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author | Victor Stinner <vstinner@redhat.com> | 2018-12-06 01:49:05 +0100 |
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committer | GitHub <noreply@github.com> | 2018-12-06 01:49:05 +0100 |
commit | 3c6b0d967eb4c95e06c4f1beddfca4f6300d92ce (patch) | |
tree | c874045460bc3d967475691fc9180648823cdeef | |
parent | c28317e4c2520f6df7a281f1664d63a6447d1ebb (diff) | |
download | cpython-git-3c6b0d967eb4c95e06c4f1beddfca4f6300d92ce.tar.gz |
[3.7] Revert "bpo-34172: multiprocessing.Pool leaks resources after being deleted (GH-8450) (GH-9676)" (#10968)
This reverts commit 97f998a4dfd6db6d867f446daa62445d0782bf39.
-rw-r--r-- | Lib/multiprocessing/pool.py | 74 | ||||
-rw-r--r-- | Lib/test/_test_multiprocessing.py | 7 | ||||
-rw-r--r-- | Misc/NEWS.d/next/Library/2018-12-06-00-29-28.bpo-34172.l7CIYt.rst | 3 |
3 files changed, 27 insertions, 57 deletions
diff --git a/Lib/multiprocessing/pool.py b/Lib/multiprocessing/pool.py index 574b5db5af..3e9a0d6b48 100644 --- a/Lib/multiprocessing/pool.py +++ b/Lib/multiprocessing/pool.py @@ -149,9 +149,8 @@ class Pool(object): ''' _wrap_exception = True - @staticmethod - def Process(ctx, *args, **kwds): - return ctx.Process(*args, **kwds) + def Process(self, *args, **kwds): + return self._ctx.Process(*args, **kwds) def __init__(self, processes=None, initializer=None, initargs=(), maxtasksperchild=None, context=None): @@ -178,15 +177,13 @@ class Pool(object): self._worker_handler = threading.Thread( target=Pool._handle_workers, - args=(self._cache, self._taskqueue, self._ctx, self.Process, - self._processes, self._pool, self._inqueue, self._outqueue, - self._initializer, self._initargs, self._maxtasksperchild, - self._wrap_exception) + args=(self, ) ) self._worker_handler.daemon = True self._worker_handler._state = RUN self._worker_handler.start() + self._task_handler = threading.Thread( target=Pool._handle_tasks, args=(self._taskqueue, self._quick_put, self._outqueue, @@ -212,62 +209,43 @@ class Pool(object): 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 util.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._ctx, self.Process, - self._processes, - self._pool, self._inqueue, - self._outqueue, self._initializer, - self._initargs, - self._maxtasksperchild, - self._wrap_exception) - - @staticmethod - def _repopulate_pool_static(ctx, Process, processes, pool, inqueue, - outqueue, initializer, initargs, - maxtasksperchild, wrap_exception): """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(ctx, target=worker, - args=(inqueue, outqueue, - initializer, - initargs, maxtasksperchild, - wrap_exception) - ) - 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._wrap_exception) + ) + self._pool.append(w) w.name = w.name.replace('Process', 'PoolWorker') w.daemon = True w.start() util.debug('added worker') - @staticmethod - def _maintain_pool(ctx, Process, processes, pool, inqueue, outqueue, - initializer, initargs, maxtasksperchild, - wrap_exception): + def _maintain_pool(self): """Clean up any exited workers and start replacements for them. """ - if Pool._join_exited_workers(pool): - Pool._repopulate_pool_static(ctx, Process, processes, pool, - inqueue, outqueue, initializer, - initargs, maxtasksperchild, - wrap_exception) + if self._join_exited_workers(): + self._repopulate_pool() def _setup_queues(self): self._inqueue = self._ctx.SimpleQueue() @@ -425,20 +403,16 @@ class Pool(object): return result @staticmethod - def _handle_workers(cache, taskqueue, ctx, Process, processes, pool, - inqueue, outqueue, initializer, initargs, - maxtasksperchild, wrap_exception): + 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(ctx, Process, processes, pool, inqueue, - outqueue, initializer, initargs, - maxtasksperchild, wrap_exception) + 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) util.debug('worker handler exiting') @staticmethod @@ -820,7 +794,7 @@ class ThreadPool(Pool): _wrap_exception = False @staticmethod - def Process(ctx, *args, **kwds): + def Process(*args, **kwds): from .dummy import Process return Process(*args, **kwds) diff --git a/Lib/test/_test_multiprocessing.py b/Lib/test/_test_multiprocessing.py index 7a657d9d12..a0daa43a55 100644 --- a/Lib/test/_test_multiprocessing.py +++ b/Lib/test/_test_multiprocessing.py @@ -2552,13 +2552,6 @@ class _TestPool(BaseTestCase): # they were released too. self.assertEqual(CountedObject.n_instances, 0) - @support.reap_threads - def test_del_pool(self): - p = self.Pool(1) - wr = weakref.ref(p) - del p - gc.collect() - self.assertIsNone(wr()) def raising(): raise KeyError("key") diff --git a/Misc/NEWS.d/next/Library/2018-12-06-00-29-28.bpo-34172.l7CIYt.rst b/Misc/NEWS.d/next/Library/2018-12-06-00-29-28.bpo-34172.l7CIYt.rst new file mode 100644 index 0000000000..e467cc9678 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2018-12-06-00-29-28.bpo-34172.l7CIYt.rst @@ -0,0 +1,3 @@ +REVERT: Fix a reference issue inside multiprocessing.Pool that caused the +pool to remain alive if it was deleted without being closed or terminated +explicitly. |