Re: February update on the Guile guix-daemon

[Ludovic Courtès]

Hello!

Thanks for the update!

Christopher Baines <mail@cbaines.net> skribis:

>  - Then there's the big areas to work on next:
>
>    - I think I'm going to need to use thread pools for SQLite operations
>      in the daemon, as the build coordinator does.

I think we should refrain from using POSIX threads directly and instead
use Fibers to its full extent.  In this case, I’d use a resource pool as
done in Cuirass (and in the Coordinator too, no? maybe that’s what you
meant?).

>    - There's the low level work of setting up the build environment, the
>      work on the guile-daemon branch helps a lot with this, but as
>      pointed out by Ludo, there might be some issues with fork and
>      similar operations in a Guile program using threads.

Right.  I think one of the things we discussed in Brussels is that,
since SQLite operations might block for a while, the daemon will have to
be multithreaded.  Which means no fork/clone, which in turn probably
means delegating forking/cloning to a separate helper process.  (That’s
also what bubblewrap does, IIUC.)

>    - While I've implemented some of the server side protocol used by the
>      daemon, I'd like to extract that code in to a module so that it's
>      not wrapped up inside the daemon script

Wo0t!

Cheers,
Ludo’.