System hangs with a lot of threads blocked at java.lang.Class.forName0(Native Method) with no indicator of where the lock is held

Solution Verified - Updated -


There are a number of threads which appear to be blocked, but there is no indication of what is holding the lock looking at the thread dumps
All the affected threads have an identical stack trace

    "ajp-" daemon prio=10 tid=0x43373800 nid=0x60dc waiting for monitor entry [0x34dfd000]
       java.lang.Thread.State: BLOCKED (on object monitor)
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(
        at com.myclass.Validator$Criteria.isPermited(
        at com.myclass.Validator.isPermitted(
            .. .. ..


  • JBoss Enterprise Application Platform (EAP)
  • Oracle JDK 1.6
  • OpenJDK 1.6

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