Update Occitan translation

Since mutter has two X connections and does damage handling on the
frontend while fence triggering is done on the backend, we have a race
between XDamageSubtract() and XSyncFenceTrigger() causing missed
redraws in the GL_EXT_X11_sync_object path.

If the fence trigger gets processed first by the server, any client
drawing that happens between that and the damage subtract being
processed and is completely contained in the last damage event box
that mutter got, won't be included in the current frame nor will it
cause a new damage event.

A simple fix for this would be XSync()ing on the frontend connection
after doing all the damage subtracts but that would add a round trip
on every frame again which defeats the asynchronous design of X
fences.

Instead, if we move fence handling to the frontend we automatically
get the right ordering between damage subtracts and fence triggers.

https://bugzilla.gnome.org/show_bug.cgi?id=728464

NEWS

@@ -1,3 +1,27 @@
+3.14.4
+======
+* Fix flash on unredirection [Chris; #743858]
+* Fix incompatibility with GLES2 GLSL [Alban; #745442]
+* Add function to refresh all background instances [Rui; #739178]
+* Fix geometry of shaded windows [Florian; #746145]
+* Misc. bug fixes [Florian, Rui; #698995, #743217, #743254]
+
+Contributors:
+  Alban Browaeys, Rui Matos, Florian Müllner, Chris Wilson
+
+Translations:
+  Matej Urbančič [sl], Muhammet Kara [tr], Samir Ribic [bs]
+
+3.14.3
+======
+* Fix crash when trying to unredirect a destroyed window [Florian; #740133]
+* Fix "flicker" during startup transition [Ray; #740377]
+* Don't leave left-over frames queued [Owen; #738686]
+* Set CRTC configuration even if it might be redundant [Rui; #740838]
+
+Contributors:
+  Rui Matos, Florian Müllner, Jasper St. Pierre, Ray Strode, Owen W. Taylor
+
 3.14.2
 ======
 * Prevent crash applying monitor config for a closed lid [Rui; #739450]

configure.ac

@@ -2,7 +2,7 @@ AC_PREREQ(2.62)
 
 m4_define([mutter_major_version], [3])
 m4_define([mutter_minor_version], [14])
-m4_define([mutter_micro_version], [2])
+m4_define([mutter_micro_version], [4])
 
 m4_define([mutter_version],
           [mutter_major_version.mutter_minor_version.mutter_micro_version])
@@ -72,7 +72,7 @@ CLUTTER_PACKAGE=clutter-1.0
 
 MUTTER_PC_MODULES="
    gtk+-3.0 >= 3.9.11
-   gio-unix-2.0 >= 2.25.10
+   gio-unix-2.0 >= 2.35.1
    pango >= 1.2.0
    cairo >= 1.10.0
    gsettings-desktop-schemas >= 3.7.3
@@ -90,6 +90,7 @@ MUTTER_PC_MODULES="
    xkeyboard-config
    xkbcommon >= 0.4.3
    xkbcommon-x11
+   xrender
    x11-xcb
    xcb-randr
 "
@@ -314,6 +315,11 @@ fi
 
 GTK_DOC_CHECK([1.15], [--flavour no-tmpl])
 
+AC_CHECK_DECL([GL_EXT_x11_sync_object],
+              [],
+              [AC_MSG_ERROR([GL_EXT_x11_sync_object definition not found, please update your GL headers])],
+              [#include <GL/glx.h>])
+
 #### Warnings (last since -Werror can disturb other tests)
 
 # Stay command-line compatible with the gnome-common configure option. Here

src/Makefile.am

@@ -126,6 +126,8 @@ libmutter_la_SOURCES =				\
 	compositor/meta-surface-actor.h		\
 	compositor/meta-surface-actor-x11.c	\
 	compositor/meta-surface-actor-x11.h	\
+	compositor/meta-sync-ring.c		\
+	compositor/meta-sync-ring.h		\
 	compositor/meta-texture-rectangle.c	\
 	compositor/meta-texture-rectangle.h	\
 	compositor/meta-texture-tower.c		\

src/backends/native/meta-launcher.c

@@ -130,8 +130,8 @@ take_device (Login1Session *session_proxy,
 {
   gboolean ret = FALSE;
   GVariant *fd_variant = NULL;
+  GUnixFDList *fd_list = NULL;
   int fd = -1;
-  GUnixFDList *fd_list;
 
   if (!login1_session_call_take_device_sync (session_proxy,
                                              dev_major,

src/backends/x11/meta-monitor-manager-xrandr.c

@@ -838,26 +838,12 @@ meta_monitor_manager_xrandr_apply_configuration (MetaMonitorManager *manager,
           unsigned int j, n_outputs;
           int width, height;
           Status ok;
-          unsigned long old_controlled_mask;
-          unsigned long new_controlled_mask;
 
           mode = crtc_info->mode;
 
           n_outputs = crtc_info->outputs->len;
           outputs = g_new (XID, n_outputs);
 
-          old_controlled_mask = 0;
-          for (j = 0; j < manager->n_outputs; j++)
-            {
-              MetaOutput *output;
-
-              output = &manager->outputs[j];
-
-              if (output->crtc == crtc)
-                old_controlled_mask |= 1UL << j;
-            }
-
-          new_controlled_mask = 0;
           for (j = 0; j < n_outputs; j++)
             {
               MetaOutput *output;
@@ -866,21 +852,10 @@ meta_monitor_manager_xrandr_apply_configuration (MetaMonitorManager *manager,
 
               output->is_dirty = TRUE;
               output->crtc = crtc;
-              new_controlled_mask |= 1UL << j;
 
               outputs[j] = output->winsys_id;
             }
 
-          if (crtc->current_mode == mode &&
-              crtc->rect.x == crtc_info->x &&
-              crtc->rect.y == crtc_info->y &&
-              crtc->transform == crtc_info->transform &&
-              old_controlled_mask == new_controlled_mask)
-            {
-              /* No change */
-              goto next;
-            }
-
           ok = XRRSetCrtcConfig (manager_xrandr->xdisplay,
                                  manager_xrandr->resources,
                                  (XID)crtc->crtc_id,

src/compositor/compositor-private.h

@@ -15,7 +15,8 @@ struct _MetaCompositor
 {
   MetaDisplay    *display;
 
-  guint           repaint_func_id;
+  guint           pre_paint_func_id;
+  guint           post_paint_func_id;
 
   gint64          server_time_query_time;
   gint64          server_time_offset;
@@ -40,6 +41,7 @@ struct _MetaCompositor
   MetaPluginManager *plugin_mgr;
 
   gboolean frame_has_updated_xsurfaces;
+  gboolean have_x11_sync_object;
 };
 
 /* Wait 2ms after vblank before starting to draw next frame */

src/compositor/compositor.c

@@ -79,6 +79,7 @@
 #include "frame.h"
 #include <X11/extensions/shape.h>
 #include <X11/extensions/Xcomposite.h>
+#include "meta-sync-ring.h"
 
 #include "backends/x11/meta-backend-x11.h"
 
@@ -125,7 +126,11 @@ meta_switch_workspace_completed (MetaCompositor *compositor)
 void
 meta_compositor_destroy (MetaCompositor *compositor)
 {
-  clutter_threads_remove_repaint_func (compositor->repaint_func_id);
+  clutter_threads_remove_repaint_func (compositor->pre_paint_func_id);
+  clutter_threads_remove_repaint_func (compositor->post_paint_func_id);
+
+  if (compositor->have_x11_sync_object)
+    meta_sync_ring_destroy ();
 }
 
 static void
@@ -468,13 +473,11 @@ meta_compositor_manage (MetaCompositor *compositor)
   MetaDisplay *display = compositor->display;
   Display *xdisplay = display->xdisplay;
   MetaScreen *screen = display->screen;
+  MetaBackend *backend = meta_get_backend ();
 
   meta_screen_set_cm_selection (display->screen);
 
-  {
-    MetaBackend *backend = meta_get_backend ();
-    compositor->stage = meta_backend_get_stage (backend);
-  }
+  compositor->stage = meta_backend_get_stage (backend);
 
   /* We use connect_after() here to accomodate code in GNOME Shell that,
    * when benchmarking drawing performance, connects to ::after-paint
@@ -510,7 +513,7 @@ meta_compositor_manage (MetaCompositor *compositor)
 
       compositor->output = screen->composite_overlay_window;
 
-      xwin = meta_backend_x11_get_xwindow (META_BACKEND_X11 (meta_get_backend ()));
+      xwin = meta_backend_x11_get_xwindow (META_BACKEND_X11 (backend));
 
       XReparentWindow (xdisplay, xwin, compositor->output, 0, 0);
 
@@ -530,6 +533,8 @@ meta_compositor_manage (MetaCompositor *compositor)
        * contents until we show the stage.
        */
       XMapWindow (xdisplay, compositor->output);
+
+      compositor->have_x11_sync_object = meta_sync_ring_init (xdisplay);
     }
 
   redirect_windows (display->screen);
@@ -614,6 +619,7 @@ set_unredirected_window (MetaCompositor *compositor,
       meta_window_actor_set_unredirected (window_actor, FALSE);
     }
 
+  meta_shape_cow_for_window (compositor, window);
   compositor->unredirected_window = window;
 
   if (compositor->unredirected_window != NULL)
@@ -621,8 +627,6 @@ set_unredirected_window (MetaCompositor *compositor,
       MetaWindowActor *window_actor = META_WINDOW_ACTOR (meta_window_get_compositor_private (compositor->unredirected_window));
       meta_window_actor_set_unredirected (window_actor, TRUE);
     }
-
-  meta_shape_cow_for_window (compositor, compositor->unredirected_window);
 }
 
 void
@@ -732,6 +736,9 @@ meta_compositor_process_event (MetaCompositor *compositor,
         process_damage (compositor, (XDamageNotifyEvent *) event, window);
     }
 
+  if (compositor->have_x11_sync_object)
+    meta_sync_ring_handle_event (event);
+
   /* Clutter needs to know about MapNotify events otherwise it will
      think the stage is invisible */
   if (!meta_is_wayland_compositor () && event->type == MapNotify)
@@ -1045,11 +1052,12 @@ frame_callback (CoglOnscreen  *onscreen,
     }
 }
 
-static void
-pre_paint_windows (MetaCompositor *compositor)
+static gboolean
+meta_pre_paint_func (gpointer data)
 {
   GList *l;
   MetaWindowActor *top_window;
+  MetaCompositor *compositor = data;
 
   if (compositor->onscreen == NULL)
     {
@@ -1061,7 +1069,7 @@ pre_paint_windows (MetaCompositor *compositor)
     }
 
   if (compositor->windows == NULL)
-    return;
+    return TRUE;
 
   top_window = g_list_last (compositor->windows)->data;
 
@@ -1078,10 +1086,12 @@ pre_paint_windows (MetaCompositor *compositor)
     {
       /* We need to make sure that any X drawing that happens before
        * the XDamageSubtract() for each window above is visible to
-       * subsequent GL rendering; the only standardized way to do this
-       * is EXT_x11_sync_object, which isn't yet widely available. For
-       * now, we count on details of Xorg and the open source drivers,
-       * and hope for the best otherwise.
+       * subsequent GL rendering; the standardized way to do this is
+       * GL_EXT_X11_sync_object. Since this isn't implemented yet in
+       * mesa, we also have a path that relies on the implementation
+       * of the open source drivers.
+       *
+       * Anything else, we just hope for the best.
        *
        * Xorg and open source driver specifics:
        *
@@ -1096,17 +1106,28 @@ pre_paint_windows (MetaCompositor *compositor)
        * round trip request at this point is sufficient to flush the
        * GLX buffers.
        */
-      XSync (compositor->display->xdisplay, False);
-
-      compositor->frame_has_updated_xsurfaces = FALSE;
+      if (compositor->have_x11_sync_object)
+        compositor->have_x11_sync_object = meta_sync_ring_insert_wait ();
+      else
+        XSync (compositor->display->xdisplay, False);
     }
+
+  return TRUE;
 }
 
 static gboolean
-meta_repaint_func (gpointer data)
+meta_post_paint_func (gpointer data)
 {
   MetaCompositor *compositor = data;
-  pre_paint_windows (compositor);
+
+  if (compositor->frame_has_updated_xsurfaces)
+    {
+      if (compositor->have_x11_sync_object)
+        compositor->have_x11_sync_object = meta_sync_ring_after_frame ();
+
+      compositor->frame_has_updated_xsurfaces = FALSE;
+    }
+
   return TRUE;
 }
 
@@ -1141,10 +1162,16 @@ meta_compositor_new (MetaDisplay *display)
                     G_CALLBACK (on_shadow_factory_changed),
                     compositor);
 
-  compositor->repaint_func_id = clutter_threads_add_repaint_func (meta_repaint_func,
-                                                                  compositor,
-                                                                  NULL);
-
+  compositor->pre_paint_func_id =
+    clutter_threads_add_repaint_func_full (CLUTTER_REPAINT_FLAGS_PRE_PAINT,
+                                           meta_pre_paint_func,
+                                           compositor,
+                                           NULL);
+  compositor->post_paint_func_id =
+    clutter_threads_add_repaint_func_full (CLUTTER_REPAINT_FLAGS_POST_PAINT,
+                                           meta_post_paint_func,
+                                           compositor,
+                                           NULL);
   return compositor;
 }
 

src/compositor/meta-background-actor.c

@@ -115,7 +115,7 @@ typedef enum {
 #define FRAGMENT_SHADER_CODE                                                   \
 "float t = 2.0 * length(position);\n"                                          \
 "t = min(t, 1.0);\n"                                                           \
-"float pixel_brightness = 1 - t * vignette_sharpness;\n"                       \
+"float pixel_brightness = 1.0 - t * vignette_sharpness;\n"                       \
 "cogl_color_out.rgb = cogl_color_out.rgb * pixel_brightness;\n"                \
 
 typedef struct _MetaBackgroundLayer MetaBackgroundLayer;

src/compositor/meta-background.c

@@ -71,6 +71,8 @@ enum
 
 G_DEFINE_TYPE (MetaBackground, meta_background, G_TYPE_OBJECT)
 
+static GSList *all_backgrounds = NULL;
+
 static void
 free_fbos (MetaBackground *self)
 {
@@ -291,6 +293,8 @@ meta_background_dispose (GObject *object)
 static void
 meta_background_finalize (GObject *object)
 {
+  all_backgrounds = g_slist_remove (all_backgrounds, object);
+
   G_OBJECT_CLASS (meta_background_parent_class)->finalize (object);
 }
 
@@ -333,6 +337,7 @@ meta_background_init (MetaBackground *self)
   self->priv = G_TYPE_INSTANCE_GET_PRIVATE (self,
                                             META_TYPE_BACKGROUND,
                                             MetaBackgroundPrivate);
+  all_backgrounds = g_slist_prepend (all_backgrounds, self);
 }
 
 static void
@@ -899,3 +904,12 @@ meta_background_set_blend (MetaBackground          *self,
   free_wallpaper_texture (self);
   mark_changed (self);
 }
+
+void
+meta_background_refresh_all (void)
+{
+  GSList *l;
+
+  for (l = all_backgrounds; l; l = l->next)
+    mark_changed (l->data);
+}

src/compositor/meta-sync-ring.c

@@ -0,0 +1,592 @@
+/*
+ * This is based on an original C++ implementation for compiz that
+ * carries the following copyright notice:
+ *
+ *
+ * Copyright © 2011 NVIDIA Corporation
+ *
+ * Permission to use, copy, modify, distribute, and sell this software
+ * and its documentation for any purpose is hereby granted without
+ * fee, provided that the above copyright notice appear in all copies
+ * and that both that copyright notice and this permission notice
+ * appear in supporting documentation, and that the name of NVIDIA
+ * Corporation not be used in advertising or publicity pertaining to
+ * distribution of the software without specific, written prior
+ * permission.  NVIDIA Corporation makes no representations about the
+ * suitability of this software for any purpose. It is provided "as
+ * is" without express or implied warranty.
+ *
+ * NVIDIA CORPORATION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL NVIDIA CORPORATION BE LIABLE FOR ANY
+ * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
+ * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
+ * SOFTWARE.
+ *
+ * Authors: James Jones <jajones@nvidia.com>
+ */
+
+#include <string.h>
+
+#include <GL/gl.h>
+#include <GL/glx.h>
+#include <X11/extensions/sync.h>
+
+#include <cogl/cogl.h>
+#include <clutter/clutter.h>
+
+#include <meta/util.h>
+
+#include "meta-sync-ring.h"
+
+/* Theory of operation:
+ *
+ * We use a ring of NUM_SYNCS fence objects. On each frame we advance
+ * to the next fence in the ring. For each fence we do:
+ *
+ * 1. fence is XSyncTriggerFence()'d and glWaitSync()'d
+ * 2. NUM_SYNCS / 2 frames later, fence should be triggered
+ * 3. fence is XSyncResetFence()'d
+ * 4. NUM_SYNCS / 2 frames later, fence should be reset
+ * 5. go back to 1 and re-use fence
+ *
+ * glClientWaitSync() and XAlarms are used in steps 2 and 4,
+ * respectively, to double-check the expectections.
+ */
+
+#define NUM_SYNCS 10
+#define MAX_SYNC_WAIT_TIME (1 * 1000 * 1000 * 1000) /* one sec */
+#define MAX_REBOOT_ATTEMPTS 2
+
+typedef enum
+{
+  META_SYNC_STATE_READY,
+  META_SYNC_STATE_WAITING,
+  META_SYNC_STATE_DONE,
+  META_SYNC_STATE_RESET_PENDING,
+} MetaSyncState;
+
+typedef struct
+{
+  Display *xdisplay;
+
+  XSyncFence xfence;
+  GLsync gl_x11_sync;
+  GLsync gpu_fence;
+
+  XSyncCounter xcounter;
+  XSyncAlarm xalarm;
+  XSyncValue next_counter_value;
+
+  MetaSyncState state;
+} MetaSync;
+
+typedef struct
+{
+  Display *xdisplay;
+  int xsync_event_base;
+  int xsync_error_base;
+
+  GHashTable *alarm_to_sync;
+
+  MetaSync *syncs_array[NUM_SYNCS];
+  guint current_sync_idx;
+  MetaSync *current_sync;
+  guint warmup_syncs;
+
+  guint reboots;
+} MetaSyncRing;
+
+static MetaSyncRing meta_sync_ring = { 0 };
+
+static XSyncValue SYNC_VALUE_ZERO;
+static XSyncValue SYNC_VALUE_ONE;
+
+static const char*      (*meta_gl_get_string) (GLenum name);
+static void             (*meta_gl_get_integerv) (GLenum  pname,
+                                                 GLint  *params);
+static const char*      (*meta_gl_get_stringi) (GLenum name,
+                                                GLuint index);
+static void             (*meta_gl_delete_sync) (GLsync sync);
+static GLenum           (*meta_gl_client_wait_sync) (GLsync sync,
+                                                     GLbitfield flags,
+                                                     GLuint64 timeout);
+static void             (*meta_gl_wait_sync) (GLsync sync,
+                                              GLbitfield flags,
+                                              GLuint64 timeout);
+static GLsync           (*meta_gl_import_sync) (GLenum external_sync_type,
+                                                GLintptr external_sync,
+                                                GLbitfield flags);
+static GLsync           (*meta_gl_fence_sync) (GLenum condition,
+                                               GLbitfield flags);
+
+static MetaSyncRing *
+meta_sync_ring_get (void)
+{
+  if (meta_sync_ring.reboots > MAX_REBOOT_ATTEMPTS)
+    return NULL;
+
+  return &meta_sync_ring;
+}
+
+static gboolean
+load_gl_symbol (const char  *name,
+                void       **func)
+{
+  *func = cogl_get_proc_address (name);
+  if (!*func)
+    {
+      meta_verbose ("MetaSyncRing: failed to resolve required GL symbol \"%s\"\n", name);
+      return FALSE;
+    }
+  return TRUE;
+}
+
+static gboolean
+check_gl_extensions (void)
+{
+  ClutterBackend *backend;
+  CoglContext *cogl_context;
+  CoglDisplay *cogl_display;
+  CoglRenderer *cogl_renderer;
+
+  backend = clutter_get_default_backend ();
+  cogl_context = clutter_backend_get_cogl_context (backend);
+  cogl_display = cogl_context_get_display (cogl_context);
+  cogl_renderer = cogl_display_get_renderer (cogl_display);
+
+  switch (cogl_renderer_get_driver (cogl_renderer))
+    {
+    case COGL_DRIVER_GL3:
+      {
+        int num_extensions, i;
+        gboolean arb_sync = FALSE;
+        gboolean x11_sync_object = FALSE;
+
+        meta_gl_get_integerv (GL_NUM_EXTENSIONS, &num_extensions);
+
+        for (i = 0; i < num_extensions; ++i)
+          {
+            const char *ext = meta_gl_get_stringi (GL_EXTENSIONS, i);
+
+            if (g_strcmp0 ("GL_ARB_sync", ext) == 0)
+              arb_sync = TRUE;
+            else if (g_strcmp0 ("GL_EXT_x11_sync_object", ext) == 0)
+              x11_sync_object = TRUE;
+          }
+
+        return arb_sync && x11_sync_object;
+      }
+    case COGL_DRIVER_GL:
+      {
+        const char *extensions = meta_gl_get_string (GL_EXTENSIONS);
+        return (extensions != NULL &&
+                strstr (extensions, "GL_ARB_sync") != NULL &&
+                strstr (extensions, "GL_EXT_x11_sync_object") != NULL);
+      }
+    default:
+      break;
+    }
+
+  return FALSE;
+}
+
+static gboolean
+load_required_symbols (void)
+{
+  static gboolean success = FALSE;
+
+  if (success)
+    return TRUE;
+
+  /* We don't link against libGL directly because cogl may want to
+   * use something else. This assumes that cogl has been initialized
+   * and dynamically loaded libGL at this point.
+   */
+
+  if (!load_gl_symbol ("glGetString", (void **) &meta_gl_get_string))
+    goto out;
+  if (!load_gl_symbol ("glGetIntegerv", (void **) &meta_gl_get_integerv))
+    goto out;
+  if (!load_gl_symbol ("glGetStringi", (void **) &meta_gl_get_stringi))
+    goto out;
+
+  if (!check_gl_extensions ())
+    {
+      meta_verbose ("MetaSyncRing: couldn't find required GL extensions\n");
+      goto out;
+    }
+
+  if (!load_gl_symbol ("glDeleteSync", (void **) &meta_gl_delete_sync))
+    goto out;
+  if (!load_gl_symbol ("glClientWaitSync", (void **) &meta_gl_client_wait_sync))
+    goto out;
+  if (!load_gl_symbol ("glWaitSync", (void **) &meta_gl_wait_sync))
+    goto out;
+  if (!load_gl_symbol ("glImportSyncEXT", (void **) &meta_gl_import_sync))
+    goto out;
+  if (!load_gl_symbol ("glFenceSync", (void **) &meta_gl_fence_sync))
+    goto out;
+
+  success = TRUE;
+ out:
+  return success;
+}
+
+static void
+meta_sync_insert (MetaSync *self)
+{
+  g_return_if_fail (self->state == META_SYNC_STATE_READY);
+
+  XSyncTriggerFence (self->xdisplay, self->xfence);
+  XFlush (self->xdisplay);
+
+  meta_gl_wait_sync (self->gl_x11_sync, 0, GL_TIMEOUT_IGNORED);
+  self->gpu_fence = meta_gl_fence_sync (GL_SYNC_GPU_COMMANDS_COMPLETE, 0);
+
+  self->state = META_SYNC_STATE_WAITING;
+}
+
+static GLenum
+meta_sync_check_update_finished (MetaSync *self,
+                                 GLuint64  timeout)
+{
+  GLenum status = GL_WAIT_FAILED;
+
+  switch (self->state)
+    {
+    case META_SYNC_STATE_DONE:
+      status = GL_ALREADY_SIGNALED;
+      break;
+    case META_SYNC_STATE_WAITING:
+      status = meta_gl_client_wait_sync (self->gpu_fence, 0, timeout);
+      if (status == GL_ALREADY_SIGNALED || status == GL_CONDITION_SATISFIED)
+        {
+          self->state = META_SYNC_STATE_DONE;
+          meta_gl_delete_sync (self->gpu_fence);
+          self->gpu_fence = 0;
+        }
+      break;
+    default:
+      break;
+    }
+
+  g_warn_if_fail (status != GL_WAIT_FAILED);
+
+  return status;
+}
+
+static void
+meta_sync_reset (MetaSync *self)
+{
+  XSyncAlarmAttributes attrs;
+  int overflow;
+
+  g_return_if_fail (self->state == META_SYNC_STATE_DONE);
+
+  XSyncResetFence (self->xdisplay, self->xfence);
+
+  attrs.trigger.wait_value = self->next_counter_value;
+
+  XSyncChangeAlarm (self->xdisplay, self->xalarm, XSyncCAValue, &attrs);
+  XSyncSetCounter (self->xdisplay, self->xcounter, self->next_counter_value);
+
+  XSyncValueAdd (&self->next_counter_value,
+                 self->next_counter_value,
+                 SYNC_VALUE_ONE,
+                 &overflow);
+
+  self->state = META_SYNC_STATE_RESET_PENDING;
+}
+
+static void
+meta_sync_handle_event (MetaSync              *self,
+                        XSyncAlarmNotifyEvent *event)
+{
+  g_return_if_fail (event->alarm == self->xalarm);
+  g_return_if_fail (self->state == META_SYNC_STATE_RESET_PENDING);
+
+  self->state = META_SYNC_STATE_READY;
+}
+
+static MetaSync *
+meta_sync_new (Display *xdisplay)
+{
+  MetaSync *self;
+  XSyncAlarmAttributes attrs;
+
+  self = g_malloc0 (sizeof (MetaSync));
+
+  self->xdisplay = xdisplay;
+
+  self->xfence = XSyncCreateFence (xdisplay, DefaultRootWindow (xdisplay), FALSE);
+  self->gl_x11_sync = 0;
+  self->gpu_fence = 0;
+
+  self->xcounter = XSyncCreateCounter (xdisplay, SYNC_VALUE_ZERO);
+
+  attrs.trigger.counter = self->xcounter;
+  attrs.trigger.value_type = XSyncAbsolute;
+  attrs.trigger.wait_value = SYNC_VALUE_ONE;
+  attrs.trigger.test_type = XSyncPositiveTransition;
+  attrs.events = TRUE;
+  self->xalarm = XSyncCreateAlarm (xdisplay,
+                                   XSyncCACounter |
+                                   XSyncCAValueType |
+                                   XSyncCAValue |
+                                   XSyncCATestType |
+                                   XSyncCAEvents,
+                                   &attrs);
+
+  XSyncIntToValue (&self->next_counter_value, 1);
+
+  self->state = META_SYNC_STATE_READY;
+
+  return self;
+}
+
+static void
+meta_sync_import (MetaSync *self)
+{
+  g_return_if_fail (self->gl_x11_sync == 0);
+  self->gl_x11_sync = meta_gl_import_sync (GL_SYNC_X11_FENCE_EXT, self->xfence, 0);
+}
+
+static Bool
+alarm_event_predicate (Display  *dpy,
+                       XEvent   *event,
+                       XPointer  data)
+{
+  MetaSyncRing *ring = meta_sync_ring_get ();
+
+  if (!ring)
+    return False;
+
+  if (event->type == ring->xsync_event_base + XSyncAlarmNotify)
+    {
+      if (((MetaSync *) data)->xalarm == ((XSyncAlarmNotifyEvent *) event)->alarm)
+        return True;
+    }
+  return False;
+}
+
+static void
+meta_sync_free (MetaSync *self)
+{
+  /* When our assumptions don't hold, something has gone wrong but we
+   * don't know what, so we reboot the ring. While doing that, we
+   * trigger fences before deleting them to try to get ourselves out
+   * of a potentially stuck GPU state.
+   */
+  switch (self->state)
+    {
+    case META_SYNC_STATE_WAITING:
+      meta_gl_delete_sync (self->gpu_fence);
+      break;
+    case META_SYNC_STATE_DONE:
+      /* nothing to do */
+      break;
+    case META_SYNC_STATE_RESET_PENDING:
+      {
+        XEvent event;
+        XIfEvent (self->xdisplay, &event, alarm_event_predicate, (XPointer) self);
+        meta_sync_handle_event (self, (XSyncAlarmNotifyEvent *) &event);
+      }
+      /* fall through */
+    case META_SYNC_STATE_READY:
+      XSyncTriggerFence (self->xdisplay, self->xfence);
+      XFlush (self->xdisplay);
+      break;
+    default:
+      break;
+    }
+
+  meta_gl_delete_sync (self->gl_x11_sync);
+  XSyncDestroyFence (self->xdisplay, self->xfence);
+  XSyncDestroyCounter (self->xdisplay, self->xcounter);
+  XSyncDestroyAlarm (self->xdisplay, self->xalarm);
+
+  g_free (self);
+}
+
+gboolean
+meta_sync_ring_init (Display *xdisplay)
+{
+  gint major, minor;
+  guint i;
+  MetaSyncRing *ring = meta_sync_ring_get ();
+
+  if (!ring)
+    return FALSE;
+
+  g_return_val_if_fail (xdisplay != NULL, FALSE);
+  g_return_val_if_fail (ring->xdisplay == NULL, FALSE);
+
+  if (!load_required_symbols ())
+    return FALSE;
+
+  if (!XSyncQueryExtension (xdisplay, &ring->xsync_event_base, &ring->xsync_error_base) ||
+      !XSyncInitialize (xdisplay, &major, &minor))
+    return FALSE;
+
+  XSyncIntToValue (&SYNC_VALUE_ZERO, 0);
+  XSyncIntToValue (&SYNC_VALUE_ONE, 1);
+
+  ring->xdisplay = xdisplay;
+
+  ring->alarm_to_sync = g_hash_table_new (NULL, NULL);
+
+  for (i = 0; i < NUM_SYNCS; ++i)
+    {
+      MetaSync *sync = meta_sync_new (ring->xdisplay);
+      ring->syncs_array[i] = sync;
+      g_hash_table_replace (ring->alarm_to_sync, (gpointer) sync->xalarm, sync);
+    }
+  /* Since the connection we create the X fences on isn't the same as
+   * the one used for the GLX context, we need to XSync() here to
+   * ensure glImportSync() succeeds. */
+  XSync (xdisplay, False);
+  for (i = 0; i < NUM_SYNCS; ++i)
+    meta_sync_import (ring->syncs_array[i]);
+
+  ring->current_sync_idx = 0;
+  ring->current_sync = ring->syncs_array[0];
+  ring->warmup_syncs = 0;
+
+  return TRUE;
+}
+
+void
+meta_sync_ring_destroy (void)
+{
+  guint i;
+  MetaSyncRing *ring = meta_sync_ring_get ();
+
+  if (!ring)
+    return;
+
+  g_return_if_fail (ring->xdisplay != NULL);
+
+  ring->current_sync_idx = 0;
+  ring->current_sync = NULL;
+  ring->warmup_syncs = 0;
+
+  for (i = 0; i < NUM_SYNCS; ++i)
+    meta_sync_free (ring->syncs_array[i]);
+
+  g_hash_table_destroy (ring->alarm_to_sync);
+
+  ring->xsync_event_base = 0;
+  ring->xsync_error_base = 0;
+  ring->xdisplay = NULL;
+}
+
+static gboolean
+meta_sync_ring_reboot (Display *xdisplay)
+{
+  MetaSyncRing *ring = meta_sync_ring_get ();
+
+  if (!ring)
+    return FALSE;
+
+  meta_sync_ring_destroy ();
+
+  ring->reboots += 1;
+
+  if (!meta_sync_ring_get ())
+    {
+      meta_warning ("MetaSyncRing: Too many reboots -- disabling\n");
+      return FALSE;
+    }
+
+  return meta_sync_ring_init (xdisplay);
+}
+
+gboolean
+meta_sync_ring_after_frame (void)
+{
+  MetaSyncRing *ring = meta_sync_ring_get ();
+
+  if (!ring)
+    return FALSE;
+
+  g_return_val_if_fail (ring->xdisplay != NULL, FALSE);
+
+  if (ring->warmup_syncs >= NUM_SYNCS / 2)
+    {
+      guint reset_sync_idx = (ring->current_sync_idx + NUM_SYNCS - (NUM_SYNCS / 2)) % NUM_SYNCS;
+      MetaSync *sync_to_reset = ring->syncs_array[reset_sync_idx];
+
+      GLenum status = meta_sync_check_update_finished (sync_to_reset, 0);
+      if (status == GL_TIMEOUT_EXPIRED)
+        {
+          meta_warning ("MetaSyncRing: We should never wait for a sync -- add more syncs?\n");
+          status = meta_sync_check_update_finished (sync_to_reset, MAX_SYNC_WAIT_TIME);
+        }
+
+      if (status != GL_ALREADY_SIGNALED && status != GL_CONDITION_SATISFIED)
+        {
+          meta_warning ("MetaSyncRing: Timed out waiting for sync object.\n");
+          return meta_sync_ring_reboot (ring->xdisplay);
+        }
+
+      meta_sync_reset (sync_to_reset);
+    }
+  else
+    {
+      ring->warmup_syncs += 1;
+    }
+
+  ring->current_sync_idx += 1;
+  ring->current_sync_idx %= NUM_SYNCS;
+
+  ring->current_sync = ring->syncs_array[ring->current_sync_idx];
+
+  return TRUE;
+}
+
+gboolean
+meta_sync_ring_insert_wait (void)
+{
+  MetaSyncRing *ring = meta_sync_ring_get ();
+
+  if (!ring)
+    return FALSE;
+
+  g_return_val_if_fail (ring->xdisplay != NULL, FALSE);
+
+  if (ring->current_sync->state != META_SYNC_STATE_READY)
+    {
+      meta_warning ("MetaSyncRing: Sync object is not ready -- were events handled properly?\n");
+      if (!meta_sync_ring_reboot (ring->xdisplay))
+        return FALSE;
+    }
+
+  meta_sync_insert (ring->current_sync);
+
+  return TRUE;
+}
+
+void
+meta_sync_ring_handle_event (XEvent *xevent)
+{
+  XSyncAlarmNotifyEvent *event;
+  MetaSync *sync;
+  MetaSyncRing *ring = meta_sync_ring_get ();
+
+  if (!ring)
+    return;
+
+  g_return_if_fail (ring->xdisplay != NULL);
+
+  if (xevent->type != (ring->xsync_event_base + XSyncAlarmNotify))
+    return;
+
+  event = (XSyncAlarmNotifyEvent *) xevent;
+
+  sync = g_hash_table_lookup (ring->alarm_to_sync, (gpointer) event->alarm);
+  if (sync)
+    meta_sync_handle_event (sync, event);
+}

src/compositor/meta-sync-ring.h

@@ -0,0 +1,14 @@
+#ifndef _META_SYNC_RING_H_
+#define _META_SYNC_RING_H_
+
+#include <glib.h>
+
+#include <X11/Xlib.h>
+
+gboolean meta_sync_ring_init (Display *dpy);
+void meta_sync_ring_destroy (void);
+gboolean meta_sync_ring_after_frame (void);
+gboolean meta_sync_ring_insert_wait (void);
+void meta_sync_ring_handle_event (XEvent *event);
+
+#endif  /* _META_SYNC_RING_H_ */

src/compositor/meta-window-actor.c

@@ -100,7 +100,7 @@ struct _MetaWindowActorPrivate
   guint		    disposed               : 1;
 
   /* If set, the client needs to be sent a _NET_WM_FRAME_DRAWN
-   * client message using the most recent frame in ->frames */
+   * client message for one or more messages in ->frames */
   guint             needs_frame_drawn      : 1;
   guint             repaint_scheduled      : 1;
 
@@ -118,10 +118,21 @@ struct _MetaWindowActorPrivate
 
 typedef struct _FrameData FrameData;
 
+/* Each time the application updates the sync request counter to a new even value
+ * value, we queue a frame into the windows list of frames. Once we're painting
+ * an update "in response" to the window, we fill in frame_counter with the
+ * Cogl counter for that frame, and send _NET_WM_FRAME_DRAWN at the end of the
+ * frame. _NET_WM_FRAME_TIMINGS is sent when we get a frame_complete callback.
+ *
+ * As an exception, if a window is completely obscured, we try to throttle drawning
+ * to a slower frame rate. In this case, frame_counter stays -1 until
+ * send_frame_message_timeout() runs, at which point we send both the
+ * _NET_WM_FRAME_DRAWN and _NET_WM_FRAME_TIMINGS messages.
+ */
 struct _FrameData
 {
-  int64_t frame_counter;
   guint64 sync_request_serial;
+  int64_t frame_counter;
   gint64 frame_drawn_time;
 };
 
@@ -655,6 +666,30 @@ clip_shadow_under_window (MetaWindowActor *self)
   return is_non_opaque (self) && priv->window->frame;
 }
 
+static void
+assign_frame_counter_to_frames (MetaWindowActor *self)
+{
+  MetaWindowActorPrivate *priv = self->priv;
+  GList *l;
+
+  /* If the window is obscured, then we're expecting to deal with sending
+   * frame messages in a timeout, rather than in this paint cycle.
+   */
+  if (priv->send_frame_messages_timer != 0)
+    return;
+
+  for (l = priv->frames; l; l = l->next)
+    {
+      FrameData *frame = l->data;
+
+      if (frame->frame_counter == -1)
+        {
+          CoglOnscreen *onscreen = COGL_ONSCREEN (cogl_get_draw_framebuffer());
+          frame->frame_counter = cogl_onscreen_get_frame_counter (onscreen);
+        }
+    }
+}
+
 static void
 meta_window_actor_paint (ClutterActor *actor)
 {
@@ -671,6 +706,8 @@ meta_window_actor_paint (ClutterActor *actor)
     {
       g_source_remove (priv->send_frame_messages_timer);
       priv->send_frame_messages_timer = 0;
+
+      assign_frame_counter_to_frames (self);
     }
 
   if (shadow != NULL)
@@ -873,16 +910,27 @@ send_frame_messages_timeout (gpointer data)
 {
   MetaWindowActor *self = (MetaWindowActor *) data;
   MetaWindowActorPrivate *priv = self->priv;
-  FrameData *frame = g_slice_new0 (FrameData);
+  GList *l;
 
-  frame->sync_request_serial = priv->window->sync_request_serial;
+  for (l = priv->frames; l;)
+    {
+      GList *l_next = l->next;
+      FrameData *frame = l->data;
 
-  do_send_frame_drawn (self, frame);
-  do_send_frame_timings (self, frame, 0, 0);
+      if (frame->frame_counter == -1)
+        {
+          do_send_frame_drawn (self, frame);
+          do_send_frame_timings (self, frame, 0, 0);
+
+          priv->frames = g_list_delete_link (priv->frames, l);
+          frame_data_free (frame);
+        }
+
+      l = l_next;
+    }
 
   priv->needs_frame_drawn = FALSE;
   priv->send_frame_messages_timer = 0;
-  frame_data_free (frame);
 
   return FALSE;
 }
@@ -891,6 +939,10 @@ static void
 queue_send_frame_messages_timeout (MetaWindowActor *self)
 {
   MetaWindowActorPrivate *priv = self->priv;
+
+  if (priv->send_frame_messages_timer != 0)
+    return;
+
   MetaDisplay *display = meta_window_get_display (priv->window);
   gint64 current_time = meta_compositor_monotonic_time_to_server_time (display, g_get_monotonic_time ());
   MetaMonitorManager *monitor_manager = meta_monitor_manager_get ();
@@ -933,6 +985,7 @@ meta_window_actor_queue_frame_drawn (MetaWindowActor *self,
     return;
 
   frame = g_slice_new0 (FrameData);
+  frame->frame_counter = -1;
 
   priv->needs_frame_drawn = TRUE;
 
@@ -1155,7 +1208,7 @@ gboolean
 meta_window_actor_should_unredirect (MetaWindowActor *self)
 {
   MetaWindowActorPrivate *priv = self->priv;
-  if (priv->surface)
+  if (!meta_window_actor_is_destroyed (self) && priv->surface)
     return meta_surface_actor_should_unredirect (priv->surface);
   else
     return FALSE;
@@ -1905,24 +1958,12 @@ meta_window_actor_handle_updates (MetaWindowActor *self)
 void
 meta_window_actor_pre_paint (MetaWindowActor *self)
 {
-  MetaWindowActorPrivate *priv = self->priv;
-  GList *l;
-
   if (meta_window_actor_is_destroyed (self))
     return;
 
   meta_window_actor_handle_updates (self);
 
-  for (l = priv->frames; l != NULL; l = l->next)
-    {
-      FrameData *frame = l->data;
-
-      if (frame->frame_counter == 0)
-        {
-          CoglOnscreen *onscreen = COGL_ONSCREEN (cogl_get_draw_framebuffer());
-          frame->frame_counter = cogl_onscreen_get_frame_counter (onscreen);
-        }
-    }
+  assign_frame_counter_to_frames (self);
 }
 
 static void
@@ -1963,16 +2004,23 @@ meta_window_actor_post_paint (MetaWindowActor *self)
   if (meta_window_actor_is_destroyed (self))
     return;
 
- /* This window had damage, but wasn't actually redrawn because
-  * it is obscured. So we should wait until timer expiration
-  * before sending _NET_WM_FRAME_* messages.
-  */
-  if (priv->send_frame_messages_timer != 0)
-    return;
-
-  if (priv->needs_frame_drawn)
+  /* If the window had damage, but wasn't actually redrawn because
+   * it is obscured, we should wait until timer expiration before
+   * sending _NET_WM_FRAME_* messages.
+   */
+  if (priv->send_frame_messages_timer == 0 &&
+      priv->needs_frame_drawn)
     {
-      do_send_frame_drawn (self, priv->frames->data);
+      GList *l;
+
+      for (l = priv->frames; l; l = l->next)
+        {
+          FrameData *frame = l->data;
+
+          if (frame->frame_drawn_time == 0)
+            do_send_frame_drawn (self, frame);
+        }
+
       priv->needs_frame_drawn = FALSE;
     }
 
@@ -2057,15 +2105,20 @@ meta_window_actor_frame_complete (MetaWindowActor *self,
     {
       GList *l_next = l->next;
       FrameData *frame = l->data;
+      gint64 frame_counter = cogl_frame_info_get_frame_counter (frame_info);
 
-      if (frame->frame_counter == cogl_frame_info_get_frame_counter (frame_info))
+      if (frame->frame_counter != -1 && frame->frame_counter <= frame_counter)
         {
-          if (frame->frame_drawn_time != 0)
-            {
-              priv->frames = g_list_delete_link (priv->frames, l);
-              send_frame_timings (self, frame, frame_info, presentation_time);
-              frame_data_free (frame);
-            }
+          if (G_UNLIKELY (frame->frame_drawn_time == 0))
+            g_warning ("%s: Frame has assigned frame counter but no frame drawn time",
+                       priv->window->desc);
+          if (G_UNLIKELY (frame->frame_counter < frame_counter))
+            g_warning ("%s: frame_complete callback never occurred for frame %" G_GINT64_FORMAT,
+                       priv->window->desc, frame->frame_counter);
+
+          priv->frames = g_list_delete_link (priv->frames, l);
+          send_frame_timings (self, frame, frame_info, presentation_time);
+          frame_data_free (frame);
         }
 
       l = l_next;

src/core/display.c

@@ -1214,7 +1214,7 @@ meta_grab_op_is_moving (MetaGrabOp op)
   if (!grab_op_is_window (op))
     return FALSE;
 
-  return (op & META_GRAB_OP_WINDOW_DIR_MASK) == 0;
+  return !meta_grab_op_is_resizing (op);
 }
 
 /**

src/core/place.c

@@ -779,7 +779,8 @@ meta_window_place (MetaWindow        *window,
 
         if (w != window &&
             meta_window_showing_on_its_workspace (w) &&
-            meta_window_located_on_workspace (w, window->workspace))
+            (window->on_all_workspaces ||
+             meta_window_located_on_workspace (w, window->workspace)))
           windows = g_list_prepend (windows, w);
 
         tmp = tmp->next;

src/core/screen.c

@@ -496,15 +496,6 @@ create_guard_window (Display *xdisplay, MetaScreen *screen)
   return guard_window;
 }
 
-/* Set a black background on the root window so that we don't
- * see confusing old copies of old windows when debugging
- * and testing. */
-static void
-meta_screen_set_background (MetaScreen *screen)
-{
-  XSetWindowBackground (screen->display->xdisplay, screen->xroot, 0x00000000);
-}
-
 MetaScreen*
 meta_screen_new (MetaDisplay *display,
                  int          number,
@@ -709,7 +700,6 @@ meta_screen_new (MetaDisplay *display,
   reload_monitor_infos (screen);
 
   meta_screen_set_cursor (screen, META_CURSOR_DEFAULT);
-  meta_screen_set_background (screen);
 
   /* Handle creating a no_focus_window for this screen */
   screen->no_focus_window =

src/meta/meta-background.h

@@ -57,6 +57,8 @@ struct _MetaBackground
   MetaBackgroundPrivate *priv;
 };
 
+void meta_background_refresh_all (void);
+
 GType meta_background_get_type (void);
 
 MetaBackground *meta_background_new  (MetaScreen *screen);

src/x11/window-x11.c

@@ -1073,9 +1073,10 @@ meta_window_x11_move_resize_internal (MetaWindow                *window,
       /* Compute new frame size */
       new_w = window->rect.width + borders.invisible.left + borders.invisible.right;
 
-      new_h = borders.invisible.top + borders.invisible.bottom;
-      if (!window->shaded)
-        new_h += window->rect.height;
+      if (window->shaded)
+        new_h = borders.total.top + borders.total.bottom;
+      else
+        new_h = window->rect.height + borders.invisible.top + borders.invisible.bottom;
 
       if (new_w != window->frame->rect.width ||
           new_h != window->frame->rect.height)
@@ -1684,7 +1685,7 @@ meta_window_x11_update_input_region (MetaWindow *window)
       /* Translate the set of XShape rectangles that we
        * get from the X server to a cairo_region. */
       XRectangle *rects = NULL;
-      int n_rects, ordering;
+      int n_rects = -1, ordering;
 
       meta_error_trap_push (window->display);
       rects = XShapeGetRectangles (window->display->xdisplay,
@@ -1694,21 +1695,46 @@ meta_window_x11_update_input_region (MetaWindow *window)
                                    &ordering);
       meta_error_trap_pop (window->display);
 
-      /* XXX: The x shape extension doesn't provide a way to only test if an
-       * input shape has been specified, so we have to query and throw away the
-       * rectangles. */
-      if (rects)
-        {
-          if (n_rects > 1 ||
-              (n_rects == 1 &&
-               (rects[0].x != 0 ||
-                rects[0].y != 0 ||
-                rects[0].width != priv->client_rect.width ||
-                rects[0].height != priv->client_rect.height)))
-            region = region_create_from_x_rectangles (rects, n_rects);
+      /* XXX: The X Shape specification is quite unfortunately specified.
+       *
+       * By default, the window has a shape the same as its bounding region,
+       * which we consider "NULL".
+       *
+       * If the window sets an empty region, then we'll get n_rects as 0
+       * and rects as NULL, which we need to transform back into an empty
+       * region.
+       *
+       * It would be great to have a less-broken extension for this, but
+       * hey, it's X11!
+       */
 
-          XFree (rects);
+      if (n_rects == -1)
+        {
+          /* We had an error. */
+          region = NULL;
         }
+      else if (n_rects == 0)
+        {
+          /* Client set an empty region. */
+          region = cairo_region_create ();
+        }
+      else if (n_rects == 1 &&
+               (rects[0].x == 0 ||
+                rects[0].y == 0 ||
+                rects[0].width == priv->client_rect.width ||
+                rects[0].height == priv->client_rect.height))
+        {
+          /* This is the bounding region case. Keep the
+           * region as NULL. */
+          region = NULL;
+        }
+      else
+        {
+          /* Window has a custom shape. */
+          region = region_create_from_x_rectangles (rects, n_rects);
+        }
+
+      meta_XFree (rects);
     }
 
   if (region != NULL)