The DRI3 extension provides mechanisms to translate between direct
rendered buffers and X pixmaps. When combined with the Present
extension, a complete direct rendering solution for OpenGL is
provided.

The direct rendered buffers are passed across the protocol via
standard POSIX file descriptor passing mechanisms. On Linux, these
buffers are DMA-BUF objects.

DRI3 also includes a mechanism to translate between Linux Futexes
and X Sync extension Fences. This provides a synchronization
mechanism which can be used to serialize access to shared render
buffers.