From 0bf7d9ce3926290b98a8613e15c9cc53337c12bb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Mon, 4 Sep 2023 17:33:37 +0200
Subject: [PATCH] gdk/wayland: Don't notify of settings changes on startup.

I was profiling Firefox startup on Wayland, and I realized that we were
doing too much work because we get extra settings changed events, posted
from here:

    #0  gdk_event_copy (event=0x7ffe9c4a7fd0) at ../gtk/gdk/gdkevents.c:659
    #1  0x00007f8b8a5060c6 in gdk_display_put_event (event=0x7ffe9c4a7fd0, display=0x7f8b8d551a00) at ../gtk/gdk/gdkdisplay.c:503
    #2  gdk_display_put_event (display=0x7f8b8d551a00, event=0x7ffe9c4a7fd0) at ../gtk/gdk/gdkdisplay.c:497
    #3  0x00007f8b8a5456e6 in notify_setting (setting=0x7f8b8a59b6d6 "gtk-xft-dpi", screen=0x7f8b8d517700) at ../gtk/gdk/wayland/gdkscreen-wayland.c:237
    #4  update_xft_settings (screen=0x7f8b8d517700) at ../gtk/gdk/wayland/gdkscreen-wayland.c:513
    #5  0x00007f8b8a53ef6d in init_settings (screen=0x7f8b8d517700) at ../gtk/gdk/wayland/gdkscreen-wayland.c:842
    #6  _gdk_wayland_screen_new (display=0x7f8b8d551a00) at ../gtk/gdk/wayland/gdkscreen-wayland.c:1367
    #7  _gdk_wayland_display_open (display_name=<optimized out>) at ../gtk/gdk/wayland/gdkdisplay-wayland.c:618
    #8  0x00007f8b8a507bc7 in gdk_display_manager_open_display (manager=<optimized out>, name=0x0) at ../gtk/gdk/gdkdisplaymanager.c:462
    #9  0x00007f8b82bda2f8 in XREMain::XRE_mainStartup(bool*) (this=this@entry=0x7ffe9c4a8398, aExitFlag=aExitFlag@entry=0x7ffe9c4a830f) at /home/emilio/src/moz/gecko-6/toolkit/xre/nsAppRunner.cpp:4760
    #10 0x00007f8b82be1742 in XREMain::XRE_main(int, char**, mozilla::BootstrapConfig const&) (this=this@entry=0x7ffe9c4a8398, argc=argc@entry=4, argv=argv@entry=0x7ffe9c4a9698, aConfig=...) at /home/emilio/src/moz/gecko-6/toolkit/xre/nsAppRunner.cpp:5874
    #11 0x00007f8b82be1c2c in XRE_main(int, char**, mozilla::BootstrapConfig const&) (argc=4, argv=0x7ffe9c4a9698, aConfig=...) at /home/emilio/src/moz/gecko-6/toolkit/xre/nsAppRunner.cpp:5942
    #12 0x000055631ef3b3e9 in do_main(int, char**, char**) (argc=4, argv=0x7ffe9c4a9698, envp=<optimized out>) at /home/emilio/src/moz/gecko-6/browser/app/nsBrowserApp.cpp:227
    #13 main(int, char**, char**) (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at /home/emilio/src/moz/gecko-6/browser/app/nsBrowserApp.cpp:445

We shouldn't post events for a screen we're just creating, because it
can make apps do too much work during startup. X11 had code for this.
---
 gdk/wayland/gdkscreen-wayland.c | 23 ++++++++++++++---------
 1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/gdk/wayland/gdkscreen-wayland.c b/gdk/wayland/gdkscreen-wayland.c
index 295180d43b..c53f00a88b 100644
--- a/gdk/wayland/gdkscreen-wayland.c
+++ b/gdk/wayland/gdkscreen-wayland.c
@@ -336,7 +336,7 @@ struct _TranslationEntry {
 static TranslationEntry * find_translation_entry_by_schema (const char *schema,
                                                             const char *key);
 static void
-update_xft_settings (GdkScreen *screen)
+update_xft_settings (GdkScreen *screen, gboolean notify)
 {
   GdkWaylandScreen *screen_wayland = GDK_WAYLAND_SCREEN (screen);
   GSettings *settings;
@@ -471,25 +471,29 @@ update_xft_settings (GdkScreen *screen)
   if (screen_wayland->xft_settings.antialias != xft_settings.antialias)
     {
       screen_wayland->xft_settings.antialias = xft_settings.antialias;
-      notify_setting (screen, "gtk-xft-antialias");
+      if (notify)
+        notify_setting (screen, "gtk-xft-antialias");
     }
 
   if (screen_wayland->xft_settings.hinting != xft_settings.hinting)
     {
       screen_wayland->xft_settings.hinting = xft_settings.hinting;
-      notify_setting (screen, "gtk-xft-hinting");
+      if (notify)
+        notify_setting (screen, "gtk-xft-hinting");
     }
 
   if (screen_wayland->xft_settings.hintstyle != xft_settings.hintstyle)
     {
       screen_wayland->xft_settings.hintstyle = xft_settings.hintstyle;
-      notify_setting (screen, "gtk-xft-hintstyle");
+      if (notify)
+        notify_setting (screen, "gtk-xft-hintstyle");
     }
 
   if (screen_wayland->xft_settings.rgba != xft_settings.rgba)
     {
       screen_wayland->xft_settings.rgba = xft_settings.rgba;
-      notify_setting (screen, "gtk-xft-rgba");
+      if (notify)
+        notify_setting (screen, "gtk-xft-rgba");
     }
 
   if (screen_wayland->xft_settings.dpi != xft_settings.dpi)
@@ -510,7 +514,8 @@ update_xft_settings (GdkScreen *screen)
 
       _gdk_screen_set_resolution (screen, dpi);
 
-      notify_setting (screen, "gtk-xft-dpi");
+      if (notify)
+        notify_setting (screen, "gtk-xft-dpi");
     }
 }
 
@@ -626,7 +631,7 @@ settings_changed (GSettings   *settings,
       else if (strcmp (key, "high-contrast") == 0)
         high_contrast_changed (screen);
       else
-        update_xft_settings (screen);
+        update_xft_settings (screen, TRUE);
     }
 }
 
@@ -658,7 +663,7 @@ apply_portal_setting (TranslationEntry *entry,
         entry->fallback.i = get_order (g_variant_get_string (value, NULL));
       else if (strcmp (entry->key, "text-scaling-factor") == 0)
         entry->fallback.i = (int) (g_variant_get_double (value) * 65536.0);
-      update_xft_settings (screen);
+      update_xft_settings (screen, TRUE);
       break;
     default:
       break;
@@ -839,7 +844,7 @@ fallback:
       g_settings_schema_unref (schema);
     }
 
-  update_xft_settings (screen);
+  update_xft_settings (screen, FALSE);
 }
 
 static void