[issue38744] python 3.8 hang in multiprocessing.Pool() locking on FreeBSD / Linux

Pablo Galindo Salgado added the comment: Closed via PR 19009 -- resolution: -> fixed stage: -> resolved status: open -> closed ___ Python tracker ___

[issue38744] python 3.8 hang in multiprocessing.Pool() locking on FreeBSD / Linux

Change by Pablo Galindo Salgado : -- versions: +Python 3.9 ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe:

[issue38744] python 3.8 hang in multiprocessing.Pool() locking on FreeBSD / Linux

Pablo Galindo Salgado added the comment: BTaskaya will create a PR to fix this soon. -- ___ Python tracker ___ ___

[issue38744] python 3.8 hang in multiprocessing.Pool() locking on FreeBSD / Linux

Pablo Galindo Salgado added the comment: I am mentoring @BTaskaya and I asked to take a look a this. After some debugging, we found that the problem is the following: When the pull is not used via the context manager or terminate() is called, there is a system in multiprocessing.util that

[issue38744] python 3.8 hang in multiprocessing.Pool() locking on FreeBSD / Linux

Pablo Galindo Salgado added the comment: Also, notice that writing Pool().map(sleep, [0.01] * 10) is out of contact as the Pool object can be collected immediately and there is no proper termination and cleanup. The correct way is to use the context manager: with Pool() as pool:

[issue38744] python 3.8 hang in multiprocessing.Pool() locking on FreeBSD / Linux

Pablo Galindo Salgado added the comment: Check out https://bugs.python.org/issue39360 foe more context on this issue. -- ___ Python tracker ___

[issue38744] python 3.8 hang in multiprocessing.Pool() locking on FreeBSD / Linux

Arkadiusz Miśkiewicz added the comment: bpo-35493 -- ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe:

[issue38744] python 3.8 hang in multiprocessing.Pool() locking on FreeBSD / Linux

Arkadiusz Miśkiewicz added the comment: Bisecting led to this commit and reverting it on 3.8 branch makes the hang go away. 7c994549dcffd0d9d3bb37475e6374f356e7240e is the first bad commit commit 7c994549dcffd0d9d3bb37475e6374f356e7240e Author: Pablo Galindo Date: Sat Mar 16 22:34:24 2019

[issue38744] python 3.8 hang in multiprocessing.Pool() locking on FreeBSD / Linux

Arkadiusz MiskiewiczArkadiusz Miskiewicz added the comment: That test program hangs even on Linux (kernel 4.9.184, glibc 2.30): $ python3 a.py Process ForkPoolWorker-13: Process ForkPoolWorker-12: Process ForkPoolWorker-16: Process ForkPoolWorker-15: Process