Bug report

Bug description:

Due of absence of the sem_getvalue C function in the MacOSX semaphore implementation, Lock and RLock representation strings are invalid in the multiprocessing module.

Call to self._semlock._get_value() raises an exception, and set part of repr with 'unknown'.

import multiprocessing as mp
print(mp.Lock()     #  <Lock(owner=unknown)> vs <Lock(owner=None)> on Linux
print(mp.RLockj())  #  <RLock(unknown, unknown)> vs <RLock(None, 0)> on Linux

I propose to replace in the __repr__ method of each class the following test:

with elif not self._semlock._is_zero():.

This method is available and valid on each OS.

CPython versions tested on:

CPython main branch

Operating systems tested on:

macOS

Linked PRs

• gh-125679: multiprocessing Lock and RLock - fix invalid representation string on MacOSX. #125680
• [3.13] gh-125679: multiprocessing Lock and RLock - fix invalid representation string on MacOSX. (GH-125680) #126533
• [3.12] gh-125679: multiprocessing Lock and RLock - fix invalid representation string on MacOSX. (GH-125680) #126534