P2
Vector content being modified outside of API calls.
To explain why this is considered to be a JVM issue:
The WMQ product has a connection pool, within that code there are 2 places where Vectors are used and are exhibiting the same behaviour. In the simplest case, a private Vector variable is constructed during class initialization, and the only permissible access to that variable are through public "add", "remove" methods, as well as a "size" method to query the vector size.
The WMQ product trace shows that only the "add" method was being called. Further tests used an instrumented Vector class "MQVector" which extends the Vector, and before each call that could affect the contents of the Vector is made, it outputs the calling stack trace as well as the content of the Vector and it's identityHashcode. It was found that the same identityHashcode was returned each time, and that whilst after the add call the Vector size increased, subsequent add calls were showing an empty Vector. The Vector object does not show any activity from other code, it appears as though the data/object reference stored by the Vector is going missing.
Please see comments session for details.
To explain why this is considered to be a JVM issue:
The WMQ product has a connection pool, within that code there are 2 places where Vectors are used and are exhibiting the same behaviour. In the simplest case, a private Vector variable is constructed during class initialization, and the only permissible access to that variable are through public "add", "remove" methods, as well as a "size" method to query the vector size.
The WMQ product trace shows that only the "add" method was being called. Further tests used an instrumented Vector class "MQVector" which extends the Vector, and before each call that could affect the contents of the Vector is made, it outputs the calling stack trace as well as the content of the Vector and it's identityHashcode. It was found that the same identityHashcode was returned each time, and that whilst after the add call the Vector size increased, subsequent add calls were showing an empty Vector. The Vector object does not show any activity from other code, it appears as though the data/object reference stored by the Vector is going missing.
Please see comments session for details.