ADDITIONAL SYSTEM INFORMATION :
Linux Java HotSpot(TM) 64-Bit Server VM (11.0.5+10-LTS mixed mode)

A DESCRIPTION OF THE PROBLEM :
 i use Arrays.parallelSort to do sort, but i never get the result, it's hangs indefinitely. when i print the jstack, i found that all the worker of ForkJoinPool.commonPool is in idle

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
use Arrays.parallelSort to sort arr[]

ACTUAL -
it's hangs indefinitely

---------- BEGIN SOURCE ----------

   public static void main(String[] args) {
      Thread[] threads = new Thread[4];

      for(int i = 0; i < 4; i++) {
         threads[i] = new Thread(() -> {
            String[] arr = new String[100000];

            for(int i1 = 0; i1 < 100000; i1++) {
               arr[i1] = UUID.randomUUID().toString();
            }

            Arrays.parallelSort(arr);
            System.out.println("End sort." + arr[0]);
         });
         threads[i].start();
      }

      for(Thread thread : threads) {
         try {
            thread.join();
         }
         catch(InterruptedException e) {
            e.printStackTrace();
         }
      }

      System.out.println("End all sort.");
   }

---------- END SOURCE ----------

FREQUENCY : rarely