twisted.py 文件源码

def addWriter(self, writer):
        """
        Add a FileDescriptor for notification of data available to write.
        """
        if writer in self._writers:
            return
        self._writers[writer] = True
        fd = writer.fileno()
        if fd in self._fds:
            (reader, _) = self._fds[fd]
            self._fds[fd] = (reader, writer)
            if reader:
                # We already registered this fd for read events,
                # update it for write events as well.
                self._io_loop.update_handler(fd, IOLoop.READ | IOLoop.WRITE)
        else:
            with NullContext():
                self._fds[fd] = (None, writer)
                self._io_loop.add_handler(fd, self._invoke_callback,
                                         IOLoop.WRITE)