object: sure up reference counting
Now we have the following behavior:
1) object_new() returns an object with ref = 1
2) object_initialize() does not increase the reference count (ref may be 0).
3) object_deref() will finalize the object when ref = 0. it does not free the
memory associated with the object.
4) both link and child properties correctly set the reference count.
The expected usage is the following:
1) child devices should generally be created via object_initialize() using
memory from the parent device. Adding the object as a child property will
take ownership of the object and tie the child's life cycle to the parent.
2) If a child device is created via qdev_create() or some other form of
object_new(), there must be an object_delete() call in the parent device's
finalize function.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/qom/object.c b/qom/object.c
index 49addef..33217b8 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -337,6 +337,8 @@
object_deinit(obj, ti);
object_property_del_all(obj);
+
+ g_assert(obj->ref == 0);
}
Object *object_new_with_type(Type type)
@@ -347,6 +349,7 @@
obj = g_malloc(type->instance_size);
object_initialize_with_type(obj, type);
+ object_ref(obj);
return obj;
}
@@ -360,7 +363,8 @@
void object_delete(Object *obj)
{
- object_finalize(obj);
+ object_unref(obj);
+ g_assert(obj->ref == 0);
g_free(obj);
}
@@ -679,6 +683,14 @@
g_free(path);
}
+static void object_finalize_child_property(Object *obj, const char *name,
+ void *opaque)
+{
+ Object *child = opaque;
+
+ object_unref(child);
+}
+
void object_property_add_child(Object *obj, const char *name,
Object *child, Error **errp)
{
@@ -687,7 +699,7 @@
type = g_strdup_printf("child<%s>", object_get_typename(OBJECT(child)));
object_property_add(obj, name, type, object_get_child_property,
- NULL, NULL, child, errp);
+ NULL, object_finalize_child_property, child, errp);
object_ref(child);
g_assert(child->parent == NULL);