X locks when deactivating composite effects

[Michel Dänzer]

On Tue, 2008-11-11 at 15:56 +0100, Lubos Lunak wrote:
> On Tuesday 11 of November 2008, Michel Dänzer wrote:
> > On Mon, 2008-11-10 at 06:35 -0800, john terragon wrote:
> > > Hi,
> > >
> > > whenever I deactivate the composite effects the x server locks up and I
> > > get the following in the Xorg log file:
> ...
> > Yes, looks like https://bugzilla.redhat.com/show_bug.cgi?id=445331
> > (http://bugs.freedesktop.org/show_bug.cgi?id=7128 is probably related,
> > http://bugs.freedesktop.org/show_bug.cgi?id=18465 possibly).
> >
> > Basically, the problem is that the (AI)GLX code keeps pointers to
> > DrawableRec structs of X windows corresponding to GLX windows without
> > preventing/tracking the destruction of the X windows. So it can happen
> > that the (AI)GLX code dereferences these pointers after the X window is
> > already destroyed.
> >
> > It might be possible for the client (is that kwin for you as well?) to
> > avoid this problem by making sure that the GLX context is unbound and
> > destroyed before the X window is destroyed, not sure about that though.
> 
>  The bug appears to be in X (GLX1.3 docs seem to suggest in section 3.3.7 ["If 
> draw is destroyed after glXMakeContextCurrent is called,..."] that destroying 
> a window while a GLXContext using it is still current is allowed).

Sure, I was merely suggesting possible workarounds until the X server is
fixed.


-- 
Earthling Michel Dänzer           |          http://tungstengraphics.com
Libre software enthusiast         |          Debian, X and DRI developer