test/jdk/java/util/concurrent/forkjoin/Starvation.java

*** 26,29 ***
   * @bug 8322732
   * @summary ForkJoinPool utilizes available workers even with arbitrary task dependencies
   */
  import java.util.concurrent.Callable;
  import java.util.concurrent.ForkJoinPool;
  import java.util.concurrent.atomic.AtomicInteger;
  
  public class Starvation {
      static final AtomicInteger count = new AtomicInteger();
      static final Callable<Void> noop = new Callable<Void>() {
              public Void call() {
                  return null; }};
      static final class AwaitCount implements Callable<Void> {
!         private int c;
          AwaitCount(int c) { this.c = c; }
          public Void call() {
              while (count.get() == c) Thread.onSpinWait();
              return null; }};
  
      public static void main(String[] args) throws Exception {
          try (var pool = new ForkJoinPool(2)) {
              for (int i = 0; i < 100_000; i++) {
                  var future1 = pool.submit(new AwaitCount(i));
!                 var future2 = pool.submit(noop);
                  future2.get();
                  count.set(i + 1);
                  future1.get();
              }
          }
--- 26,30 ---
   * @bug 8322732
   * @summary ForkJoinPool utilizes available workers even with arbitrary task dependencies
   */
  import java.util.concurrent.Callable;
  import java.util.concurrent.ForkJoinPool;
+ import java.util.concurrent.ForkJoinTask;
  import java.util.concurrent.atomic.AtomicInteger;
  
  public class Starvation {
      static final AtomicInteger count = new AtomicInteger();
      static final Callable<Void> noop = new Callable<Void>() {
              public Void call() {
                  return null; }};
      static final class AwaitCount implements Callable<Void> {
!         private volatile int c;
          AwaitCount(int c) { this.c = c; }
          public Void call() {
              while (count.get() == c) Thread.onSpinWait();
              return null; }};
  
      public static void main(String[] args) throws Exception {
          try (var pool = new ForkJoinPool(2)) {
              for (int i = 0; i < 100_000; i++) {
                  var future1 = pool.submit(new AwaitCount(i));
!                 var future2 = pool.submit(ForkJoinTask.adapt(noop));
                  future2.get();
                  count.set(i + 1);
                  future1.get();
              }
          }