elementary-dev-community team mailing list archive

[Сергей <shnatsel@xxxxxxxxx>]

2012/4/18 Victor Eduardo <victoreduardm@xxxxxxxxx>

> Hey Sergey, all these are awesome ideas!
>
> I can rewrite your script on my free time (i.e. after I'm done with
> relevant Noise stuff). Coding it in directly C might be safer in my
> opinion. Did you push it to some branch?
>
> Regards,
> Victor
>

Hey Victor,

I'm glad to hear that!

Tom Beckmann already wrote a proof-of-concept in Vala, see
http://pastebin.com/BVTGsMmK
It's not production-ready for two reasons: first, it uses Process.
spawn_command_line_sync() which is a wrapper to system() function which is
dreadfully insecure. It should use setpriority() function instead (see "man
setpriority" or view it online at
http://manpages.ubuntu.com/manpages/precise/en/man3/setpriority.3posix.html).
Second, it doesn't prevent process children from inheriting high
priority, and doesn't drop priorities of child processes on unfocusing the
window.

I've recently discovered that ulatencyd provides a D-bus interface to
manage process priorities, it probably would be better just to signal it
instead of doing everything ourselves. It will also solve the priority
inheritance puzzle.

Also, I still haven't figured out how ulatencyd's Xorg "data provider"
works. All I know is that it's polling-based (which is not necessarily a
bad idea, because quick focus switching with e.g. Alt+Tab can switch focus
very quickly and make ulatencyd use CPU a lot) and it doesn't seem to work
unless ulatencyd is started from X manually (probably doesn't detect
session changes). Maybe it's better to fix ulatencyd's data provider than
to write something custom. I suppose I'll be posting a message to ulatencyd
mailing list soon, I'll ask why it's so and what approach should we take.

--
Sergey "Shnatsel" Davidoff