Fix and test for: https://issues.apache.org/jira/browse/AMQ-4513 Makes the locking in RegionBroker a bit more fine grained. We hold a lock only for a short time and allow destination adds that aren't on the same destination to continue on concurrently.
activemq/trunk/activemq-broker/src/main/java/org/apache/activemq/broker/region/RegionBroker.java