| """Event loop using a proactor and related classes. |
| |
| A proactor is a "notify-on-completion" multiplexer. Currently a |
| proactor is only implemented on Windows with IOCP. |
| """ |
| |
| import socket |
| |
| from . import base_events |
| from . import constants |
| from . import futures |
| from . import transports |
| from .log import logger |
| |
| |
| class _ProactorBasePipeTransport(transports.BaseTransport): |
| """Base class for pipe and socket transports.""" |
| |
| def __init__(self, loop, sock, protocol, waiter=None, |
| extra=None, server=None): |
| super().__init__(extra) |
| self._set_extra(sock) |
| self._loop = loop |
| self._sock = sock |
| self._protocol = protocol |
| self._server = server |
| self._buffer = [] |
| self._read_fut = None |
| self._write_fut = None |
| self._conn_lost = 0 |
| self._closing = False # Set when close() called. |
| self._eof_written = False |
| if self._server is not None: |
| self._server.attach(self) |
| self._loop.call_soon(self._protocol.connection_made, self) |
| if waiter is not None: |
| self._loop.call_soon(waiter.set_result, None) |
| |
| def _set_extra(self, sock): |
| self._extra['pipe'] = sock |
| |
| def close(self): |
| if self._closing: |
| return |
| self._closing = True |
| self._conn_lost += 1 |
| if not self._buffer and self._write_fut is None: |
| self._loop.call_soon(self._call_connection_lost, None) |
| if self._read_fut is not None: |
| self._read_fut.cancel() |
| |
| def _fatal_error(self, exc): |
| logger.exception('Fatal error for %s', self) |
| self._force_close(exc) |
| |
| def _force_close(self, exc): |
| if self._closing: |
| return |
| self._closing = True |
| self._conn_lost += 1 |
| if self._write_fut: |
| self._write_fut.cancel() |
| if self._read_fut: |
| self._read_fut.cancel() |
| self._write_fut = self._read_fut = None |
| self._buffer = [] |
| self._loop.call_soon(self._call_connection_lost, exc) |
| |
| def _call_connection_lost(self, exc): |
| try: |
| self._protocol.connection_lost(exc) |
| finally: |
| # XXX If there is a pending overlapped read on the other |
| # end then it may fail with ERROR_NETNAME_DELETED if we |
| # just close our end. First calling shutdown() seems to |
| # cure it, but maybe using DisconnectEx() would be better. |
| if hasattr(self._sock, 'shutdown'): |
| self._sock.shutdown(socket.SHUT_RDWR) |
| self._sock.close() |
| server = self._server |
| if server is not None: |
| server.detach(self) |
| self._server = None |
| |
| |
| class _ProactorReadPipeTransport(_ProactorBasePipeTransport, |
| transports.ReadTransport): |
| """Transport for read pipes.""" |
| |
| def __init__(self, loop, sock, protocol, waiter=None, |
| extra=None, server=None): |
| super().__init__(loop, sock, protocol, waiter, extra, server) |
| self._read_fut = None |
| self._paused = False |
| self._loop.call_soon(self._loop_reading) |
| |
| def pause_reading(self): |
| assert not self._closing, 'Cannot pause_reading() when closing' |
| assert not self._paused, 'Already paused' |
| self._paused = True |
| |
| def resume_reading(self): |
| assert self._paused, 'Not paused' |
| self._paused = False |
| if self._closing: |
| return |
| self._loop.call_soon(self._loop_reading, self._read_fut) |
| |
| def _loop_reading(self, fut=None): |
| if self._paused: |
| return |
| data = None |
| |
| try: |
| if fut is not None: |
| assert self._read_fut is fut or (self._read_fut is None and |
| self._closing) |
| self._read_fut = None |
| data = fut.result() # deliver data later in "finally" clause |
| |
| if self._closing: |
| # since close() has been called we ignore any read data |
| data = None |
| return |
| |
| if data == b'': |
| # we got end-of-file so no need to reschedule a new read |
| return |
| |
| # reschedule a new read |
| self._read_fut = self._loop._proactor.recv(self._sock, 4096) |
| except ConnectionAbortedError as exc: |
| if not self._closing: |
| self._fatal_error(exc) |
| except ConnectionResetError as exc: |
| self._force_close(exc) |
| except OSError as exc: |
| self._fatal_error(exc) |
| except futures.CancelledError: |
| if not self._closing: |
| raise |
| else: |
| self._read_fut.add_done_callback(self._loop_reading) |
| finally: |
| if data: |
| self._protocol.data_received(data) |
| elif data is not None: |
| keep_open = self._protocol.eof_received() |
| if not keep_open: |
| self.close() |
| |
| |
| class _ProactorWritePipeTransport(_ProactorBasePipeTransport, |
| transports.WriteTransport): |
| """Transport for write pipes.""" |
| |
| def write(self, data): |
| assert isinstance(data, bytes), repr(data) |
| if self._eof_written: |
| raise IOError('write_eof() already called') |
| |
| if not data: |
| return |
| |
| if self._conn_lost: |
| if self._conn_lost >= constants.LOG_THRESHOLD_FOR_CONNLOST_WRITES: |
| logger.warning('socket.send() raised exception.') |
| self._conn_lost += 1 |
| return |
| self._buffer.append(data) |
| if self._write_fut is None: |
| self._loop_writing() |
| |
| def _loop_writing(self, f=None): |
| try: |
| assert f is self._write_fut |
| self._write_fut = None |
| if f: |
| f.result() |
| data = b''.join(self._buffer) |
| self._buffer = [] |
| 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) |
| return |
| self._write_fut = self._loop._proactor.send(self._sock, data) |
| 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) |
| |
| def can_write_eof(self): |
| return True |
| |
| def write_eof(self): |
| self.close() |
| |
| def abort(self): |
| self._force_close(None) |
| |
| |
| class _ProactorDuplexPipeTransport(_ProactorReadPipeTransport, |
| _ProactorWritePipeTransport, |
| transports.Transport): |
| """Transport for duplex pipes.""" |
| |
| def can_write_eof(self): |
| return False |
| |
| def write_eof(self): |
| raise NotImplementedError |
| |
| |
| class _ProactorSocketTransport(_ProactorReadPipeTransport, |
| _ProactorWritePipeTransport, |
| transports.Transport): |
| """Transport for connected sockets.""" |
| |
| def _set_extra(self, sock): |
| self._extra['socket'] = sock |
| try: |
| self._extra['sockname'] = sock.getsockname() |
| except (socket.error, AttributeError): |
| pass |
| if 'peername' not in self._extra: |
| try: |
| self._extra['peername'] = sock.getpeername() |
| except (socket.error, AttributeError): |
| pass |
| |
| def can_write_eof(self): |
| return True |
| |
| def write_eof(self): |
| if self._closing or self._eof_written: |
| return |
| self._eof_written = True |
| if self._write_fut is None: |
| self._sock.shutdown(socket.SHUT_WR) |
| |
| |
| class BaseProactorEventLoop(base_events.BaseEventLoop): |
| |
| def __init__(self, proactor): |
| super().__init__() |
| logger.debug('Using proactor: %s', proactor.__class__.__name__) |
| self._proactor = proactor |
| self._selector = proactor # convenient alias |
| proactor.set_loop(self) |
| self._make_self_pipe() |
| |
| def _make_socket_transport(self, sock, protocol, waiter=None, |
| extra=None, server=None): |
| return _ProactorSocketTransport(self, sock, protocol, waiter, |
| extra, server) |
| |
| def _make_duplex_pipe_transport(self, sock, protocol, waiter=None, |
| extra=None): |
| return _ProactorDuplexPipeTransport(self, |
| sock, protocol, waiter, extra) |
| |
| def _make_read_pipe_transport(self, sock, protocol, waiter=None, |
| extra=None): |
| return _ProactorReadPipeTransport(self, sock, protocol, waiter, extra) |
| |
| def _make_write_pipe_transport(self, sock, protocol, waiter=None, |
| extra=None, check_for_hangup=True): |
| if check_for_hangup: |
| # We want connection_lost() to be called when other end closes |
| return _ProactorDuplexPipeTransport(self, |
| sock, protocol, waiter, extra) |
| else: |
| # If other end closes we may not notice for a long time |
| return _ProactorWritePipeTransport(self, sock, protocol, waiter, |
| extra) |
| |
| def close(self): |
| if self._proactor is not None: |
| self._close_self_pipe() |
| self._proactor.close() |
| self._proactor = None |
| self._selector = None |
| super().close() |
| |
| def sock_recv(self, sock, n): |
| return self._proactor.recv(sock, n) |
| |
| def sock_sendall(self, sock, data): |
| return self._proactor.send(sock, data) |
| |
| def sock_connect(self, sock, address): |
| return self._proactor.connect(sock, address) |
| |
| def sock_accept(self, sock): |
| return self._proactor.accept(sock) |
| |
| def _socketpair(self): |
| raise NotImplementedError |
| |
| def _close_self_pipe(self): |
| self._ssock.close() |
| self._ssock = None |
| self._csock.close() |
| self._csock = None |
| self._internal_fds -= 1 |
| |
| def _make_self_pipe(self): |
| # A self-socket, really. :-) |
| self._ssock, self._csock = self._socketpair() |
| self._ssock.setblocking(False) |
| self._csock.setblocking(False) |
| self._internal_fds += 1 |
| self.call_soon(self._loop_self_reading) |
| |
| def _loop_self_reading(self, f=None): |
| try: |
| if f is not None: |
| f.result() # may raise |
| f = self._proactor.recv(self._ssock, 4096) |
| except: |
| self.close() |
| raise |
| else: |
| f.add_done_callback(self._loop_self_reading) |
| |
| def _write_to_self(self): |
| self._csock.send(b'x') |
| |
| def _start_serving(self, protocol_factory, sock, ssl=None, server=None): |
| assert not ssl, 'IocpEventLoop is incompatible with SSL.' |
| |
| def loop(f=None): |
| try: |
| if f is not None: |
| conn, addr = f.result() |
| protocol = protocol_factory() |
| self._make_socket_transport( |
| conn, protocol, |
| extra={'peername': addr}, server=server) |
| f = self._proactor.accept(sock) |
| except OSError: |
| if sock.fileno() != -1: |
| logger.exception('Accept failed') |
| sock.close() |
| except futures.CancelledError: |
| sock.close() |
| else: |
| f.add_done_callback(loop) |
| |
| self.call_soon(loop) |
| |
| def _process_events(self, event_list): |
| pass # XXX hard work currently done in poll |
| |
| def _stop_serving(self, sock): |
| self._proactor._stop_serving(sock) |
| sock.close() |