1 /*
2 * Copyright (c) 2025, 2026, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24 /*
25 * @test
26 * @bug 8368799
27 * @summary Verify heapwalking API does not report array classes several times.
28 * @requires vm.jvmti
29 * @modules java.base/jdk.internal.vm.annotation java.base/jdk.internal.value
30 * @enablePreview
31 * @run main/othervm/native -agentlib:HeapwalkDupClasses HeapwalkDupClasses
32 */
33
34 import java.lang.ref.Reference;
35 import jdk.internal.value.ValueClass;
36 import jdk.internal.vm.annotation.NullRestricted;
37
38 public class HeapwalkDupClasses {
39
40 static native int tagWithFollowReferences(long tag);
41 static native int tagWithIterateOverReachableObjects(long tag);
42 static native Object[] getObjectsWithTags(long tag);
43
44 public static void main(String[] args) throws Exception {
45 System.loadLibrary("HeapwalkDupClasses");
46
47 Integer instance = new Integer(0);
48 Object[] testObjects = new Object[] {
49 new Integer[5],
50 ValueClass.newNullableAtomicArray(Integer.class, 5),
51 ValueClass.newNullRestrictedNonAtomicArray(Integer.class, 5, instance)
52 };
53
54 for (long tag = 1; tag <= 2; tag++) {
55 int taggedClasses;
56 if (tag == 1) {
57 System.out.println("FollowReferences");
58 taggedClasses = tagWithFollowReferences(tag);
59 } else {
60 System.out.println("IterateOverReachableObjects");
61 taggedClasses = tagWithIterateOverReachableObjects(tag);
62 }
63 System.out.println("Tagged " + taggedClasses + " classes");
64
65 Object[] taggedObjects = getObjectsWithTags(tag);
66 System.out.println("Tagged objects (total " + taggedObjects.length + "):");
67
68 int duplicates = 0;
69 boolean foundTestObjectClass[] = new boolean[testObjects.length];
70
71 for (int i = 0; i < taggedObjects.length; i++) {
72 System.out.println("[" + i + "] " + taggedObjects[i]);
73 for (int j = 0; j < i; j++) {
74 if (taggedObjects[i].equals(taggedObjects[j])) {
75 duplicates++;
76 System.out.println(" ERROR: duplicate (" + j + ")");
77 }
78 }
79 for (int j = 0; j < testObjects.length; j++) {
80 if (taggedObjects[i].equals(testObjects[j].getClass())) {
81 foundTestObjectClass[j] = true;
82 System.out.println(" FOUND expected array class");
83 }
84 }
85 }
86 if (duplicates != 0) {
87 throw new RuntimeException("Found " + duplicates + " duplicate classes");
88 }
89 for (int i = 0; i < foundTestObjectClass.length; i++) {
90 if (!foundTestObjectClass[i]) {
91 throw new RuntimeException("Expected class not found: " + testObjects[i].getClass());
92 }
93 }
94 }
95 }
96 }