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