Misbehaving User Threads

[Karthik Veeramani]

I wrote a c++ wrapper to launch jvm and run a java app. The main class is not a thread, but starts some (user) threads. The cpp program killed all the threads once main returned. So I was trying to retain it, by joining the main thread to one of the user threads. This worked fine (ie, the app ran fine as long as i wanted).
Now I'm making that cpp program as a service. This join() call hangs the service, so the service doesnt start fully. I removed the join call, and started the service. This runs fine for a few seconds, and again all user threads die after that brief moment.
Is there anyway to keep the threads alive?