"adrian(a)jboss.org" wrote : | 4) Thread 1: Submit some work - pool is busy so wait | NOTE: Without this requirement in step 4 which isn't a policy available in java.util.concurrent you can't have the race condition. The submission of the work will either throw an error immediately, after a timeout or run the work on Thread 1 But for an MDB singleton none of those options are what we want. ;-) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4187348#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...