scheduler: Implement task observers

content/renderer/scheduler/webthread_impl_for_scheduler_unittest.cc

Index: content/renderer/scheduler/webthread_impl_for_scheduler_unittest.cc
diff --git a/content/renderer/scheduler/webthread_impl_for_scheduler_unittest.cc b/content/renderer/scheduler/webthread_impl_for_scheduler_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..68d3197e58521322d6b2bbb3a902b8d452589f54
--- /dev/null
+++ b/content/renderer/scheduler/webthread_impl_for_scheduler_unittest.cc
@@ -0,0 +1,197 @@
+// 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/renderer/scheduler/webthread_impl_for_scheduler.h"
+
+#include "base/run_loop.h"
+#include "content/renderer/scheduler/renderer_scheduler_impl.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/WebKit/public/platform/WebTraceLocation.h"
+
+namespace content {
+namespace {
+
+const int kWorkBatchSize = 2;
+
+class MockTask : public blink::WebThread::Task {
+ public:
+  MOCK_METHOD0(run, void());
+};
+
+class MockTaskObserver : public blink::WebThread::TaskObserver {
+ public:
+  MOCK_METHOD0(willProcessTask, void());
+  MOCK_METHOD0(didProcessTask, void());
+};
+}  // namespace
+
+class WebThreadImplForSchedulerTest : public testing::Test {
+ public:
+  WebThreadImplForSchedulerTest()
+      : scheduler_(message_loop_.task_runner()),
+        default_task_runner_(scheduler_.DefaultTaskRunner()),
+        thread_(&scheduler_) {}
+
+  ~WebThreadImplForSchedulerTest() override {}
+
+ protected:
+  void EatDefaultTask(MockTaskObserver* observer) {
+    // The scheduler posts one extra DoWork() task automatically.
+    EXPECT_CALL(*observer, willProcessTask());
+    EXPECT_CALL(*observer, didProcessTask());
+  }
+
+  base::MessageLoop message_loop_;
+  RendererSchedulerImpl scheduler_;
+  scoped_refptr<base::SingleThreadTaskRunner> default_task_runner_;
+  WebThreadImplForScheduler thread_;
+
+  DISALLOW_COPY_AND_ASSIGN(WebThreadImplForSchedulerTest);
+};
+
+TEST_F(WebThreadImplForSchedulerTest, TestTaskObserver) {
+  MockTaskObserver observer;
+  thread_.addTaskObserver(&observer);
+  scoped_ptr<MockTask> task(new MockTask());
+
+  {
+    testing::InSequence sequence;
+    EXPECT_CALL(observer, willProcessTask());
+    EXPECT_CALL(*task, run());
+    EXPECT_CALL(observer, didProcessTask());
+
+    EatDefaultTask(&observer);
+  }
+
+  thread_.postTask(blink::WebTraceLocation(), task.release());
+  message_loop_.RunUntilIdle();
+  thread_.removeTaskObserver(&observer);
+}
+
+TEST_F(WebThreadImplForSchedulerTest, TestWorkBatchWithOneTask) {
+  MockTaskObserver observer;
+  thread_.addTaskObserver(&observer);
+  scoped_ptr<MockTask> task(new MockTask());
+
+  scheduler_.SetWorkBatchSizeForTesting(kWorkBatchSize);
+  {
+    testing::InSequence sequence;
+    EXPECT_CALL(observer, willProcessTask());
+    EXPECT_CALL(*task, run());
+    EXPECT_CALL(observer, didProcessTask());
+
+    EatDefaultTask(&observer);
+  }
+
+  thread_.postTask(blink::WebTraceLocation(), task.release());
+  message_loop_.RunUntilIdle();
+  thread_.removeTaskObserver(&observer);
+}
+
+TEST_F(WebThreadImplForSchedulerTest, TestWorkBatchWithTwoTasks) {
+  MockTaskObserver observer;
+  thread_.addTaskObserver(&observer);
+  scoped_ptr<MockTask> task1(new MockTask());
+  scoped_ptr<MockTask> task2(new MockTask());
+
+  scheduler_.SetWorkBatchSizeForTesting(kWorkBatchSize);
+  {
+    testing::InSequence sequence;
+    EXPECT_CALL(observer, willProcessTask());
+    EXPECT_CALL(*task1, run());
+    EXPECT_CALL(observer, didProcessTask());
+
+    EXPECT_CALL(observer, willProcessTask());
+    EXPECT_CALL(*task2, run());
+    EXPECT_CALL(observer, didProcessTask());
+
+    EatDefaultTask(&observer);
+  }
+
+  thread_.postTask(blink::WebTraceLocation(), task1.release());
+  thread_.postTask(blink::WebTraceLocation(), task2.release());
+  message_loop_.RunUntilIdle();
+  thread_.removeTaskObserver(&observer);
+}
+
+TEST_F(WebThreadImplForSchedulerTest, TestWorkBatchWithThreeTasks) {
+  MockTaskObserver observer;
+  thread_.addTaskObserver(&observer);
+  scoped_ptr<MockTask> task1(new MockTask());
+  scoped_ptr<MockTask> task2(new MockTask());
+  scoped_ptr<MockTask> task3(new MockTask());
+
+  scheduler_.SetWorkBatchSizeForTesting(kWorkBatchSize);
+  {
+    testing::InSequence sequence;
+    EXPECT_CALL(observer, willProcessTask());
+    EXPECT_CALL(*task1, run());
+    EXPECT_CALL(observer, didProcessTask());
+
+    EXPECT_CALL(observer, willProcessTask());
+    EXPECT_CALL(*task2, run());
+    EXPECT_CALL(observer, didProcessTask());
+
+    EXPECT_CALL(observer, willProcessTask());
+    EXPECT_CALL(*task3, run());
+    EXPECT_CALL(observer, didProcessTask());
+
+    EatDefaultTask(&observer);
+  }
+
+  thread_.postTask(blink::WebTraceLocation(), task1.release());
+  thread_.postTask(blink::WebTraceLocation(), task2.release());
+  thread_.postTask(blink::WebTraceLocation(), task3.release());
+  message_loop_.RunUntilIdle();
+  thread_.removeTaskObserver(&observer);
+}
+
+class ExitRunLoopTask : public blink::WebThread::Task {
+ public:
+  ExitRunLoopTask(base::RunLoop* run_loop) : run_loop_(run_loop) {}
+
+  virtual void run() { run_loop_->Quit(); }
+
+ private:
+  base::RunLoop* run_loop_;
+};
+
+void EnterRunLoop(base::MessageLoop* message_loop, blink::WebThread* thread) {
+  // Note: WebThreads do not support nested run loops, which is why we use a
+  // run loop directly.
+  base::RunLoop run_loop;
+  thread->postTask(blink::WebTraceLocation(), new ExitRunLoopTask(&run_loop));
+  message_loop->SetNestableTasksAllowed(true);
+  run_loop.Run();
+}
+
+TEST_F(WebThreadImplForSchedulerTest, TestNestedRunLoop) {
+  MockTaskObserver observer;
+  thread_.addTaskObserver(&observer);
+
+  {
+    testing::InSequence sequence;
+
+    // One callback for EnterRunLoop.
+    EXPECT_CALL(observer, willProcessTask());
+
+    // A pair for ExitRunLoopTask.
+    EXPECT_CALL(observer, willProcessTask());
+    EXPECT_CALL(observer, didProcessTask());
+
+    // A final callback for EnterRunLoop.
+    EXPECT_CALL(observer, didProcessTask());
+
+    EatDefaultTask(&observer);
+  }
+
+  message_loop_.PostTask(
+      FROM_HERE, base::Bind(&EnterRunLoop, base::Unretained(&message_loop_),
+                            base::Unretained(&thread_)));
+  message_loop_.RunUntilIdle();
+  thread_.removeTaskObserver(&observer);
+}
+
+}  // namespace content