Re: [Qemu-devel] [PATCH bugfix v1 3/3] qom: object.h: Update object_get_canon_path* doc

[Peter Crosthwaite <peter.crosthwaite@xilinx.com>]

On Thu, Aug 21, 2014 at 1:58 AM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> Il 20/08/2014 11:07, Peter Maydell ha scritto:
>> The other thing you need to say is that the returned string is
>> only valid for as long as the object remains a child property
>> of its parent. (Is that right? I'm not clear. It also sounds like
>> a really awkward lifetime management requirement, which
>> suggests to me that really the "return-a-copy" semantics are
>> nicer.)
>
> They are indeed nicer, but harder to use in C.
>
> Unparenting is (currently) always done under the BQL, so guaranteeing
> that the returned string stays alive as long as you use it is currently
> not a problem.  This might change in the future, but I don't see many
> reasons to get rid completely of the BQL (as opposed to the surgical
> moving of stuff outside it that we've been doing so far).
>
>> Having object_get_canonical_path_component() and
>> object_get_canonical_path() having different return value
>> ownership semantics is likely to be a bit confusing I think.
>
> Right, though that could be solved by renaming the _component() function.
>

Yes that had crossed my mind too. object_get_canonical_path_component
is a mouthful and it's usages suggest object_get_name or
object_get_instance_name would be more fitting.

The fact that it is a canonical_path_component is more of an
implementation detail rather than its externally useful functionality.

Regards,
Peter

> Paolo
>