[RFC] DRI2 synchronization and swap bits

[Eric Anholt]

On Fri, 2009-10-30 at 10:59 -0700, Jesse Barnes wrote:
> I've put up some trees (after learning my lesson about working in the
> main tree) with the latest DRI2 sync/swap bits:
>   git://git.freedesktop.org/home/jbarnes/xserver master branch
>   git://git.freedesktop.org/home/jbarnes/mesa master branch
> 
> They includes support for some new DRI2 requests (proto for which is in
> the dri2-swapbuffers branch of dri2proto), including:
>   DRI2SwapBuffers
>   DRI2GetMSC
>   DRI2WaitMSC
> and
>   DRI2WaitSBC
> 
> These allow us to support GLX extensions like SGI_video_sync,
> OML_swap_control and SGI_swap_interval.
> 
> There have been a few comments about the protocol so far:
>   1) DRI2SwapBuffers
>      a) Concern about doing another round trip to fetch new buffers
> 	following the swap.
>         I think this is a valid concern, we could potentially respond
>         from the swap with the new buffers, but this would make some
>         memory saving optimizations more difficult (e.g. freeing
>         buffers if no drawing comes in for a short time after the swap).

You're doing one round-trip anyway, and if users are concerned about the
second one, go use XCB already.  (We need to go fix Mesa to do that).

-- 
Eric Anholt
eric at anholt.net                         eric.anholt at intel.com


-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 198 bytes
Desc: This is a digitally signed message part
Url : http://lists.x.org/archives/xorg-devel/attachments/20091030/b76035a9/attachment.pgp