Question about linux-explicit-synchronization
scott.anderson at collabora.com
Mon Feb 18 03:27:06 UTC 2019
I have a question about the usage of
In the Weston implementation, it's simply a case of the compositor
getting the fence from the client, using eglWaitSyncKHR (or equivilent)
on it, and passing back a release fence from OUT_FENCE_FD.
However, is the protocol intended to allow a compositor which takes a
more active role in monitoring the fences? For example, a compositor
could check the state of the fence at drawing time and decide to use the
client's previous buffer if the fence hasn't been signalled.
Is it worth a compositor being implemented like this? As far as I
understand, doing this would stop any particuarly slow clients from
stalling the compositor's drawing too much and possibly missing vblank.
But I'm not an expert on fences or how eglWaitSyncKHR affects anything
at a driver level.
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