TimeTicks deadline) {
+  *deadline_out = deadline;
+}
+};  // namespace
+
+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 WorkerSchedulerImpl(nestable_task_runner_)),
+        default_task_runner_(scheduler_->DefaultTaskRunner()),
+        idle_task_runner_(scheduler_->IdleTaskRunner()) {
+    scheduler_->SetTimeSourceForTesting(clock_);
+    scheduler_->Init();
+  }
+
+  ~WorkerSchedulerImplTest() override {}
+
+  void TearDown() override {
+    // Check that all tests stop posting tasks.
+    while (mock_task_runner_->RunUntilIdle()) {
+    }
+  }
+
+  void RunUntilIdle() { mock_task_runner_->RunUntilIdle(); }
+
+  void PostDelayedWakeupTask() {
+    // 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(&NopTask),
+        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();
+      }
+    }
+  }
+
+ 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<WorkerSchedulerImpl> scheduler_;
+  scoped_refptr<base::SingleThreadTaskRunner> default_task_runner_;
+  scoped_refptr<SingleThreadIdleTaskRunner> idle_task_runner_;
+
+  DISALLOW_COPY_AND_ASSIGN(WorkerSchedulerImplTest);
+};
+
+TEST_F(WorkerSchedulerImplTest, TestPostDefaultTask) {
+  PostDelayedWakeupTask();
+
+  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) {
+  PostDelayedWakeupTask();
+
+  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) {
+  std::vector<std::string> run_order;
+  PostTestTasks(&run_order, "I1");
+
+  RunUntilIdle();
+  EXPECT_TRUE(run_order.empty());

[rmcilroy, 2015/04/02 11:01:26]

Hmm, I see why this is happening but I'm wondering if we actually want it to
happen. Generally I don't think this situation would ever happen because the
idle task being posted would be being posted by another task which had been
posted (and thus would wake-up the scheduler). Maybe we should be testing that
situation instead, or alternatively, maybe we could ensure that if an idle-task
is posted it wakes-up the initiate_long_idle_period closure assuming it is
asleep (I'm not quite sure how we would do this cleanly though) - either way
this is possibly something for a future CL - lets, discuss in-person.

+}
+
+TEST_F(WorkerSchedulerImplTest, TestPostDefaultAndIdleTasks) {
+  PostDelayedWakeupTask();
+
+  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) {
+  PostDelayedWakeupTask();
+
+  RunUntilIdle();
+  // The delayed call to InitiateLongIdlePeriod happened and it posted a call to
+  // InitiateLongIdlePeriod 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, TestPostIdleTaskWithWakeupNeeded_Wakeup) {
+  RunUntilIdle();
+  // The delayed call to InitiateLongIdlePeriod happened and it posted a call to
+  // InitiateLongIdlePeriod on the after wakeup control queue.
+
+  std::vector<std::string> run_order;
+  PostTestTasks(&run_order, "I1 D2");
+
+  RunUntilIdle();
+  EXPECT_THAT(run_order,
+              testing::ElementsAre(std::string("D2"), std::string("I1")));
+}
+
+TEST_F(WorkerSchedulerImplTest, TestPostDefaultDelayedAndIdleTasks) {
+  PostDelayedWakeupTask();
+
+  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) {
+  PostDelayedWakeupTask();
+
+  base::TimeDelta delay = base::TimeDelta::FromMilliseconds(140);
+  default_task_runner_->PostDelayedTask(FROM_HERE, base::Bind(&NopTask), delay);
+  base::TimeTicks deadline;
+  idle_task_runner_->PostIdleTask(FROM_HERE,
+                                  base::Bind(&IdleTestTask, &deadline));
+
+  base::TimeTicks expected_deadline = clock_->Now() + delay;
+  clock_->AdvanceNow(base::TimeDelta::FromMilliseconds(100));
+
+  RunUntilIdle();
+  EXPECT_EQ(expected_deadline, deadline);
+}
+
+TEST_F(WorkerSchedulerImplTest,
+       TestIdleDeadlineWithPendingDelayedTaskFarInTheFuture) {
+  PostDelayedWakeupTask();
+
+  base::TimeDelta delay = base::TimeDelta::FromMilliseconds(1000);
+  base::TimeTicks task_run_time = clock_->Now() + delay;
+  default_task_runner_->PostDelayedTask(FROM_HERE, base::Bind(&NopTask), delay);
+  base::TimeTicks deadline;
+  idle_task_runner_->PostIdleTask(FROM_HERE,
+                                  base::Bind(&IdleTestTask, &deadline));
+
+  clock_->AdvanceNow(base::TimeDelta::FromMilliseconds(100));
+
+  RunUntilIdle();
+  EXPECT_LT(deadline, task_run_time);
+}
+
+TEST_F(WorkerSchedulerImplTest,
+       TestPostIdleTaskAfterRunningUntilIdle_NoWakeUp) {
+  PostDelayedWakeupTask();
+
+  default_task_runner_->PostDelayedTask(
+      FROM_HERE, base::Bind(&NopTask), base::TimeDelta::FromMilliseconds(1000));
+  RunUntilIdle();
+
+  // The delayed call to InitiateLongIdlePeriod happened and it posted a call to
+  // InitiateLongIdlePeriod 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) {
+
+  PostDelayedWakeupTask();
+
+  default_task_runner_->PostDelayedTask(
+      FROM_HERE, base::Bind(&NopTask), base::TimeDelta::FromMilliseconds(1000));
+  RunUntilIdle();
+  // The delayed call to InitiateLongIdlePeriod happened and it posted a call to
+  // InitiateLongIdlePeriod 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")));
+}
+

[rmcilroy, 2015/04/02 11:01:26]

could you also add a test similar to 
SchedulerHelperTest::TestLongIdlePeriodDoesNotWakeScheduler to ensure that
posting after-wakeup idle tasks doesn't wake up the scheduler and cause the
initiate-long-idle tasks to keep ticking. 

[alex clarke (OOO till 29th), 2015/04/02 15:19:28]

Done.

+}  // namespace content