Naive question about grant/map

[Jonathan S. Shapiro]

On Fri, 2003-12-05 at 05:58, Joshua LeVasseur wrote:
> On Dec 4, 2003, at 21:41, Jonathan S. Shapiro wrote:
> 
> >
> > I am looking for a sequence in which A maps to B and B ??? to C and the
> > result would look like:
> >
> >    A -> B
> >    A -> C
> >
> > Is there such an operation?
> >
> > Also, I forgot to ask: is there some reason why such an operation would
> > be inadvisable?
> 
> 
> If you look at the mapping database as a *cache*, then your scenario 
> becomes one which describes the cache behavior, and thus isn't so 
> important in light of the semantics of user-level correctness.  In any 
> cache, it is possible for the entries to disappear, and they must be 
> resupplied when needed later.

Josh:

Thank you. I have always been very confused about this view of the
mapping cache. It seems tied up with some sharing deficiencies. Would
you be kind enough to expand a bit on how the cache gets rebuilt after
some element gets removed?

Thanks!