Re: sysbus_create_simple Vs qdev_create

[Eduardo Habkost]

On Fri, Jul 17, 2020 at 07:10:57AM +0200, Markus Armbruster wrote:
> Eduardo Habkost <ehabkost@redhat.com> writes:
> 
> > I'd also note that the use of "parent" in the code is also
> > ambiguous.  It can mean:
> >
> > * QOM parent type, i.e. TypeInfo.parent.  Related fields:
> >   * parent_class members of class structs
> >   * parent_obj members of object structs
> 
> I hate the use of "parent" and "child" for a super- / subtype relation.
> 
> Correcting the terminology there would be short term pain for long term
> gain.  Worthwhile?

I don't know.  It looks like the terminology came from GObject.

> 
> > * QOM composition tree parent object, i.e. Object::parent
> > * qdev device parent bus, i.e. DeviceState::parent_bus
> > * parent device of of qdev bus, i.e. BusState::parent
> 
> These are tree relations.  Use of "parent" and "child" is perfectly
> fine.

The terms are fine but still ambiguous, as devices belong to two
separate trees at the same time (the QOM composition tree, and
the qdev tree).

I never understood why we have two separate independent object
trees.

-- 
Eduardo