Calling pselect/ppoll/epoll_pwait

[Weatherby,Gerard]

Signalfd and select could probably be made to work if one codes around the race conditions pselect is provided to avoid. I’m not sure if using the GIL (for CPython) is sufficient or if a dedicated concurrency control (e.g. lock, mutex, semaphore) is necessary.


An alternative is to call the C library function via a wrapper. I had need to use setfsuid on a project a couple of years ago and found this example:

https://gist.github.com/atdt/ebafa299e843a767139b



From: Python-list <python-list-bounces+gweatherby=uchc.edu at python.org> on behalf of Barry <barry at barrys-emacs.org>
Date: Friday, December 2, 2022 at 7:02 PM
To: Ian Pilcher <arequipeno at gmail.com>
Cc: python-list at python.org <python-list at python.org>
Subject: Re: Calling pselect/ppoll/epoll_pwait
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> On 2 Dec 2022, at 20:03, Ian Pilcher <arequipeno at gmail.com> wrote:
>
> Does Python provide any way to call the "p" variants of the I/O
> multiplexing functions?
>
> Looking at the documentation of the select[1] and selectors[2] modules,
> it appears that they expose only the "non-p" variants.
>
> [1] https://urldefense.com/v3/__https://docs.python.org/3/library/select.html__;!!Cn_UX_p3!hClFFo4XdiwQAhHxDbHA5zFr490Of9uheHSf84V9cREMHyw1kX-baG5HzXWMt-hFLP30q6DpSUb2G_OD5qBjeA$<https://urldefense.com/v3/__https:/docs.python.org/3/library/select.html__;!!Cn_UX_p3!hClFFo4XdiwQAhHxDbHA5zFr490Of9uheHSf84V9cREMHyw1kX-baG5HzXWMt-hFLP30q6DpSUb2G_OD5qBjeA$>
> [2] https://urldefense.com/v3/__https://docs.python.org/3/library/selectors.html__;!!Cn_UX_p3!hClFFo4XdiwQAhHxDbHA5zFr490Of9uheHSf84V9cREMHyw1kX-baG5HzXWMt-hFLP30q6DpSUb2G_MwNjgO8A$<https://urldefense.com/v3/__https:/docs.python.org/3/library/selectors.html__;!!Cn_UX_p3!hClFFo4XdiwQAhHxDbHA5zFr490Of9uheHSf84V9cREMHyw1kX-baG5HzXWMt-hFLP30q6DpSUb2G_MwNjgO8A$>

Can you use signalfd and select/poll/epoll?

Barry

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