NVIDIA Publishes Code For X Synchronization Fences

While NVIDIA may not release specifications for the GPU hardware or support any open-source drivers for their graphics processors after dropping their open-source X.Org driver, they do contribute a bit to the development of the X.Org Server. NVIDIA engineers like Aaron Plattner have contributed various patches and fixes against the server in the past and for features like VDPAU for DRI2. This afternoon there's a big patch-set coming out of NVIDIA that touches several X components. This set of patches adds support for X Synchronization Fences.

NVIDIA has been working on X Synchronization Fences for a while and was publicly talked about at least year's X Developers' Summit by Aaron Plattner, but now they are ready with a code drop for this new type of X Synchronization counters. As said in the mailing list announcement, the new X Synchronization Fences "can be used to synchronize X rendering with direct rendering X clients such as OpenGL and vice versa. They are especially useful in synchronizing GL-based composite managers¹ screen updates with Xs rendering."

NVIDIA's X Synchronization Fences support requires changes to the X Server, xextproto, libXext, damageproto, and libXdamage. NVIDIA's James Jones is also working on XCB support. NVIDIA is hoping the X Synchronization Fences will be ready to merge in X.Org Server 1.10.