unique id for wayland objects

[zou lan]

Hi pekka

Thank you for your clearly analysis. I understand the presentation protocol
is enough for the requirement now.

I used to not study the protocol deeply because the code is a little more
than just record the flip timestamp. The
test want to do this as simple as possible.

I will try the presentation first. Thank you!

Best Regards
Nancy

2018-05-02 16:59 GMT+08:00 Pekka Paalanen <ppaalanen at gmail.com>:

> On Wed, 2 May 2018 16:33:43 +0800
> zou lan <nancy.lan.zou at gmail.com> wrote:
>
> > Add to wayland mail list.
> >
> > Hi pekka
> >
> > I used to consider the time line and presentation protocol. But they are
> > all focus on surface, not buffer. The test want to know the buffer
> latency,
> > although they are the same as surface's on
> > most cases. Applications think maybe some buffers doesn't display and
> used
> > again.
> >
> > By the way, could add a event to wl_buffer's protocol achieve the
> > requirement? Thank you.
>
> Hi Nancy,
>
> when a client creates a wp_presentation_feedback object, that object
> tracks the particular wl_surface.commit carrying an attached wl_buffer.
> So it is specific to the particular commit, not just to the surface
> or even to the buffer (buffers get re-used or could theoretically be
> used on multiple surfaces).
>
> Can you not have the client record both the current time at sending
> wl_surface.commit and the corresponding timestamp it gets from
> wp_presentation_feedback? Why would this not be enough?
>
> Please, see clients/presentation-shm.c in the Weston repository for an
> example that tracks this kind of presentation latencies.
>
>
> Thanks,
> pq
>
> > ---------- Forwarded message ----------
> > From: Pekka Paalanen <ppaalanen at gmail.com>
> > Date: 2018-05-02 15:48 GMT+08:00
> > Subject: Re: unique id for wayland objects
> > To: zou lan <nancy.lan.zou at gmail.com>
> >
> >
> > On Wed, 2 May 2018 10:57:17 +0800
> > zou lan <nancy.lan.zou at gmail.com> wrote:
> >
> > > Hi pekka
> > >
> > > I want to get the accurate buffer latency from a buffer commit by
> client
> > to
> > > display on the screen. The client can get the timestamp when buffer
> commit
> > > and release. So weston only need to give a
> > > timestamp when call on_pageflip.
> > >
> > > When do the real time analysis, there are many clients,  I want to use
> one
> > > unique id to distinguish from each other quickly.
> >
> > Hi,
> >
> > is there any reason you don't use presentation_feedback interface? To
> > me it sounds like that would provide exactly what you need.
> >
> > https://cgit.freedesktop.org/wayland/wayland-protocols/
> > tree/stable/presentation-time
> >
> > Also, could we have this coversation on the mailing list, please?
> >
> >
> > Thanks,
> > pq
>
>
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