Introduce the concept of media task runner.

chromecast/media/cma/base/balanced_media_task_runner_unittest.cc

+// Copyright 2014 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 <list>
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/bind.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/threading/thread.h"
+#include "base/time/time.h"
+#include "chromecast/media/cma/base/balanced_media_task_runner_factory.h"
+#include "chromecast/media/cma/base/media_task_runner.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace chromecast {
+namespace media {
+
+namespace {
+
+struct MediaTaskRunnerTestContext {
+  MediaTaskRunnerTestContext();
+  ~MediaTaskRunnerTestContext();
+
+  scoped_refptr<MediaTaskRunner> media_task_runner;
+
+  bool is_pending_task;
+
+  std::vector<base::TimeDelta> task_timestamp_list;
+
+  size_t task_index;
+  base::TimeDelta max_timestamp;
+};
+
+MediaTaskRunnerTestContext::MediaTaskRunnerTestContext() {
+}
+
+MediaTaskRunnerTestContext::~MediaTaskRunnerTestContext() {
+}
+
+}  // namespace
+
+class BalancedMediaTaskRunnerTest : public testing::Test {
+ public:
+  BalancedMediaTaskRunnerTest();
+  virtual ~BalancedMediaTaskRunnerTest();
+
+  void SetupTest(base::TimeDelta max_delta,
+                 const std::vector<std::vector<int> >& timestamps_in_ms,
+                 const std::vector<size_t>& pattern,
+                 const std::vector<int>& expected_task_timestamps_ms);
+  void ProcessAllTasks();
+
+ protected:
+  // Expected task order based on their timestamps.
+  std::list<base::TimeDelta> expected_task_timestamps_;
+
+ private:
+  void ScheduleTask();
+  void Task(size_t task_runner_id, base::TimeDelta timestamp);
+
+  void OnTestTimeout();
+
+  scoped_refptr<BalancedMediaTaskRunnerFactory> media_task_runner_factory_;
+
+  // Schedule first a task on media task runner #scheduling_pattern[0]
+  // then a task on media task runner #scheduling_pattern[1] and so on.
+  // Wrap around when reaching the end of the pattern.
+  std::vector<size_t> scheduling_pattern_;
+  size_t pattern_index_;
+
+  // For each media task runner, keep a track of which task has already been
+  // scheduled.
+  std::vector<MediaTaskRunnerTestContext> contexts_;
+
+  DISALLOW_COPY_AND_ASSIGN(BalancedMediaTaskRunnerTest);
+};
+
+BalancedMediaTaskRunnerTest::BalancedMediaTaskRunnerTest() {
+}
+
+BalancedMediaTaskRunnerTest::~BalancedMediaTaskRunnerTest() {
+}
+
+void BalancedMediaTaskRunnerTest::SetupTest(
+    base::TimeDelta max_delta,
+    const std::vector<std::vector<int> >& timestamps_in_ms,
+    const std::vector<size_t>& pattern,
+    const std::vector<int>& expected_task_timestamps_ms) {
+  media_task_runner_factory_ = new BalancedMediaTaskRunnerFactory(max_delta);
+
+  scheduling_pattern_ = pattern;
+  pattern_index_ = 0;
+
+  // Setup each task runner.
+  size_t n = timestamps_in_ms.size();
+  contexts_.resize(n);
+  for (size_t k = 0; k < n; k++) {
+    contexts_[k].media_task_runner =
+        media_task_runner_factory_->CreateMediaTaskRunner(
+            base::MessageLoopProxy::current());
+    contexts_[k].is_pending_task = false;
+    contexts_[k].task_index = 0;
+    contexts_[k].task_timestamp_list.resize(
+        timestamps_in_ms[k].size());
+    for (size_t i = 0; i < timestamps_in_ms[k].size(); i++) {
+      contexts_[k].task_timestamp_list[i] =
+          base::TimeDelta::FromMilliseconds(timestamps_in_ms[k][i]);
+    }
+  }
+
+  // Expected task order (for tasks that are actually run).
+  for (size_t k = 0; k < expected_task_timestamps_ms.size(); k++) {
+    expected_task_timestamps_.push_back(
+        base::TimeDelta::FromMilliseconds(expected_task_timestamps_ms[k]));
+  }
+}
+
+void BalancedMediaTaskRunnerTest::ProcessAllTasks() {
+  base::MessageLoop::current()->PostDelayedTask(
+      FROM_HERE,
+      base::Bind(&BalancedMediaTaskRunnerTest::OnTestTimeout,
+                 base::Unretained(this)),
+      base::TimeDelta::FromSeconds(5));
+  ScheduleTask();
+}
+
+void BalancedMediaTaskRunnerTest::ScheduleTask() {
+  bool has_task = false;
+  for (size_t k = 0; k < contexts_.size(); k++) {
+    if (contexts_[k].task_index < contexts_[k].task_timestamp_list.size())
+      has_task = true;
+  }
+  if (!has_task) {
+    base::MessageLoop::current()->QuitWhenIdle();
+    return;
+  }
+
+  size_t next_pattern_index =
+      (pattern_index_ + 1) % scheduling_pattern_.size();
+
+  size_t task_runner_id = scheduling_pattern_[pattern_index_];
+  MediaTaskRunnerTestContext& context = contexts_[task_runner_id];
+
+  // Check whether all tasks have been scheduled for that task runner
+  // or if there is already one pending task.
+  if (context.task_index >= context.task_timestamp_list.size() ||
+      context.is_pending_task) {
+    pattern_index_ = next_pattern_index;
+    base::MessageLoopProxy::current()->PostTask(
+        FROM_HERE,
+        base::Bind(&BalancedMediaTaskRunnerTest::ScheduleTask,
+                   base::Unretained(this)));
+    return;
+  }
+
+  bool expected_may_run = false;
+  if (context.task_timestamp_list[context.task_index] >=
+      context.max_timestamp) {
+    expected_may_run = true;
+    context.max_timestamp = context.task_timestamp_list[context.task_index];
+  }
+
+  bool may_run = context.media_task_runner->PostMediaTask(
+      FROM_HERE,
+      base::Bind(&BalancedMediaTaskRunnerTest::Task,
+                 base::Unretained(this),
+                 task_runner_id,
+                 context.task_timestamp_list[context.task_index]),
+      context.task_timestamp_list[context.task_index]);
+  EXPECT_EQ(may_run, expected_may_run);
+
+  if (may_run)
+    context.is_pending_task = true;
+
+  context.task_index++;
+  pattern_index_ = next_pattern_index;
+  base::MessageLoopProxy::current()->PostTask(
+      FROM_HERE,
+      base::Bind(&BalancedMediaTaskRunnerTest::ScheduleTask,
+                 base::Unretained(this)));
+}
+
+void BalancedMediaTaskRunnerTest::Task(
+    size_t task_runner_id, base::TimeDelta timestamp) {
+  ASSERT_FALSE(expected_task_timestamps_.empty());
+  EXPECT_EQ(timestamp, expected_task_timestamps_.front());
+  expected_task_timestamps_.pop_front();
+
+  contexts_[task_runner_id].is_pending_task = false;
+}
+
+void BalancedMediaTaskRunnerTest::OnTestTimeout() {
+  ADD_FAILURE() << "Test timed out";
+  if (base::MessageLoop::current())
+    base::MessageLoop::current()->QuitWhenIdle();
+}
+
+TEST_F(BalancedMediaTaskRunnerTest, OneTaskRunner) {
+  scoped_ptr<base::MessageLoop> message_loop(new base::MessageLoop());
+
+  // Timestamps of tasks for the single task runner.
+  int timestamps0_ms[] = {0, 10, 20, 30, 40, 30, 50, 60, 20, 30, 70};
+  std::vector<std::vector<int> > timestamps_ms(1);
+  timestamps_ms[0] = std::vector<int>(
+      timestamps0_ms, timestamps0_ms + arraysize(timestamps0_ms));
+
+  // Scheduling pattern.
+  std::vector<size_t> scheduling_pattern(1);
+  scheduling_pattern[0] = 0;
+
+  // Expected results.
+  int expected_timestamps[] = {0, 10, 20, 30, 40, 50, 60, 70};
+  std::vector<int> expected_timestamps_ms(std::vector<int>(
+      expected_timestamps,
+      expected_timestamps + arraysize(expected_timestamps)));
+
+  SetupTest(base::TimeDelta::FromMilliseconds(30),
+            timestamps_ms,
+            scheduling_pattern,
+            expected_timestamps_ms);
+  ProcessAllTasks();
+  message_loop->Run();
+  EXPECT_TRUE(expected_task_timestamps_.empty());
+}
+
+TEST_F(BalancedMediaTaskRunnerTest, TwoTaskRunnerUnbalanced) {
+  scoped_ptr<base::MessageLoop> message_loop(new base::MessageLoop());
+
+  // Timestamps of tasks for the 2 task runners.
+  int timestamps0_ms[] = {0, 10, 20, 30, 40, 30, 50, 60, 20, 30, 70};
+  int timestamps1_ms[] = {5, 15, 25, 35, 45, 35, 55, 65, 25, 35, 75};
+  std::vector<std::vector<int> > timestamps_ms(2);
+  timestamps_ms[0] = std::vector<int>(
+      timestamps0_ms, timestamps0_ms + arraysize(timestamps0_ms));
+  timestamps_ms[1] = std::vector<int>(
+      timestamps1_ms, timestamps1_ms + arraysize(timestamps1_ms));
+
+  // Scheduling pattern.
+  size_t pattern[] = {1, 0, 0, 0, 0};
+  std::vector<size_t> scheduling_pattern = std::vector<size_t>(
+      pattern, pattern + arraysize(pattern));
+
+  // Expected results.
+  int expected_timestamps[] = {
+    5, 0, 10, 20, 30, 15, 40, 25, 50, 35, 60, 45, 70, 55, 65, 75 };
+  std::vector<int> expected_timestamps_ms(std::vector<int>(
+      expected_timestamps,
+      expected_timestamps + arraysize(expected_timestamps)));
+
+  SetupTest(base::TimeDelta::FromMilliseconds(30),
+            timestamps_ms,
+            scheduling_pattern,
+            expected_timestamps_ms);
+  ProcessAllTasks();
+  message_loop->Run();
+  EXPECT_TRUE(expected_task_timestamps_.empty());
+}
+
+}  // namespace media
+}  // namespace chromecast