Hello, I'm trying to write code for a webapp which allows me to start and stop the webapp no matter whether an ActiveMQ JMS server is running or not with ActiveMQ 4.1.1. This means:
- Create the connection in a worker thread, so the webapp doesn't hang during startup - Interrupt the connection creation and kill the worker thread at shutdown time if the server never came up This works until the point when I have to shutdown the worker. In this situation, we have two threads: Worker and Main. Everything happens in ActiveMQConnection. Worker hangs in ensureConnectionInfoSent() in syncSendPacket(), waiting for the server to come up. Note that ensureConnectionInfoSent() is synchronized; the connection is the lock object. Main tries to stop the ActiveMQ client and calls "close()" on the connection. close() calls checkClosed() which is also synchronized on the connection object. This creates a deadlock since Worker won't release the lock any time soon. Is there a reason why checkClosed() is synchronized? It's only using a AtomicBoolean and possibly throwing an exception. The next obstacle would be checkClosedOrFailed() which is also synchronized. Again, I see no obvious reason why it has to be. Unfortunately, then I run into a wall. stop() also wants to synchronize on the connection. My next idea was to interrupt the Worker thread. This doesn't work but creates an endless loop in FailoverTransport.oneway() (the inner while() loop isn't terminated on InterruptedException). So all in all, I see no way to create an ActiveMQConnection in a worker thread and reliably stop the thread at shutdown of the webapp (*not* the VM). Has anyone solved this problem or do you just accept that your webapps hang when the JMS server is not around? Regards, -- Aaron Digulla -- View this message in context: http://www.nabble.com/Reliably-starting-and-stopping-of-a-producer-consumer-tf4600635s2354.html#a13135407 Sent from the ActiveMQ - User mailing list archive at Nabble.com.
