I've need to block all thread (servlet and queue) which access to an ArrayList stored in cache, if one thread is using (reading) the ArrayList. I'm running this on Jboss 4.0.5 in a cluster of 2 computers with JbossCache 1.4.1 SP3.
I don't know how to realize it, eventualy to do this a kind of semaphore , distribued on all farm, or to use a another mbean cache (as I use cache in PESSIMISTIC/NONE mode with other nodes) with PESSIMISTIC/SERIALIZABLE ???