Test for a thread lock gets stuck on thread.join()

Question

I was writing my own implementation for Memcachelock in my python project, but got stucked on testing it out. My code:

if __name__ == "__main__":
    from threading import Thread

    # demo of the lock in use
    def mock_process_image(idx):
        with ImageLock("image-name"):
            print("process %d: processing image" % idx)
            time.sleep(3)  # seconds of "processing"
            print("process %d: completed processing of the image" % idx)

    threads = []
    for idx in range(3):  # count of parallel processing
        thread = Thread(target=mock_process_image, args=(idx,))
        thread.start()
        threads.append(thread)
    for thread in threads:
        thread.join()

With ImageLock defined as:

class ImageLock(MemcacheLock):
    """Preconfigured memcached lock for images."""

    def __init__(self, image: str) -> None:
        """
        Initialize image lock.

        Args:
            image (str): image name (unique string)
        """
        super().__init__(
            image,
            key_prefix="image:",
            expiration=(10 * MINUTE),
            timeout=(11 * MINUTE),
            sleep_interval=(1 * SECOND),
        )

I was trying to test if the threads get executed in sequence as expected, but instead I am unable to get any output from mock_process_image, it seems like the threading gets stuck at first thread.join() and I am unable to debug it or figure out what's wrong. Anyone who could help me out?

Edit: After reducing the expiration/timeout time as Nullman sugested I am getting these prints:

process 0: processing image
Lock timeouts: repository:repository-name
Lock timeouts: repository:repository-name
process 1: processing image
process 2: processing image
process 0: completed processing of the image
process 1: completed processing of the image
process 2: completed processing of the image ```
Which I suppose means that the threads are not locked properly?