socket.py 文件源码

def wait(io, timeout=None, timeout_exc=timeout('timed out')):
    """Block the current greenlet until *io* is ready.

    If *timeout* is non-negative, then *timeout_exc* is raised after *timeout* second has passed.
    By default *timeout_exc* is ``socket.timeout('timed out')``.

    If :func:`cancel_wait` is called, raise ``socket.error(EBADF, 'File descriptor was closed in another greenlet')``.
    """
    assert io.callback is None, 'This socket is already used by another greenlet: %r' % (io.callback, )
    if timeout is not None:
        timeout = Timeout.start_new(timeout, timeout_exc)
    try:
        return get_hub().wait(io)
    finally:
        if timeout is not None:
            timeout.cancel()
    # rename "io" to "watcher" because wait() works with any watcher