[clutter] gdk: Fix mapping between frame clock and stages

[Emmanuele Bassi <ebassi src gnome org>]

commit 4f8643cea3cf867bfbaa43e5183c144ffdf19314
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Mon Mar 23 10:56:32 2015 +0000

    gdk: Fix mapping between frame clock and stages
    
    While each stage has at most a GdkFrameClock, the same GdkFrameClock
    instance may drive multiple stages per frame. This means that the
    mapping between a GdkFrameClock and a ClutterStage is a 1:M one, not a
    1:1.
    
    We should store a list of stages associated to each frame clock
    instance, so that we can iterate over it when we need to update the
    stages.
    
    This commit fixes redraws of applications using multiple stages,
    especially when using clutter-gtk.

 clutter/gdk/clutter-master-clock-gdk.c |  104 +++++++++++++++++++++----------
 1 files changed, 70 insertions(+), 34 deletions(-)
---
diff --git a/clutter/gdk/clutter-master-clock-gdk.c b/clutter/gdk/clutter-master-clock-gdk.c
index 49379ae..f93e9ae 100644
--- a/clutter/gdk/clutter-master-clock-gdk.c
+++ b/clutter/gdk/clutter-master-clock-gdk.c
@@ -66,9 +66,13 @@ struct _ClutterMasterClockGdk
   /* the list of timelines handled by the clock */
   GSList *timelines;
 
-  /* mapping between ClutterStages and GdkFrameClocks */
-  GHashTable *clock_to_stage;
+  /* mapping between ClutterStages and GdkFrameClocks.
+   *
+   * @stage_to_clock: a direct mapping because each stage has at most one clock
+   * @clock_to_stage: each clock can have more than one stage
+   */
   GHashTable *stage_to_clock;
+  GHashTable *clock_to_stage;
 
   /* the current state of the clock, in usecs */
   gint64 cur_tick;
@@ -234,39 +238,48 @@ static void
 clutter_master_clock_gdk_update (GdkFrameClock         *frame_clock,
                                  ClutterMasterClockGdk *master_clock)
 {
-  ClutterStage *stage;
-
-  CLUTTER_NOTE (SCHEDULER, "Master clock [tick]");
+  GList *stages, *l;
 
   _clutter_threads_acquire_lock ();
 
-  stage = g_hash_table_lookup (master_clock->clock_to_stage, frame_clock);
-
   /* Get the time to use for this frame */
   master_clock->cur_tick = g_get_monotonic_time ();
 
 #ifdef CLUTTER_ENABLE_DEBUG
+  /* Update the remaining budget */
   master_clock->remaining_budget = master_clock->frame_budget;
 #endif
 
-  /* Each frame is split into three separate phases: */
+  stages = g_hash_table_lookup (master_clock->clock_to_stage, frame_clock);
+  CLUTTER_NOTE (SCHEDULER, "Updating %d stages tied to frame clock %p",
+                g_list_length (stages), frame_clock);
+  for (l = stages; l != NULL; l = l->next)
+    {
+      ClutterStage *stage = l->data;
 
-  /* 1. process all the events; goes through the stage's event queue
-   *    and processes each event according to its type, then emits the
-   *    various signals that are associated with the event
-   */
-  master_clock_process_stage_events (master_clock, stage);
+      CLUTTER_NOTE (SCHEDULER, "Master clock (stage:%p, clock:%p) [tick]", stage, frame_clock);
 
-  /* 2. advance the timelines */
-  master_clock_advance_timelines (master_clock);
+      /* Each frame is split into three separate phases: */
 
-  /* 3. relayout and redraw the stage; the stage might have been
-   *    destroyed in 1. when processing events, check whether it's
-   *    still alive. */
-  if (g_hash_table_lookup (master_clock->clock_to_stage, frame_clock) != NULL)
-    {
-      master_clock_update_stage (master_clock, stage);
-      master_clock_schedule_stage_update (master_clock, stage, frame_clock);
+      /* 1. process all the events; goes through the stage's event queue
+       *    and processes each event according to its type, then emits the
+       *    various signals that are associated with the event
+       */
+      master_clock_process_stage_events (master_clock, stage);
+
+      /* 2. advance the timelines */
+      master_clock_advance_timelines (master_clock);
+
+      /* 3. relayout and redraw the stage; the stage might have been
+       *    destroyed in 1. when processing events, check whether it's
+       *    still alive.
+       */
+
+      if (g_hash_table_lookup (master_clock->stage_to_clock, stage) != NULL)
+        {
+          master_clock_update_stage (master_clock, stage);
+          master_clock_schedule_stage_update (master_clock, stage, frame_clock);
+        }
     }
 
   master_clock->prev_tick = master_clock->cur_tick;
@@ -279,15 +292,27 @@ clutter_master_clock_gdk_remove_stage_clock (ClutterMasterClockGdk *master_clock
                                              ClutterStage          *stage)
 {
   gpointer frame_clock = g_hash_table_lookup (master_clock->stage_to_clock, stage);
+  GList *stages;
+
   if (frame_clock == NULL)
-      return;
+    return;
 
-  g_signal_handlers_disconnect_by_func (frame_clock,
-                                        clutter_master_clock_gdk_update,
-                                        master_clock);
+  CLUTTER_NOTE (SCHEDULER, "Removing stage %p with clock %p", stage, frame_clock);
 
   g_hash_table_remove (master_clock->stage_to_clock, stage);
-  g_hash_table_remove (master_clock->clock_to_stage, frame_clock);
+
+  stages = g_hash_table_lookup (master_clock->clock_to_stage, frame_clock);
+  if (stages != NULL)
+    {
+      stages = g_list_remove (stages, stage);
+      if (stages == NULL)
+        {
+          g_signal_handlers_disconnect_by_func (frame_clock,
+                                                clutter_master_clock_gdk_update,
+                                                master_clock);
+          g_hash_table_remove (master_clock->clock_to_stage, frame_clock);
+        }
+    }
 }
 
 static void
@@ -295,14 +320,26 @@ clutter_master_clock_gdk_add_stage_clock (ClutterMasterClockGdk *master_clock,
                                           ClutterStage          *stage,
                                           GdkFrameClock         *frame_clock)
 {
+  GList *stages;
+
   clutter_master_clock_gdk_remove_stage_clock (master_clock, stage);
 
+  CLUTTER_NOTE (SCHEDULER, "Adding stage %p with clock %p", stage, frame_clock);
+
   g_hash_table_insert (master_clock->stage_to_clock, stage, g_object_ref (frame_clock));
-  g_hash_table_insert (master_clock->clock_to_stage, g_object_ref (frame_clock), stage);
 
-  g_signal_connect (frame_clock, "update",
-                    G_CALLBACK (clutter_master_clock_gdk_update),
-                    master_clock);
+  stages = g_hash_table_lookup (master_clock->clock_to_stage, frame_clock);
+  if (stages == NULL)
+    {
+      g_hash_table_insert (master_clock->clock_to_stage, g_object_ref (frame_clock),
+                           g_list_append (NULL, stage));
+
+      g_signal_connect (frame_clock, "update",
+                        G_CALLBACK (clutter_master_clock_gdk_update),
+                        master_clock);
+    }
+  else
+    stages = g_list_append (stages, stage);
 
   if (master_clock->timelines != NULL)
     _clutter_master_clock_start_running ((ClutterMasterClock *) clock);
@@ -418,7 +455,7 @@ clutter_master_clock_gdk_init (ClutterMasterClockGdk *self)
   const GSList *stages, *l;
 
   self->clock_to_stage = g_hash_table_new_full (g_direct_hash, g_direct_equal,
-                                                g_object_unref, NULL);
+                                                g_object_unref, (GDestroyNotify) g_list_free);
   self->stage_to_clock = g_hash_table_new_full (g_direct_hash, g_direct_equal,
                                                 NULL, g_object_unref);
 
@@ -433,8 +470,7 @@ clutter_master_clock_gdk_init (ClutterMasterClockGdk *self)
     clutter_master_clock_gdk_stage_added (manager, l->data, self);
 
 
-  if (G_UNLIKELY (clutter_paint_debug_flags &
-                  CLUTTER_DEBUG_CONTINUOUS_REDRAW))
+  if (G_UNLIKELY (clutter_paint_debug_flags & CLUTTER_DEBUG_CONTINUOUS_REDRAW))
     g_warning ("Continuous redraw is not supported with the GDK backend.");
 }