How can you test if a thread is the only remaining thread in Java?

Question

I want a thread in a Java program to loop until all other threads die, and then end the loop. How can I know when my loop thread is the only thread remaining?

In my situation, the loop thread will have no reference to any other threads, so I don't think isAlive() helps me.

Answer 1

This might or might not help, depending on your use-case.

Set your loop thread to daemon mode

setDaemon(true); 

and Java will kill it for you if all the non-daemon threads are gone.

Answer 2

Would this not be a situation where you would consider the Thread Pool Pattern?

If not, would it not be better to maintain a list of active threads, removing each as they are destroyed?