From: Kent Gibson <warthog618@gmail.com>
To: "Hollerer Franz, Schrack Seconet AG,
Entwicklung" <f.hollerer@schrack-seconet.com>
Cc: "linux-gpio@vger.kernel.org" <linux-gpio@vger.kernel.org>,
"Ullrich Lucas, Schrack Seconet AG,
Entwicklung" <l.ullrich@schrack-seconet.com>,
Bartosz Golaszewski <brgl@bgdev.pl>
Subject: Re: [libgpiod]: non-exclusive use of input lines
Date: Thu, 13 Jul 2023 19:08:41 +0800 [thread overview]
Message-ID: <ZK/bOWcl0x/1zIY2@sol> (raw)
In-Reply-To: <1337f994e3ad45f49dc86787bcb3a019@schrack-seconet.com>
On Thu, Jul 13, 2023 at 09:24:03AM +0000, Hollerer Franz, Schrack Seconet AG, Entwicklung wrote:
>
> I have several processes (one of them is a shell scripts, others are
> C/C++ programs) which need to read the same input line.
> Is it somehow possible to request input lines for non-exclusive use?
No, it is not possible.
> If not, is this a feature which will be added sometime in the future?
>
No, there are no plans for such a feature, AFAIAA.
The solution is to have a userspace process monitor the line and share
the value with the other processes. How best to do that is up to you.
A simple approach would be to write the value to a file.
(which might be a useful mode to add to gpiomon??)
Bart is working on a daemon that may provided shared read access, but
I'm just guessing.
Cheers,
Kent.
prev parent reply other threads:[~2023-07-13 11:08 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-13 9:24 [libgpiod]: non-exclusive use of input lines Hollerer Franz, Schrack Seconet AG, Entwicklung
2023-07-13 11:08 ` Kent Gibson [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=ZK/bOWcl0x/1zIY2@sol \
--to=warthog618@gmail.com \
--cc=brgl@bgdev.pl \
--cc=f.hollerer@schrack-seconet.com \
--cc=l.ullrich@schrack-seconet.com \
--cc=linux-gpio@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).