Re: [Qemu-devel] [PATCH 15/22] qapi: add new QMP server that uses CharDriverState

[Anthony Liguori]

On 03/07/2011 07:52 AM, Stefan Hajnoczi wrote:
> On Mon, Mar 7, 2011 at 1:22 AM, Anthony Liguori<address@hidden>  wrote:
>    
> > +static void qmp_chr_send_greeting(QmpSession *s)
> > +{
> > +    VersionInfo *info;
> > +    QObject *vers;
> > +    QObject *greeting;
> > +    QString *str;
> > +
> > +    info = qmp_query_version(NULL);
> > +    vers = qmp_marshal_type_VersionInfo(info);
> > +    qmp_free_version_info(info);
> > +
> > +    greeting = qobject_from_jsonf("{'QMP': {'version': %p, 'capabilities': []} 
> > }",
> > +                                  vers);
> > +    str = qobject_to_json(greeting);
> > +    qobject_decref(greeting);
> > +
> > +    qemu_chr_write(s->chr, (void *)str->string, str->length);
> > +    qemu_chr_write(s->chr, (void *)"\n", 1);
> > +    QDECREF(str);
> > +}
> >      
> Is vers leaked?
>    

No, %p takes ownership of the object.  qdict_put* also does FWIW.

The ownership semantics of QObject functions are very challenging.  We 
really need a concept of floating references to let stuff like this 
continue to work without explicitly transferring ownership.

But really, a big part of this refactoring is isolating QObject so that 
we can eventually replace it with GVariant so it may not be worth 
worrying about.

Regards,

Anthony Liguori

> Stefan
>
>