I noticed an instance where double checked-locking (DCL) is used in Struts: org.apache.struts.action.ActionServlet lines 1561 - 1586 According to the article below: http://www.cs.umd.edu/~pugh/java/memoryModel/DoubleCheckedLocking.html But after further inspection, I think that what goes on in this case is OK, since the 'actions' FastHashMap acts as a memory barrier (not sure if I'm using this terminology correctly) for the new Action instances that are created. So this email is now just an FYI... - Gidado
