thread.py 文件源码

def acquire(self, blocking=True, timeout=-1):
            # Transform the default -1 argument into the None that our
            # semaphore implementation expects, and raise the same error
            # the stdlib implementation does.
            if timeout == -1:
                timeout = None
            if not blocking and timeout is not None:
                raise ValueError("can't specify a timeout for a non-blocking call")
            if timeout is not None:
                if timeout < 0:
                    # in C: if(timeout < 0 && timeout != -1)
                    raise ValueError("timeout value must be strictly positive")
                if timeout > self._TIMEOUT_MAX:
                    raise OverflowError('timeout value is too large')

            return BoundedSemaphore.acquire(self, blocking, timeout)