Re: [Qemu-devel] [PATCH 06/15] piix: create i8254 through composition

[Paolo Bonzini]

On 01/31/2012 03:51 PM, Jan Kiszka wrote:
> > >
> > >  BTW, this is yet another benefit of making structures public.  You can take 
> > the
> > >  address of a child and set link fields directly without accessors.
> Well, that has two sides. We introduced properties to avoid this direct
> messing.
>
> Does linking also work without exposing internals?

Perhaps it doesn't need to expose internals.  Just like we create 
interfaces automatically when creating a parent object, perhaps we can 
create children as well, like

    TypeInfo type_piix3 = {
        ...
        .children = {
             { "pic[0]", TYPE_I8259, offsetof(PIIX3, pic[0]) },
             { "pic[1]", TYPE_I8259, offsetof(PIIX3, pic[1]) },
             { "pit, TYPE_I8254, offsetof(PIIX3, pit) },
             { "rtc", TYPE_RTC, offsetof(PIIX3, rtc) },
             { }
        }
    }

QOM's object_init would allocate a single malloced block for all of 
them, carve out space for the parent and all children, and add the 
properties.

Paolo