[Python-checkins] Revert "[2.7] bpo-34172: multiprocessing.Pool leaks resources after being deleted (GH-9686)" (GH-10970)
Victor Stinner
webhook-mailer at python.org
Wed Dec 5 19:49:44 EST 2018
https://github.com/python/cpython/commit/358fc87f53cf97a1768d5b1ded08f2a564f9fd85
commit: 358fc87f53cf97a1768d5b1ded08f2a564f9fd85
branch: 2.7
author: Victor Stinner <vstinner at redhat.com>
committer: GitHub <noreply at github.com>
date: 2018-12-06T01:49:41+01:00
summary:
Revert "[2.7] bpo-34172: multiprocessing.Pool leaks resources after being deleted (GH-9686)" (GH-10970)
This reverts commit 4a7dd30f5810e8861a3834159a222ab32d5c97d0.
files:
D Misc/NEWS.d/next/Library/2018-07-26-10-31-52.bpo-34172.8ovLNi.rst
M Lib/multiprocessing/pool.py
M Lib/test/test_multiprocessing.py
diff --git a/Lib/multiprocessing/pool.py b/Lib/multiprocessing/pool.py
index 489c7d67cf34..a47cd0f58a05 100644
--- a/Lib/multiprocessing/pool.py
+++ b/Lib/multiprocessing/pool.py
@@ -162,9 +162,7 @@ def __init__(self, processes=None, initializer=None, initargs=(),
self._worker_handler = threading.Thread(
target=Pool._handle_workers,
- args=(self._cache, self._processes, self._pool, self.Process,
- self._inqueue, self._outqueue, self._initializer,
- self._initargs, self._maxtasksperchild, self._taskqueue)
+ args=(self, )
)
self._worker_handler.daemon = True
self._worker_handler._state = RUN
@@ -196,56 +194,42 @@ def __init__(self, processes=None, initializer=None, initargs=(),
exitpriority=15
)
- @staticmethod
- def _join_exited_workers(pool):
+ def _join_exited_workers(self):
"""Cleanup after any worker processes which have exited due to reaching
their specified lifetime. Returns True if any workers were cleaned up.
"""
cleaned = False
- for i in reversed(range(len(pool))):
- worker = pool[i]
+ for i in reversed(range(len(self._pool))):
+ worker = self._pool[i]
if worker.exitcode is not None:
# worker exited
debug('cleaning up worker %d' % i)
worker.join()
cleaned = True
- del pool[i]
+ del self._pool[i]
return cleaned
def _repopulate_pool(self):
- return self._repopulate_pool_static(self._processes, self._pool,
- self.Process, self._inqueue,
- self._outqueue, self._initializer,
- self._initargs,
- self._maxtasksperchild)
-
- @staticmethod
- def _repopulate_pool_static(processes, pool, Process, inqueue, outqueue,
- initializer, initargs, maxtasksperchild):
"""Bring the number of pool processes up to the specified number,
for use after reaping workers which have exited.
"""
- for i in range(processes - len(pool)):
- w = Process(target=worker,
- args=(inqueue, outqueue,
- initializer,
- initargs, maxtasksperchild)
- )
- pool.append(w)
+ for i in range(self._processes - len(self._pool)):
+ w = self.Process(target=worker,
+ args=(self._inqueue, self._outqueue,
+ self._initializer,
+ self._initargs, self._maxtasksperchild)
+ )
+ self._pool.append(w)
w.name = w.name.replace('Process', 'PoolWorker')
w.daemon = True
w.start()
debug('added worker')
- @staticmethod
- def _maintain_pool(processes, pool, Process, inqueue, outqueue,
- initializer, initargs, maxtasksperchild):
+ def _maintain_pool(self):
"""Clean up any exited workers and start replacements for them.
"""
- if Pool._join_exited_workers(pool):
- Pool._repopulate_pool_static(processes, pool, Process, inqueue,
- outqueue, initializer, initargs,
- maxtasksperchild)
+ if self._join_exited_workers():
+ self._repopulate_pool()
def _setup_queues(self):
from .queues import SimpleQueue
@@ -335,18 +319,16 @@ def map_async(self, func, iterable, chunksize=None, callback=None):
return result
@staticmethod
- def _handle_workers(cache, processes, pool, Process, inqueue, outqueue,
- initializer, initargs, maxtasksperchild, taskqueue):
+ def _handle_workers(pool):
thread = threading.current_thread()
# Keep maintaining workers until the cache gets drained, unless the pool
# is terminated.
- while thread._state == RUN or (cache and thread._state != TERMINATE):
- Pool._maintain_pool(processes, pool, Process, inqueue, outqueue,
- initializer, initargs, maxtasksperchild)
+ while thread._state == RUN or (pool._cache and thread._state != TERMINATE):
+ pool._maintain_pool()
time.sleep(0.1)
# send sentinel to stop workers
- taskqueue.put(None)
+ pool._taskqueue.put(None)
debug('worker handler exiting')
@staticmethod
diff --git a/Lib/test/test_multiprocessing.py b/Lib/test/test_multiprocessing.py
index d3192181e5ad..ff299feed894 100644
--- a/Lib/test/test_multiprocessing.py
+++ b/Lib/test/test_multiprocessing.py
@@ -1359,13 +1359,6 @@ def test_release_task_refs(self):
# they were released too.
self.assertEqual(CountedObject.n_instances, 0)
- def test_del_pool(self):
- p = self.Pool(1)
- wr = weakref.ref(p)
- del p
- gc.collect()
- self.assertIsNone(wr())
-
def unpickleable_result():
return lambda: 42
diff --git a/Misc/NEWS.d/next/Library/2018-07-26-10-31-52.bpo-34172.8ovLNi.rst b/Misc/NEWS.d/next/Library/2018-07-26-10-31-52.bpo-34172.8ovLNi.rst
deleted file mode 100644
index d1c5a7721019..000000000000
--- a/Misc/NEWS.d/next/Library/2018-07-26-10-31-52.bpo-34172.8ovLNi.rst
+++ /dev/null
@@ -1 +0,0 @@
-Fix a reference issue inside multiprocessing.Pool that caused the pool to remain alive if it was deleted without being closed or terminated explicitly.
More information about the Python-checkins
mailing list