X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=include%2Fbabeltrace%2Fobject-internal.h;h=545a20aadd21a7f9f9bd3b78971f9e64b0c5182b;hb=f167d3c0c0904ef36e19fcd37f4f20d33b0e76b6;hp=e130a81e883d620cba525cffc28a4ffba2f90fcd;hpb=087bc0603db40d8cd5f4fddf933f3ded4829369e;p=babeltrace.git

diff --git a/include/babeltrace/object-internal.h b/include/babeltrace/object-internal.h
index e130a81e..545a20aa 100644
--- a/include/babeltrace/object-internal.h
+++ b/include/babeltrace/object-internal.h
@@ -38,8 +38,10 @@
  */
 struct bt_object {
 	struct bt_ref ref_count;
-	/* Class-specific release function. */
+	/* Class-specific, optional release function. */
 	bt_object_release_func release;
+	/* Class-specific, optional "parent is owner" notification listener. */
+	bt_object_release_func parent_is_owner_listener;
 	/* @see doc/ref-counting.md */
 	struct bt_object *parent;
 };
@@ -66,8 +68,20 @@ static inline
 void generic_release(struct bt_object *obj)
 {
 	if (obj->parent) {
+		void *parent = obj->parent;
+
+		if (obj->parent_is_owner_listener) {
+			/*
+			 * Object has a chance to destroy itself here
+			 * under certain conditions and notify its
+			 * parent. At this point the parent is
+			 * guaranteed to exist because it's not put yet.
+			 */
+			obj->parent_is_owner_listener(obj);
+		}
+
 		/* The release function will be invoked by the parent. */
-		bt_put(obj->parent);
+		bt_put(parent);
 	} else {
 		bt_object_release(obj);
 	}
@@ -116,4 +130,12 @@ void bt_object_init(void *ptr, bt_object_release_func release)
 	bt_ref_init(&obj->ref_count, generic_release);
 }
 
+static inline
+void bt_object_set_parent_is_owner_listener(void *obj,
+		bt_object_release_func cb)
+{
+	assert(obj);
+	((struct bt_object *) obj)->parent_is_owner_listener = cb;
+}
+
 #endif /* BABELTRACE_OBJECT_INTERNAL_H */