Re: [libvirt] [PATCH 2/4] Update modified mac address in place in virGetInterface

On Wed, Jul 22, 2009 at 01:20:57AM -0400, Laine Stump wrote: > If the mac address of an interface is changed, we must either create a > new virInterface object in the cache that has the new name/mac, or > modify the existing object in the cache. Because the cache is in a > hash that's indexed by name only, we can't create a new entry having > the same name without destroying the old one first (which isn't a > possibility as someone else is already referencing the old one), so > we're stuck modifying the existing entry. We have to do that without > changing the pointer to the mac though, so we really can only do it if > the length of the new mac is equal to or less than the old > mac. Otherwise, we have to just bail. > > Fixing this problem to properly handle this corner case would require > a hash table that used both name and mac as keys, but that would be > inefficient (using the existing hash table implementation, which only > allows a single key), and probably unnecessary, as the length of mac > for any given interface will never change in practice. Yep, the odds of this error case happening are sooooo small, that giving a fatal error here is more than good enough.