From 845157c11138ed189221f5c8164fb17945d1d493 Mon Sep 17 00:00:00 2001 From: Olivier Fourdan Date: Tue, 19 Nov 2019 14:08:45 +0100 Subject: [PATCH] window/x11: Add `freeze_commits()/thaw_commits()` Xwayland may post damages for an X11 window as soon as the frame callback is triggered, while the X11 window manager/compositor has not yet finished updating the windows. If Xwayland becomes compliant enough to not permit updates after the buffer has been committed (see [1]), then the partial redraw of the X11 window at the time it was posted will show on screen. To avoid that issue, the X11 window manager can use the X11 property `_XWAYLAND_ALLOW_COMMITS` to control when Xwayland should be allowed to post the pending damages. Add `freeze_commits()` and `thaw_commits()` methods to `MetaWindowX11` which are a no-op on plain X11, but sets `_XWAYLAND_ALLOW_COMMITS` on the toplevel X11 windows running on Xwayland. [1] https://gitlab.freedesktop.org/xorg/xserver/merge_requests/316 See-also: https://gitlab.gnome.org/GNOME/mutter/merge_requests/855 https://gitlab.gnome.org/GNOME/mutter/merge_requests/942 --- src/wayland/meta-window-xwayland.c | 64 ++++++++++++++++++++++++++++++ src/x11/atomnames.h | 1 + src/x11/window-x11-private.h | 3 ++ src/x11/window-x11.c | 27 +++++++++++++ src/x11/window-x11.h | 3 ++ 5 files changed, 98 insertions(+) diff --git a/src/wayland/meta-window-xwayland.c b/src/wayland/meta-window-xwayland.c index 9967f439a..5b1c4198e 100644 --- a/src/wayland/meta-window-xwayland.c +++ b/src/wayland/meta-window-xwayland.c @@ -18,6 +18,8 @@ #include "config.h" +#include "core/frame.h" +#include "meta/meta-x11-errors.h" #include "x11/window-x11.h" #include "x11/window-x11-private.h" #include "x11/xprops.h" @@ -40,6 +42,7 @@ struct _MetaWindowXwayland MetaWindowX11 parent; gboolean xwayland_may_grab_keyboard; + int freeze_count; }; struct _MetaWindowXwaylandClass @@ -159,6 +162,63 @@ meta_window_xwayland_shortcuts_inhibited (MetaWindow *window, return meta_wayland_compositor_is_shortcuts_inhibited (compositor, source); } +static void +apply_allow_commits_x11_property (MetaWindowXwayland *xwayland_window, + gboolean allow_commits) +{ + MetaWindow *window = META_WINDOW (xwayland_window); + MetaDisplay *display = window->display; + MetaX11Display *x11_display = display->x11_display; + Display *xdisplay = x11_display->xdisplay; + MetaFrame *frame; + Window xwin; + guint32 property[1]; + + frame = meta_window_get_frame (window); + if (!frame) + xwin = window->xwindow; + else + xwin = meta_frame_get_xwindow (frame); + + if (!xwin) + return; + + property[0] = !!allow_commits; + + meta_x11_error_trap_push (x11_display); + XChangeProperty (xdisplay, xwin, + x11_display->atom__XWAYLAND_ALLOW_COMMITS, + XA_CARDINAL, 32, PropModeReplace, + (guchar*) &property, 1); + meta_x11_error_trap_pop (x11_display); + XFlush (xdisplay); +} + +static void +meta_window_xwayland_freeze_commits (MetaWindow *window) +{ + MetaWindowXwayland *xwayland_window = META_WINDOW_XWAYLAND (window); + + if (xwayland_window->freeze_count == 0) + apply_allow_commits_x11_property (xwayland_window, FALSE); + + xwayland_window->freeze_count++; +} + +static void +meta_window_xwayland_thaw_commits (MetaWindow *window) +{ + MetaWindowXwayland *xwayland_window = META_WINDOW_XWAYLAND (window); + + g_return_if_fail (xwayland_window->freeze_count > 0); + + xwayland_window->freeze_count--; + if (xwayland_window->freeze_count > 0) + return; + + apply_allow_commits_x11_property (xwayland_window, TRUE); +} + static void meta_window_xwayland_get_property (GObject *object, guint prop_id, @@ -201,12 +261,16 @@ static void meta_window_xwayland_class_init (MetaWindowXwaylandClass *klass) { MetaWindowClass *window_class = META_WINDOW_CLASS (klass); + MetaWindowX11Class *window_x11_class = META_WINDOW_X11_CLASS (klass); GObjectClass *gobject_class = G_OBJECT_CLASS (klass); window_class->adjust_fullscreen_monitor_rect = meta_window_xwayland_adjust_fullscreen_monitor_rect; window_class->force_restore_shortcuts = meta_window_xwayland_force_restore_shortcuts; window_class->shortcuts_inhibited = meta_window_xwayland_shortcuts_inhibited; + window_x11_class->freeze_commits = meta_window_xwayland_freeze_commits; + window_x11_class->thaw_commits = meta_window_xwayland_thaw_commits; + gobject_class->get_property = meta_window_xwayland_get_property; gobject_class->set_property = meta_window_xwayland_set_property; diff --git a/src/x11/atomnames.h b/src/x11/atomnames.h index 4099d5d31..4c1b49ede 100644 --- a/src/x11/atomnames.h +++ b/src/x11/atomnames.h @@ -82,6 +82,7 @@ item(_XKB_RULES_NAMES) item(WL_SURFACE_ID) item(_XWAYLAND_MAY_GRAB_KEYBOARD) item(_XWAYLAND_RANDR_EMU_MONITOR_RECTS) +item(_XWAYLAND_ALLOW_COMMITS) /* Oddities: These are used, and we need atoms for them, * but when we need all _NET_WM hints (i.e. when we're making diff --git a/src/x11/window-x11-private.h b/src/x11/window-x11-private.h index c582118c7..a073a5b8a 100644 --- a/src/x11/window-x11-private.h +++ b/src/x11/window-x11-private.h @@ -33,6 +33,9 @@ typedef struct _MetaWindowX11Private MetaWindowX11Private; struct _MetaWindowX11Class { MetaWindowClass parent_class; + + void (*freeze_commits) (MetaWindow *window); + void (*thaw_commits) (MetaWindow *window); }; struct _MetaWindowX11 diff --git a/src/x11/window-x11.c b/src/x11/window-x11.c index 6378111b5..9caf75ad6 100644 --- a/src/x11/window-x11.c +++ b/src/x11/window-x11.c @@ -1973,6 +1973,16 @@ meta_window_x11_calculate_layer (MetaWindow *window) return layer; } +static void +meta_window_x11_impl_freeze_commits (MetaWindow *window) +{ +} + +static void +meta_window_x11_impl_thaw_commits (MetaWindow *window) +{ +} + static void meta_window_x11_map (MetaWindow *window) { @@ -2024,6 +2034,9 @@ meta_window_x11_class_init (MetaWindowX11Class *klass) window_class->calculate_layer = meta_window_x11_calculate_layer; window_class->map = meta_window_x11_map; window_class->unmap = meta_window_x11_unmap; + + klass->freeze_commits = meta_window_x11_impl_freeze_commits; + klass->thaw_commits = meta_window_x11_impl_thaw_commits; } void @@ -3995,3 +4008,17 @@ meta_window_x11_get_toplevel_xwindow (MetaWindow *window) { return window->frame ? window->frame->xwindow : window->xwindow; } + +void +meta_window_x11_freeze_commits (MetaWindow *window) +{ + MetaWindowX11 *window_x11 = META_WINDOW_X11 (window); + META_WINDOW_X11_GET_CLASS (window_x11)->freeze_commits (window); +} + +void +meta_window_x11_thaw_commits (MetaWindow *window) +{ + MetaWindowX11 *window_x11 = META_WINDOW_X11 (window); + META_WINDOW_X11_GET_CLASS (window_x11)->thaw_commits (window); +} diff --git a/src/x11/window-x11.h b/src/x11/window-x11.h index f3f3f1de1..2180ce976 100644 --- a/src/x11/window-x11.h +++ b/src/x11/window-x11.h @@ -81,4 +81,7 @@ void meta_window_x11_configure_notify (MetaWindow *window, Window meta_window_x11_get_toplevel_xwindow (MetaWindow *window); +void meta_window_x11_freeze_commits (MetaWindow *window); +void meta_window_x11_thaw_commits (MetaWindow *window); + #endif