I recently wrote sun.awt.AppContext.dispose() which, among other things, calls
ThreadGroup.stop() and waits for ThreadGroup.activeCount() to return 0 before
calling ThreadGroup.destroy().

The problem is that ThreadGroup.activeCount() never goes down to 0 when
appletviewer calls my sun.awt.AppContext.dispose() method. activeCount()
returns 1, but ThreadGroup.enumerate() returns 0, so I can't even determine
the offending Thread.

In ThreadGroup.java, activeCount() returns nthreads, but enumerate() counts
only those Threads for which isAlive() returns true. Shouldn't these work
the same?