Rights Amplification

[Neal H. Walfield]

At Fri, 10 Jun 2005 15:15:09 +0200,
Bernhard Kauer wrote:
> > Usage scenario 2: Reference counting.
> 
> the main problem with reference counting is that the clients have to
> explicitly release the reference. Thus cooperation is needed, since L4
> do not send a notification if an object e.g. a task is destroyed...

Clients can voluntarily release a reference, however, they are not
required to do so.  The task server, which is part of the TCB, knows
when every task terminates.  It can provide this information to the
reference monitor.

> > Situation:  S -> C -> (1 reference) A -> B
> > 
> > 
> > Goal:             /-> (1 reference) A
> >             S-> C
> >                   \-> (1 reference) B
> > 
> 
> In your scenario both clients A and B have to cooperate with C

C needn't trust either A or B.

Thanks,
Neal