from threading import Thread, Lock

# 由_acquire解锁执行后释放_release锁

def _print(_id: str, _acquire: Lock, _release: Lock) -> None:

    for i in range(10):

        _acquire.acquire()

        print(f"id:{_id}")

        _release.release()

if __name__ == '__main__':

    # 创建三个锁供3个线程使用

    mutex1 = Lock()

    mutex2 = Lock()

    mutex3 = Lock()

    # 定义三个线程A、B、C

    # 线程A需要mutex1解锁执行后释放mutex2

    # 线程B需要mutex2解锁执行后释放mutex3

    # 线程C需要mutex3解锁执行后释放mutex1

    # 元组中第一位是自定义的线程ID，第二位是解锁需要的锁，第三位是释放的锁

    threads = [Thread(target=_print, args=[i[0], i[1], i[2]]) for i in

               [('A', mutex1, mutex2), ('B', mutex2, mutex3), ('C', mutex3, mutex1)]]

    # 把mutex2和mutex3这两把锁先用了以便阻塞线程2和线程3的执行

    mutex2.acquire()

    mutex3.acquire()

    # 接下来只有线程A可以先执行是因为mutex1并没有被占用

    # 线程B和线程C需要分别等待着锁2和锁3的释放才能继续执行

    [thr.start() for thr in threads]

    [thr.join() for thr in threads]