Testing quick join.
Thread 2 should finish before thread 3 starts.
Thread 2 iteration 0
Thread 2 iteration 1
Thread 2 iteration 2
Thread 2 iteration 3
Thread 2 iteration 4
Thread 2 done!
Thread 3 iteration 0
Thread 3 iteration 1
Thread 3 iteration 2
Thread 3 iteration 3
Thread 3 iteration 4
Thread 3 done!
Quick join test done.