On Wed, 20 Dec 2017 13:18:45 +0200 Pekka Paalanen <[email protected]> wrote:
> From: Pekka Paalanen <[email protected]> > > If an X11 app draws a little here, some there, and a tiny bit in the > opposite corner, using RegionExtents for the damage to be sent to the > Wayland compositor will cause massive over-damaging. > > However, we cannot blindly send an arbitrary number of damage > rectangles, because there is a risk of overflowing the Wayland > connection. If that happens, it triggers an abort in libwayland-client. > > Try to be more accurate with the damage by sending up to 500 rectangles > per window, and fall back to extents otherwise. The number is completely > arbitrary. > > Signed-off-by: Pekka Paalanen <[email protected]> > --- > hw/xwayland/xwayland.c | 18 +++++++++++++++--- > 1 file changed, 15 insertions(+), 3 deletions(-) > > diff --git a/hw/xwayland/xwayland.c b/hw/xwayland/xwayland.c > index c5a3ae7ae..383680d7a 100644 > --- a/hw/xwayland/xwayland.c > +++ b/hw/xwayland/xwayland.c > @@ -629,6 +629,7 @@ xwl_window_post_damage(struct xwl_window *xwl_window) > BoxPtr box; > struct wl_buffer *buffer; > PixmapPtr pixmap; > + int i; > > assert(!xwl_window->frame_callback); > > @@ -644,9 +645,20 @@ xwl_window_post_damage(struct xwl_window *xwl_window) > > wl_surface_attach(xwl_window->surface, buffer, 0, 0); > > - box = RegionExtents(region); > - wl_surface_damage(xwl_window->surface, box->x1, box->y1, > - box->x2 - box->x1, box->y2 - box->y1); > + /* Arbitrary limit to try to avoid flooding the Wayland > + * connection. If we flood it too much anyway, this could > + * abort in libwayland-client. > + */ > + if (RegionNumRects(region) > 500) { > + box = RegionExtents(region); > + wl_surface_damage(xwl_window->surface, box->x1, box->y1, > + box->x2 - box->x1, box->y2 - box->y1); > + } else { > + box = RegionRects(region); > + for (i = 0; i < RegionNumRects(region); i++, box++) > + wl_surface_damage(xwl_window->surface, box->x1, box->y1, > + box->x2 - box->x1, box->y2 - box->y1); > + } > > xwl_window->frame_callback = wl_surface_frame(xwl_window->surface); > wl_callback_add_listener(xwl_window->frame_callback, &frame_listener, > xwl_window); Hi, should I invest the effort on a better algorithm than in this patch or would this be acceptable for landing? Thanks, pq _______________________________________________ [email protected]: X.Org development Archives: http://lists.x.org/archives/xorg-devel Info: https://lists.x.org/mailman/listinfo/xorg-devel
