twisted.py 文件源码

def addReader(self, reader):
        if reader in self._readers:
            # Don't add the reader if it's already there
            return
        fd = reader.fileno()
        self._readers[reader] = fd
        if fd in self._fds:
            (_, writer) = self._fds[fd]
            self._fds[fd] = (reader, writer)
            if writer:
                # We already registered this fd for write events,
                # update it for read events as well.
                self._io_loop.update_handler(fd, IOLoop.READ | IOLoop.WRITE)
        else:
            with NullContext():
                self._fds[fd] = (reader, None)
                self._io_loop.add_handler(fd, self._invoke_callback,
                                          IOLoop.READ)