A nullable child can be detached from its parent by setting the property to NULL. This provides a mechanism for a management tool to delete certain types of objects.
Signed-off-by: Anthony Liguori <aligu...@us.ibm.com> object: link<>: release reference on finalize, externalize getter/setter Reported-by: Ping Fan Signed-off-by: Anthony Liguori <aligu...@us.ibm.com> --- include/qemu/object.h | 9 +++++ qom/object.c | 78 ++++++++++++++++++++++++++++++++++++++++++------ 2 files changed, 77 insertions(+), 10 deletions(-) diff --git a/include/qemu/object.h b/include/qemu/object.h index 8bc9935..5bb62dd 100644 --- a/include/qemu/object.h +++ b/include/qemu/object.h @@ -907,6 +907,9 @@ Object *object_resolve_path_component(Object *parent, gchar *part); void object_property_add_child(Object *obj, const char *name, Object *child, struct Error **errp); +void object_property_add_nullable_child(Object *obj, const char *name, + Object *child, struct Error **errp); + /** * object_property_add_link: * @obj: the object to add a property to @@ -925,6 +928,12 @@ void object_property_add_link(Object *obj, const char *name, const char *type, Object **child, struct Error **errp); +void object_get_link_property(Object *obj, struct Visitor *v, void *opaque, + const char *name, struct Error **errp); + +void object_set_link_property(Object *obj, struct Visitor *v, void *opaque, + const char *name, struct Error **errp); + /** * object_property_add_str: * @obj: the object to add a property to diff --git a/qom/object.c b/qom/object.c index 1144f79..61fa40f 100644 --- a/qom/object.c +++ b/qom/object.c @@ -744,8 +744,17 @@ char *object_property_get_str(Object *obj, const char *name, void object_property_set_link(Object *obj, Object *value, const char *name, Error **errp) { - object_property_set_str(obj, object_get_canonical_path(value), - name, errp); + char *str; + + if (value == NULL) { + str = g_strdup(""); + } else { + str = object_get_canonical_path(value); + } + + object_property_set_str(obj, str, name, errp); + + g_free(str); } Object *object_property_get_link(Object *obj, const char *name, @@ -882,6 +891,27 @@ static void object_get_child_property(Object *obj, Visitor *v, void *opaque, g_free(path); } +static void object_set_child_property(Object *obj, Visitor *v, void *opaque, + const char *name, Error **errp) +{ + gchar *path = NULL; + Error *local_err = NULL; + + visit_type_str(v, &path, name, &local_err); + if (local_err) { + error_propagate(errp, local_err); + return; + } + + if (path && *path) { + error_set(errp, ERROR_CLASS_GENERIC_ERROR, + "Cannot set child properties to anything but empty string"); + return; + } + + object_property_del(obj, name, errp); +} + static void object_finalize_child_property(Object *obj, const char *name, void *opaque) { @@ -890,15 +920,17 @@ static void object_finalize_child_property(Object *obj, const char *name, object_unref(child); } -void object_property_add_child(Object *obj, const char *name, - Object *child, Error **errp) +static void object_property_add_child_full(Object *obj, const char *name, + Object *child, bool writable, + Error **errp) { gchar *type; type = g_strdup_printf("child<%s>", object_get_typename(OBJECT(child))); object_property_add(obj, name, type, object_get_child_property, - NULL, object_finalize_child_property, child, errp); + writable ? object_set_child_property : NULL, + object_finalize_child_property, child, errp); object_ref(child); g_assert(child->parent == NULL); @@ -907,8 +939,20 @@ void object_property_add_child(Object *obj, const char *name, g_free(type); } -static void object_get_link_property(Object *obj, Visitor *v, void *opaque, - const char *name, Error **errp) +void object_property_add_child(Object *obj, const char *name, + Object *child, Error **errp) +{ + object_property_add_child_full(obj, name, child, false, errp); +} + +void object_property_add_nullable_child(Object *obj, const char *name, + Object *child, Error **errp) +{ + object_property_add_child_full(obj, name, child, true, errp); +} + +void object_get_link_property(Object *obj, Visitor *v, void *opaque, + const char *name, Error **errp) { Object **child = opaque; gchar *path; @@ -923,8 +967,8 @@ static void object_get_link_property(Object *obj, Visitor *v, void *opaque, } } -static void object_set_link_property(Object *obj, Visitor *v, void *opaque, - const char *name, Error **errp) +void object_set_link_property(Object *obj, Visitor *v, void *opaque, + const char *name, Error **errp) { Object **child = opaque; Object *old_target; @@ -970,6 +1014,16 @@ static void object_set_link_property(Object *obj, Visitor *v, void *opaque, } } +static void object_finalize_link_property(Object *obj, const char *name, + void *opaque) +{ + Object **child = opaque; + + if (*child != NULL) { + object_unref(*child); + } +} + void object_property_add_link(Object *obj, const char *name, const char *type, Object **child, Error **errp) @@ -981,7 +1035,11 @@ void object_property_add_link(Object *obj, const char *name, object_property_add(obj, name, full_type, object_get_link_property, object_set_link_property, - NULL, child, errp); + object_finalize_link_property, child, errp); + + if (*child) { + object_ref(*child); + } g_free(full_type); } -- 1.7.5.4