Web MIDI: implement TaskService

media/midi/task_service_unittest.cc

Index: media/midi/task_service_unittest.cc
diff --git a/media/midi/task_service_unittest.cc b/media/midi/task_service_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..614e950f392517ed124b9ee18c5075a0ba9deb55
--- /dev/null
+++ b/media/midi/task_service_unittest.cc
@@ -0,0 +1,311 @@
+// Copyright 2017 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 "media/midi/task_service.h"
+
+#include <memory>
+
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/callback.h"
+#include "base/memory/ptr_util.h"
+#include "base/memory/ref_counted.h"
+#include "base/run_loop.h"
+#include "base/synchronization/lock.h"
+#include "base/test/test_simple_task_runner.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "base/time/time.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace midi {
+
+namespace {
+
+enum {
+  kDefaultRunner = TaskService::kDefaultRunnerId,
+  kFirstRunner,
+  kSecondRunner
+};
+
+base::WaitableEvent* GetEvent() {
+  static base::WaitableEvent* event =
+      new base::WaitableEvent(base::WaitableEvent::ResetPolicy::MANUAL,
+                              base::WaitableEvent::InitialState::NOT_SIGNALED);
+  return event;
+}
+
+void SignalEvent() {
+  GetEvent()->Signal();
+}
+
+void WaitEvent() {
+  GetEvent()->Wait();
+}
+
+void ResetEvent() {
+  GetEvent()->Reset();
+}
+
+class TaskServiceClient {
+ public:
+  TaskServiceClient(TaskService* task_service)
+      : task_service_(task_service),
+        wait_task_event_(base::MakeUnique<base::WaitableEvent>(
+            base::WaitableEvent::ResetPolicy::MANUAL,
+            base::WaitableEvent::InitialState::NOT_SIGNALED)),
+        count_(0u) {
+    DCHECK(task_service);
+  }
+
+  bool Bind() { return task_service()->BindInstance(); }
+
+  bool Unbind() { return task_service()->UnbindInstance(); }
+
+  void PostBoundTask(TaskService::RunnerId runner_id) {
+    task_service()->PostBoundTask(
+        runner_id, base::BindOnce(&TaskServiceClient::IncrementCount,
+                                  base::Unretained(this)));
+  }
+
+  void PostBoundSignalTask(TaskService::RunnerId runner_id) {
+    task_service()->PostBoundTask(
+        runner_id, base::BindOnce(&TaskServiceClient::SignalEvent,
+                                  base::Unretained(this)));
+  }
+
+  void PostBoundWaitTask(TaskService::RunnerId runner_id) {
+    wait_task_event_->Reset();
+    task_service()->PostBoundTask(
+        runner_id,
+        base::BindOnce(&TaskServiceClient::WaitEvent, base::Unretained(this)));
+  }
+
+  void PostBoundDelayedSignalTask(TaskService::RunnerId runner_id) {
+    task_service()->PostBoundDelayedTask(
+        runner_id,
+        base::BindOnce(&TaskServiceClient::SignalEvent, base::Unretained(this)),
+        base::TimeDelta::FromMilliseconds(100));
+  }
+
+  void WaitTask() { wait_task_event_->Wait(); }
+
+  size_t count() {
+    base::AutoLock lock(lock_);
+    return count_;
+  }
+
+ private:
+  TaskService* task_service() { return task_service_; }
+
+  void IncrementCount() {
+    base::AutoLock lock(lock_);
+    count_++;
+  }
+
+  void SignalEvent() {
+    midi::SignalEvent();
+    IncrementCount();
+  }
+
+  void WaitEvent() {
+    wait_task_event_->Signal();
+    midi::WaitEvent();
+    IncrementCount();
+  }
+
+  base::Lock lock_;
+  TaskService* task_service_;
+  std::unique_ptr<base::WaitableEvent> wait_task_event_;
+  size_t count_;
+
+  DISALLOW_COPY_AND_ASSIGN(TaskServiceClient);
+};
+
+class MidiTaskServiceTest : public ::testing::Test {
+ public:
+  MidiTaskServiceTest() {}
+
+ protected:
+  TaskService* task_service() { return &task_service_; }
+  void RunUntilIdle() { task_runner_->RunUntilIdle(); }
+
+ private:
+  void SetUp() override {
+    ResetEvent();
+    task_runner_ = new base::TestSimpleTaskRunner();
+    thread_task_runner_handle_ =
+        base::MakeUnique<base::ThreadTaskRunnerHandle>(task_runner_);
+  }
+
+  void TearDown() override {
+    thread_task_runner_handle_.reset();
+    task_runner_ = NULL;
+  }
+
+  scoped_refptr<base::TestSimpleTaskRunner> task_runner_;
+  std::unique_ptr<base::ThreadTaskRunnerHandle> thread_task_runner_handle_;
+  TaskService task_service_;
+
+  DISALLOW_COPY_AND_ASSIGN(MidiTaskServiceTest);
+};
+
+// Tests if posted static tasks can be processed without any bound instance.
+TEST_F(MidiTaskServiceTest, RunStaticTask) {
+  task_service()->PostStaticTask(kFirstRunner, base::BindOnce(&SignalEvent));
+  WaitEvent();
+}
+
+// Tests if posted tasks without calling BindInstance() are ignored.
+TEST_F(MidiTaskServiceTest, RunUnauthorizedBoundTask) {
+  std::unique_ptr<TaskServiceClient> client =
+      base::MakeUnique<TaskServiceClient>(task_service());
+
+  client->PostBoundTask(kFirstRunner);
+
+  // Destruct |client| immediately, then see if the posted task is just ignored.
+  // If it isn't, another thread will touch the destructed instance and will
+  // cause a crash due to a use-after-free.
+  client = nullptr;
+}
+
+// Tests if invalid BindInstance() calls are correctly rejected, and it does not
+// make the service insanity.
+TEST_F(MidiTaskServiceTest, BindTwice) {
+  std::unique_ptr<TaskServiceClient> client =
+      base::MakeUnique<TaskServiceClient>(task_service());
+
+  EXPECT_TRUE(client->Bind());
+
+  // Should not be able to call BindInstance() twice before unbinding current
+  // bound instance.
+  EXPECT_FALSE(client->Bind());
+
+  // Should be able to unbind only the first instance.
+  EXPECT_TRUE(client->Unbind());
+  EXPECT_FALSE(client->Unbind());
+}
+
+// Tests if posted static tasks can be processed even with a bound instance.
+TEST_F(MidiTaskServiceTest, RunStaticTaskWithBoundInstance) {
+  std::unique_ptr<TaskServiceClient> client =
+      base::MakeUnique<TaskServiceClient>(task_service());
+
+  EXPECT_TRUE(client->Bind());
+  // Should be able to post a static task even with a bound instance.
+  task_service()->PostStaticTask(kFirstRunner, base::BindOnce(&SignalEvent));
+  WaitEvent();
+  EXPECT_TRUE(client->Unbind());
+
+  ResetEvent();
+
+  EXPECT_TRUE(client->Bind());
+  task_service()->PostStaticTask(kFirstRunner, base::Bind(&SignalEvent));
+  // Should be able to unbind the instance to process a static task.
+  EXPECT_TRUE(client->Unbind());
+  WaitEvent();
+}
+
+// Tests functionalities to run bound tasks.
+TEST_F(MidiTaskServiceTest, RunBoundTasks) {
+  std::unique_ptr<TaskServiceClient> client =
+      base::MakeUnique<TaskServiceClient>(task_service());
+
+  EXPECT_TRUE(client->Bind());
+
+  // Tests if a post task run.
+  EXPECT_EQ(0u, client->count());
+  client->PostBoundSignalTask(kFirstRunner);
+  WaitEvent();
+  EXPECT_EQ(1u, client->count());
+
+  // Tests if another posted task is handled correctly even if the instance is
+  // unbound immediately. The posted task should run safely if it starts before
+  // UnboundInstance() is call. Otherwise, it should be ignored. It completely
+  // depends on timing.
+  client->PostBoundTask(kFirstRunner);
+  EXPECT_TRUE(client->Unbind());
+  client = base::MakeUnique<TaskServiceClient>(task_service());
+
+  // Tests if an immediate call of another BindInstance() works correctly.
+  EXPECT_TRUE(client->Bind());
+
+  // Runs two tasks in two runners.
+  ResetEvent();
+  client->PostBoundSignalTask(kFirstRunner);
+  client->PostBoundTask(kSecondRunner);
+
+  // Waits only the first runner completion to see if the second runner handles
+  // the task correctly even if the bound instance is destructed.
+  WaitEvent();
+  EXPECT_TRUE(client->Unbind());
+  client = nullptr;
+}
+
+// Tests if a blocking task does not block other task runners.
+TEST_F(MidiTaskServiceTest, RunBlockingTask) {
+  std::unique_ptr<TaskServiceClient> client =
+      base::MakeUnique<TaskServiceClient>(task_service());
+
+  EXPECT_TRUE(client->Bind());
+
+  // Posts a task that waits until the event is signaled.
+  client->PostBoundWaitTask(kFirstRunner);
+  // Confirms if the posted task starts. Now, the task should block in the task
+  // until the second task is invoked.
+  client->WaitTask();
+
+  // Posts another task to the second runner. The task should be able to run
+  // even though another posted task is blocking inside a critical section that
+  // protects running tasks from an instance unbinding.
+  client->PostBoundSignalTask(kSecondRunner);
+
+  // Wait until the second task runs.
+  WaitEvent();
+
+  // UnbindInstance() should wait until any running task finishes so that the
+  // instance can be destructed safely.
+  EXPECT_TRUE(client->Unbind());
+  EXPECT_EQ(2u, client->count());
+  client = nullptr;
+}
+
+// Tests if a bound delayed task runs correctly.
+TEST_F(MidiTaskServiceTest, RunBoundDelayedTask) {
+  std::unique_ptr<TaskServiceClient> client =
+      base::MakeUnique<TaskServiceClient>(task_service());
+
+  EXPECT_TRUE(client->Bind());
+
+  // Posts a delayed task that signals after 100msec.
+  client->PostBoundDelayedSignalTask(kFirstRunner);
+
+  // Wait until the delayed task runs.
+  WaitEvent();
+
+  EXPECT_TRUE(client->Unbind());
+  EXPECT_EQ(1u, client->count());
+  client = nullptr;
+}
+
+// Tests if a bound task runs on the thread that bound the instance.
+TEST_F(MidiTaskServiceTest, RunBoundTaskOnDefaultRunner) {
+  std::unique_ptr<TaskServiceClient> client =
+      base::MakeUnique<TaskServiceClient>(task_service());
+
+  EXPECT_TRUE(client->Bind());
+
+  // Posts a task that increments the count on the caller thread.
+  client->PostBoundTask(kDefaultRunner);
+
+  // The posted task should not run until the current message loop is processed.
+  EXPECT_EQ(0u, client->count());
+  RunUntilIdle();
+  EXPECT_EQ(1u, client->count());
+
+  EXPECT_TRUE(client->Unbind());
+}
+
+}  // namespace
+
+}  // namespace midi