threading.py 文件源码

def RLock(*args, **kwargs):
    """Factory function that returns a new reentrant lock.

    A reentrant lock must be released by the thread that acquired it. Once a
    thread has acquired a reentrant lock, the same thread may acquire it again
    without blocking; the thread must release it once for each time it has
    acquired it.

    """
    if _CRLock is None:
        return _PyRLock(*args, **kwargs)
    return _CRLock(*args, **kwargs)