Re: [libgpiod][PATCH] libgpiod: Allow to gracefully exit from a wait event

[Bartosz Golaszewski <brgl@xxxxxxxx>]

On Tue, Nov 14, 2023 at 11:10 AM Adrien Zinger <zinger.ad@xxxxxxxxx> wrote:
>
> > This sounds like an oddly specific API... I wonder, why does
> > gpiod_line_request_get_fd [1] + doing the polling in your code
> > not work
> > for you? Since you already got a file descriptor for the
> > notification that seems like little extra work. Or
> > did you consider that but find
> > it too verbose?
>
> Until now it works like you said and it's not so verbose.
>
> Actually I had the issue some weeks ago. And before digging inside the
> library I have searched in the documentation and also asked on
> stackoverflow [1] for a suggestion. Despite everything me and other
> developers were not able to guess how to cancel a wait event from
> another thread, without reading the code of the library. I thought
> that it could be a good thing to provide that feature.
>
> [1]
> https://stackoverflow.com/questions/77222869/how-to-gracefully-cancel-gpiod-line-event-wait
>
> Best regards,
> Adrien
>
>

I agree with Erik, this looks like a very specific (obscure?) use-case
that's best implemented in-place using the fd getter. I try to keep
the library minimal and simple and this doesn't seem like a good fit
IMO.

Bart