test/task_runner_thread.cc

/*
 * Copyright (C) 2018 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <thread>

#include "test/task_runner_thread.h"

namespace perfetto {

TaskRunnerThread::TaskRunnerThread() = default;
TaskRunnerThread::~TaskRunnerThread() {
  {
    std::unique_lock<std::mutex> lock(mutex_);
    if (runner_)
      runner_->Quit();
  }

  if (thread_.joinable())
    thread_.join();
}

void TaskRunnerThread::Start(std::unique_ptr<ThreadDelegate> delegate) {
  // Begin holding the lock for the condition variable.
  std::unique_lock<std::mutex> lock(mutex_);

  // Start the thread.
  PERFETTO_DCHECK(!runner_);
  thread_ = std::thread(&TaskRunnerThread::Run, this, std::move(delegate));

  // Wait for runner to be ready.
  ready_.wait_for(lock, std::chrono::seconds(10),
                  [this]() { return runner_ != nullptr; });
}

void TaskRunnerThread::Run(std::unique_ptr<ThreadDelegate> delegate) {
  // Create the task runner and execute the specicalised code.
  base::PlatformTaskRunner task_runner;
  delegate->Initialize(&task_runner);

  // Pass the runner back to the main thread.
  {
    std::unique_lock<std::mutex> lock(mutex_);
    runner_ = &task_runner;
  }

  // Notify the main thread that the runner is ready.
  ready_.notify_one();

  // Spin the loop.
  task_runner.Run();

  // Ensure we clear out the delegate before runner goes out
  // of scope.
  delegate.reset();

  // Cleanup the runner.
  {
    std::unique_lock<std::mutex> lock(mutex_);
    runner_ = nullptr;
  }
}

}  // namespace perfetto