test/jdk/java/util/Map/LockStep.java

@@ -1,7 +1,7 @@
  /*
-  * Copyright (c) 2008, 2013, Oracle and/or its affiliates. All rights reserved.
+  * Copyright (c) 2008, 2024, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.

@@ -21,11 +21,11 @@
   * questions.
   */
  
  /*
   * @test
-  * @bug 6612102
+  * @bug 6612102 8336669
   * @summary Test Map implementations for mutual compatibility
   * @key randomness
   */
  
  import java.util.Collections;

@@ -47,10 +47,27 @@
   * (coll) IdentityHashMap.iterator().remove() might decrement size twice
   *
   * It would be good to add more "Lockstep-style" tests to this file.
   */
  public class LockStep {
+     // An interned identity class holding an int (like non-Preview Integer)
+     // interned for IdentityHashMap
+     // identity for WeakHashMap
+     private record Int(int intValue) implements Comparable<Int> {
+         private static final Map<Integer, Int> interned = new HashMap<>(100);
+ 
+         // Return a unique Ini for each int.
+         static Int intern(int intValue) {
+             return interned.computeIfAbsent(intValue, (i) -> new Int(i));
+         }
+ 
+         @Override
+         public int compareTo(Int o) {
+             return Integer.compare(intValue, o.intValue);
+         }
+     }
+ 
      void mapsEqual(Map m1, Map m2) {
          equal(m1, m2);
          equal(m2, m1);
          equal(m1.size(), m2.size());
          equal(m1.isEmpty(), m2.isEmpty());

@@ -110,19 +127,19 @@
                  new WeakHashMap(16),
                  new Hashtable(16),
                  new TreeMap(),
                  new ConcurrentHashMap(16),
                  new ConcurrentSkipListMap(),
-                 Collections.checkedMap(new HashMap(16), Integer.class, Integer.class),
-                 Collections.checkedSortedMap(new TreeMap(), Integer.class, Integer.class),
-                 Collections.checkedNavigableMap(new TreeMap(), Integer.class, Integer.class),
+                 Collections.checkedMap(new HashMap(16), Int.class, Integer.class),
+                 Collections.checkedSortedMap(new TreeMap(), Int.class, Integer.class),
+                 Collections.checkedNavigableMap(new TreeMap(), Int.class, Integer.class),
                  Collections.synchronizedMap(new HashMap(16)),
                  Collections.synchronizedSortedMap(new TreeMap()),
                  Collections.synchronizedNavigableMap(new TreeMap()));
  
              for (int j = 0; j < 10; j++)
-                 put(maps, r.nextInt(100), r.nextInt(100));
+                 put(maps, Int.intern(r.nextInt(100)), r.nextInt(100));
              removeLastTwo(maps);
          }
      }
  
      //--------------------- Infrastructure ---------------------------