iostream.py 文件源码

def connect(self, address, callback=None):
        """Connects the socket to a remote address without blocking.

        May only be called if the socket passed to the constructor was
        not previously connected.  The address parameter is in the
        same format as for socket.connect, i.e. a (host, port) tuple.
        If callback is specified, it will be called when the
        connection is completed.

        Note that it is safe to call IOStream.write while the
        connection is pending, in which case the data will be written
        as soon as the connection is ready.  Calling IOStream read
        methods before the socket is connected works on some platforms
        but is non-portable.
        """
        self._connecting = True
        try:
            self.socket.connect(address)
        except socket.error, e:
            # In non-blocking mode connect() always raises an exception
            if e.args[0] not in (errno.EINPROGRESS, errno.EWOULDBLOCK):
                raise
        self._connect_callback = stack_context.wrap(callback)
        self._add_io_state(self.io_loop.WRITE)