Date: Fri, 08 Nov 2019 12:46:54 +0000 From: bugzilla-noreply@freebsd.org To: python@FreeBSD.org Subject: [Bug 241801] lang/python38: regression: hang in locking in multiprocessing.Pool Message-ID: <bug-241801-21822@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=241801 Bug ID: 241801 Summary: lang/python38: regression: hang in locking in multiprocessing.Pool Product: Ports & Packages Version: Latest Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: Individual Port(s) Assignee: python@FreeBSD.org Reporter: amdmi3@FreeBSD.org Flags: maintainer-feedback?(python@FreeBSD.org) Assignee: python@FreeBSD.org 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: <Finalize object, dead> 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 = 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: Process ForkPoolWorker-3: Process ForkPoolWorker-1: % python3.8 1.py ^CException ignored in: <Finalize object, dead> 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 = 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: Process ForkPoolWorker-2: % python3.8 1.py ^CException ignored in: <Finalize object, dead> 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 = 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 worker task = get() File "/usr/local/lib/python3.8/multiprocessing/pool.py", line 114, in worker task = get() File "/usr/local/lib/python3.8/multiprocessing/queues.py", line 355, in get with self._rlock: File "/usr/local/lib/python3.8/multiprocessing/queues.py", line 355, in get 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: 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 worker task = get() File "/usr/local/lib/python3.8/multiprocessing/queues.py", line 356, in get res = self._reader.recv_bytes() File "/usr/local/lib/python3.8/multiprocessing/connection.py", line 216, in recv_bytes buf = self._recv_bytes(maxlength) File "/usr/local/lib/python3.8/multiprocessing/connection.py", line 414, in _recv_bytes buf = self._recv(4) File "/usr/local/lib/python3.8/multiprocessing/connection.py", line 379, in _recv chunk = read(handle, remaining) KeyboardInterrupt Process ForkPoolWorker-4: Should I submit this upstream? -- You are receiving this mail because: You are the assignee for the bug.help
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