gh-87063: Add is_closed method to multiprocessing.Process

[rruuaanng]

• Issue: gh-87063

for example:

import multiprocessing


def f():
    print('hello')
    print('world')

if __name__ == "__main__":
    p = multiprocessing.Process(target=f)
    p.start()
    p.join()

    # In a more context, it's closed
    p.close()
    
    # Currnet context
    # It's thrown a ValueError
    if p.exitcode == 0:
        pass

    # Changed
    if not p.is_closed():
        print(p.exitcode)

[rruuaanng]

It seems that this NEWS error can be ignored.

[bedevere-app[bot]]

A Python core developer has requested some changes be made to your pull request before we can consider merging it. If you could please address their requests along with any other requests in other reviews from core developers that would be appreciated.

Once you have made the requested changes, please leave a comment on this pull request containing the phrase I have made the requested changes; please review again. I will then notify any core developers who have left a review that you're ready for them to take another look at this pull request.

[rruuaanng]

Sorry for my misunderstanding. I thought it was to change NEWS to what's NEWS, but it was actually to add to it. I'm sorry for that. I've made change :)

[rruuaanng]

Thanks to Bénédikt for taking responsibility for this PR. And, thanks to erlend for pointing out my mistake.👍

[rruuaanng]

I've made change. Thank for your review!

[rruuaanng]

@erlend-aasland Please review them again! :)

[erlend-aasland]

@erlend-aasland Please review them again! :)

I asked some questions on the issue; IMO, they should be clarified before eventually landing this PR. In other words: I believe more discussion and perhaps a larger audience is needed.

[rruuaanng]

Happy New Year, everyone. It's been a long time since the last review. Do we still need to keep this open?