[PATCH wayland-protocols v4] unstable: add xdg-toplevel-decoration protocol

Jonas Ådahl jadahl at gmail.com
Wed Apr 18 16:22:25 UTC 2018

On Wed, Apr 18, 2018 at 11:32:09AM -0400, Simon Ser wrote:
> On April 18, 2018 1:05 PM, Jonas Ådahl <jadahl at gmail.com> wrote:
> > Since the issue is more of a race condition kind of issue, it might not
> > be easily reproducable with a demo client, but must be solved by coming
> > up with a type of negotiation that doesn't result in incorrect
> > intermediate states for example the one described above.
> > 
> > A race free protocol is what we need though, to continue with the "every
> > frame is perfect" concept we are striving for.
> I see where you're getting at and agree with you.
> I can think of a fix which would make it mandatory for clients to issue a
> set_mode request after receiving a preferred_mode event. A serial is probably
> needed for this. What do you think?

Not sure serials will do any good here. One idea that comes to mind
would be to the client send a series of supported modes in order of
preference, then always let the compositor decide via the configure.

> Like you said, it's probably better to take preferred_mode/set_mode out of the
> protocol for now, move forward and add them later (making sure there's no race).
> I'll send a v5 with the renaming and the simplification.

That'd definitely be the best way to get a first version landed faster,
while still experimenting with how to solve the other problem race free.


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