[overlord-issues] [JBoss JIRA] (RTGOV-112) Experiment with using WeakRef for list of active change listeners

Experiment with using WeakRef for list of active change listeners ----------------------------------------------------------------- Key: RTGOV-112 URL: https://issues.jboss.org/browse/RTGOV-112 Project: RTGov (Run Time Governance) Issue Type: Task Reporter: Gary Brown Assignee: Gary Brown Priority: Minor Fix For: 1.1 Currently the ActiveCollection uses a standard list to maintain the list of active change listeners interested in changes to the collection. The issue with this approach is if clients setup active change listeners, but then fail to unregister them when they are no longer required. This could lead to an accumulation of unnecessary listeners, causing the collection to do more work than required when distributing change notifications. One approach to overcome this would be to use a list of WeakReferences to the listeners, so then we don't need to rely on the clients to tidy up. We need to experiment with the performance implications of such a change, including explicit removal of the listener, which would need to iterate through the list of listeners to check each reference in turn - although this should be a relatively infrequent task, so hopefully shouldn't impact the overall performance too much.