Re: [AD] x color conversion again (w/ responsiveness patch)

[Elias Pschernig <elias@xxxxxxxxxx>]

On Mon, 2004-07-19 at 18:23 -0700, Chris wrote:
> Evert Glebbeek wrote:
> > Ok, I tried some of the earlier WIPs.
> > The sigalrm version is broken for me in WIPs 4.1.14 and 4.1.12 at least.
> 
> If I understand the sigalrm code, I'm honestly surprised it works for 
> anyone. As Elias said XLOCK does next to nothing, except increment a 
> variable and lock out input handling. There's async problems all over 
> the place for Xlib to trip over, and I think it's just been luck that 
> we've had so little problems with it. Of course, there could be things 
> in 4.1.12+ that aggrivate the situation for your system. As mentioned, 
> mixing interrupt behavior in a threaded environment is usually a bad 
> idea and bound to cause problems.
> 

It's not *that* bad I think. That one variable should work most of the
time, after all X11 should only be used concurrently in the signals
version by the events signal handler. Problems would occur if
a) using that simple variable as lock mechanism fails or
b) we don't pay attention to this somewhere, and an X11 calls is made
e.g. in a timer or any other signal handler.

And, likely it is b) what Elver is seeing, and between 4.1.11 and 4.1.12
something was added to cause concurrent X11 operations.

Oh, and, there's no evidence at all the problem is an interrupting X11
operation, it might be something entirely else :|

-- 
Elias Pschernig