[Libvir] Re: [PATCH] Python bindings now generate exceptions for libvirt errors (third version)

[Daniel P. Berrange]

On Wed, Mar 28, 2007 at 10:45:34AM -0400, Daniel Veillard wrote:
> On Wed, Mar 28, 2007 at 03:13:28PM +0100, Daniel P. Berrange wrote:
> > On Wed, Mar 28, 2007 at 07:07:32AM -0400, Daniel Veillard wrote:
> > > If the fact of being inactive is only represented internally by having
> > > id == -1 then we probably made a mistake, we should have
> > >    domain->flags & DOMAIN_IS_DEFINED 
> > > bit set.
> > 
> > We already have a state flag for it
> > 
> >   VIR_DOMAIN_SHUTOFF
> > 
> > which is set in virDomainInfoPtr, we can fix virt-manager not to call get_id
> > if the domain is shutdown.
> 
>   It would be nice though if each time you look whether the domain is
> defined or not, libvirt could give teh answer directly instead of going
> though the potentially expensive Info call. This would also require
> to double check invalidation of the _virDomain cached data at the 
> proper places.

The virDomainGetInfo is a fast-path call - its either a direct hypercall,
or a hypercall via the proxy - we never make an expensive XenD call unless
they've broken the proxy somehow. 

Dan.
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