proactor_events.py 文件源码

def _loop_writing(self, f=None, data=None):
        try:
            assert f is self._write_fut
            self._write_fut = None
            self._pending_write = 0
            if f:
                f.result()
            if data is None:
                data = self._buffer
                self._buffer = None
            if not data:
                if self._closing:
                    self._loop.call_soon(self._call_connection_lost, None)
                if self._eof_written:
                    self._sock.shutdown(socket.SHUT_WR)
                # Now that we've reduced the buffer size, tell the
                # protocol to resume writing if it was paused.  Note that
                # we do this last since the callback is called immediately
                # and it may add more data to the buffer (even causing the
                # protocol to be paused again).
                self._maybe_resume_protocol()
            else:
                self._write_fut = self._loop._proactor.send(self._sock, data)
                if not self._write_fut.done():
                    assert self._pending_write == 0
                    self._pending_write = len(data)
                    self._write_fut.add_done_callback(self._loop_writing)
                    self._maybe_pause_protocol()
                else:
                    self._write_fut.add_done_callback(self._loop_writing)
        except ConnectionResetError as exc:
            self._force_close(exc)
        except OSError as exc:
            self._fatal_error(exc, 'Fatal write error on pipe transport')