Not to knock over the apple cart or anything, but had a 15 second chat with Greg today and he had an idea that
sounded good. His idea was to eliminate the cleanup bit entirely and fold the function it is providing into
the refcount. With the code in HEAD right now, a cache object sitting in the cache hash table unreferenced by
any worker threads has a refcount of 0. The change is to bump the refcount of a cache object by 1 to reflect
that it is being 'referenced' by the hash table. This simplifies the code quite a bit (assuming I'm not
overlooking a hole that will need plugging). Patch against HEAD on the way.
Bill
