"jason.greene(a)jboss.com" wrote : "manik.surtani(a)jboss.com" wrote : Actually, getLock().4 should read: | | | | 4. after acquisition, test that lock acquired is same as lock created in 1, otherwise unluck, discard lock and try again. | | Why is this step needed? If everything is using putIfAbsent you shouldn't have a problem. Ah I see this is to handle the case of a blocked/queued thread acquiring a lock. Hmm this kind of defeats the performance benefit of aqs lock queueing View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4219198#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...