test/jdk/java/lang/Thread/virtual/ParkWithFixedThreadPool.java

*** 28,18 ***
   * @modules java.base/java.lang:+open
   * @library /test/lib
   * @run main ParkWithFixedThreadPool
   */
  
! import java.util.concurrent.*;
! import java.util.concurrent.atomic.*;
  import java.util.concurrent.locks.LockSupport;
  import jdk.test.lib.thread.VThreadScheduler;
  
  public class ParkWithFixedThreadPool {
      public static void main(String[] args) throws Exception {
!         try (ExecutorService scheduler = Executors.newFixedThreadPool(8)) {
              int vthreadCount = 300;
              Thread[] vthreads = new Thread[vthreadCount];
              Runnable target = new Runnable() {
                  public void run() {
                      int myIndex = -1;
--- 28,20 ---
   * @modules java.base/java.lang:+open
   * @library /test/lib
   * @run main ParkWithFixedThreadPool
   */
  
! import java.util.concurrent.Executor;
! import java.util.concurrent.ExecutorService;
+ import java.util.concurrent.Executors;
+ import java.util.concurrent.ThreadFactory;
  import java.util.concurrent.locks.LockSupport;
  import jdk.test.lib.thread.VThreadScheduler;
  
  public class ParkWithFixedThreadPool {
      public static void main(String[] args) throws Exception {
!         try (var scheduler = new Scheduler(8)) {
              int vthreadCount = 300;
              Thread[] vthreads = new Thread[vthreadCount];
              Runnable target = new Runnable() {
                  public void run() {
                      int myIndex = -1;

*** 72,6 ***
--- 74,29 ---
              for (int i = 0; i < vthreadCount; i++) {
                  vthreads[i].join();
              }
          }
      }
+ 
+     static class Scheduler implements Executor, AutoCloseable {
+         private final ExecutorService pool;
+ 
+         Scheduler(int poolSize) {
+             pool = Executors.newFixedThreadPool(poolSize);
+         }
+ 
+         @Override
+         public void execute(Runnable task) {
+             try {
+                 pool.execute(task);
+             } finally {
+                 // ExecutorService::execute may consume parking permit
+                 LockSupport.unpark(Thread.currentThread());
+             }
+         }
+ 
+         @Override
+         public void close() {
+             pool.close();
+         }
+     }
  }