Re: [PATCH 2/2] docs: Add information about serials and timestamps
On Mar 31, 2013 3:42 AM, "Daniel Stone" wrote: > > Hi, > > On 30 March 2013 22:37, Jason Ekstrand wrote: >> >> I think this should be re-worded. It's correct, it just seems >> awkward. For example: >> >> Input events also carry timestamps in milliseconds. The base for >> these timestamps is left up to the compositor. Therefore, they should >> not be compared against anything except other compositor-provided >> timestamps. > > > I think 'unspecified' provides a little more clarity than 'left up to the compositor', but that really is bikeshedding. :) > > Even then though, I think you're guaranteeing too much: I'm not sure we even currently guarantee that timestamps are comparable across all compositor interfaces. They certainly have to be comparable per-interface, but that's it I think. Kristian? If the timestamps should be comparable cross interfaces we wouldn't be able to use high precision time stamps from page flips and similar time sources as they are not guaranteed to have the same root as the ones from for example evdev. Jonas > > Cheers, > Daniel > > ___ > wayland-devel mailing list > wayland-devel@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/wayland-devel > ___ wayland-devel mailing list wayland-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/wayland-devel
Re: [PATCH 2/2] docs: Add information about serials and timestamps
Hi, On 30 March 2013 22:37, Jason Ekstrand wrote: > I think this should be re-worded. It's correct, it just seems > awkward. For example: > > Input events also carry timestamps in milliseconds. The base for > these timestamps is left up to the compositor. Therefore, they should > not be compared against anything except other compositor-provided > timestamps. I think 'unspecified' provides a little more clarity than 'left up to the compositor', but that really is bikeshedding. :) Even then though, I think you're guaranteeing too much: I'm not sure we even currently guarantee that timestamps are comparable across all compositor interfaces. They certainly have to be comparable per-interface, but that's it I think. Kristian? Cheers, Daniel ___ wayland-devel mailing list wayland-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/wayland-devel
Re: [PATCH 2/2] docs: Add information about serials and timestamps
On Sat, Mar 30, 2013 at 1:09 PM, wrote: > From: Matthias Clasen > > Add some information about serials, timestamps and their uses > to the Input section in the protocol overview. > --- > doc/Wayland/en_US/Protocol.xml | 16 > 1 file changed, 16 insertions(+) > > diff --git a/doc/Wayland/en_US/Protocol.xml b/doc/Wayland/en_US/Protocol.xml > index b94e9ca..5c7ef76 100644 > --- a/doc/Wayland/en_US/Protocol.xml > +++ b/doc/Wayland/en_US/Protocol.xml > @@ -241,6 +241,22 @@ >with a pointer grab. > > > + To avoid race conditions, input events that are likely to > + trigger further requests (such as button presses, key events, > + pointer motions) carry serial numbers, and requests such as > + wl_surface.set_popup require that the serial number of the > + triggering event is specified. The server maintains a > + monotonically increasing counter for these serial numbers. > + > + > + Input events also carry timestamps with millisecond granularity. > + Their base is undefined, so they can't be compared against > + system time (as obtained with clock_gettime or gettimeofday). > + They can be compared with each other though, and for instance > + be used to identify sequences of button presses as double > + or triple clicks. I think this should be re-worded. It's correct, it just seems awkward. For example: Input events also carry timestamps in milliseconds. The base for these timestamps is left up to the compositor. Therefore, they should not be compared against anything except other compositor-provided timestamps. > + > + >See for the >protocol description. > > -- > 1.8.2 > > ___ > wayland-devel mailing list > wayland-devel@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/wayland-devel ___ wayland-devel mailing list wayland-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/wayland-devel
[PATCH 2/2] docs: Add information about serials and timestamps
From: Matthias Clasen Add some information about serials, timestamps and their uses to the Input section in the protocol overview. --- doc/Wayland/en_US/Protocol.xml | 16 1 file changed, 16 insertions(+) diff --git a/doc/Wayland/en_US/Protocol.xml b/doc/Wayland/en_US/Protocol.xml index b94e9ca..5c7ef76 100644 --- a/doc/Wayland/en_US/Protocol.xml +++ b/doc/Wayland/en_US/Protocol.xml @@ -241,6 +241,22 @@ with a pointer grab. + To avoid race conditions, input events that are likely to + trigger further requests (such as button presses, key events, + pointer motions) carry serial numbers, and requests such as + wl_surface.set_popup require that the serial number of the + triggering event is specified. The server maintains a + monotonically increasing counter for these serial numbers. + + + Input events also carry timestamps with millisecond granularity. + Their base is undefined, so they can't be compared against + system time (as obtained with clock_gettime or gettimeofday). + They can be compared with each other though, and for instance + be used to identify sequences of button presses as double + or triple clicks. + + See for the protocol description. -- 1.8.2 ___ wayland-devel mailing list wayland-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/wayland-devel
