+void g_clear_object (volatile GObject **object_ptr);
+#define g_clear_object(object_ptr) \
+ G_STMT_START { \
+ /* Only one access, please */ \
+ gpointer *_p = (gpointer) (object_ptr); \
+ gpointer _o; \
+ \
+ do \
+ _o = g_atomic_pointer_get (_p); \
+ while G_UNLIKELY (!g_atomic_pointer_compare_and_exchange (_p, _o, NULL));\
+ \
+ if (_o) \
+ g_object_unref (_o); \
+ } G_STMT_END
+