Official SecondLife linux client crashes under primus

[Thulinma]

The official SL linux client works using either mesa or optirun - but not using primus. It boots up just fine, but then crashes when the first 3D visuals are about to be displayed.

As discussed over IRC - here's a link to the apitrace: http://www.mediafire.com/?jrcozgu0kc0pvfp

[amonakov]

The problem here is that the game wishes to track buffer objects itself, which is a rather unusual mode of operation. The readback thread in primus is sharing GL objects with the game (it needs to share a GL sync object to avoid reading back incomplete frames), but uses glGen-ned "names" for its own buffer objects. Eventually the game modifies storage of those buffer objects, leading to a crash.

The following patch should fix SL for you, but may break everything else

diff --git a/libglfork.cpp b/libglfork.cpp
index d3fb593..c65e444 100644
--- a/libglfork.cpp
+++ b/libglfork.cpp
@@ -384,7 +384,7 @@ static void* readback_work(void *vd)
   die_if(!primus.afns.glXIsDirect(primus.adpy, context),
         "failed to acquire direct rendering context for readback thread\n");
   primus.afns.glXMakeCurrent(primus.adpy, di.pbuffer, context);
-  primus.afns.glGenBuffers(2, &pbos[0]);
+  pbos[0] = 65534; pbos[1] = 65535; // should be enough for everybody
   primus.afns.glReadBuffer(GL_BACK);
   for (;;)
   {

[Thulinma]

Indeed - it runs just fine with that patch. What would be the proper way to handle this? Besides yelling at the SL devs for doing bad things, of course.

[amonakov]

What would be the proper way to handle this?

Add an environment variable to tune primus behavior, I suppose.