src/java.base/share/classes/java/lang/ThreadBuilders.java

*** 33,10 ***
--- 33,12 ---
  import java.util.Objects;
  import java.util.concurrent.Executor;
  import java.util.concurrent.ThreadFactory;
  import jdk.internal.misc.Unsafe;
  import jdk.internal.invoke.MhUtil;
+ import jdk.internal.reflect.CallerSensitive;
+ import jdk.internal.reflect.Reflection;
  import jdk.internal.vm.ContinuationSupport;
  
  /**
   * Defines static methods to create platform and virtual thread builders.
   */

*** 213,17 ***
          private Executor scheduler;
  
          VirtualThreadBuilder() {
          }
  
-         // invoked by tests
-         VirtualThreadBuilder(Executor scheduler) {
-             if (!ContinuationSupport.isSupported())
-                 throw new UnsupportedOperationException();
-             this.scheduler = Objects.requireNonNull(scheduler);
-         }
- 
          @Override
          public OfVirtual name(String name) {
              setName(name);
              return this;
          }
--- 215,10 ---

*** 266,10 ***
--- 261,22 ---
          @Override
          public ThreadFactory factory() {
              return new VirtualThreadFactory(scheduler, name(), counter(), characteristics(),
                      uncaughtExceptionHandler());
          }
+ 
+         @CallerSensitive
+         @Override
+         public OfVirtual scheduler(Executor scheduler) {
+             Class<?> caller = Reflection.getCallerClass();
+             caller.getModule().ensureNativeAccess(OfVirtual.class, "scheduler", caller, false);
+             if (!ContinuationSupport.isSupported()) {
+                 throw new UnsupportedOperationException();
+             }
+             this.scheduler = Objects.requireNonNull(scheduler);
+             return this;
+         }
      }
  
      /**
       * Base ThreadFactory implementation.
       */