[mutter] Fix freezing of windows with keyboard resizing

[Owen Taylor <otaylor src gnome org>]

commit 592374bc6236c13497527733c970e575e4e0339f
Author: Owen W. Taylor <otaylor fishsoup net>
Date:   Wed Mar 13 13:09:33 2013 -0400

    Fix freezing of windows with keyboard resizing
    
    During resizing we froze window updates when configuring the
    window, and unfroze the window updates when processing the
    next resize. This wasn't absolutely reliable, because we might
    not have a next resize. Instead tie window freezing more
    directly to the current sync request value - a window is
    frozen until it catches up with the last value we sent it
    in _NET_WM_SYNC_REQUEST.
    
    Testing with unresponsive clients showed that there was a bug
    where window->disable_sync once set, would not actually disable
    sync, but it *would* disable noticing that the client was
    unresponsive for the next resize. Fix that by checking for
    ->disable_sync before sending _NET_WM_SYNC_REQUEST.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=694046

 src/core/display-private.h |    3 ---
 src/core/window-private.h  |    4 +---
 src/core/window.c          |   41 ++++++++++++++++++-----------------------
 3 files changed, 19 insertions(+), 29 deletions(-)
---
diff --git a/src/core/display-private.h b/src/core/display-private.h
index 3d8a848..1f73fc3 100644
--- a/src/core/display-private.h
+++ b/src/core/display-private.h
@@ -220,9 +220,6 @@ struct _MetaDisplay
   int         xkb_base_event_type;
   guint32     last_bell_time;
 #endif
-#ifdef HAVE_XSYNC
-  gint64      grab_sync_counter_wait_serial;
-#endif
   int        grab_resize_timeout_id;
 
   /* Keybindings stuff */
diff --git a/src/core/window-private.h b/src/core/window-private.h
index 311af19..60e64bd 100644
--- a/src/core/window-private.h
+++ b/src/core/window-private.h
@@ -343,9 +343,6 @@ struct _MetaWindow
   /* if TRUE, window is attached to its parent */
   guint attached : 1;
 
-  /* if TRUE, we are freezing updates during a resize */
-  guint updates_frozen_for_resize : 1;
-
   /* whether or not the window is from a program running on another machine */
   guint is_remote : 1;
 
@@ -366,6 +363,7 @@ struct _MetaWindow
   /* XSync update counter */
   XSyncCounter sync_request_counter;
   gint64 sync_request_serial;
+  gint64 sync_request_wait_serial;
   GTimeVal sync_request_time;
   /* alarm monitoring client's _NET_WM_SYNC_REQUEST_COUNTER */
   XSyncAlarm sync_request_alarm;
diff --git a/src/core/window.c b/src/core/window.c
index caadfb7..1947d35 100644
--- a/src/core/window.c
+++ b/src/core/window.c
@@ -4631,7 +4631,7 @@ send_sync_request (MetaWindow *window)
    */
   wait_serial = window->sync_request_serial + 240;
 
-  window->display->grab_sync_counter_wait_serial = wait_serial;
+  window->sync_request_wait_serial = wait_serial;
 
   ev.type = ClientMessage;
   ev.window = window->xwindow;
@@ -4655,6 +4655,9 @@ send_sync_request (MetaWindow *window)
              window->xwindow, False, 0, (XEvent*) &ev);
 
   g_get_current_time (&window->sync_request_time);
+
+  meta_compositor_set_updates_frozen (window->display->compositor, window,
+                                      meta_window_updates_are_frozen (window));
 }
 #endif
 
@@ -4677,22 +4680,12 @@ meta_window_updates_are_frozen (MetaWindow *window)
   if (window->extended_sync_request_counter &&
       window->sync_request_serial % 2 == 1)
     return TRUE;
-#endif
 
-  return window->updates_frozen_for_resize;
-}
+  if (window->sync_request_serial < window->sync_request_wait_serial)
+    return TRUE;
+#endif
 
-static void
-meta_window_set_updates_frozen_for_resize (MetaWindow *window,
-                                           gboolean    updates_frozen)
-{
-  if (updates_frozen != window->updates_frozen_for_resize)
-    {
-      window->updates_frozen_for_resize = updates_frozen;
-      if (window->display->compositor)
-        meta_compositor_set_updates_frozen (window->display->compositor, window,
-                                            meta_window_updates_are_frozen (window));
-    }
+  return FALSE;
 }
 
 static gboolean
@@ -5210,14 +5203,12 @@ meta_window_move_resize_internal (MetaWindow          *window,
 #ifdef HAVE_XSYNC
       if (window == window->display->grab_window &&
           meta_grab_op_is_resizing (window->display->grab_op) &&
+          !window->disable_sync &&
           window->sync_request_counter != None &&
          window->sync_request_alarm != None &&
          window->sync_request_time.tv_usec == 0 &&
          window->sync_request_time.tv_sec == 0)
        {
-         /* turn off updating */
-          meta_window_set_updates_frozen_for_resize (window, TRUE);
-
          send_sync_request (window);
        }
 #endif
@@ -8860,6 +8851,14 @@ check_moveresize_frequency (MetaWindow *window,
               * application to respond to the sync request
               */
              window->disable_sync = TRUE;
+
+              /* Reset the wait serial, so we don't continue freezing
+               * window updates
+               */
+              window->sync_request_wait_serial = 0;
+              meta_compositor_set_updates_frozen (window->display->compositor, window,
+                                                  meta_window_updates_are_frozen (window));
+
              return TRUE;
            }
        }
@@ -9405,9 +9404,6 @@ update_resize (MetaWindow *window,
       return;
     }
 
-  /* If we get here, it means the client should have redrawn itself */
-  meta_window_set_updates_frozen_for_resize (window, FALSE);
-
   /* Remove any scheduled compensation events */
   if (window->display->grab_resize_timeout_id)
     {
@@ -9616,7 +9612,7 @@ meta_window_update_sync_request_counter (MetaWindow *window,
 
   if (window == window->display->grab_window &&
       meta_grab_op_is_resizing (window->display->grab_op) &&
-      new_counter_value >= window->display->grab_sync_counter_wait_serial &&
+      new_counter_value >= window->sync_request_wait_serial &&
       (!window->extended_sync_request_counter || new_counter_value % 2 == 0))
     {
       meta_topic (META_DEBUG_RESIZING,
@@ -9682,7 +9678,6 @@ meta_window_handle_mouse_grab_op_event (MetaWindow *window,
                                xev->root_x,
                                xev->root_y,
                                TRUE);
-              meta_window_set_updates_frozen_for_resize (window, FALSE);
 
               /* If a tiled window has been dragged free with a
                * mouse resize without snapping back to the tiled