javax/management/remote/mandatory/connection/BrokenConnectionTest.java fails intermittently

This is run in concurrency with:
-agentvm -a -ea -esa -v:fail,error,time -retain:fail,error -ignore:quiet -timeoutFactor:8 -J-Xmx512m -vmoption:-Xmx512m -concurrency:10


Test 4: removeNotificationListener(NL), break, removeNotificationListener(NL)
Created and started connector server
Client connected OK
Client ran removeNotificationListener(NL) OK
FAILED WITH EXCEPTION:
java.util.ConcurrentModificationException
at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:913)
at java.util.ArrayList$Itr.remove(ArrayList.java:877)
at BrokenConnectionTest$BreakableServerSocket.setBroken(BrokenConnectionTest.java:643)
at BrokenConnectionTest$BreakableRMIServerSocketFactory.setBroken(BrokenConnectionTest.java:558)
at BrokenConnectionTest$BreakableRMI.setBroken(BrokenConnectionTest.java:527)
at BrokenConnectionTest$Operation.test(BrokenConnectionTest.java:120)
at BrokenConnectionTest.test(BrokenConnectionTest.java:478)
at BrokenConnectionTest.rmiTest(BrokenConnectionTest.java:537)
at BrokenConnectionTest.test(BrokenConnectionTest.java:90)
at BrokenConnectionTest.main(BrokenConnectionTest.java:69)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:502)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:92)
at java.lang.Thread.run(Thread.java:745)

------- Testing for jmxmp -------
JMXMP broken connection test
Optional classes not present, skipping test

TEST FAILED FOR: rmi
----------System.err:(0/0)----------

result: Failed. Unexpected exit from test [exit code: 1]