[libvirt] Connection release is not correct in libvirt and libvrt java

[Claudio Bley]

Hi, sorry for replying so late.

At Wed, 19 Dec 2012 15:31:54 -0700,
Eric Blake wrote:
> 
> On 12/18/2012 08:14 AM, Benjamin Wang (gendwang) wrote:
> > For libvirt java, there are similar issue. I have changed code as following in Collect.java. Please also give your comments.
> >     public int close() throws LibvirtException {
> >         int success = 0;
> >         if (VCP != null) {
> > +            try {
> >              success = libvirt.virConnectClose(VCP);
> >                 processError();
> > +            }
> > +            finally {
> >                 // If leave an invalid pointer dangling around JVM crashes and burns
> >                 // if someone tries to call a method on us
> >                 // We rely on the underlying libvirt error handling to detect that
> >                 // it's called with a null virConnectPointer
> >                 VCP = null;
> >  +           }
> 
> Unfortunately, I'm not familiar enough with libvirt-java to know if this
> patch makes sense.

Basically, when applying this patch it gives you only a one-chance
opportunity to call virConnectClose.

If an exception is thrown, it will set VCP to null, no matter what.

Might be that there was only a temporary problem, and you could
retry... ? Or do some other stuff if the VCP is still valid. But that
depends on the error.

So, is it ensured, that when virConnectClose returns an error, the
virConnectPtr is "wasted" and should be invalidated?

Claudio
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