On 24 April 2018 at 08:13, Johan Helsing <johan.hels...@qt.io> wrote: > Emil: Your alternative patch won't work because dri_make_current is not > necessarily called with NULL after a buffer has been destroyed. > Interesting, the trace attached in the bugreport does a proper makecurrent/surface dance. Namely, MakeCurrent(..., NULL, NULL, ...) is called before DestroySurface().
Hope you can see how that may be confusing wrt the patch in question. > > The problematic sequence is a pattern we use in QtWayland: > > > //create temporary context > > surface1 = eglCreateWindowSurface() <-- dri_drawable pointer is malloced > > eglMakeCurrent(surface1) <-- ctx->dPriv is set > > > // ... (Get some information about available GL extensions etc) > > > eglDestroySurface(surface1) <-- pointer is freed, ctx->dPriv is now dangling > As others have pointed out pointer must not be freed at this point. We have plenty of refcounting and locking to ensure that, so I'm a bit suspicious if this happens. Can you observed that, or it's more of an educated guess? > surface2 = eglCreateWindowSurface() <-- Creating a new surface. Sometimes > it's address will be the same as the free'd pointer. > Repeating my earlier question - what do you mean with "it will be the same"? A malloc call returns the same pointer as previously freed memory, other? Thanks Emil _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
