Re: kqueue for glib (was Re: CVS commit: wikisrc/light-desktop)

[Julio Merino <jmmv%NetBSD.org@localhost>]

On Tue, May 22, 2012 at 1:28 PM, Jeremy C. Reed <reed%netbsd.org@localhost> 
wrote:
> Changed from www-changes to pkgsrc-users and bcc'd Julio:
>
> On Tue, 22 May 2012, Julio Merino wrote:
>
>> > Log Message:
>> > mention fam
>>
>> Ew (for FAM).
>>
>> What exactly uses FAM?  Is it because something depends on gio-fam?
>> We should be able to use the new kqueue support in glib2 instead if
>> that's the case!
>
> The desktop and the filemanager (same software) use gio-fam to monitor
> for file changes.

No, they use gio.  Whatever is pulling in gio-fam as a dependency is
bogus, because gio-fam is an optional plugin.

>  No kqueue mentioned in the glib-2.32.3 source.

It's not integrated yet.

> I see it in pkgsrc options.... commented out. And no checksum. And the
> patch is for 2.30.3 and doesn't apply against 2.32.3

There is a newer patch (as you have discovered).  Dmitry sent it to me
but I forgot to apply it.

> Ah, I forgot about it:
> https://github.com/dmatveev/glib-gio-kqueue-integration
> http://netbsd-soc.sourceforge.net/projects/kqueue4gio/
> (The other webpages for the student are not available now.)
>
> I don't know if is integrated upstream or not.

Dmitry was going to work on that next, but he didn't have a chance
yet.  He wanted to abstract some of the code in an auxiliary library,
but I don't think this should be a blocker for integration.
Maintaining a separate patch is nasty.

> I couldn't find any glib bugs about it. I couldn't find changelog (I
> didn't fetch source). I only found kqueue in old ticket for macosx:
> https://bugzilla.gnome.org/show_bug.cgi?id=543148
>
> I found that openbsd uses it by default for its glib and points to a
> newer patch that does apply.

Maybe we should switch the default?  (Setting up rpc services for fam
will not fly in any desktop environment unless it's automated -- and
at the moment isn't.)

> I had to update automake to 1.11 but I installed 1.12. pkgsrc failed on
> many warnings from it. Actually the Makefile bugs are from many places
> (even some unrelated to patch) due to automake being more strict. After
> patching a few makefiles, I got it to build and install. I stopped
> rpcbind and famd. I deleted my gio-fam package. And restarted my desktop
> by itself. It appears to work to recognize file changes immediately. (In
> fact, several seconds faster than FAM.)

FAM uses polling, with a frequency of 6-7 seconds IIRC.  kqueue is,
well, as immediate as it should be!

> Thanks for the hint.
>
> So who will maintain the patch? Who will work with glib to integrate it?
> (I can respond to the macos bug.)

Dmitry is actively maintaining it.  (Except that he'll now be
unavailable for a while due to real life issues.)

I might be able to try to give it a try.

> On that note, pkgsrc has 38 patches for glib2. We need to get them
> submitted upstream. Anyone working on that?

I tried at some point.  It's Hard (TM).

-- 
Julio Merino / @jmmv