"timfox" wrote : | Since isPaging() and addSize() are not done together as an atomic operation, it is possible that many threads could call isPaging() at the same time and return false to all of them. The way it works is... We aways call page(Message) before routing... if (!page(Message)) { route(); addSize(....); } addSize is what starts the page-mode, and addSize is only called after routing. Meaning that anything after that will be routed. You could eventually have simultaneous threads overlapping the maxSize... but I'm not sure if the cost of synchronizing this would be worth. We could maybe add another check on the last addSize. But i don't want to add any synchronization on this. I can double check this after Xmas. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4197901#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...