[PATCH 00/40] convert virObjects to GObject

Daniel P. Berrangé berrange at redhat.com
Wed Jun 3 09:38:18 UTC 2020

On Fri, May 15, 2020 at 04:13:21PM +0100, Daniel P. Berrangé wrote:
> On Fri, May 15, 2020 at 02:34:01PM +0200, Michal Privoznik wrote:
> > On 5/13/20 1:56 PM, Rafael Fonseca wrote:
> > > This patch series convert various simple instances of virObject to a
> > > GObject equivalent.
> > 
> > I'm sorry upfront for misusing your patchset and I'm also sorry for bringing
> > this up again.
> > 
> > I think we need to step back and re-evaluate whether this is worth it.
> > GObject is horrible and frightening part of GLib. Not only one has to define
> > empty functions, but we can't mix virObject and GObject. For instance:
> > virObjectRef() called over GObject will corrupt memory.
> > 
> > Worse, there is no way to check whether your patches converted everything
> > (and clearly they did not because I see couple of tests crashing; or maybe
> > they did at the time of send but now the code has changed - anyway, point
> > proven).
> > 
> > I started reviewing and stopped at the first patch realizing, I have no idea
> > whether you converted every virObjectRef()/virObjectUnref() with
> > corresponding glib call.
> > 
> > I also wanted to write a cocci spatch that might at least identify places
> > where that is happening, but apparently my spatch skills are poor.
> > 
> > Does anybody have an idea how to verify these patches?
> My preferred option was to make virObject be a subclass of GObject.
> I tried this initially but hit a key problem - g_object_unref is void
> and virObjectUnref returns bool - true if any refs still exist. We
> rely on that for the virConnectPtr and virFDStream objects.
> I couldn't come up with a way to solve that at the time, but I've
> just had another think and believe we can solve it using a thread
> local set by the finalize. So I'll have another go at doing this
> inheritance.

My conversion  to make virObject a subclass of GObject has now merged,
which eliminates the danger that Michael was concerned about.

So we should be able to move forward with Rafael's patches now.

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