8356080: Address post-integration comments for Stable Values

Reviewed-by: liach

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

@@ -384,8 +384,8 @@ import java.util.function.Supplier;
  * <p>
  * The method {@link #orElseSet(Supplier)} guarantees that the provided
  * {@linkplain Supplier} is invoked successfully at most once, even under race.
- * Invocations of {@link #setOrThrow(Object)} form a total order of zero or more
+ * Invocations of {@link #orElseSet(Supplier)} form a total order of zero or
- * exceptional invocations followed by zero (if the contents were already set) or one
+ * more exceptional invocations followed by zero (if the contents were already set) or one
  * successful invocation. Since stable functions and stable collections are built on top
  * of the same principles as {@linkplain StableValue#orElseSet(Supplier) orElseSet()} they
  * too are thread safe and guarantee at-most-once-per-input invocation.
@@ -444,8 +444,6 @@ import java.util.function.Supplier;
 public sealed interface StableValue<T>
         permits StableValueImpl {
 
-    // Principal methods
-
     /**
      * Tries to set the contents of this StableValue to the provided {@code contents}.
      * The contents of this StableValue can only be set once, implying this method only
@@ -509,8 +507,6 @@ public sealed interface StableValue<T>
      */
     T orElseSet(Supplier<? extends T> supplier);
 
-    // Convenience methods
-
     /**
      * Sets the contents of this StableValue to the provided {@code contents}, or, if
      * already set, throws {@code IllegalStateException}.
@@ -519,6 +515,9 @@ public sealed interface StableValue<T>
      *
      * @param contents to set
      * @throws IllegalStateException if the contents was already set
+     * @throws IllegalStateException if a supplier invoked by {@link #orElseSet(Supplier)}
+     *         recursively attempts to set this stable value by calling this method
+     *         directly or indirectly.
      */
     void setOrThrow(T contents);
 
@@ -573,8 +572,8 @@ public sealed interface StableValue<T>
      * at most once even in a multi-threaded environment. Competing threads invoking the
      * returned supplier's {@linkplain Supplier#get() get()} method when a value is
      * already under computation will block until a value is computed or an exception is
-     * thrown by the computing thread. The computing threads will then observe the newly
+     * thrown by the computing thread. The competing threads will then observe the newly
-     * computed value (if any) and will then never execute.
+     * computed value (if any) and will then never execute the {@code underlying} supplier.
      * <p>
      * If the provided {@code underlying} supplier throws an exception, it is rethrown
      * to the initial caller and no contents is recorded.
@@ -614,9 +613,9 @@ public sealed interface StableValue<T>
      * function for the same input, an {@linkplain IllegalStateException} will
      * be thrown.
      *
-     * @param size       the size of the allowed inputs in the continuous
+     * @param size       the upper bound of the range {@code [0, size)} indicating
-     *                   interval {@code [0, size)}
+     *                   the allowed inputs
-     * @param underlying IntFunction used to compute cached values
+     * @param underlying {@code IntFunction} used to compute cached values
      * @param <R>        the type of results delivered by the returned IntFunction
      * @throws IllegalArgumentException if the provided {@code size} is negative.
      */
@@ -684,7 +683,7 @@ public sealed interface StableValue<T>
      * If invoking the provided {@code mapper} function throws an exception, it
      * is rethrown to the initial caller and no value for the element is recorded.
      * <p>
-     * Any direct {@link List#subList(int, int) subList} or {@link List#reversed()} views
+     * Any {@link List#subList(int, int) subList} or {@link List#reversed()} views
      * of the returned list are also stable.
      * <p>
      * The returned list and its {@link List#subList(int, int) subList} or
@@ -727,8 +726,8 @@ public sealed interface StableValue<T>
      * is rethrown to the initial caller and no value associated with the provided key
      * is recorded.
      * <p>
-     * Any direct {@link Map#values()} or {@link Map#entrySet()} views
+     * Any {@link Map#values()} or {@link Map#entrySet()} views of the returned map are
-     * of the returned map are also stable.
+     * also stable.
      * <p>
      * The returned map is unmodifiable and does not implement the
      * {@linkplain Collection##optional-operations optional operations} in the

src/java.base/share/classes/java/util/ImmutableCollections.java

@@ -47,7 +47,6 @@ import jdk.internal.lang.stable.StableUtil;
 import jdk.internal.lang.stable.StableValueImpl;
 import jdk.internal.misc.CDS;
 import jdk.internal.util.ArraysSupport;
-import jdk.internal.util.NullableKeyValueHolder;
 import jdk.internal.vm.annotation.ForceInline;
 import jdk.internal.vm.annotation.Stable;
 
@@ -137,9 +136,11 @@ class ImmutableCollections {
                     return ImmutableCollections.listFromTrustedArrayNullsAllowed(array);
                 }
                 public <E> List<E> stableList(int size, IntFunction<? extends E> mapper) {
-                    return ImmutableCollections.stableList(size, mapper);
+                    // A stable list is not Serializable, so we cannot return `List.of()` if `size == 0`
+                    return new StableList<>(size, mapper);
                 }
                 public <K, V> Map<K, V> stableMap(Set<K> keys, Function<? super K, ? extends V> mapper) {
+                    // A stable map is not Serializable, so we cannot return `Map.of()` if `keys.isEmpty()`
                     return new StableMap<>(keys, mapper);
                 }
             });
@@ -264,11 +265,6 @@ class ImmutableCollections {
         }
     }
 
-    static <E> List<E> stableList(int size, IntFunction<? extends E> mapper) {
-        // A lazy list is not Serializable so, we cannot return `List.of()` if size == 0
-        return new StableList<>(size, mapper);
-    }
-
     // ---------- List Implementations ----------
 
     @jdk.internal.ValueBased
@@ -454,17 +450,17 @@ class ImmutableCollections {
         }
     }
 
-    static final class SubList<E> extends AbstractImmutableList<E>
+    static sealed class SubList<E> extends AbstractImmutableList<E>
             implements RandomAccess {
 
         @Stable
-        private final AbstractImmutableList<E> root;
+        final AbstractImmutableList<E> root;
 
         @Stable
-        private final int offset;
+        final int offset;
 
         @Stable
-        private final int size;
+        final int size;
 
         private SubList(AbstractImmutableList<E> root, int offset, int size) {
             assert root instanceof List12 || root instanceof ListN || root instanceof StableList;
@@ -517,9 +513,8 @@ class ImmutableCollections {
             }
         }
 
-        private boolean allowNulls() {
+        boolean allowNulls() {
-            return root instanceof ListN<?> listN && listN.allowNulls
+            return root instanceof ListN<?> listN && listN.allowNulls;
-                    || root instanceof StableList<E>;
         }
 
         @Override
@@ -572,14 +567,6 @@ class ImmutableCollections {
             return array;
         }
 
-        @Override
-        public String toString() {
-            if (root instanceof StableList<E> stableList) {
-                return StableUtil.renderElements(root, "StableList", stableList.delegates, offset, size);
-            } else {
-                return super.toString();
-            }
-        }
     }
 
     @jdk.internal.ValueBased
@@ -797,8 +784,15 @@ class ImmutableCollections {
         }
     }
 
+    @FunctionalInterface
+    interface HasStableDelegates<E> {
+        StableValueImpl<E>[] delegates();
+    }
+
     @jdk.internal.ValueBased
-    static final class StableList<E> extends AbstractImmutableList<E> {
+    static final class StableList<E>
+            extends AbstractImmutableList<E>
+            implements HasStableDelegates<E> {
 
         @Stable
         private final IntFunction<? extends E> mapper;
@@ -879,11 +873,69 @@ class ImmutableCollections {
         }
 
         @Override
-        public String toString() {
+        public List<E> subList(int fromIndex, int toIndex) {
-            return StableUtil.renderElements(this, "StableList", delegates);
+            subListRangeCheck(fromIndex, toIndex, size());
+            return StableSubList.fromStableList(this, fromIndex, toIndex);
         }
 
-        private static final class StableReverseOrderListView<E> extends ReverseOrderListView.Rand<E> {
+        @Override
+        public String toString() {
+            return StableUtil.renderElements(this, "StableCollection", delegates);
+        }
+
+        @Override
+        public StableValueImpl<E>[] delegates() {
+            return delegates;
+        }
+
+        private static final class StableSubList<E> extends SubList<E>
+                implements HasStableDelegates<E> {
+
+            private StableSubList(AbstractImmutableList<E> root, int offset, int size) {
+                super(root, offset, size);
+            }
+
+            @Override
+            public List<E> reversed() {
+                return new StableReverseOrderListView<>(this);
+            }
+
+            @Override
+            public List<E> subList(int fromIndex, int toIndex) {
+                subListRangeCheck(fromIndex, toIndex, size());
+                return StableSubList.fromStableSubList(this, fromIndex, toIndex);
+            }
+
+            @Override
+            public String toString() {
+                return StableUtil.renderElements(this, "StableCollection", delegates());
+            }
+
+            @Override
+            boolean allowNulls() {
+                return true;
+            }
+
+            @Override
+            public StableValueImpl<E>[] delegates() {
+                @SuppressWarnings("unchecked")
+                final var rootDelegates = ((HasStableDelegates<E>) root).delegates();
+                return Arrays.copyOfRange(rootDelegates, offset, offset + size);
+            }
+
+            static <E> SubList<E> fromStableList(StableList<E> list, int fromIndex, int toIndex) {
+                return new StableSubList<>(list, fromIndex, toIndex - fromIndex);
+            }
+
+            static <E> SubList<E> fromStableSubList(StableSubList<E> parent, int fromIndex, int toIndex) {
+                return new StableSubList<>(parent.root, parent.offset + fromIndex, toIndex - fromIndex);
+            }
+
+        }
+
+        private static final class StableReverseOrderListView<E>
+                extends ReverseOrderListView.Rand<E>
+                implements HasStableDelegates<E> {
 
             private StableReverseOrderListView(List<E> base) {
                 super(base, false);
@@ -892,17 +944,23 @@ class ImmutableCollections {
             // This method does not evaluate the elements
             @Override
             public String toString() {
-                final StableValueImpl<E>[] delegates = ((StableList<E>)base).delegates;
+                return StableUtil.renderElements(this, "StableCollection", delegates());
-                final StableValueImpl<E>[] reversed = ArraysSupport.reverse(
-                        Arrays.copyOf(delegates, delegates.length));
-                return StableUtil.renderElements(base, "Collection", reversed);
             }
 
             @Override
-            public List<E> reversed() {
+            public List<E> subList(int fromIndex, int toIndex) {
-                return base;
+                final int size = base.size();
+                subListRangeCheck(fromIndex, toIndex, size);
+                return new StableReverseOrderListView<>(base.subList(size - toIndex, size - fromIndex));
             }
 
+            @Override
+            public StableValueImpl<E>[] delegates() {
+                @SuppressWarnings("unchecked")
+                final var baseDelegates = ((HasStableDelegates<E>) base).delegates();
+                return ArraysSupport.reverse(
+                        Arrays.copyOf(baseDelegates, baseDelegates.length));
+            }
         }
 
     }
@@ -1560,7 +1618,7 @@ class ImmutableCollections {
 
         @Override public boolean              containsKey(Object o) { return delegate.containsKey(o); }
         @Override public int                  size() { return delegate.size(); }
-        @Override public Set<Map.Entry<K, V>> entrySet() { return new StableMapEntrySet(); }
+        @Override public Set<Map.Entry<K, V>> entrySet() { return StableMapEntrySet.of(this); }
 
         @ForceInline
         @Override
@@ -1582,32 +1640,49 @@ class ImmutableCollections {
         }
 
         @jdk.internal.ValueBased
-        final class StableMapEntrySet extends AbstractImmutableSet<Map.Entry<K, V>> {
+        static final class StableMapEntrySet<K, V> extends AbstractImmutableSet<Map.Entry<K, V>> {
+
+            // Use a separate field for the outer class in order to facilitate
+            // a @Stable annotation.
+            @Stable
+            private final StableMap<K, V> outer;
 
             @Stable
             private final Set<Map.Entry<K, StableValueImpl<V>>> delegateEntrySet;
 
-            StableMapEntrySet() {
+            private StableMapEntrySet(StableMap<K, V> outer) {
-                this.delegateEntrySet = delegate.entrySet();
+                this.outer = outer;
+                this.delegateEntrySet = outer.delegate.entrySet();
             }
 
-            @Override public Iterator<Map.Entry<K, V>> iterator() { return new LazyMapIterator(); }
+            @Override public Iterator<Map.Entry<K, V>> iterator() { return LazyMapIterator.of(this); }
             @Override public int                       size() { return delegateEntrySet.size(); }
-            @Override public int                       hashCode() { return StableMap.this.hashCode(); }
+            @Override public int                       hashCode() { return outer.hashCode(); }
 
             @Override
             public String toString() {
-                return StableUtil.renderMappings(this, "StableSet", delegateEntrySet, false);
+                return StableUtil.renderMappings(this, "StableCollection", delegateEntrySet, false);
+            }
+
+            // For @ValueBased
+            private static <K, V> StableMapEntrySet<K, V> of(StableMap<K, V> outer) {
+                return new StableMapEntrySet<>(outer);
             }
 
             @jdk.internal.ValueBased
-            final class LazyMapIterator implements Iterator<Map.Entry<K, V>> {
+            static final class LazyMapIterator<K, V> implements Iterator<Map.Entry<K, V>> {
+
+                // Use a separate field for the outer class in order to facilitate
+                // a @Stable annotation.
+                @Stable
+                private final StableMapEntrySet<K, V> outer;
 
                 @Stable
                 private final Iterator<Map.Entry<K, StableValueImpl<V>>> delegateIterator;
 
-                LazyMapIterator() {
+                private LazyMapIterator(StableMapEntrySet<K, V> outer) {
-                    this.delegateIterator = delegateEntrySet.iterator();
+                    this.outer = outer;
+                    this.delegateIterator = outer.delegateEntrySet.iterator();
                 }
 
                 @Override public boolean hasNext() { return delegateIterator.hasNext(); }
@@ -1616,8 +1691,8 @@ class ImmutableCollections {
                 public Entry<K, V> next() {
                     final Map.Entry<K, StableValueImpl<V>> inner = delegateIterator.next();
                     final K k = inner.getKey();
-                    return new NullableKeyValueHolder<>(k, inner.getValue().orElseSet(new Supplier<V>() {
+                    return new StableEntry<>(k, inner.getValue(), new Supplier<V>() {
-                        @Override public V get() { return mapper.apply(k); }}));
+                        @Override public V get() { return outer.outer.mapper.apply(k); }});
                 }
 
                 @Override
@@ -1627,25 +1702,60 @@ class ImmutableCollections {
                                 @Override
                                 public void accept(Entry<K, StableValueImpl<V>> inner) {
                                     final K k = inner.getKey();
-                                    action.accept(new NullableKeyValueHolder<>(k, inner.getValue().orElseSet(new Supplier<V>() {
+                                    action.accept(new StableEntry<>(k, inner.getValue(), new Supplier<V>() {
-                                        @Override public V get() { return mapper.apply(k); }})));
+                                        @Override public V get() { return outer.outer.mapper.apply(k); }}));
                                 }
                             };
                     delegateIterator.forEachRemaining(innerAction);
                 }
+
+                // For @ValueBased
+                private static  <K, V> LazyMapIterator<K, V> of(StableMapEntrySet<K, V> outer) {
+                    return new LazyMapIterator<>(outer);
+                }
+
             }
         }
 
+        private record StableEntry<K, V>(K getKey, // trick
+                                         StableValueImpl<V> stableValue,
+                                         Supplier<? extends V> supplier) implements Map.Entry<K, V> {
+
+            @Override public V setValue(V value) { throw uoe(); }
+            @Override public V getValue() { return stableValue.orElseSet(supplier); }
+            @Override public int hashCode() { return hash(getKey()) ^ hash(getValue()); }
+            @Override public String toString() { return getKey() + "=" + stableValue.toString(); }
+            @Override public boolean equals(Object o) {
+                return o instanceof Map.Entry<?, ?> e
+                        && Objects.equals(getKey(), e.getKey())
+                        // Invoke `getValue()` as late as possible to avoid evaluation
+                        && Objects.equals(getValue(), e.getValue());
+            }
+
+            private int hash(Object obj) { return (obj == null) ? 0 : obj.hashCode(); }
+        }
+
         @Override
         public Collection<V> values() {
-            return new StableMapValues();
+            return StableMapValues.of(this);
         }
 
-        final class StableMapValues extends AbstractImmutableCollection<V> {
+        @jdk.internal.ValueBased
-            @Override public Iterator<V> iterator() { return new ValueIterator(); }
+        static final class StableMapValues<V> extends AbstractImmutableCollection<V> {
-            @Override public int size() { return StableMap.this.size(); }
+
-            @Override public boolean isEmpty() { return StableMap.this.isEmpty();}
+            // Use a separate field for the outer class in order to facilitate
-            @Override public boolean contains(Object v) { return StableMap.this.containsValue(v); }
+            // a @Stable annotation.
+            @Stable
+            private final StableMap<?, V> outer;
+
+            private StableMapValues(StableMap<?, V> outer) {
+                this.outer = outer;
+            }
+
+            @Override public Iterator<V> iterator() { return outer.new ValueIterator(); }
+            @Override public int size() { return outer.size(); }
+            @Override public boolean isEmpty() { return outer.isEmpty();}
+            @Override public boolean contains(Object v) { return outer.containsValue(v); }
 
             private static final IntFunction<StableValueImpl<?>[]> GENERATOR = new IntFunction<StableValueImpl<?>[]>() {
                 @Override
@@ -1656,9 +1766,15 @@ class ImmutableCollections {
 
             @Override
             public String toString() {
-                final StableValueImpl<?>[] values = delegate.values().toArray(GENERATOR);
+                final StableValueImpl<?>[] values = outer.delegate.values().toArray(GENERATOR);
-                return StableUtil.renderElements(StableMap.this, "StableMap", values);
+                return StableUtil.renderElements(this, "StableCollection", values);
             }
+
+            // For @ValueBased
+            private static <V> StableMapValues<V> of(StableMap<?, V> outer) {
+                return new StableMapValues<>(outer);
+            }
+
         }
 
         @Override

src/java.base/share/classes/java/util/ReverseOrderListView.java

@@ -33,14 +33,17 @@ import java.util.function.UnaryOperator;
 import java.util.stream.Stream;
 import java.util.stream.StreamSupport;
 import jdk.internal.util.ArraysSupport;
+import jdk.internal.vm.annotation.Stable;
 
 /**
  * Provides a reverse-ordered view of a List. Not serializable.
  */
 class ReverseOrderListView<E> implements List<E> {
 
+    @Stable
     final List<E> base;
-    final boolean modifiable;
+    @Stable
+    final Boolean modifiable;
 
     public static <T> List<T> of(List<T> list, boolean modifiable) {
         if (list instanceof RandomAccess) {

src/java.base/share/classes/jdk/internal/lang/stable/StableEnumFunction.java

@@ -46,7 +46,10 @@ import java.util.function.Supplier;
  * @implNote This implementation can be used early in the boot sequence as it does not
  *           rely on reflection, MethodHandles, Streams etc.
  *
+ * @param enumType     the class type of the Enum
  * @param firstOrdinal the lowest ordinal used
+ * @param member       an int predicate that can be used to test if an enum is a member
+ *                     of the valid inputs (as there might be "holes")
  * @param delegates    a delegate array of inputs to StableValue mappings
  * @param original     the original Function
  * @param <E>          the type of the input to the function
@@ -64,10 +67,8 @@ public record StableEnumFunction<E extends Enum<E>, R>(Class<E> enumType,
             throw new IllegalArgumentException("Input not allowed: " + value);
         }
         final int index = value.ordinal() - firstOrdinal;
-        final StableValueImpl<R> delegate;
         // Since we did the member.test above, we know the index is in bounds
-        delegate = delegates[index];
+        return delegates[index].orElseSet(new Supplier<R>() {
-        return delegate.orElseSet(new Supplier<R>() {
                     @Override public R get() { return original.apply(value); }});
 
     }
@@ -84,8 +85,8 @@ public record StableEnumFunction<E extends Enum<E>, R>(Class<E> enumType,
 
     @Override
     public String toString() {
+        final Collection<Map.Entry<E, StableValueImpl<R>>> entries = new ArrayList<>(delegates.length);
         final E[] enumElements = enumType.getEnumConstants();
-        final Collection<Map.Entry<E, StableValueImpl<R>>> entries = new ArrayList<>(enumElements.length);
         int ordinal = firstOrdinal;
         for (int i = 0; i < delegates.length; i++, ordinal++) {
             if (member.test(ordinal)) {
@@ -99,7 +100,7 @@ public record StableEnumFunction<E extends Enum<E>, R>(Class<E> enumType,
     public static <T, E extends Enum<E>, R> Function<T, R> of(Set<? extends T> inputs,
                                                               Function<? super T, ? extends R> original) {
         // The input set is not empty
-        final Class<E> enumType = (Class<E>)inputs.iterator().next().getClass();
+        final Class<E> enumType = ((E) inputs.iterator().next()).getDeclaringClass();
         final BitSet bitSet = new BitSet(enumType.getEnumConstants().length);
         int min = Integer.MAX_VALUE;
         int max = Integer.MIN_VALUE;

src/java.base/share/classes/jdk/internal/lang/stable/StableFunction.java

@@ -32,7 +32,7 @@ import java.util.Set;
 import java.util.function.Function;
 import java.util.function.Supplier;
 
-// Note: It would be possible to just use `LazyMap::get` with some additional logic
+// Note: It would be possible to just use `StableMap::get` with some additional logic
 // instead of this class but explicitly providing a class like this provides better
 // debug capability, exception handling, and may provide better performance.
 /**

src/java.base/share/classes/jdk/internal/lang/stable/StableIntFunction.java

@@ -31,9 +31,6 @@ import jdk.internal.vm.annotation.Stable;
 import java.util.function.IntFunction;
 import java.util.function.Supplier;
 
-// Note: It would be possible to just use `LazyList::get` instead of this
-// class but explicitly providing a class like this provides better
-// debug capability, exception handling, and may provide better performance.
 /**
  * Implementation of a stable IntFunction.
  * <p>

src/java.base/share/classes/jdk/internal/lang/stable/StableSupplier.java

@@ -58,7 +58,7 @@ public record StableSupplier<T>(StableValueImpl<T> delegate,
 
     @Override
     public String toString() {
-        final Object t = delegate.wrappedContentAcquire();
+        final Object t = delegate.wrappedContentsAcquire();
         return t == this ? "(this StableSupplier)" : StableValueImpl.renderWrapped(t);
     }
 

src/java.base/share/classes/jdk/internal/lang/stable/StableUtil.java

@@ -47,7 +47,7 @@ public final class StableUtil {
                                             int length) {
         final StringJoiner sj = new StringJoiner(", ", "[", "]");
         for (int i = 0; i < length; i++) {
-            final Object value = delegates[i + offset].wrappedContentAcquire();
+            final Object value = delegates[i + offset].wrappedContentsAcquire();
             if (value == self) {
                 sj.add("(this " + selfName + ")");
             } else {
@@ -63,10 +63,10 @@ public final class StableUtil {
                                                boolean curly) {
         final StringJoiner sj = new StringJoiner(", ", curly ? "{" : "[", curly ? "}" : "]");
         for (var e : delegates) {
-            final Object value = e.getValue().wrappedContentAcquire();
+            final Object value = e.getValue().wrappedContentsAcquire();
             final String valueString;
             if (value == self) {
-                valueString = ("(this ") + selfName + ")";
+                valueString = "(this " + selfName + ")";
             } else {
                 valueString = StableValueImpl.renderWrapped(value);
             }

src/java.base/share/classes/jdk/internal/lang/stable/StableValueImpl.java

@@ -51,10 +51,10 @@ public final class StableValueImpl<T> implements StableValue<T> {
 
     // Unsafe offsets for direct field access
 
-    private static final long CONTENT_OFFSET =
+    private static final long CONTENTS_OFFSET =
             UNSAFE.objectFieldOffset(StableValueImpl.class, "contents");
-    // Used to indicate a holder value is `null` (see field `value` below)
+
-    // A wrapper method `nullSentinel()` is used for generic type conversion.
+    // Used to indicate a holder value is `null` (see field `contents` below)
     private static final Object NULL_SENTINEL = new Object();
 
     // Generally, fields annotated with `@Stable` are accessed by the JVM using special
@@ -77,13 +77,13 @@ public final class StableValueImpl<T> implements StableValue<T> {
     @ForceInline
     @Override
     public boolean trySet(T contents) {
-        if (wrappedContentAcquire() != null) {
+        if (wrappedContentsAcquire() != null) {
             return false;
         }
         // Prevent reentry via an orElseSet(supplier)
         preventReentry();
         // Mutual exclusion is required here as `orElseSet` might also
-        // attempt to modify the `wrappedValue`
+        // attempt to modify `this.contents`
         synchronized (this) {
             return wrapAndSet(contents);
         }
@@ -102,7 +102,7 @@ public final class StableValueImpl<T> implements StableValue<T> {
     @ForceInline
     @Override
     public T orElseThrow() {
-        final Object t = wrappedContentAcquire();
+        final Object t = wrappedContentsAcquire();
         if (t == null) {
             throw new NoSuchElementException("No contents set");
         }
@@ -112,21 +112,21 @@ public final class StableValueImpl<T> implements StableValue<T> {
     @ForceInline
     @Override
     public T orElse(T other) {
-        final Object t = wrappedContentAcquire();
+        final Object t = wrappedContentsAcquire();
         return (t == null) ? other : unwrap(t);
     }
 
     @ForceInline
     @Override
     public boolean isSet() {
-        return wrappedContentAcquire() != null;
+        return wrappedContentsAcquire() != null;
     }
 
     @ForceInline
     @Override
     public T orElseSet(Supplier<? extends T> supplier) {
         Objects.requireNonNull(supplier);
-        final Object t = wrappedContentAcquire();
+        final Object t = wrappedContentsAcquire();
         return (t == null) ? orElseSetSlowPath(supplier) : unwrap(t);
     }
 
@@ -149,7 +149,7 @@ public final class StableValueImpl<T> implements StableValue<T> {
 
     @Override
     public String toString() {
-        final Object t = wrappedContentAcquire();
+        final Object t = wrappedContentsAcquire();
         return t == this
                 ? "(this StableValue)"
                 : renderWrapped(t);
@@ -158,8 +158,8 @@ public final class StableValueImpl<T> implements StableValue<T> {
     // Internal methods shared with other internal classes
 
     @ForceInline
-    public Object wrappedContentAcquire() {
+    public Object wrappedContentsAcquire() {
-        return UNSAFE.getReferenceAcquire(this, CONTENT_OFFSET);
+        return UNSAFE.getReferenceAcquire(this, CONTENTS_OFFSET);
     }
 
     static String renderWrapped(Object t) {
@@ -185,11 +185,11 @@ public final class StableValueImpl<T> implements StableValue<T> {
      * @return if the contents was set
      */
     @ForceInline
-    private boolean wrapAndSet(Object newValue) {
+    private boolean wrapAndSet(T newValue) {
         assert Thread.holdsLock(this);
         // We know we hold the monitor here so plain semantic is enough
         if (contents == null) {
-            UNSAFE.putReferenceRelease(this, CONTENT_OFFSET, wrap(newValue));
+            UNSAFE.putReferenceRelease(this, CONTENTS_OFFSET, wrap(newValue));
             return true;
         }
         return false;

test/jdk/java/lang/StableValue/StableFunctionTest.java

@@ -52,7 +52,13 @@ final class StableFunctionTest {
         ZERO(0),
         ILLEGAL_BEFORE(-1),
         // Valid values
-        THIRTEEN(13),
+        THIRTEEN(13) {
+            @Override
+            public String toString() {
+                // getEnumConstants will be `null` for this enum as it is overridden
+                return super.toString()+" (Overridden)";
+            }
+        },
         ILLEGAL_BETWEEN(-2),
         FORTY_TWO(42),
         // Illegal values (not in the input set)
@@ -196,6 +202,13 @@ final class StableFunctionTest {
         assertEquals("jdk.internal.lang.stable.StableFunction", emptyFunction.getClass().getName());
     }
 
+    @Test
+    void overriddenEnum() {
+        final var overridden = Value.THIRTEEN;
+        Function<Value, Integer> enumFunction = StableValue.function(EnumSet.of(overridden), Value::asInt);
+        assertEquals(MAPPER.apply(overridden), enumFunction.apply(overridden));
+    }
+
     private static Stream<Set<Value>> nonEmptySets() {
         return Stream.of(
                 Set.of(Value.FORTY_TWO, Value.THIRTEEN),

test/jdk/java/lang/StableValue/StableListTest.java

@@ -35,7 +35,6 @@ import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.MethodSource;
 
 import java.io.Serializable;
-import java.util.Arrays;
 import java.util.Comparator;
 import java.util.IdentityHashMap;
 import java.util.List;
@@ -46,7 +45,9 @@ import java.util.Set;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Consumer;
+import java.util.function.Function;
 import java.util.function.IntFunction;
+import java.util.function.UnaryOperator;
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 import java.util.stream.Stream;
@@ -242,18 +243,8 @@ final class StableListTest {
         assertEquals(eq.toString(), lazy.toString());
     }
 
-    @Test
+    void assertUnevaluated(List<Integer> subList) {
-    void subListToString() {
-        subListToString0(newList());
-        subListToString0(newList().subList(1, SIZE));
-        subListToString0(newList().subList(1, SIZE).subList(0, SIZE - 2));
-    }
-
-    void subListToString0(List<Integer> subList) {
         assertEquals(asString(".unset", subList), subList.toString());
-
-        var first = subList.getFirst();
-        assertEquals(asString(first.toString(), subList), subList.toString());
     }
 
     @Test
@@ -272,17 +263,47 @@ final class StableListTest {
     }
 
     @Test
-    void reversedToString() {
+    void sublistReversedToString() {
-        var reversed = newList().reversed();
+        var actual = StableValue.list(4, IDENTITY);
-        subListToString0(reversed);
+        var expected = List.of(0, 1, 2, 3);
+        for (UnaryOperation op : List.of(
+                new UnaryOperation("subList", l -> l.subList(1, 3)),
+                new UnaryOperation("reversed", List::reversed))) {
+            actual = op.apply(actual);
+            expected = op.apply(expected);
+        }
+        // Touch one of the elements
+        actual.getLast();
+
+        var actualToString = actual.toString();
+        var expectedToString = expected.toString().replace("2", ".unset");
+        assertEquals(expectedToString, actualToString);
     }
 
+    // This test makes sure successive view operations retains the property
+    // of being a Stable view.
     @Test
-    void subListReversedToString() {
+    void viewsStable() {
-        var list = newList().subList(1, SIZE - 1).reversed();
+        viewOperations().forEach(op0 -> {
-        // This combination is not lazy. There has to be a limit somewhere.
+            viewOperations().forEach( op1 -> {
-        var regularList = newRegularList().subList(1, SIZE - 1).reversed();
+                viewOperations().forEach(op2 -> {
-        assertEquals(regularList.toString(), list.toString());
+                    var list = newList();
+                    var view1 = op0.apply(list);
+                    var view2 = op1.apply(view1);
+                    var view3 = op2.apply(view2);
+                    var className3 = className(view3);
+                    var transitions = className(list) + ", " +
+                            op0 + " -> " + className(view1) + ", " +
+                            op1 + " -> " + className(view2) + ", " +
+                            op2 + " -> " + className3;
+                    assertTrue(className3.contains("Stable"), transitions);
+                    assertUnevaluated(list);
+                    assertUnevaluated(view1);
+                    assertUnevaluated(view2);
+                    assertUnevaluated(view3);
+                });
+            });
+        });
     }
 
     @Test
@@ -294,6 +315,23 @@ final class StableListTest {
         assertEquals("Recursive initialization of a stable value is illegal", x.getMessage());
     }
 
+    @Test
+    void indexOfNullInViews() {
+        final int size = 5;
+        final int middle = 2;
+        viewOperations().forEach(op0 -> {
+            viewOperations().forEach( op1 -> {
+                viewOperations().forEach(op2 -> {
+                    var list = StableValue.list(size, x -> x == middle ? null : x);;
+                    var view1 = op0.apply(list);
+                    var view2 = op1.apply(view1);
+                    var view3 = op2.apply(view2);
+                    assertEquals(middle, view3.indexOf(null));
+                });
+            });
+        });
+    }
+
     // Immutability
 
     @ParameterizedTest
@@ -362,6 +400,39 @@ final class StableListTest {
         assertEquals(SIZE, idMap.size());
     }
 
+    @Test
+    void childObjectOpsLazy() {
+        viewOperations().forEach(op0 -> {
+            viewOperations().forEach(op1 -> {
+                viewOperations().forEach(op2 -> {
+                    childOperations().forEach(co -> {
+                        var list = newList();
+                        var view1 = op0.apply(list);
+                        var view2 = op1.apply(view1);
+                        var view3 = op2.apply(view2);
+                        var child = co.apply(view3);
+                        var childClassName = className(child);
+                        var transitions = className(list) + ", " +
+                                op0 + " -> " + className(view1) + ", " +
+                                op1 + " -> " + className(view2) + ", " +
+                                op2 + " -> " + className(view3) + ", " +
+                                co + " -> " + childClassName;
+
+                        // None of these operations should trigger evaluation
+                        var childToString = child.toString();
+                        int childHashCode = child.hashCode();
+                        boolean childEqualToNewObj = child.equals(new Object());
+
+                        assertUnevaluated(list);
+                        assertUnevaluated(view1);
+                        assertUnevaluated(view2);
+                        assertUnevaluated(view3);
+                    });
+                });
+            });
+        });
+    }
+
     // Support constructs
 
     record Operation(String name,
@@ -370,6 +441,36 @@ final class StableListTest {
         @Override public String toString() { return name; }
     }
 
+    record UnaryOperation(String name,
+                     UnaryOperator<List<Integer>> operator) implements UnaryOperator<List<Integer>> {
+        @Override public List<Integer> apply(List<Integer> list) { return operator.apply(list); }
+        @Override public String toString() { return name; }
+    }
+
+    record ListFunction(String name,
+                        Function<List<Integer>, Object> function) implements Function<List<Integer>, Object> {
+        @Override public Object apply(List<Integer> list) { return function.apply(list); }
+        @Override public String toString() { return name; }
+    }
+
+    static Stream<UnaryOperation> viewOperations() {
+        return Stream.of(
+                // We need identity to capture all combinations
+                new UnaryOperation("identity", l -> l),
+                new UnaryOperation("reversed", List::reversed),
+                new UnaryOperation("subList", l -> l.subList(0, l.size()))
+        );
+    }
+
+    static Stream<ListFunction> childOperations() {
+        return Stream.of(
+                // We need identity to capture all combinations
+                new ListFunction("iterator", List::iterator),
+                new ListFunction("listIterator", List::listIterator),
+                new ListFunction("listIterator", List::stream)
+        );
+    }
+
     static Stream<Operation> nullAverseOperations() {
         return Stream.of(
                 new Operation("forEach",     l -> l.forEach(null)),
@@ -433,4 +534,7 @@ final class StableListTest {
                 .collect(Collectors.joining(", ")) + "]";
     }
 
+    static String className(Object o) {
+        return o.getClass().getName();
+    }
 }

test/jdk/java/lang/StableValue/StableMapTest.java

@@ -248,6 +248,37 @@ final class StableMapTest {
         assertEquals(KEYS, encountered);
     }
 
+    @Test
+    void stableEntry() {
+        var map = newMap();
+        var entry = map.entrySet().stream()
+                .filter(e -> e.getKey().equals(KEY))
+                .findAny()
+                .orElseThrow();
+
+        assertEquals(KEY + "=.unset", entry.toString());
+        var otherDifferent = Map.entry(-1, -1);
+        assertNotEquals(entry, otherDifferent);
+        assertEquals(KEY + "=.unset", entry.toString());
+        var otherEqual = Map.entry(KEY, KEY);
+        assertEquals(entry, otherEqual);
+        assertEquals(KEY + "=" + KEY, entry.toString());
+        assertEquals(entry.hashCode(), otherEqual.hashCode());
+    }
+
+    @Test
+    void stableForEachEntry() {
+        var map = newMap();
+        // Only touch the key.
+        map.entrySet().iterator().forEachRemaining(Map.Entry::getKey);
+        map.entrySet().iterator()
+                .forEachRemaining(e -> assertTrue(e.toString().contains(".unset")));
+        // Only touch the value.
+        map.entrySet().iterator().forEachRemaining(Map.Entry::getValue);
+        map.entrySet().iterator()
+                .forEachRemaining(e -> assertFalse(e.toString().contains(".unset")));
+    }
+
     // Immutability
     @ParameterizedTest
     @MethodSource("unsupportedOperations")

test/jdk/java/lang/StableValue/StableValueTest.java

@@ -29,6 +29,7 @@
 
 import org.junit.jupiter.api.Test;
 
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.NoSuchElementException;
@@ -355,12 +356,14 @@ final class StableValueTest {
 
     void race(BiPredicate<StableValue<Integer>, Integer> winnerPredicate) {
         int noThreads = 10;
-        CountDownLatch starter = new CountDownLatch(1);
+        CountDownLatch starter = new CountDownLatch(noThreads);
         StableValue<Integer> stable = StableValue.of();
         Map<Integer, Boolean> winners = new ConcurrentHashMap<>();
         List<Thread> threads = IntStream.range(0, noThreads).mapToObj(i -> new Thread(() -> {
                     try {
-                        // Ready, set ...
+                        // Ready ...
+                        starter.countDown();
+                        // ... set ...
                         starter.await();
                         // Here we go!
                         winners.put(i, winnerPredicate.test(stable, i));
@@ -370,9 +373,6 @@ final class StableValueTest {
                 }))
                 .toList();
         threads.forEach(Thread::start);
-        LockSupport.parkNanos(TimeUnit.MILLISECONDS.toNanos(1));
-        // Start the race
-        starter.countDown();
         threads.forEach(StableValueTest::join);
         // There can only be one winner
         assertEquals(1, winners.values().stream().filter(b -> b).count());

test/micro/org/openjdk/bench/java/lang/stable/StableMethodHandleBenchmark.java

@@ -65,7 +65,8 @@ public class StableMethodHandleBenchmark {
 
     private static final MethodHandle FINAL_MH = identityHandle();
     private static final StableValue<MethodHandle> STABLE_MH;
-    private static MethodHandle mh = identityHandle();
+
+    private static /* intentionally not final */ MethodHandle mh = identityHandle();
     private static final Dcl<MethodHandle> DCL = new Dcl<>(StableMethodHandleBenchmark::identityHandle);
     private static final AtomicReference<MethodHandle> ATOMIC_REFERENCE = new AtomicReference<>(identityHandle());
     private static final Map<String, MethodHandle> MAP = new ConcurrentHashMap<>();
@@ -112,14 +113,6 @@ public class StableMethodHandleBenchmark {
         return (int) STABLE_MH.orElseThrow().invokeExact(1);
     }
 
-    Object cp() {
-        CodeBuilder cob = null;
-        ConstantPoolBuilder cp = ConstantPoolBuilder.of();
-        cob.ldc(cp.constantDynamicEntry(cp.bsmEntry(cp.methodHandleEntry(BSM_CLASS_DATA), List.of()),
-                cp.nameAndTypeEntry(DEFAULT_NAME, CD_MethodHandle)));
-        return null;
-    }
-
     static MethodHandle identityHandle() {
         var lookup = MethodHandles.lookup();
         try {