On 12.07.2018 18:52, Eduardo Habkost wrote: > On Thu, Jul 12, 2018 at 05:30:59PM +0200, Thomas Huth wrote: >> A lot of code is using the object_initialize() function followed by a call to >> object_property_add_child() to add the newly initialized object as a child of >> the current object. Both functions increase the reference counter of the new >> object, but many spots that call these two functions then forget to drop one >> of the superfluous references. So the newly created object is often not >> cleaned >> up correctly when the parent is destroyed. In the worst case, this can cause >> crashes, e.g. because device objects are not correctly removed from their >> parent_bus. >> Since this is a common pattern between many code spots, let's introdcue a >> new function that takes care of calling all three required initialization >> functions, first object_initialize(), then object_property_add_child() and >> finally object_unref(). >> >> Signed-off-by: Thomas Huth <th...@redhat.com> >> --- >> include/qom/object.h | 19 +++++++++++++++++++ >> qom/object.c | 14 ++++++++++++++ >> 2 files changed, 33 insertions(+) >> >> diff --git a/include/qom/object.h b/include/qom/object.h >> index f3d2308..c1b254c 100644 >> --- a/include/qom/object.h >> +++ b/include/qom/object.h >> @@ -749,6 +749,25 @@ int object_set_propv(Object *obj, >> void object_initialize(void *obj, size_t size, const char *typename); >> >> /** >> + * object_initialize_as_child: >> + * @parentobj: The parent object to add a property to >> + * @propname: The name of the property >> + * @childobj: A pointer to the memory to be used for the object. >> + * @size: The maximum size available at @obj for the object. >> + * @type: The name of the type of the object to instantiate. >> + * @errp: If an error occurs, a pointer to an area to store the area >> + * >> + * This function will initialize an object. The memory for the object should >> + * have already been allocated. The object will then be added as child >> property >> + * to a parent with object_property_add_child() function. The returned >> object >> + * has a reference count of 1, and will be finalized when the last >> reference is >> + * dropped. >> + */ >> +void object_initialize_as_child(Object *parentobj, const char *propname, >> + void *childobj, size_t size, const char >> *type, >> + Error **errp); > > Why did you use void* instead of Object*?
That's the same what object_initialize() is doing (see above). Otherwise all the callers have to cast their pointers with OBJECT() first. Thomas
