07:18 <wlb> weston Issue #649 closed \o/ (Crash in weston_signal_emit_mutable on surface destruction https://gitlab.freedesktop.org/wayland/weston/-/issues/649)

07:41 <MrCooper> pac85[m]: there's no fundamental difference for vsync of fullscreen windows between rootful Xwayland and Xorg

10:40 <pac85> MrCooper: x stores a crtc id for each window based on which output their center lies in. When vsync is handled drmModeWaitVblank is called passing that crtc, a client is vsynced to the output it lies in. When no compositor is used and images are blitted to the front buffer vsync is therefore handled correcly (same goes for tear free where each monitor has it's own buffer and contents are copied to them individually). When a comp

10:41 <pac85> When a compositor is used apps will still be synced correctly but the compositor will not. Rootless Xwayland has no way of syncing apps to an individual output since it only creates one window.

10:42 <MrCooper> pac85: with Xorg, only windows which fully cover the root window can be unredirected, which is equivalent to rootful Xwayland

10:44 <pac85> MrCooper: mmm, well still you can disable the compositor and vsync will work as it should

10:44 <MrCooper> apart from the tearing, sure

10:44 <pac85> MrCooper: what do you mean?

10:45 <MrCooper> there can be tearing in that case

10:45 <pac85> I get no tearing when using vsync under xorg, perhaps a slow enough machine would

10:45 <pac85> Due to the fact that thinhs are front buffer rendered

10:46 <MrCooper> we've been over this before :) it's not so much about (GPU) performance as it is about the mode timings

10:46 <pac85> Yeah I remember that

10:47 <pac85> But it still works in many cases, rootful xwayland just won't ever handle it

10:47 <MrCooper> "won't ever" are bold words :)

10:47 <pac85> Mm yeah it could be changed to handle it

10:47 <pac85> You could have one wayland window for each screen

10:48 <MrCooper> we've only just started exploring how rootful Xwayland could be made more useful

10:48 <MrCooper> yep, exactly

10:48 <pq> rootful Xwayland could probably use some life quality improvements, like allowing to specify the initial size and resize - IIRC it doesn't have these yet, right?

10:50 <MrCooper> looks like you're right for the former; not sure if -decorate (which uses libdecor) covers the latter

10:51 <pq> oh it uses libdecor nowadays, that's nice news to me :-)

10:52 <MrCooper> the next Xwayland major release will have optional libdecor support

12:50 <vyivel> should xdg-shellmake creating xdg toplevel parent-child loops an error?

12:51 <vyivel> right now, creating a simple loop with two toplevels freezes weston

12:51 <vyivel> and a bit more complicated setup freezes sway

12:52 <vyivel> mutter is smart about this though

12:52 <emersion> it really sounds like this should be an error

13:00 <wlb> wayland-protocols Issue #105 opened by Kirill Primak (vyivel) xdg-shell: forbid creating parent-child loops https://gitlab.freedesktop.org/wayland/wayland-protocols/-/issues/105

14:15 <leandrohrb> emersion: yes! I do have interest in working with dma-buf feedback for vulkan wl wsi again. I'll probably have time to revive that MR soon. I'll take a closer look, rebase and then I'll ping you.

14:24 <emersion> leandrohrb: thanks!

15:57 <wlb> weston Merge request !990 opened by Marius Vlad (mvlad) libweston/desktop, desktop-shell: Add getters for pending state https://gitlab.freedesktop.org/wayland/weston/-/merge_requests/990

18:48 <DemiMarie> Can we make sure there is a nesting depth limit, and that clients know what that limit is?

18:49 <daniels> if it's about resource consumption, they could just create an infinite number of toplevels without bothering to specify relationships between them

18:49 <DemiMarie> It’s about stack overflows in compositors

18:50 <daniels> shrug, just pick an extremely arbitrary limit and kill the client whenever it's exceeded

18:50 <daniels> beyond that limit the UI would be so unusable that killing the app could not possibly represent a loss

18:50 <DemiMarie> With a `wl_display.implementation` error?

18:54 <daniels> yeah

19:10 <DemiMarie> Thoughts on https://gitlab.freedesktop.org/wayland/wayland/-/merge_requests/161?

20:13 <wlb> weston Merge request !991 opened by Derek Foreman (derekf) libweston-desktop: reduce spurious pointer focus signals during grabs https://gitlab.freedesktop.org/wayland/weston/-/merge_requests/991 [libweston-desktop]