Default threads like, DestroyJavaVM, Reference Handler, Signal Dispatcher
- DestroyJavaVM is a thread that unloads the Java VM on programexit. Most of the time it should be waiting, until apocalypse of your VM.
- Signal Dispatcher is a thread that handles the native signals sent by the OS to your jvm.
- Finalizer threads pull objects from the finalization queue and calls it finalize method.
- Reference Handler is a high-priority thread to enqueue pending References. Its defined in java.lang.ref.References.java