Re: libGL bug in your source tree?

On Thu, 19 Apr 2007, leon zadorin wrote:

> Hi, I am thinking that there may be a bug in libGL in your XFree project...

> In xc/lib/GL/glx/glxext.c, AllocAndFetchScreenConfigs:

> line 979 locks the display: LockDisplay(dpy);
> then line 1013 unlocks the display once: UnlockDisplay(dpy);
> ... but the code which follows line 1013 (e.g. any of the lines: 1016,
> 1028, 1038, 1083) will result in double unlocking (i.e. unlocking the
> already unlocked display which on some systems such as
> NetBSD-current's macppc port raises the "unlocking already unlocked
> mutex" error and the process is killed).

> My suggestion is to take out line 979.
> The following (albeit from Mesa) file in OpenBSD repository appears to
> have it solved:
> http://www.openbsd.org/cgi-bin/cvsweb/xenocara/dist/Mesa/src/glx/x11/glxext.c?rev=1.2&content-type=text/x-cvsweb-markup

> Am sorry if I am mistaken in thinking that it is a bug in XFree's
> libGL, if so, however - can anyone explain why line 979 (and
> subsequent double unlocking of the display) is actually needed in the
> first place?

This bug was reported in freedesktop's Bugzilla.  See 
http://bugs.freedesktop.org/show_bug.cgi?id=8521  I have just now 
committed the fix suggested therein.  Thanks for reporting the problem.

Marc.

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