如果其他人正在等待,是否有标准的STL或Qt方法来生成互斥,否则就保留它?

在我的工作线程中,最方便的外循环逻辑是

lock (mutex_foo);

while (not done)
{
    do_some_work ();

    if (someone_is_waiting_for (mutex_foo))
    {
        unlock (mutex_foo);

        wait_until_someone_else_locks (mutex_foo);

        // expect this lock to already be taken,
        // this thread will now wait its turn
        lock (mutex_foo);
    }
}

unlock (mutex_foo);

主线程将

while (not_done)
{
    do_stuff ();

    lock (mutex_foo); // this will interrupt the worker thread's main loop

    use_shared_resource ();

    unlock (mutex_foo);
}

我使用C++11和Qt 5。我应该如何实现这一点?