On Mon, Aug 10, 2015 at 9:16 AM, Matt Turner <matts...@gmail.com> wrote: > On Fri, Aug 7, 2015 at 10:09 AM, Ian Romanick <i...@freedesktop.org> wrote: >> I know we've talked about this about 100 times, but something in the >> back of my mind tells me that we have a pre-existing race. What happens >> if the p_atomic_dec_zero happens on thread A while thread B is between >> the _mesa_lookup_renderbuffer call and the _mesa_reference_renderbuffer >> call on the same object? Won't thread A free the memory out from under >> thread B? > > Generally: > > RefCount is initialized to 1 (in all cases but renderbuffers... that > might be a bug -- did you choose renderbuffers in your example for > this reason?). When Bind is called the first time, RefCount is > incremented to 2. > > When Delete is called, RefCount is decremented -- RefCount only goes > to 0 only if the object isn't bound anywhere, in which case it's > actually deleted. If The object is still bound somewhere and RefCount > is decremented to non-zero, the object cannot be rebound and will be > deleted when its last reference is unbound. > > Commit 42aaa548 changed the renderbuffer code from RefCount = 1 to = > 0. It seems pretty clearly wrong to me, since a > glGenRenderbuffers()/glDeleteRenderBuffers() pair would fail to > actually delete the renderbuffers. Does anyone else read it > differently?
Ian, does this make sense? Does it seem like initializing RefCount to 1 for renderbuffers is a bug? _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
