Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 1 | # |
| 2 | # Module implementing queues |
| 3 | # |
| 4 | # multiprocessing/queues.py |
| 5 | # |
R. David Murray | 3fc969a | 2010-12-14 01:38:16 +0000 | [diff] [blame] | 6 | # Copyright (c) 2006-2008, R Oudkerk |
Richard Oudkerk | 3e268aa | 2012-04-30 12:13:55 +0100 | [diff] [blame] | 7 | # Licensed to PSF under a Contributor Agreement. |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 8 | # |
| 9 | |
Jesse Noller | 14f3ae2 | 2009-03-31 03:37:07 +0000 | [diff] [blame] | 10 | __all__ = ['Queue', 'SimpleQueue', 'JoinableQueue'] |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 11 | |
| 12 | import sys |
| 13 | import os |
| 14 | import threading |
| 15 | import collections |
| 16 | import time |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 17 | import weakref |
Antoine Pitrou | dc19c24 | 2011-07-16 01:51:58 +0200 | [diff] [blame] | 18 | import errno |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 19 | |
| 20 | from queue import Empty, Full |
Richard Oudkerk | 84ed9a6 | 2013-08-14 15:35:41 +0100 | [diff] [blame] | 21 | |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 22 | import _multiprocessing |
Richard Oudkerk | 84ed9a6 | 2013-08-14 15:35:41 +0100 | [diff] [blame] | 23 | |
| 24 | from . import connection |
Richard Oudkerk | b1694cf | 2013-10-16 16:41:56 +0100 | [diff] [blame] | 25 | from . import context |
Davin Potts | 5458647 | 2016-09-09 18:03:10 -0500 | [diff] [blame] | 26 | _ForkingPickler = context.reduction.ForkingPickler |
Richard Oudkerk | 84ed9a6 | 2013-08-14 15:35:41 +0100 | [diff] [blame] | 27 | |
| 28 | from .util import debug, info, Finalize, register_after_fork, is_exiting |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 29 | |
| 30 | # |
| 31 | # Queue type using a pipe, buffer and thread |
| 32 | # |
| 33 | |
| 34 | class Queue(object): |
| 35 | |
Richard Oudkerk | b1694cf | 2013-10-16 16:41:56 +0100 | [diff] [blame] | 36 | def __init__(self, maxsize=0, *, ctx): |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 37 | if maxsize <= 0: |
Berker Peksag | 7ecfc82 | 2015-04-08 17:56:30 +0300 | [diff] [blame] | 38 | # Can raise ImportError (see issues #3770 and #23400) |
| 39 | from .synchronize import SEM_VALUE_MAX as maxsize |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 40 | self._maxsize = maxsize |
Richard Oudkerk | 84ed9a6 | 2013-08-14 15:35:41 +0100 | [diff] [blame] | 41 | self._reader, self._writer = connection.Pipe(duplex=False) |
Richard Oudkerk | b1694cf | 2013-10-16 16:41:56 +0100 | [diff] [blame] | 42 | self._rlock = ctx.Lock() |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 43 | self._opid = os.getpid() |
| 44 | if sys.platform == 'win32': |
| 45 | self._wlock = None |
| 46 | else: |
Richard Oudkerk | b1694cf | 2013-10-16 16:41:56 +0100 | [diff] [blame] | 47 | self._wlock = ctx.Lock() |
| 48 | self._sem = ctx.BoundedSemaphore(maxsize) |
Antoine Pitrou | dc19c24 | 2011-07-16 01:51:58 +0200 | [diff] [blame] | 49 | # For use by concurrent.futures |
| 50 | self._ignore_epipe = False |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 51 | |
| 52 | self._after_fork() |
| 53 | |
| 54 | if sys.platform != 'win32': |
| 55 | register_after_fork(self, Queue._after_fork) |
| 56 | |
| 57 | def __getstate__(self): |
Richard Oudkerk | b1694cf | 2013-10-16 16:41:56 +0100 | [diff] [blame] | 58 | context.assert_spawning(self) |
Antoine Pitrou | fb96089 | 2011-07-20 02:01:39 +0200 | [diff] [blame] | 59 | return (self._ignore_epipe, self._maxsize, self._reader, self._writer, |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 60 | self._rlock, self._wlock, self._sem, self._opid) |
| 61 | |
| 62 | def __setstate__(self, state): |
Antoine Pitrou | fb96089 | 2011-07-20 02:01:39 +0200 | [diff] [blame] | 63 | (self._ignore_epipe, self._maxsize, self._reader, self._writer, |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 64 | self._rlock, self._wlock, self._sem, self._opid) = state |
| 65 | self._after_fork() |
| 66 | |
| 67 | def _after_fork(self): |
| 68 | debug('Queue._after_fork()') |
| 69 | self._notempty = threading.Condition(threading.Lock()) |
| 70 | self._buffer = collections.deque() |
| 71 | self._thread = None |
| 72 | self._jointhread = None |
| 73 | self._joincancelled = False |
| 74 | self._closed = False |
| 75 | self._close = None |
Charles-François Natali | 84e4316 | 2013-03-25 18:20:40 +0100 | [diff] [blame] | 76 | self._send_bytes = self._writer.send_bytes |
| 77 | self._recv_bytes = self._reader.recv_bytes |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 78 | self._poll = self._reader.poll |
| 79 | |
| 80 | def put(self, obj, block=True, timeout=None): |
Zackery Spytz | 0461704 | 2018-10-13 03:26:09 -0600 | [diff] [blame] | 81 | if self._closed: |
| 82 | raise ValueError(f"Queue {self!r} is closed") |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 83 | if not self._sem.acquire(block, timeout): |
| 84 | raise Full |
| 85 | |
Charles-François Natali | a924fc7 | 2014-05-25 14:12:12 +0100 | [diff] [blame] | 86 | with self._notempty: |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 87 | if self._thread is None: |
| 88 | self._start_thread() |
| 89 | self._buffer.append(obj) |
| 90 | self._notempty.notify() |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 91 | |
| 92 | def get(self, block=True, timeout=None): |
Zackery Spytz | 0461704 | 2018-10-13 03:26:09 -0600 | [diff] [blame] | 93 | if self._closed: |
| 94 | raise ValueError(f"Queue {self!r} is closed") |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 95 | if block and timeout is None: |
Charles-François Natali | 84e4316 | 2013-03-25 18:20:40 +0100 | [diff] [blame] | 96 | with self._rlock: |
| 97 | res = self._recv_bytes() |
| 98 | self._sem.release() |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 99 | else: |
| 100 | if block: |
Victor Stinner | c2368cb | 2018-07-06 13:51:52 +0200 | [diff] [blame] | 101 | deadline = time.monotonic() + timeout |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 102 | if not self._rlock.acquire(block, timeout): |
| 103 | raise Empty |
| 104 | try: |
Antoine Pitrou | a365113 | 2011-11-10 00:37:09 +0100 | [diff] [blame] | 105 | if block: |
Victor Stinner | c2368cb | 2018-07-06 13:51:52 +0200 | [diff] [blame] | 106 | timeout = deadline - time.monotonic() |
Victor Stinner | 1b7863c | 2017-06-10 13:10:13 +0200 | [diff] [blame] | 107 | if not self._poll(timeout): |
Antoine Pitrou | a365113 | 2011-11-10 00:37:09 +0100 | [diff] [blame] | 108 | raise Empty |
| 109 | elif not self._poll(): |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 110 | raise Empty |
Charles-François Natali | 84e4316 | 2013-03-25 18:20:40 +0100 | [diff] [blame] | 111 | res = self._recv_bytes() |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 112 | self._sem.release() |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 113 | finally: |
| 114 | self._rlock.release() |
Charles-François Natali | 84e4316 | 2013-03-25 18:20:40 +0100 | [diff] [blame] | 115 | # unserialize the data after having released the lock |
Davin Potts | 5458647 | 2016-09-09 18:03:10 -0500 | [diff] [blame] | 116 | return _ForkingPickler.loads(res) |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 117 | |
| 118 | def qsize(self): |
Benjamin Peterson | 87c8d87 | 2009-06-11 22:54:11 +0000 | [diff] [blame] | 119 | # Raises NotImplementedError on Mac OSX because of broken sem_getvalue() |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 120 | return self._maxsize - self._sem._semlock._get_value() |
| 121 | |
| 122 | def empty(self): |
| 123 | return not self._poll() |
| 124 | |
| 125 | def full(self): |
| 126 | return self._sem._semlock._is_zero() |
| 127 | |
| 128 | def get_nowait(self): |
| 129 | return self.get(False) |
| 130 | |
| 131 | def put_nowait(self, obj): |
| 132 | return self.put(obj, False) |
| 133 | |
| 134 | def close(self): |
| 135 | self._closed = True |
Serhiy Storchaka | 7e7a3db | 2015-04-10 13:24:41 +0300 | [diff] [blame] | 136 | try: |
| 137 | self._reader.close() |
| 138 | finally: |
| 139 | close = self._close |
| 140 | if close: |
| 141 | self._close = None |
| 142 | close() |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 143 | |
| 144 | def join_thread(self): |
| 145 | debug('Queue.join_thread()') |
Allen W. Smith, Ph.D | bd73e72 | 2017-08-29 17:52:18 -0500 | [diff] [blame] | 146 | assert self._closed, "Queue {0!r} not closed".format(self) |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 147 | if self._jointhread: |
| 148 | self._jointhread() |
| 149 | |
| 150 | def cancel_join_thread(self): |
| 151 | debug('Queue.cancel_join_thread()') |
| 152 | self._joincancelled = True |
| 153 | try: |
| 154 | self._jointhread.cancel() |
| 155 | except AttributeError: |
| 156 | pass |
| 157 | |
| 158 | def _start_thread(self): |
| 159 | debug('Queue._start_thread()') |
| 160 | |
| 161 | # Start thread which transfers data from buffer to pipe |
| 162 | self._buffer.clear() |
| 163 | self._thread = threading.Thread( |
| 164 | target=Queue._feed, |
Charles-François Natali | 84e4316 | 2013-03-25 18:20:40 +0100 | [diff] [blame] | 165 | args=(self._buffer, self._notempty, self._send_bytes, |
Thomas Moreau | 94459fd | 2018-01-05 11:15:54 +0100 | [diff] [blame] | 166 | self._wlock, self._writer.close, self._ignore_epipe, |
Thomas Moreau | e2f33ad | 2018-03-21 16:50:28 +0100 | [diff] [blame] | 167 | self._on_queue_feeder_error, self._sem), |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 168 | name='QueueFeederThread' |
Thomas Moreau | 94459fd | 2018-01-05 11:15:54 +0100 | [diff] [blame] | 169 | ) |
Benjamin Peterson | 7275370 | 2008-08-18 18:09:21 +0000 | [diff] [blame] | 170 | self._thread.daemon = True |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 171 | |
| 172 | debug('doing self._thread.start()') |
| 173 | self._thread.start() |
| 174 | debug('... done self._thread.start()') |
| 175 | |
Victor Stinner | 3b69d91 | 2017-07-10 12:45:21 +0200 | [diff] [blame] | 176 | if not self._joincancelled: |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 177 | self._jointhread = Finalize( |
| 178 | self._thread, Queue._finalize_join, |
| 179 | [weakref.ref(self._thread)], |
| 180 | exitpriority=-5 |
| 181 | ) |
| 182 | |
| 183 | # Send sentinel to the thread queue object when garbage collected |
| 184 | self._close = Finalize( |
| 185 | self, Queue._finalize_close, |
| 186 | [self._buffer, self._notempty], |
| 187 | exitpriority=10 |
| 188 | ) |
| 189 | |
| 190 | @staticmethod |
| 191 | def _finalize_join(twr): |
| 192 | debug('joining queue thread') |
| 193 | thread = twr() |
| 194 | if thread is not None: |
| 195 | thread.join() |
| 196 | debug('... queue thread joined') |
| 197 | else: |
| 198 | debug('... queue thread already dead') |
| 199 | |
| 200 | @staticmethod |
| 201 | def _finalize_close(buffer, notempty): |
| 202 | debug('telling queue thread to quit') |
Charles-François Natali | a924fc7 | 2014-05-25 14:12:12 +0100 | [diff] [blame] | 203 | with notempty: |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 204 | buffer.append(_sentinel) |
| 205 | notempty.notify() |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 206 | |
| 207 | @staticmethod |
Thomas Moreau | 94459fd | 2018-01-05 11:15:54 +0100 | [diff] [blame] | 208 | def _feed(buffer, notempty, send_bytes, writelock, close, ignore_epipe, |
Thomas Moreau | e2f33ad | 2018-03-21 16:50:28 +0100 | [diff] [blame] | 209 | onerror, queue_sem): |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 210 | debug('starting thread to feed data to pipe') |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 211 | nacquire = notempty.acquire |
| 212 | nrelease = notempty.release |
| 213 | nwait = notempty.wait |
| 214 | bpopleft = buffer.popleft |
| 215 | sentinel = _sentinel |
| 216 | if sys.platform != 'win32': |
| 217 | wacquire = writelock.acquire |
| 218 | wrelease = writelock.release |
| 219 | else: |
| 220 | wacquire = None |
| 221 | |
grzgrzgrz3 | bc50f03 | 2017-05-25 16:22:57 +0200 | [diff] [blame] | 222 | while 1: |
| 223 | try: |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 224 | nacquire() |
| 225 | try: |
| 226 | if not buffer: |
| 227 | nwait() |
| 228 | finally: |
| 229 | nrelease() |
| 230 | try: |
| 231 | while 1: |
| 232 | obj = bpopleft() |
| 233 | if obj is sentinel: |
| 234 | debug('feeder thread got sentinel -- exiting') |
| 235 | close() |
| 236 | return |
| 237 | |
Charles-François Natali | 84e4316 | 2013-03-25 18:20:40 +0100 | [diff] [blame] | 238 | # serialize the data before acquiring the lock |
Davin Potts | 5458647 | 2016-09-09 18:03:10 -0500 | [diff] [blame] | 239 | obj = _ForkingPickler.dumps(obj) |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 240 | if wacquire is None: |
Charles-François Natali | 84e4316 | 2013-03-25 18:20:40 +0100 | [diff] [blame] | 241 | send_bytes(obj) |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 242 | else: |
| 243 | wacquire() |
| 244 | try: |
Charles-François Natali | 84e4316 | 2013-03-25 18:20:40 +0100 | [diff] [blame] | 245 | send_bytes(obj) |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 246 | finally: |
| 247 | wrelease() |
| 248 | except IndexError: |
| 249 | pass |
grzgrzgrz3 | bc50f03 | 2017-05-25 16:22:57 +0200 | [diff] [blame] | 250 | except Exception as e: |
| 251 | if ignore_epipe and getattr(e, 'errno', 0) == errno.EPIPE: |
| 252 | return |
| 253 | # Since this runs in a daemon thread the resources it uses |
| 254 | # may be become unusable while the process is cleaning up. |
| 255 | # We ignore errors which happen after the process has |
| 256 | # started to cleanup. |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 257 | if is_exiting(): |
| 258 | info('error in queue thread: %s', e) |
grzgrzgrz3 | bc50f03 | 2017-05-25 16:22:57 +0200 | [diff] [blame] | 259 | return |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 260 | else: |
Thomas Moreau | e2f33ad | 2018-03-21 16:50:28 +0100 | [diff] [blame] | 261 | # Since the object has not been sent in the queue, we need |
| 262 | # to decrease the size of the queue. The error acts as |
| 263 | # if the object had been silently removed from the queue |
| 264 | # and this step is necessary to have a properly working |
| 265 | # queue. |
| 266 | queue_sem.release() |
Thomas Moreau | 94459fd | 2018-01-05 11:15:54 +0100 | [diff] [blame] | 267 | onerror(e, obj) |
| 268 | |
| 269 | @staticmethod |
| 270 | def _on_queue_feeder_error(e, obj): |
| 271 | """ |
| 272 | Private API hook called when feeding data in the background thread |
| 273 | raises an exception. For overriding by concurrent.futures. |
| 274 | """ |
| 275 | import traceback |
| 276 | traceback.print_exc() |
| 277 | |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 278 | |
| 279 | _sentinel = object() |
| 280 | |
| 281 | # |
| 282 | # A queue type which also supports join() and task_done() methods |
| 283 | # |
| 284 | # Note that if you do not call task_done() for each finished task then |
| 285 | # eventually the counter's semaphore may overflow causing Bad Things |
| 286 | # to happen. |
| 287 | # |
| 288 | |
| 289 | class JoinableQueue(Queue): |
| 290 | |
Richard Oudkerk | b1694cf | 2013-10-16 16:41:56 +0100 | [diff] [blame] | 291 | def __init__(self, maxsize=0, *, ctx): |
| 292 | Queue.__init__(self, maxsize, ctx=ctx) |
| 293 | self._unfinished_tasks = ctx.Semaphore(0) |
| 294 | self._cond = ctx.Condition() |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 295 | |
| 296 | def __getstate__(self): |
| 297 | return Queue.__getstate__(self) + (self._cond, self._unfinished_tasks) |
| 298 | |
| 299 | def __setstate__(self, state): |
| 300 | Queue.__setstate__(self, state[:-2]) |
| 301 | self._cond, self._unfinished_tasks = state[-2:] |
| 302 | |
Benjamin Peterson | 8719ad5 | 2009-09-11 22:24:02 +0000 | [diff] [blame] | 303 | def put(self, obj, block=True, timeout=None): |
Zackery Spytz | 0461704 | 2018-10-13 03:26:09 -0600 | [diff] [blame] | 304 | if self._closed: |
| 305 | raise ValueError(f"Queue {self!r} is closed") |
Benjamin Peterson | 8719ad5 | 2009-09-11 22:24:02 +0000 | [diff] [blame] | 306 | if not self._sem.acquire(block, timeout): |
| 307 | raise Full |
| 308 | |
Charles-François Natali | a924fc7 | 2014-05-25 14:12:12 +0100 | [diff] [blame] | 309 | with self._notempty, self._cond: |
Benjamin Peterson | 8719ad5 | 2009-09-11 22:24:02 +0000 | [diff] [blame] | 310 | if self._thread is None: |
| 311 | self._start_thread() |
| 312 | self._buffer.append(obj) |
| 313 | self._unfinished_tasks.release() |
| 314 | self._notempty.notify() |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 315 | |
| 316 | def task_done(self): |
Charles-François Natali | a924fc7 | 2014-05-25 14:12:12 +0100 | [diff] [blame] | 317 | with self._cond: |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 318 | if not self._unfinished_tasks.acquire(False): |
| 319 | raise ValueError('task_done() called too many times') |
| 320 | if self._unfinished_tasks._semlock._is_zero(): |
| 321 | self._cond.notify_all() |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 322 | |
| 323 | def join(self): |
Charles-François Natali | a924fc7 | 2014-05-25 14:12:12 +0100 | [diff] [blame] | 324 | with self._cond: |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 325 | if not self._unfinished_tasks._semlock._is_zero(): |
| 326 | self._cond.wait() |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 327 | |
| 328 | # |
| 329 | # Simplified Queue type -- really just a locked pipe |
| 330 | # |
| 331 | |
| 332 | class SimpleQueue(object): |
| 333 | |
Richard Oudkerk | b1694cf | 2013-10-16 16:41:56 +0100 | [diff] [blame] | 334 | def __init__(self, *, ctx): |
Richard Oudkerk | 84ed9a6 | 2013-08-14 15:35:41 +0100 | [diff] [blame] | 335 | self._reader, self._writer = connection.Pipe(duplex=False) |
Richard Oudkerk | b1694cf | 2013-10-16 16:41:56 +0100 | [diff] [blame] | 336 | self._rlock = ctx.Lock() |
Antoine Pitrou | bdb1cf1 | 2012-03-05 19:28:37 +0100 | [diff] [blame] | 337 | self._poll = self._reader.poll |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 338 | if sys.platform == 'win32': |
| 339 | self._wlock = None |
| 340 | else: |
Richard Oudkerk | b1694cf | 2013-10-16 16:41:56 +0100 | [diff] [blame] | 341 | self._wlock = ctx.Lock() |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 342 | |
| 343 | def empty(self): |
Antoine Pitrou | bdb1cf1 | 2012-03-05 19:28:37 +0100 | [diff] [blame] | 344 | return not self._poll() |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 345 | |
| 346 | def __getstate__(self): |
Richard Oudkerk | b1694cf | 2013-10-16 16:41:56 +0100 | [diff] [blame] | 347 | context.assert_spawning(self) |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 348 | return (self._reader, self._writer, self._rlock, self._wlock) |
| 349 | |
| 350 | def __setstate__(self, state): |
| 351 | (self._reader, self._writer, self._rlock, self._wlock) = state |
Xiang Zhang | 6f75bc0 | 2017-05-17 21:04:00 +0800 | [diff] [blame] | 352 | self._poll = self._reader.poll |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 353 | |
Charles-François Natali | 84e4316 | 2013-03-25 18:20:40 +0100 | [diff] [blame] | 354 | def get(self): |
| 355 | with self._rlock: |
| 356 | res = self._reader.recv_bytes() |
| 357 | # unserialize the data after having released the lock |
Davin Potts | 5458647 | 2016-09-09 18:03:10 -0500 | [diff] [blame] | 358 | return _ForkingPickler.loads(res) |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 359 | |
Charles-François Natali | 84e4316 | 2013-03-25 18:20:40 +0100 | [diff] [blame] | 360 | def put(self, obj): |
| 361 | # serialize the data before acquiring the lock |
Davin Potts | 5458647 | 2016-09-09 18:03:10 -0500 | [diff] [blame] | 362 | obj = _ForkingPickler.dumps(obj) |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 363 | if self._wlock is None: |
| 364 | # writes to a message oriented win32 pipe are atomic |
Charles-François Natali | 84e4316 | 2013-03-25 18:20:40 +0100 | [diff] [blame] | 365 | self._writer.send_bytes(obj) |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 366 | else: |
Charles-François Natali | 84e4316 | 2013-03-25 18:20:40 +0100 | [diff] [blame] | 367 | with self._wlock: |
| 368 | self._writer.send_bytes(obj) |