Expose PIDFD_NONBLOCK as os.PIDFD_NONBLOCK

[kumaraditya303]

Feature or enhancement

Expose PIDFD_NONBLOCK as os.PIDFD_NONBLOCK to be used with os.waitid.

Pitch

pidfd_open returns a nonblocking file descriptor if PIDFD_NONBLOCK is supplied as flag. If the process
referred to by the file descriptor has not yet terminated,
then an attempt to wait on the file descriptor using
waitid(2) will immediately return the error EAGAIN rather
than blocking.

Linked PRs

• gh-93312: Include <sys/pidfd.h> to get PIDFD_NONBLOCK #127593
• [3.13] gh-93312: Include <sys/pidfd.h> to get PIDFD_NONBLOCK (GH-127593) #127630
• [3.12] gh-93312: Include <sys/pidfd.h> to get PIDFD_NONBLOCK (#127593) #127631

[kumaraditya303]

Fixed by #93313

[n6koma7a]

according to documentation it should be available, yet it is not there:

python3.13 Wed 04 Dec 2024 01:57:39 AM +03
Python 3.13.0 (main, Oct 8 2024, 00:00:00) [GCC 14.2.1 20240912 (Red Hat 14.2.1-3)] on linux
Type "help", "copyright", "credits" or "license" for more information.

import os
os.PIDFD_NONBLOCK
Traceback (most recent call last):
File "", line 1, in
os.PIDFD_NONBLOCK
AttributeError: module 'os' has no attribute 'PIDFD_NONBLOCK'. Did you mean: 'EFD_NONBLOCK'?

[vstinner]

AttributeError: module 'os' has no attribute 'PIDFD_NONBLOCK'

Correct, something is wrong. I wrote #127593 to fix the constant.