Re: [Nicolas Graves] [PATCH v6 01/10] rde: emacs: Start emacs in --daemon mode, with shepherd and pid-file

[Ludovic Courtès]

Hi,

Björn Bidar <bjorn.bidar@thaodan.de> skribis:

> Stefan Monnier <monnier@iro.umontreal.ca> writes:
>
>>> Maybe some feedback on the Emacs side about this? There are indeed very
>>> few places where systemd sd_* functions are called in emacs.c, should we
>>> try and re-implement them instead of using the library as is? Would that
>>> be a contribution Emacs devs would be interested in? That would
>>> definitely be beneficial for Emacs on Guix as highlighted by Ludo'.
>>
>> It's hard to tell without seeing the actual patch.
>>
>> But if the code is sufficiently simple, it implements a protocol that's
>> well documented, and it allows us to eliminate the dependency on the
>> systemd library, we might like it.
>
> Would that make sense on systems where systemd is used? If libsystem is
> already installed it would be more convenient for the user to use the
> already installed and very likely loaded libsystemd instead of
> reimplementing the feature.

As I wrote, in the wake of the xz backdoor, many came to the conclusion
that linking against libsystemd “just” to check a couple of environment
variables (for socket activation) is hard to justify (libsystemd
provides much more functionality than this bit.)

> Ideally the support for other initrd system could implement a function
> that is then called instead of the systemd codepath  be it something
> different or to reimplenent sd-notify. Maybe shepherd as something like
> sd-notify of it's own?

Shepherd does not implement the sd-notify protocol, but it implements
socket activation, which is what Emacs currently uses AFAICS.

HTH,
Ludo’.