193 lines
6.6 KiB
Python
193 lines
6.6 KiB
Python
###############################################################################
|
|
# Queue and SimpleQueue implementation for loky
|
|
#
|
|
# authors: Thomas Moreau, Olivier Grisel
|
|
#
|
|
# based on multiprocessing/queues.py (16/02/2017)
|
|
# * Add some custom reducers for the Queues/SimpleQueue to tweak the
|
|
# pickling process. (overload Queue._feed/SimpleQueue.put)
|
|
#
|
|
import os
|
|
import sys
|
|
import errno
|
|
import weakref
|
|
import threading
|
|
from multiprocessing import util
|
|
from multiprocessing.queues import (
|
|
Full,
|
|
Queue as mp_Queue,
|
|
SimpleQueue as mp_SimpleQueue,
|
|
_sentinel,
|
|
)
|
|
from multiprocessing.context import assert_spawning
|
|
|
|
from .reduction import dumps
|
|
|
|
|
|
__all__ = ['Queue', 'SimpleQueue', 'Full']
|
|
|
|
|
|
class Queue(mp_Queue):
|
|
|
|
def __init__(self, maxsize=0, reducers=None, ctx=None):
|
|
super().__init__(maxsize=maxsize, ctx=ctx)
|
|
self._reducers = reducers
|
|
|
|
# Use custom queue set/get state to be able to reduce the custom reducers
|
|
def __getstate__(self):
|
|
assert_spawning(self)
|
|
return (self._ignore_epipe, self._maxsize, self._reader, self._writer,
|
|
self._reducers, self._rlock, self._wlock, self._sem,
|
|
self._opid)
|
|
|
|
def __setstate__(self, state):
|
|
(self._ignore_epipe, self._maxsize, self._reader, self._writer,
|
|
self._reducers, self._rlock, self._wlock, self._sem,
|
|
self._opid) = state
|
|
if sys.version_info >= (3, 9):
|
|
self._reset()
|
|
else:
|
|
self._after_fork()
|
|
|
|
# Overload _start_thread to correctly call our custom _feed
|
|
def _start_thread(self):
|
|
util.debug('Queue._start_thread()')
|
|
|
|
# Start thread which transfers data from buffer to pipe
|
|
self._buffer.clear()
|
|
self._thread = threading.Thread(
|
|
target=Queue._feed,
|
|
args=(self._buffer, self._notempty, self._send_bytes,
|
|
self._wlock, self._writer.close, self._reducers,
|
|
self._ignore_epipe, self._on_queue_feeder_error, self._sem),
|
|
name='QueueFeederThread'
|
|
)
|
|
self._thread.daemon = True
|
|
|
|
util.debug('doing self._thread.start()')
|
|
self._thread.start()
|
|
util.debug('... done self._thread.start()')
|
|
|
|
# On process exit we will wait for data to be flushed to pipe.
|
|
#
|
|
# However, if this process created the queue then all
|
|
# processes which use the queue will be descendants of this
|
|
# process. Therefore waiting for the queue to be flushed
|
|
# is pointless once all the child processes have been joined.
|
|
created_by_this_process = (self._opid == os.getpid())
|
|
if not self._joincancelled and not created_by_this_process:
|
|
self._jointhread = util.Finalize(
|
|
self._thread, Queue._finalize_join,
|
|
[weakref.ref(self._thread)],
|
|
exitpriority=-5
|
|
)
|
|
|
|
# Send sentinel to the thread queue object when garbage collected
|
|
self._close = util.Finalize(
|
|
self, Queue._finalize_close,
|
|
[self._buffer, self._notempty],
|
|
exitpriority=10
|
|
)
|
|
|
|
# Overload the _feed methods to use our custom pickling strategy.
|
|
@staticmethod
|
|
def _feed(buffer, notempty, send_bytes, writelock, close, reducers,
|
|
ignore_epipe, onerror, queue_sem):
|
|
util.debug('starting thread to feed data to pipe')
|
|
nacquire = notempty.acquire
|
|
nrelease = notempty.release
|
|
nwait = notempty.wait
|
|
bpopleft = buffer.popleft
|
|
sentinel = _sentinel
|
|
if sys.platform != 'win32':
|
|
wacquire = writelock.acquire
|
|
wrelease = writelock.release
|
|
else:
|
|
wacquire = None
|
|
|
|
while True:
|
|
try:
|
|
nacquire()
|
|
try:
|
|
if not buffer:
|
|
nwait()
|
|
finally:
|
|
nrelease()
|
|
try:
|
|
while True:
|
|
obj = bpopleft()
|
|
if obj is sentinel:
|
|
util.debug('feeder thread got sentinel -- exiting')
|
|
close()
|
|
return
|
|
|
|
# serialize the data before acquiring the lock
|
|
obj_ = dumps(obj, reducers=reducers)
|
|
if wacquire is None:
|
|
send_bytes(obj_)
|
|
else:
|
|
wacquire()
|
|
try:
|
|
send_bytes(obj_)
|
|
finally:
|
|
wrelease()
|
|
# Remove references early to avoid leaking memory
|
|
del obj, obj_
|
|
except IndexError:
|
|
pass
|
|
except BaseException as e:
|
|
if ignore_epipe and getattr(e, 'errno', 0) == errno.EPIPE:
|
|
return
|
|
# Since this runs in a daemon thread the resources it uses
|
|
# may be become unusable while the process is cleaning up.
|
|
# We ignore errors which happen after the process has
|
|
# started to cleanup.
|
|
if util.is_exiting():
|
|
util.info(f'error in queue thread: {e}')
|
|
return
|
|
else:
|
|
queue_sem.release()
|
|
onerror(e, obj)
|
|
|
|
def _on_queue_feeder_error(self, e, obj):
|
|
"""
|
|
Private API hook called when feeding data in the background thread
|
|
raises an exception. For overriding by concurrent.futures.
|
|
"""
|
|
import traceback
|
|
traceback.print_exc()
|
|
|
|
|
|
class SimpleQueue(mp_SimpleQueue):
|
|
|
|
def __init__(self, reducers=None, ctx=None):
|
|
super().__init__(ctx=ctx)
|
|
|
|
# Add possiblity to use custom reducers
|
|
self._reducers = reducers
|
|
|
|
def close(self):
|
|
self._reader.close()
|
|
self._writer.close()
|
|
|
|
# Use custom queue set/get state to be able to reduce the custom reducers
|
|
def __getstate__(self):
|
|
assert_spawning(self)
|
|
return (self._reader, self._writer, self._reducers, self._rlock,
|
|
self._wlock)
|
|
|
|
def __setstate__(self, state):
|
|
(self._reader, self._writer, self._reducers, self._rlock,
|
|
self._wlock) = state
|
|
|
|
# Overload put to use our customizable reducer
|
|
def put(self, obj):
|
|
# serialize the data before acquiring the lock
|
|
obj = dumps(obj, reducers=self._reducers)
|
|
if self._wlock is None:
|
|
# writes to a message oriented win32 pipe are atomic
|
|
self._writer.send_bytes(obj)
|
|
else:
|
|
with self._wlock:
|
|
self._writer.send_bytes(obj)
|