qom: make object_delete usable for statically-allocated objects

Store in the object the freeing function that will be used at deletion
time.  This makes it possible to use object_delete on statically-allocated
(embedded) objects.  Dually, it makes it possible to use object_unparent
and object_unref without leaking memory, when the lifetime of object
might extend until after the call to object_delete.

Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/qemu/object.h b/include/qemu/object.h
index 232463b3c7..5ddcb4aa5f 100644
--- a/include/qemu/object.h
+++ b/include/qemu/object.h
@@ -239,6 +239,14 @@ typedef struct ObjectProperty
 typedef void (ObjectUnparent)(Object *obj);
 
 /**
+ * ObjectFree:
+ * @obj: the object being freed
+ *
+ * Called when an object's last reference is removed.
+ */
+typedef void (ObjectFree)(void *obj);
+
+/**
  * ObjectClass:
  *
  * The base for all classes.  The only thing that #ObjectClass contains is an
@@ -272,6 +280,7 @@ struct Object
 {
     /*< private >*/
     ObjectClass *class;
+    ObjectFree *free;
     QTAILQ_HEAD(, ObjectProperty) properties;
     uint32_t ref;
     Object *parent;