Re: [libgpiod] - fast writing while waiting for edge events

[Mathias Dobler <mathias.dob@xxxxxxxxx>]

Hello Bartosz,
I am writing a libgpiod 2 C# binding/abstraction for the dotnet
community that I want to use personally. My use case is to monitor
edge events from a hardware PWM signal, to react by reading some other
GPIOs in a relatively short amount of time. This is likely a very
specific use case but my goal is to make the binding cover as much
uses cases as possible. And before searching for an alternative (like
writing a kernel driver or so) I wanted to make sure I am not doing
things wrong.

Regards Mathias

Am Di., 12. Dez. 2023 um 12:12 Uhr schrieb Bartosz Golaszewski <brgl@xxxxxxxx>:
>
> On Tue, Dec 12, 2023 at 10:55 AM Mathias Dobler <mathias.dob@xxxxxxxxx> wrote:
> >
> > Hello,
> > From reading other conversations I've learned that it's not a good
> > idea to have more than 1 thread accessing libgpiod objects. But this
> > raises the question of how to react to events and let reads/writes
> > through as quickly as possible at the same time. I have already played
> > around with the file descriptor of the request object to interrupt the
> > wait for edge events, but this solution is not good because it comes
> > at the expense of responsiveness to events, and requires complicated
> > synchronization.
> > How bad would it be to have 1 thread waiting for events and 1 other
> > thread reading/writing?
> >
> > Regards,
> > Mathias
> >
>
> Are you bitbanging? It totally sounds like bitbanging. Have you
> considered writing a kernel driver for whatever you're doing?
>
> Bart