socket.py 文件源码

def wait_write(fileno, timeout=None, timeout_exc=timeout('timed out'), event=None):
    """Block the current greenlet until *fileno* is ready to write.

    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')``.
    """
    io = get_hub().loop.io(fileno, 2)
    return wait(io, timeout, timeout_exc)