javax/management/remote/mandatory/threads/ExecutorTest.java fails intermittently, NPE in tie class

javax/management/remote/mandatory/threads/ExecutorTest.java
Failed intermittently in TL nightly.

This is one failure log:
----------System.out:(14/283)----------

TEST: rmi
Test with no executor in env
Got notifications
Test with null executor in env
Got notifications
Test with non-null executor in env
Got notifications
Executor was called enough times

TEST: iiop
Test with no executor in env
Got notifications
Test with null executor in env
----------System.err:(16/1548)----------
java.lang.NullPointerException
at org.omg.stub.javax.management.remote.rmi._RMIConnectionImpl_Tie._invoke(Unknown Source)
at com.sun.corba.se.impl.protocol.CorbaServerRequestDispatcherImpl.dispatchToServant(CorbaServerRequestDispatcherImpl.java:654)
at com.sun.corba.se.impl.protocol.CorbaServerRequestDispatcherImpl.dispatch(CorbaServerRequestDispatcherImpl.java:205)
at com.sun.corba.se.impl.protocol.CorbaMessageMediatorImpl.handleRequestRequest(CorbaMessageMediatorImpl.java:1700)
at com.sun.corba.se.impl.protocol.SharedCDRClientRequestDispatcherImpl.marshalingComplete(SharedCDRClientRequestDispatcherImpl.java:171)
at com.sun.corba.se.impl.protocol.CorbaClientDelegateImpl.invoke(CorbaClientDelegateImpl.java:148)
at org.omg.CORBA.portable.ObjectImpl._invoke(ObjectImpl.java:475)
at com.sun.jmx.remote.protocol.iiop.ProxyStub._invoke(Unknown Source)
at org.omg.stub.javax.management.remote.rmi._RMIConnection_Stub.fetchNotifications(Unknown Source)
at javax.management.remote.rmi.RMIConnector$RMINotifClient.fetchNotifs(RMIConnector.java:1337)
at com.sun.jmx.remote.internal.ClientNotifForwarder$NotifFetcher.fetchNotifs(ClientNotifForwarder.java:588)
at com.sun.jmx.remote.internal.ClientNotifForwarder$NotifFetcher.doRun(ClientNotifForwarder.java:470)
at com.sun.jmx.remote.internal.ClientNotifForwarder$NotifFetcher.run(ClientNotifForwarder.java:451)
at com.sun.jmx.remote.internal.ClientNotifForwarder$LinearExecutor$1.run(ClientNotifForwarder.java:107)
STATUS:Failed.`main' threw exception: java.lang.NullPointerException
result: Failed. Execution failed: `main' threw exception: java.lang.NullPointerException


test result: Failed. Execution failed: `main' threw exception: java.lang.NullPointerException