clutter/frame-clock: Add explicit destroy function

The frame clock owner should be able to explicitly destroy (i.e. make
defunct) a frame clock, e.g. when a stage view is destructed. This is so
that other objects can keep reference to its without it being left
around even after stopped being usable.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285

clutter/clutter/clutter-frame-clock.c

@@ -24,6 +24,15 @@
 #include "clutter/clutter-timeline-private.h"
 #include "cogl/cogl-trace.h"
 
+enum
+{
+  DESTROY,
+
+  N_SIGNALS
+};
+
+static guint signals[N_SIGNALS];
+
 /* Wait 2ms after vblank before starting to draw next frame */
 #define SYNC_DELAY_US ms2us (2)
 
@@ -495,18 +504,26 @@ clutter_frame_clock_new (float                            refresh_rate,
   return frame_clock;
 }
 
+void
+clutter_frame_clock_destroy (ClutterFrameClock *frame_clock)
+{
+  g_object_run_dispose (G_OBJECT (frame_clock));
+  g_object_unref (frame_clock);
+}
+
 static void
-clutter_frame_clock_finalize (GObject *object)
+clutter_frame_clock_dispose (GObject *object)
 {
 ClutterFrameClock *frame_clock = CLUTTER_FRAME_CLOCK (object);
 
   if (frame_clock->source)
     {
+      g_signal_emit (frame_clock, signals[DESTROY], 0);
       g_source_destroy (frame_clock->source);
-      g_source_unref (frame_clock->source);
+      g_clear_pointer (&frame_clock->source, g_source_unref);
     }
 
-  G_OBJECT_CLASS (clutter_frame_clock_parent_class)->finalize (object);
+  G_OBJECT_CLASS (clutter_frame_clock_parent_class)->dispose (object);
 }
 
 static void
@@ -520,5 +537,14 @@ clutter_frame_clock_class_init (ClutterFrameClockClass *klass)
 {
   GObjectClass *object_class = G_OBJECT_CLASS (klass);
 
-  object_class->finalize = clutter_frame_clock_finalize;
+  object_class->dispose = clutter_frame_clock_dispose;
+
+  signals[DESTROY] =
+    g_signal_new (I_("destroy"),
+                  G_TYPE_FROM_CLASS (object_class),
+                  G_SIGNAL_RUN_LAST,
+                  0,
+                  NULL, NULL, NULL,
+                  G_TYPE_NONE,
+                  0);
 }

clutter/clutter/clutter-frame-clock.h

@@ -56,6 +56,9 @@ ClutterFrameClock * clutter_frame_clock_new (float                            re
                                              const ClutterFrameListenerIface *iface,
                                              gpointer                         user_data);
 
+CLUTTER_EXPORT
+void clutter_frame_clock_destroy (ClutterFrameClock *frame_clock);
+
 CLUTTER_EXPORT
 void clutter_frame_clock_notify_presented (ClutterFrameClock *frame_clock,
                                            ClutterFrameInfo  *frame_info);

clutter/clutter/clutter-stage-view.c

@@ -1274,7 +1274,7 @@ clutter_stage_view_dispose (GObject *object)
   g_clear_pointer (&priv->offscreen, cogl_object_unref);
   g_clear_pointer (&priv->offscreen_pipeline, cogl_object_unref);
   g_clear_pointer (&priv->redraw_clip, cairo_region_destroy);
-  g_clear_object (&priv->frame_clock);
+  g_clear_pointer (&priv->frame_clock, clutter_frame_clock_destroy);
 
   G_OBJECT_CLASS (clutter_stage_view_parent_class)->dispose (object);
 }

src/tests/clutter/conform/frame-clock-timeline.c

@@ -109,7 +109,7 @@ frame_clock_timeline_basic (void)
   g_main_loop_unref (main_loop);
   g_object_unref (timeline);
   g_assert_null (timeline);
-  g_object_unref (frame_clock);
+  clutter_frame_clock_destroy (frame_clock);
   g_assert_null (frame_clock);
 }
 
@@ -192,9 +192,9 @@ frame_clock_timeline_switch (void)
   g_main_loop_unref (main_loop);
   g_object_unref (timeline);
   g_assert_null (timeline);
-  g_object_unref (frame_clock1);
+  clutter_frame_clock_destroy (frame_clock1);
   g_assert_null (frame_clock1);
-  g_object_unref (frame_clock2);
+  clutter_frame_clock_destroy (frame_clock2);
   g_assert_null (frame_clock2);
 }
 

src/tests/clutter/conform/frame-clock.c

@@ -166,7 +166,7 @@ frame_clock_schedule_update (void)
 
   g_main_loop_unref (test.main_loop);
 
-  g_object_unref (frame_clock);
+  clutter_frame_clock_destroy (frame_clock);
   g_source_destroy (source);
   g_source_unref (source);
 }
@@ -242,7 +242,7 @@ frame_clock_immediate_present (void)
   g_assert_cmpint (after_us - before_us, >, 9 * refresh_interval_us);
 
   g_main_loop_unref (main_loop);
-  g_object_unref (frame_clock);
+  clutter_frame_clock_destroy (frame_clock);
 }
 
 static gboolean
@@ -323,7 +323,7 @@ frame_clock_delayed_damage (void)
   g_assert_cmpint (after_us - before_us, >, 100000 + refresh_interval_us);
 
   g_main_loop_unref (test.main_loop);
-  g_object_unref (frame_clock);
+  clutter_frame_clock_destroy (frame_clock);
   g_source_destroy (source);
   g_source_unref (source);
 }
@@ -372,7 +372,7 @@ frame_clock_no_damage (void)
   g_main_loop_run (main_loop);
 
   g_main_loop_unref (main_loop);
-  g_object_unref (frame_clock);
+  clutter_frame_clock_destroy (frame_clock);
 }
 
 typedef struct _UpdateNowFrameClockTest
@@ -472,7 +472,7 @@ frame_clock_schedule_update_now (void)
 
   g_main_loop_unref (test.base.main_loop);
 
-  g_object_unref (frame_clock);
+  clutter_frame_clock_destroy (frame_clock);
   g_source_destroy (source);
   g_source_unref (source);
 }
@@ -543,7 +543,7 @@ frame_clock_before_frame (void)
   g_assert_cmpint (expected_frame_count, >, 2);
 
   g_main_loop_unref (main_loop);
-  g_object_unref (frame_clock);
+  clutter_frame_clock_destroy (frame_clock);
 }
 
 typedef struct _InhibitTest
@@ -625,7 +625,7 @@ frame_clock_inhibit (void)
   g_assert_cmpint (test.frame_count, ==, 2);
 
   g_main_loop_unref (test.main_loop);
-  g_object_unref (test.frame_clock);
+  clutter_frame_clock_destroy (test.frame_clock);
 }
 
 typedef struct _RescheduleOnIdleFrameClockTest
@@ -687,7 +687,7 @@ frame_clock_reschedule_on_idle (void)
   g_main_loop_run (test.base.main_loop);
 
   g_main_loop_unref (test.base.main_loop);
-  g_object_unref (frame_clock);
+  clutter_frame_clock_destroy (frame_clock);
 }
 
 CLUTTER_TEST_SUITE (