8355022: Implement JEP 506: Scoped Values

Reviewed-by: liach, alanb

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

@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2020, 2025, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2020, 2022, Red Hat Inc.
+ * Copyright (c) 2020, 2025, Red Hat Inc.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -34,7 +34,6 @@ import java.util.concurrent.StructureViolationException;
 import java.util.function.Supplier;
 import jdk.internal.access.JavaUtilConcurrentTLRAccess;
 import jdk.internal.access.SharedSecrets;
-import jdk.internal.javac.PreviewFeature;
 import jdk.internal.vm.annotation.ForceInline;
 import jdk.internal.vm.annotation.Hidden;
 import jdk.internal.vm.ScopedValueContainer;
@@ -237,9 +236,8 @@ import jdk.internal.vm.ScopedValueContainer;
  * have to be regenerated after a blocking operation.
  *
  * @param <T> the type of the value
- * @since 21
+ * @since 25
  */
-@PreviewFeature(feature = PreviewFeature.Feature.SCOPED_VALUES)
 public final class ScopedValue<T> {
     private final int hash;
 
@@ -310,9 +308,8 @@ public final class ScopedValue<T> {
      * <p> Unless otherwise specified, passing a {@code null} argument to a method in
      * this class will cause a {@link NullPointerException} to be thrown.
      *
-     * @since 21
+     * @since 25
      */
-    @PreviewFeature(feature = PreviewFeature.Feature.SCOPED_VALUES)
     public static final class Carrier {
         // Bit masks: a 1 in position n indicates that this set of bound values
         // hits that slot in the cache.
@@ -413,7 +410,6 @@ public final class ScopedValue<T> {
          * @return the result
          * @throws StructureViolationException if a structure violation is detected
          * @throws X if {@code op} completes with an exception
-         * @since 23
          */
         public <R, X extends Throwable> R call(CallableOp<? extends R, X> op) throws X {
             Objects.requireNonNull(op);
@@ -497,9 +493,8 @@ public final class ScopedValue<T> {
      *
      * @param <T> result type of the operation
      * @param <X> type of the exception thrown by the operation
-     * @since 23
+     * @since 25
      */
-    @PreviewFeature(feature = PreviewFeature.Feature.SCOPED_VALUES)
     @FunctionalInterface
     public interface CallableOp<T, X extends Throwable> {
         /**
@@ -612,10 +607,11 @@ public final class ScopedValue<T> {
      * Returns the value of this scoped value if bound in the current thread, otherwise
      * returns {@code other}.
      *
-     * @param other the value to return if not bound, can be {@code null}
+     * @param other the value to return if not bound
      * @return the value of the scoped value if bound, otherwise {@code other}
      */
     public T orElse(T other) {
+        Objects.requireNonNull(other);
         Object obj = findBinding();
         if (obj != Snapshot.NIL) {
             @SuppressWarnings("unchecked")

src/java.base/share/classes/javax/security/auth/Subject.java

@@ -300,7 +300,7 @@ public final class Subject implements java.io.Serializable {
      * @since 18
      */
     public static Subject current() {
-        return SCOPED_SUBJECT.orElse(null);
+        return SCOPED_SUBJECT.isBound() ? SCOPED_SUBJECT.get() : null;
     }
 
     /**

src/java.base/share/classes/jdk/internal/javac/PreviewFeature.java

@@ -69,7 +69,6 @@ public @interface PreviewFeature {
 
         //---
         IMPLICIT_CLASSES, //to be removed when boot JDK is 25
-        @JEP(number=487, title="Scoped Values", status="Fourth Preview")
         SCOPED_VALUES,
         @JEP(number=505, title="Structured Concurrency", status="Fifth Preview")
         STRUCTURED_CONCURRENCY,

test/jdk/java/lang/ScopedValue/ManyBindings.java

@@ -24,7 +24,6 @@
 /*
  * @test
  * @summary Stress test ScopedValue with many bindings and rebindings
- * @enablePreview
  * @library /test/lib
  * @key randomness
  * @run junit ManyBindings

test/jdk/java/lang/ScopedValue/ScopedValueAPI.java

@@ -24,7 +24,6 @@
 /*
  * @test
  * @summary Test ScopedValue API
- * @enablePreview
  * @run junit ScopedValueAPI
  */
 
@@ -175,18 +174,15 @@ class ScopedValueAPI {
     void testOrElse(ThreadFactory factory) throws Exception {
         test(factory, () -> {
             ScopedValue<String> name = ScopedValue.newInstance();
-            assertNull(name.orElse(null));
             assertEquals("default", name.orElse("default"));
 
             // where
             ScopedValue.where(name, "duke").run(() -> {
-                assertEquals("duke", name.orElse(null));
                 assertEquals("duke", name.orElse("default"));
             });
 
             // callWhere
             ScopedValue.where(name, "duke").call(() -> {
-                assertEquals("duke", name.orElse(null));
                 assertEquals("duke", name.orElse("default"));
                 return null;
             });
@@ -416,6 +412,7 @@ class ScopedValueAPI {
         assertThrows(NullPointerException.class, () -> ScopedValue.where(null, "duke").call(() -> ""));
         assertThrows(NullPointerException.class, () -> ScopedValue.where(name, "duke").call(null));
 
+        assertThrows(NullPointerException.class, () -> name.orElse(null));
         assertThrows(NullPointerException.class, () -> name.orElseThrow(null));
 
         var carrier = ScopedValue.where(name, "duke");
@@ -423,6 +420,7 @@ class ScopedValueAPI {
         assertThrows(NullPointerException.class, () -> carrier.get((ScopedValue<?>)null));
         assertThrows(NullPointerException.class, () -> carrier.run(null));
         assertThrows(NullPointerException.class, () -> carrier.call(null));
+        assertThrows(NullPointerException.class, () -> carrier.run(() -> name.orElse(null)));
     }
 
     @FunctionalInterface

test/jdk/java/lang/ScopedValue/UnboundValueAfterOOME.java

@@ -26,7 +26,6 @@ import java.util.NoSuchElementException;
 /*
  * @test
  * @bug 8319120
- * @enablePreview
  * @run main/othervm -Xmx10m UnboundValueAfterOOME
  */
 public class UnboundValueAfterOOME {