socket.py 文件源码

def _wait(self, watcher, timeout_exc=timeout('timed out')):
        """Block the current greenlet until *watcher* has pending events.

        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 watcher.callback is None, 'This socket is already used by another greenlet: %r' % (watcher.callback, )
        if self.timeout is not None:
            timeout = Timeout.start_new(self.timeout, timeout_exc, ref=False)
        else:
            timeout = None
        try:
            self.hub.wait(watcher)
        finally:
            if timeout is not None:
                timeout.cancel()