From owner-freebsd-python@freebsd.org Fri Nov 8 12:46:55 2019 Return-Path: Delivered-To: freebsd-python@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id B7E931B17E9 for ; Fri, 8 Nov 2019 12:46:55 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mailman.nyi.freebsd.org (mailman.nyi.freebsd.org [IPv6:2610:1c1:1:606c::50:13]) by mx1.freebsd.org (Postfix) with ESMTP id 478g5C4XPPz4JyX for ; Fri, 8 Nov 2019 12:46:55 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.nyi.freebsd.org (Postfix) id 997531B17E8; Fri, 8 Nov 2019 12:46:55 +0000 (UTC) Delivered-To: python@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 993911B17E7 for ; Fri, 8 Nov 2019 12:46:55 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 478g5C3Xc3z4JyW for ; Fri, 8 Nov 2019 12:46:55 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 5CDB8263C8 for ; Fri, 8 Nov 2019 12:46:55 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.5]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id xA8CktWZ016900 for ; Fri, 8 Nov 2019 12:46:55 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id xA8CktI4016899 for python@FreeBSD.org; Fri, 8 Nov 2019 12:46:55 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="UTF-8" From: bugzilla-noreply@freebsd.org To: python@FreeBSD.org Subject: maintainer-feedback requested: [Bug 241801] lang/python38: regression: hang in locking in multiprocessing.Pool Date: Fri, 08 Nov 2019 12:46:54 +0000 X-Bugzilla-Type: request X-Bugzilla-Product: Ports & Packages X-Bugzilla-Component: Individual Port(s) X-Bugzilla-Version: Latest X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: python@FreeBSD.org X-Bugzilla-Flags: maintainer-feedback? Message-ID: In-Reply-To: References: X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-python@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: FreeBSD-specific Python issues List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 08 Nov 2019 12:46:55 -0000 Bugzilla Automation has asked freebsd-python mailing list for maintainer-feedback: Bug 241801: lang/python38: regression: hang in locking in multiprocessing.P= ool https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D241801 --- Description --- This simple program from multiprocessing import Pool from time import sleep Pool().map(sleep, [0.01] * 10) works fine with python 3.7, but is likely (about 20-50% probability on my 4 core box) to hang with python 3.8. Example backtraces after interruption: % python3.8 1.py ^CException ignored in: Traceback (most recent call last): File "/usr/local/lib/python3.8/multiprocessing/util.py", line 201, in __call__ Process ForkPoolWorker-2: Process ForkPoolWorker-4: res =3D self._callback(*self._args, **self._kwargs) File "/usr/local/lib/python3.8/multiprocessing/pool.py", line 689, in _terminate_pool cls._help_stuff_finish(inqueue, task_handler, len(pool)) File "/usr/local/lib/python3.8/multiprocessing/pool.py", line 674, in _help_stuff_finish inqueue._rlock.acquire() KeyboardInterrupt:=20 Process ForkPoolWorker-3: Process ForkPoolWorker-1: % python3.8 1.py ^CException ignored in: Traceback (most recent call last): File "/usr/local/lib/python3.8/multiprocessing/util.py", line 201, in __call__ Process ForkPoolWorker-3: Process ForkPoolWorker-4: Process ForkPoolWorker-1: res =3D self._callback(*self._args, **self._kwargs) File "/usr/local/lib/python3.8/multiprocessing/pool.py", line 689, in _terminate_pool cls._help_stuff_finish(inqueue, task_handler, len(pool)) File "/usr/local/lib/python3.8/multiprocessing/pool.py", line 674, in _help_stuff_finish inqueue._rlock.acquire() KeyboardInterrupt:=20 Process ForkPoolWorker-2: % python3.8 1.py ^CException ignored in: Process ForkPoolWorker-2: Process ForkPoolWorker-3: Traceback (most recent call last): File "/usr/local/lib/python3.8/multiprocessing/util.py", line 201, in __call__ Process ForkPoolWorker-1: res =3D self._callback(*self._args, **self._kwargs) File "/usr/local/lib/python3.8/multiprocessing/pool.py", line 689, in _terminate_pool cls._help_stuff_finish(inqueue, task_handler, len(pool)) File "/usr/local/lib/python3.8/multiprocessing/pool.py", line 674, in _help_stuff_finish Traceback (most recent call last): Traceback (most recent call last): File "/usr/local/lib/python3.8/multiprocessing/process.py", line 313, in _bootstrap self.run() File "/usr/local/lib/python3.8/multiprocessing/process.py", line 313, in _bootstrap self.run() File "/usr/local/lib/python3.8/multiprocessing/process.py", line 108, in = run self._target(*self._args, **self._kwargs) File "/usr/local/lib/python3.8/multiprocessing/process.py", line 108, in = run self._target(*self._args, **self._kwargs) File "/usr/local/lib/python3.8/multiprocessing/pool.py", line 114, in wor= ker task =3D get() File "/usr/local/lib/python3.8/multiprocessing/pool.py", line 114, in wor= ker task =3D get() File "/usr/local/lib/python3.8/multiprocessing/queues.py", line 355, in g= et with self._rlock: File "/usr/local/lib/python3.8/multiprocessing/queues.py", line 355, in g= et with self._rlock: File "/usr/local/lib/python3.8/multiprocessing/synchronize.py", line 95, = in __enter__ return self._semlock.__enter__() File "/usr/local/lib/python3.8/multiprocessing/synchronize.py", line 95, = in __enter__ return self._semlock.__enter__() KeyboardInterrupt KeyboardInterrupt inqueue._rlock.acquire() KeyboardInterrupt:=20 Traceback (most recent call last): File "/usr/local/lib/python3.8/multiprocessing/process.py", line 313, in _bootstrap self.run() File "/usr/local/lib/python3.8/multiprocessing/process.py", line 108, in = run self._target(*self._args, **self._kwargs) File "/usr/local/lib/python3.8/multiprocessing/pool.py", line 114, in wor= ker task =3D get() File "/usr/local/lib/python3.8/multiprocessing/queues.py", line 356, in g= et res =3D self._reader.recv_bytes() File "/usr/local/lib/python3.8/multiprocessing/connection.py", line 216, = in recv_bytes buf =3D self._recv_bytes(maxlength) File "/usr/local/lib/python3.8/multiprocessing/connection.py", line 414, = in _recv_bytes buf =3D self._recv(4) File "/usr/local/lib/python3.8/multiprocessing/connection.py", line 379, = in _recv chunk =3D read(handle, remaining) KeyboardInterrupt Process ForkPoolWorker-4: Should I submit this upstream?