jmx-dev Review Request: 7195779 javax/management/remote/mandatory/threads/ExecutorTest.java fail intermittently

[Jaroslav Bachorik]

The ExecutorTest.java fails in cca. 30-40% of runs with NPE in the part
testing IIOP connection.

The failure is caused by the JMX notification processing - ideally, once
the RMIConnector is closed the client JMX notification processing should
quit as well and should not try to fetch any more notifications over the
already closed remote connection. But achieving this is particularly
difficult mostly due to the synchronous nature of the
fetchNotifications() method. The RMIConnector can get closed after the
fetchNotifications() method was entered but before attempting to invoke
its remote counterpart. At this moment the remote connection is
effectively closed and any attempt to use it will throw an exception - a
NPE in this case.

The patch does not solve the core problem as it would probably require
significant changes in the client JMX notification processing - rather
it targets the NPE which becomes expected when the RMIConnector is
closed. This is handled by adding a new "catch (NullPointerException)"
block and, inside that block, checking for the connection state and
rethrowing the exception in case the connection is still open
(RMIConnector is started). For any other state of RMIConnector the NPE
is ignored.

The webrev is located at: http://washi.ru.oracle.com/jb198685/webrev/7195779

-JB-