Paolo Bonzini <pbonz...@redhat.com> writes:
> On 16/12/20 08:53, Marc-André Lureau wrote: >> >> On the principle, I fully agree. But the risk is high to introduce >> regression if objects are manipulated in strange ways. >> >> I remember I wanted object_unref() to automatically remove itself from >> the parent when the last ref is dropped. I think there were similar >> concerns. > > unref and unparent are two very different operations; the former means > *I* am done with this object, the latter means *QEMU* is done with this > object (even though there may be a few reference held, e.g. on the call > stack or by RCU). Since object_unparent operates on global state, you > can even call object_unparent if you don't own yourself a reference to > the object and just got the pointer from the caller. > > While unref is a "mechanical" operation of dropping a reference and > possibly freeing the object, unparent is an active operation that > includes for example dropping reference cycles or in general detaching > from other places that are known to hold references to this object. This all sounds like good material for a QOM object lifetime section of docs/devel/qom.rst > > This is not a concept that is specific to QEMU, I think I read somewhere > that LibreOffice's UI library does something similar, calling it "dispose". > > Paolo -- Alex Bennée
