gst: make _get_type() in gst/* thread safe

This is not really necessary here because everything is
initialized from gst_init() already but using G_DEFINE_TYPE()
removes some copy&paste boilerplate code.

gst/gstbufferlist.c

@@ -165,7 +165,8 @@ struct _GstBufferListIterator
 };
 
 static GType _gst_buffer_list_type = 0;
-static GstMiniObjectClass *parent_class = NULL;
+
+G_DEFINE_TYPE (GstBufferList, gst_buffer_list, GST_TYPE_MINI_OBJECT);
 
 void
 _gst_buffer_list_initialize (void)
@@ -174,11 +175,8 @@ _gst_buffer_list_initialize (void)
 }
 
 static void
-gst_buffer_list_init (GTypeInstance * instance, gpointer g_class)
+gst_buffer_list_init (GstBufferList * list)
 {
-  GstBufferList *list;
-
-  list = (GstBufferList *) instance;
   list->buffers = NULL;
 
   GST_LOG ("init %p", list);
@@ -202,7 +200,8 @@ gst_buffer_list_finalize (GstBufferList * list)
   }
   g_list_free (list->buffers);
 
-  parent_class->finalize (GST_MINI_OBJECT_CAST (list));
+  GST_MINI_OBJECT_CLASS (gst_buffer_list_parent_class)->finalize
+      (GST_MINI_OBJECT_CAST (list));
 }
 
 static GstBufferList *
@@ -231,12 +230,8 @@ _gst_buffer_list_copy (GstBufferList * list)
 }
 
 static void
-gst_buffer_list_class_init (gpointer g_class, gpointer class_data)
+gst_buffer_list_class_init (GstBufferListClass * list_class)
 {
-  GstBufferListClass *list_class = GST_BUFFER_LIST_CLASS (g_class);
-
-  parent_class = g_type_class_peek_parent (g_class);
-
   list_class->mini_object_class.copy =
       (GstMiniObjectCopyFunction) _gst_buffer_list_copy;
   list_class->mini_object_class.finalize =
@@ -420,30 +415,6 @@ gst_buffer_list_get (GstBufferList * list, guint group, guint idx)
   return NULL;
 }
 
-GType
-gst_buffer_list_get_type (void)
-{
-  if (G_UNLIKELY (_gst_buffer_list_type == 0)) {
-    static const GTypeInfo buffer_list_info = {
-      sizeof (GstBufferListClass),
-      NULL,
-      NULL,
-      gst_buffer_list_class_init,
-      NULL,
-      NULL,
-      sizeof (GstBufferList),
-      0,
-      gst_buffer_list_init,
-      NULL
-    };
-
-    _gst_buffer_list_type = g_type_register_static (GST_TYPE_MINI_OBJECT,
-        "GstBufferList", &buffer_list_info, 0);
-  }
-
-  return _gst_buffer_list_type;
-}
-
 /**
  * gst_buffer_list_iterate:
  * @list: a #GstBufferList

gst/gstminiobject.c

@@ -68,9 +68,10 @@ static void gst_mini_object_finalize (GstMiniObject * obj);
 GType
 gst_mini_object_get_type (void)
 {
-  static GType _gst_mini_object_type = 0;
+  static volatile GType _gst_mini_object_type = 0;
 
-  if (G_UNLIKELY (_gst_mini_object_type == 0)) {
+  if (g_once_init_enter (&_gst_mini_object_type)) {
+    GType _type;
     static const GTypeValueTable value_table = {
       gst_value_mini_object_init,
       gst_value_mini_object_free,
@@ -102,14 +103,14 @@ gst_mini_object_get_type (void)
           G_TYPE_FLAG_DERIVABLE | G_TYPE_FLAG_DEEP_DERIVABLE)
     };
 
-    _gst_mini_object_type = g_type_fundamental_next ();
-    g_type_register_fundamental (_gst_mini_object_type, "GstMiniObject",
+    _type = g_type_fundamental_next ();
+    g_type_register_fundamental (_type, "GstMiniObject",
         &mini_object_info, &mini_object_fundamental_info, G_TYPE_FLAG_ABSTRACT);
 
 #ifndef GST_DISABLE_TRACE
-    _gst_mini_object_trace =
-        gst_alloc_trace_register (g_type_name (_gst_mini_object_type));
+    _gst_mini_object_trace = gst_alloc_trace_register (g_type_name (_type));
 #endif
+    g_once_init_leave (&_gst_mini_object_type, _type);
   }
 
   return _gst_mini_object_type;

gst/gstvalue.c

@@ -4178,13 +4178,15 @@ static GTypeFundamentalInfo _finfo = {
 #define FUNC_VALUE_GET_TYPE(type, name)                         \
 GType gst_ ## type ## _get_type (void)                          \
 {                                                               \
-  static GType gst_ ## type ## _type = 0;                       \
+  static volatile GType gst_ ## type ## _type = 0;                       \
                                                                 \
-  if (G_UNLIKELY (gst_ ## type ## _type == 0)) {		\
+  if (g_once_init_enter (&gst_ ## type ## _type)) {		\
+    GType _type;					\
     _info.value_table = & _gst_ ## type ## _value_table;        \
-    gst_ ## type ## _type = g_type_register_fundamental (       \
+    _type = g_type_register_fundamental (       \
         g_type_fundamental_next (),                             \
         name, &_info, &_finfo, 0);                              \
+    g_once_init_leave(&gst_ ## type ## _type, _type);	\
   }                                                             \
                                                                 \
   return gst_ ## type ## _type;                                 \