Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 1 | """Event loop using a proactor and related classes. |
| 2 | |
| 3 | A proactor is a "notify-on-completion" multiplexer. Currently a |
| 4 | proactor is only implemented on Windows with IOCP. |
| 5 | """ |
| 6 | |
| 7 | import socket |
| 8 | |
| 9 | from . import base_events |
| 10 | from . import constants |
| 11 | from . import futures |
| 12 | from . import transports |
Guido van Rossum | fc29e0f | 2013-10-17 15:39:45 -0700 | [diff] [blame^] | 13 | from .log import logger |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 14 | |
| 15 | |
| 16 | class _ProactorBasePipeTransport(transports.BaseTransport): |
| 17 | """Base class for pipe and socket transports.""" |
| 18 | |
| 19 | def __init__(self, loop, sock, protocol, waiter=None, |
| 20 | extra=None, server=None): |
| 21 | super().__init__(extra) |
| 22 | self._set_extra(sock) |
| 23 | self._loop = loop |
| 24 | self._sock = sock |
| 25 | self._protocol = protocol |
| 26 | self._server = server |
| 27 | self._buffer = [] |
| 28 | self._read_fut = None |
| 29 | self._write_fut = None |
| 30 | self._conn_lost = 0 |
| 31 | self._closing = False # Set when close() called. |
| 32 | self._eof_written = False |
| 33 | if self._server is not None: |
| 34 | self._server.attach(self) |
| 35 | self._loop.call_soon(self._protocol.connection_made, self) |
| 36 | if waiter is not None: |
| 37 | self._loop.call_soon(waiter.set_result, None) |
| 38 | |
| 39 | def _set_extra(self, sock): |
| 40 | self._extra['pipe'] = sock |
| 41 | |
| 42 | def close(self): |
| 43 | if self._closing: |
| 44 | return |
| 45 | self._closing = True |
| 46 | self._conn_lost += 1 |
| 47 | if not self._buffer and self._write_fut is None: |
| 48 | self._loop.call_soon(self._call_connection_lost, None) |
| 49 | if self._read_fut is not None: |
| 50 | self._read_fut.cancel() |
| 51 | |
| 52 | def _fatal_error(self, exc): |
Guido van Rossum | fc29e0f | 2013-10-17 15:39:45 -0700 | [diff] [blame^] | 53 | logger.exception('Fatal error for %s', self) |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 54 | self._force_close(exc) |
| 55 | |
| 56 | def _force_close(self, exc): |
| 57 | if self._closing: |
| 58 | return |
| 59 | self._closing = True |
| 60 | self._conn_lost += 1 |
| 61 | if self._write_fut: |
| 62 | self._write_fut.cancel() |
| 63 | if self._read_fut: |
| 64 | self._read_fut.cancel() |
| 65 | self._write_fut = self._read_fut = None |
| 66 | self._buffer = [] |
| 67 | self._loop.call_soon(self._call_connection_lost, exc) |
| 68 | |
| 69 | def _call_connection_lost(self, exc): |
| 70 | try: |
| 71 | self._protocol.connection_lost(exc) |
| 72 | finally: |
| 73 | # XXX If there is a pending overlapped read on the other |
| 74 | # end then it may fail with ERROR_NETNAME_DELETED if we |
| 75 | # just close our end. First calling shutdown() seems to |
| 76 | # cure it, but maybe using DisconnectEx() would be better. |
| 77 | if hasattr(self._sock, 'shutdown'): |
| 78 | self._sock.shutdown(socket.SHUT_RDWR) |
| 79 | self._sock.close() |
| 80 | server = self._server |
| 81 | if server is not None: |
| 82 | server.detach(self) |
| 83 | self._server = None |
| 84 | |
| 85 | |
| 86 | class _ProactorReadPipeTransport(_ProactorBasePipeTransport, |
| 87 | transports.ReadTransport): |
| 88 | """Transport for read pipes.""" |
| 89 | |
| 90 | def __init__(self, loop, sock, protocol, waiter=None, |
| 91 | extra=None, server=None): |
| 92 | super().__init__(loop, sock, protocol, waiter, extra, server) |
| 93 | self._read_fut = None |
| 94 | self._paused = False |
| 95 | self._loop.call_soon(self._loop_reading) |
| 96 | |
| 97 | def pause(self): |
| 98 | assert not self._closing, 'Cannot pause() when closing' |
| 99 | assert not self._paused, 'Already paused' |
| 100 | self._paused = True |
| 101 | |
| 102 | def resume(self): |
| 103 | assert self._paused, 'Not paused' |
| 104 | self._paused = False |
| 105 | if self._closing: |
| 106 | return |
| 107 | self._loop.call_soon(self._loop_reading, self._read_fut) |
| 108 | |
| 109 | def _loop_reading(self, fut=None): |
| 110 | if self._paused: |
| 111 | return |
| 112 | data = None |
| 113 | |
| 114 | try: |
| 115 | if fut is not None: |
| 116 | assert self._read_fut is fut or (self._read_fut is None and |
| 117 | self._closing) |
| 118 | self._read_fut = None |
| 119 | data = fut.result() # deliver data later in "finally" clause |
| 120 | |
| 121 | if self._closing: |
| 122 | # since close() has been called we ignore any read data |
| 123 | data = None |
| 124 | return |
| 125 | |
| 126 | if data == b'': |
| 127 | # we got end-of-file so no need to reschedule a new read |
| 128 | return |
| 129 | |
| 130 | # reschedule a new read |
| 131 | self._read_fut = self._loop._proactor.recv(self._sock, 4096) |
| 132 | except ConnectionAbortedError as exc: |
| 133 | if not self._closing: |
| 134 | self._fatal_error(exc) |
| 135 | except ConnectionResetError as exc: |
| 136 | self._force_close(exc) |
| 137 | except OSError as exc: |
| 138 | self._fatal_error(exc) |
| 139 | except futures.CancelledError: |
| 140 | if not self._closing: |
| 141 | raise |
| 142 | else: |
| 143 | self._read_fut.add_done_callback(self._loop_reading) |
| 144 | finally: |
| 145 | if data: |
| 146 | self._protocol.data_received(data) |
| 147 | elif data is not None: |
| 148 | keep_open = self._protocol.eof_received() |
| 149 | if not keep_open: |
| 150 | self.close() |
| 151 | |
| 152 | |
| 153 | class _ProactorWritePipeTransport(_ProactorBasePipeTransport, |
| 154 | transports.WriteTransport): |
| 155 | """Transport for write pipes.""" |
| 156 | |
| 157 | def write(self, data): |
| 158 | assert isinstance(data, bytes), repr(data) |
| 159 | if self._eof_written: |
| 160 | raise IOError('write_eof() already called') |
| 161 | |
| 162 | if not data: |
| 163 | return |
| 164 | |
| 165 | if self._conn_lost: |
| 166 | if self._conn_lost >= constants.LOG_THRESHOLD_FOR_CONNLOST_WRITES: |
Guido van Rossum | fc29e0f | 2013-10-17 15:39:45 -0700 | [diff] [blame^] | 167 | logger.warning('socket.send() raised exception.') |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 168 | self._conn_lost += 1 |
| 169 | return |
| 170 | self._buffer.append(data) |
| 171 | if self._write_fut is None: |
| 172 | self._loop_writing() |
| 173 | |
| 174 | def _loop_writing(self, f=None): |
| 175 | try: |
| 176 | assert f is self._write_fut |
| 177 | self._write_fut = None |
| 178 | if f: |
| 179 | f.result() |
| 180 | data = b''.join(self._buffer) |
| 181 | self._buffer = [] |
| 182 | if not data: |
| 183 | if self._closing: |
| 184 | self._loop.call_soon(self._call_connection_lost, None) |
| 185 | if self._eof_written: |
| 186 | self._sock.shutdown(socket.SHUT_WR) |
| 187 | return |
| 188 | self._write_fut = self._loop._proactor.send(self._sock, data) |
| 189 | self._write_fut.add_done_callback(self._loop_writing) |
| 190 | except ConnectionResetError as exc: |
| 191 | self._force_close(exc) |
| 192 | except OSError as exc: |
| 193 | self._fatal_error(exc) |
| 194 | |
| 195 | def can_write_eof(self): |
| 196 | return True |
| 197 | |
| 198 | def write_eof(self): |
| 199 | self.close() |
| 200 | |
| 201 | def abort(self): |
| 202 | self._force_close(None) |
| 203 | |
| 204 | |
| 205 | class _ProactorDuplexPipeTransport(_ProactorReadPipeTransport, |
| 206 | _ProactorWritePipeTransport, |
| 207 | transports.Transport): |
| 208 | """Transport for duplex pipes.""" |
| 209 | |
| 210 | def can_write_eof(self): |
| 211 | return False |
| 212 | |
| 213 | def write_eof(self): |
| 214 | raise NotImplementedError |
| 215 | |
| 216 | |
| 217 | class _ProactorSocketTransport(_ProactorReadPipeTransport, |
| 218 | _ProactorWritePipeTransport, |
| 219 | transports.Transport): |
| 220 | """Transport for connected sockets.""" |
| 221 | |
| 222 | def _set_extra(self, sock): |
| 223 | self._extra['socket'] = sock |
| 224 | try: |
| 225 | self._extra['sockname'] = sock.getsockname() |
| 226 | except (socket.error, AttributeError): |
| 227 | pass |
| 228 | if 'peername' not in self._extra: |
| 229 | try: |
| 230 | self._extra['peername'] = sock.getpeername() |
| 231 | except (socket.error, AttributeError): |
| 232 | pass |
| 233 | |
| 234 | def can_write_eof(self): |
| 235 | return True |
| 236 | |
| 237 | def write_eof(self): |
| 238 | if self._closing or self._eof_written: |
| 239 | return |
| 240 | self._eof_written = True |
| 241 | if self._write_fut is None: |
| 242 | self._sock.shutdown(socket.SHUT_WR) |
| 243 | |
| 244 | |
| 245 | class BaseProactorEventLoop(base_events.BaseEventLoop): |
| 246 | |
| 247 | def __init__(self, proactor): |
| 248 | super().__init__() |
Guido van Rossum | fc29e0f | 2013-10-17 15:39:45 -0700 | [diff] [blame^] | 249 | logger.debug('Using proactor: %s', proactor.__class__.__name__) |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 250 | self._proactor = proactor |
| 251 | self._selector = proactor # convenient alias |
| 252 | proactor.set_loop(self) |
| 253 | self._make_self_pipe() |
| 254 | |
| 255 | def _make_socket_transport(self, sock, protocol, waiter=None, |
| 256 | extra=None, server=None): |
| 257 | return _ProactorSocketTransport(self, sock, protocol, waiter, |
| 258 | extra, server) |
| 259 | |
| 260 | def _make_duplex_pipe_transport(self, sock, protocol, waiter=None, |
| 261 | extra=None): |
| 262 | return _ProactorDuplexPipeTransport(self, |
| 263 | sock, protocol, waiter, extra) |
| 264 | |
| 265 | def _make_read_pipe_transport(self, sock, protocol, waiter=None, |
| 266 | extra=None): |
| 267 | return _ProactorReadPipeTransport(self, sock, protocol, waiter, extra) |
| 268 | |
| 269 | def _make_write_pipe_transport(self, sock, protocol, waiter=None, |
| 270 | extra=None): |
| 271 | return _ProactorWritePipeTransport(self, sock, protocol, waiter, extra) |
| 272 | |
| 273 | def close(self): |
| 274 | if self._proactor is not None: |
| 275 | self._close_self_pipe() |
| 276 | self._proactor.close() |
| 277 | self._proactor = None |
| 278 | self._selector = None |
| 279 | |
| 280 | def sock_recv(self, sock, n): |
| 281 | return self._proactor.recv(sock, n) |
| 282 | |
| 283 | def sock_sendall(self, sock, data): |
| 284 | return self._proactor.send(sock, data) |
| 285 | |
| 286 | def sock_connect(self, sock, address): |
| 287 | return self._proactor.connect(sock, address) |
| 288 | |
| 289 | def sock_accept(self, sock): |
| 290 | return self._proactor.accept(sock) |
| 291 | |
| 292 | def _socketpair(self): |
| 293 | raise NotImplementedError |
| 294 | |
| 295 | def _close_self_pipe(self): |
| 296 | self._ssock.close() |
| 297 | self._ssock = None |
| 298 | self._csock.close() |
| 299 | self._csock = None |
| 300 | self._internal_fds -= 1 |
| 301 | |
| 302 | def _make_self_pipe(self): |
| 303 | # A self-socket, really. :-) |
| 304 | self._ssock, self._csock = self._socketpair() |
| 305 | self._ssock.setblocking(False) |
| 306 | self._csock.setblocking(False) |
| 307 | self._internal_fds += 1 |
| 308 | self.call_soon(self._loop_self_reading) |
| 309 | |
| 310 | def _loop_self_reading(self, f=None): |
| 311 | try: |
| 312 | if f is not None: |
| 313 | f.result() # may raise |
| 314 | f = self._proactor.recv(self._ssock, 4096) |
| 315 | except: |
| 316 | self.close() |
| 317 | raise |
| 318 | else: |
| 319 | f.add_done_callback(self._loop_self_reading) |
| 320 | |
| 321 | def _write_to_self(self): |
| 322 | self._csock.send(b'x') |
| 323 | |
| 324 | def _start_serving(self, protocol_factory, sock, ssl=None, server=None): |
| 325 | assert not ssl, 'IocpEventLoop is incompatible with SSL.' |
| 326 | |
| 327 | def loop(f=None): |
| 328 | try: |
| 329 | if f is not None: |
| 330 | conn, addr = f.result() |
| 331 | protocol = protocol_factory() |
| 332 | self._make_socket_transport( |
| 333 | conn, protocol, |
| 334 | extra={'peername': addr}, server=server) |
| 335 | f = self._proactor.accept(sock) |
| 336 | except OSError: |
| 337 | if sock.fileno() != -1: |
Guido van Rossum | fc29e0f | 2013-10-17 15:39:45 -0700 | [diff] [blame^] | 338 | logger.exception('Accept failed') |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 339 | sock.close() |
| 340 | except futures.CancelledError: |
| 341 | sock.close() |
| 342 | else: |
| 343 | f.add_done_callback(loop) |
| 344 | |
| 345 | self.call_soon(loop) |
| 346 | |
| 347 | def _process_events(self, event_list): |
| 348 | pass # XXX hard work currently done in poll |
| 349 | |
| 350 | def _stop_serving(self, sock): |
| 351 | self._proactor._stop_serving(sock) |
| 352 | sock.close() |