The JBossMQ UIL2 WriteTask shutdowns when it is signaled by the ReadTask using an Thread.interrupt().

If however, something "eats" that interrupt status of the thread then the WriteTask will block forever and never stop.
This leads to thread leaks.

The solution is not to wait forever for an interrupt. Instead the thread should periodically wake up
and check the "started" flag. e.g. Here is the suggest patch in outline

while (true)
{
+ synchronized (running)
+

BaseMsg msg = null;
try
{

• msg = (BaseMsg) sendQueue.take();
  + // Only wait for 10 seconds
  + msg = (BaseMsg) sendQueue.poll(10000l);
  + if (msg == null)
  + continue; // re-start the loop when no message after 10 seconds