controlbinding: Store object in a thread-safe GWeakRef

g_object_weak_ref() is not thread-safe.

gst/gstcontrolbinding.c

@@ -71,6 +71,11 @@ static void gst_control_binding_finalize (GObject * object);
 G_DEFINE_ABSTRACT_TYPE_WITH_CODE (GstControlBinding, gst_control_binding,
     GST_TYPE_OBJECT, _do_init);
 
+struct _GstControlBindingPrivate
+{
+  GWeakRef object;
+};
+
 enum
 {
   PROP_0,
@@ -86,6 +91,8 @@ gst_control_binding_class_init (GstControlBindingClass * klass)
 {
   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 
+  g_type_class_add_private (klass, sizeof (GstControlBindingPrivate));
+
   gobject_class->constructor = gst_control_binding_constructor;
   gobject_class->set_property = gst_control_binding_set_property;
   gobject_class->get_property = gst_control_binding_get_property;
@@ -108,6 +115,10 @@ gst_control_binding_class_init (GstControlBindingClass * klass)
 static void
 gst_control_binding_init (GstControlBinding * binding)
 {
+  binding->ABI.abi.priv =
+      G_TYPE_INSTANCE_GET_PRIVATE (binding, GST_TYPE_CONTROL_BINDING,
+      GstControlBindingPrivate);
+  g_weak_ref_init (&binding->ABI.abi.priv->object, NULL);
 }
 
 static GObject *
@@ -116,19 +127,26 @@ gst_control_binding_constructor (GType type, guint n_construct_params,
 {
   GstControlBinding *binding;
   GParamSpec *pspec;
+  GstObject *object;
 
   binding =
       GST_CONTROL_BINDING (G_OBJECT_CLASS (gst_control_binding_parent_class)
       ->constructor (type, n_construct_params, construct_params));
 
-  GST_INFO_OBJECT (binding->object, "trying to put property '%s' under control",
+  object = g_weak_ref_get (&binding->ABI.abi.priv->object);
+  if (!object) {
+    GST_WARNING_OBJECT (object, "no object set");
+    return (GObject *) binding;
+  }
+
+  GST_INFO_OBJECT (object, "trying to put property '%s' under control",
       binding->name);
 
   /* check if the object has a property of that name */
   if ((pspec =
-          g_object_class_find_property (G_OBJECT_GET_CLASS (binding->object),
+          g_object_class_find_property (G_OBJECT_GET_CLASS (object),
               binding->name))) {
-    GST_DEBUG_OBJECT (binding->object, "  psec->flags : 0x%08x", pspec->flags);
+    GST_DEBUG_OBJECT (object, "  psec->flags : 0x%08x", pspec->flags);
 
     /* check if this param is witable && controlable && !construct-only */
     if ((pspec->flags & (G_PARAM_WRITABLE | GST_PARAM_CONTROLLABLE |
@@ -136,15 +154,18 @@ gst_control_binding_constructor (GType type, guint n_construct_params,
         (G_PARAM_WRITABLE | GST_PARAM_CONTROLLABLE)) {
       binding->pspec = pspec;
     } else {
-      GST_WARNING_OBJECT (binding->object,
+      GST_WARNING_OBJECT (object,
           "property '%s' on class '%s' needs to "
           "be writeable, controlable and not construct_only", binding->name,
-          G_OBJECT_TYPE_NAME (binding->object));
+          G_OBJECT_TYPE_NAME (object));
     }
   } else {
-    GST_WARNING_OBJECT (binding->object, "class '%s' has no property '%s'",
-        G_OBJECT_TYPE_NAME (binding->object), binding->name);
+    GST_WARNING_OBJECT (object, "class '%s' has no property '%s'",
+        G_OBJECT_TYPE_NAME (object), binding->name);
   }
+
+  gst_object_unref (object);
+
   return (GObject *) binding;
 }
 
@@ -154,9 +175,10 @@ gst_control_binding_dispose (GObject * object)
   GstControlBinding *self = GST_CONTROL_BINDING (object);
 
   /* we did not took a reference */
-  g_object_remove_weak_pointer ((GObject *) self->object,
-      (gpointer *) & self->object);
-  self->object = NULL;
+  g_object_remove_weak_pointer ((GObject *) self->__object,
+      (gpointer *) & self->__object);
+  self->__object = NULL;
+  g_weak_ref_clear (&self->ABI.abi.priv->object);
 
   ((GObjectClass *) gst_control_binding_parent_class)->dispose (object);
 }
@@ -180,9 +202,11 @@ gst_control_binding_set_property (GObject * object, guint prop_id,
   switch (prop_id) {
     case PROP_OBJECT:
       /* do not ref to avoid a ref cycle */
-      self->object = g_value_get_object (value);
-      g_object_add_weak_pointer ((GObject *) self->object,
-          (gpointer *) & self->object);
+      self->__object = g_value_get_object (value);
+      g_object_add_weak_pointer ((GObject *) self->__object,
+          (gpointer *) & self->__object);
+
+      g_weak_ref_set (&self->ABI.abi.priv->object, self->__object);
       break;
     case PROP_NAME:
       self->name = g_value_dup_string (value);
@@ -201,7 +225,7 @@ gst_control_binding_get_property (GObject * object, guint prop_id,
 
   switch (prop_id) {
     case PROP_OBJECT:
-      g_value_set_object (value, self->object);
+      g_value_take_object (value, g_weak_ref_get (&self->ABI.abi.priv->object));
       break;
     case PROP_NAME:
       g_value_set_string (value, self->name);

gst/gstcontrolbinding.h

@@ -46,6 +46,7 @@ G_BEGIN_DECLS
 
 typedef struct _GstControlBinding GstControlBinding;
 typedef struct _GstControlBindingClass GstControlBindingClass;
+typedef struct _GstControlBindingPrivate GstControlBindingPrivate;
 
 /* FIXME(2.0): remove, this is unused */
 typedef void (* GstControlBindingConvert) (GstControlBinding *binding, gdouble src_value, GValue *dest_value);
@@ -59,17 +60,26 @@ typedef void (* GstControlBindingConvert) (GstControlBinding *binding, gdouble s
  */
 struct _GstControlBinding {
   GstObject parent;
-  
+
   /*< public >*/
   gchar *name;
   GParamSpec *pspec;
 
   /*< private >*/
+#ifndef GST_DISABLE_DEPRECATED
   GstObject *object;            /* GstObject owning the property
                                  * (== parent when bound) */
+#else
+  gpointer __object;
+#endif
   gboolean disabled;
 
-  gpointer _gst_reserved[GST_PADDING];
+  union {
+    struct {
+      GstControlBindingPrivate *priv;
+    } abi;
+    gpointer _gst_reserved[GST_PADDING];
+  } ABI;
 };
 
 /**