问C++11 condition_variable同步问题

EN

void ThreadPool::addTask(ThreadTaskFunction task, void *arg) {
    std::lock_guard<std::mutex> t_lock(task_lock);
    tasks.push_back(ThreadTask(task, arg));

    // For every tasks that is added, I increment a counter
    assignedTasks++;
}

void ThreadPool::join() {
    std::unique_lock<std::mutex> lock(join_lock);
    joinCondition.wait(lock, [this](){
        return assignedTasks == 0;
    });
}

void Thread::threadLoop() {
    while (!shouldDie) {
        ThreadTask task;

        if (pool.hasTasks()) {
            {
                std::lock_guard<std::mutex> lock(pool.task_lock);

                if (!pool.hasTasks()) continue;

                task = pool.getTask();
            }

            task.function(task.argument);
            this->completeTask();
        }
    }

    this->isThreadFinished = true;
}

void Thread::completeTask() {
    std::lock_guard<std::mutex> guard(pool.task_lock);

    // When a task is completed, I decrement the counter and notify the main thread that a task has completed.
    pool.assignedTasks--;    
    pool.joinCondition.notify_one();
}