1 /*
2 * Copyright (c) 2018, 2025, 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 package jdk.jfr.event.oldobject;
25
26 import java.lang.reflect.Modifier;
27 import java.util.HashSet;
28 import java.util.List;
29 import java.util.Set;
30
31 import jdk.jfr.Recording;
32 import jdk.jfr.consumer.RecordedEvent;
33 import jdk.jfr.consumer.RecordedObject;
34 import jdk.jfr.internal.test.WhiteBox;
35 import jdk.test.lib.Asserts;
36 import jdk.test.lib.jfr.EventNames;
37 import jdk.test.lib.jfr.Events;
38
39 /**
40 * @test
41 * @requires vm.flagless
42 * @requires vm.hasJFR
43 * @requires !(vm.opt.final.UseCompactObjectHeaders == true | vm.opt.final.UseShenandoahGC == true)
44 * @library /test/lib /test/jdk
45 * @modules jdk.jfr/jdk.jfr.internal.test
46 * @run main/othervm -XX:TLABSize=2k -Xlog:gc+tlab=trace jdk.jfr.event.oldobject.TestFieldInformation
47 */
48 public class TestFieldInformation {
49
50 public static final Object[] testField = new Object[50];
51
52 public static void main(String[] args) throws Exception {
53 WhiteBox.setWriteAllObjectSamples(true);
54
55 try (Recording recording = new Recording()) {
56 recording.enable(EventNames.OldObjectSample).withoutStackTrace().with("cutoff", "infinity");
57 recording.start();
58
59 addToTestField();
60
61 recording.stop();
62
63 List<RecordedEvent> events = Events.fromRecording(recording);
64 Events.hasEvents(events);
65 for (RecordedEvent e : events) {
66 if (hasValidField(e)) {
67 return;
68 }
69 }
70 System.out.println(events);
71 Asserts.fail("Could not find old object with field 'testField'");
72 }
73 }
74
75 private static boolean hasValidField(RecordedEvent e) throws Exception {
76 RecordedObject object = e.getValue("object");
77 Set<Long> visited = new HashSet<>();
78 while (object != null) {
79 Long address = object.getValue("address");
80 if (visited.contains(address)) {
81 return false;
82 }
83 visited.add(address);
84 RecordedObject referrer = object.getValue("referrer");
85 RecordedObject fieldObject = referrer != null ? referrer.getValue("field") : null;
86 if (fieldObject != null) {
87 String name = fieldObject.getValue("name");
88 if (name != null && name.equals("testField")) {
89 int modifiers = (short) fieldObject.getValue("modifiers");
90 if (!Modifier.isStatic(modifiers)) {
91 throw new Exception("Field should be static");
92 }
93 if (!Modifier.isPublic(modifiers)) {
94 throw new Exception("Field should be private");
95 }
96 if (!Modifier.isFinal(modifiers)) {
97 throw new Exception("Field should be final");
98 }
99 if (Modifier.isTransient(modifiers)) {
100 throw new Exception("Field should not be transient");
101 }
102 if (Modifier.isVolatile(modifiers)) {
103 throw new Exception("Field should not be volatile");
104 }
105 return true;
106 }
107 }
108 object = referrer != null ? referrer.getValue("object") : null;
109 }
110 return false;
111 }
112
113 private static void addToTestField() {
114 for (int i = 0; i < testField.length; i++) {
115 // Allocate array to trigger sampling code path for interpreter / c1
116 testField[i] = new Object[1_000_000];
117 }
118 }
119 }