1 /*
2 * Copyright (c) 2013, 2015, 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 import java.io.BufferedReader;
25 import java.io.InputStreamReader;
26 import java.lang.Class;
27 import java.lang.String;
28 import java.lang.System;
29 import java.lang.management.ManagementFactory;
30 import java.lang.management.RuntimeMXBean;
31 import java.util.ArrayList;
32 import java.util.List;
33 import java.util.concurrent.CyclicBarrier;
34 import java.util.regex.Matcher;
35 import java.util.regex.Pattern;
36 import java.lang.reflect.Field;
37 import java.lang.reflect.Modifier;
38 import sun.misc.Unsafe;
39 import jdk.internal.vm.annotation.Contended;
40
41 /*
42 * @test
43 * @bug 8014509
44 * @summary \@Contended: explicit default value behaves differently from the implicit value
45 *
46 * @modules java.base/jdk.internal.vm.annotation
47 * @run main/othervm -XX:-RestrictContended DefaultValue
48 */
49 public class DefaultValue {
50
51 private static final Unsafe U;
52 private static int ADDRESS_SIZE;
53 private static int HEADER_SIZE;
54
55 static {
56 // steal Unsafe
57 try {
58 Field unsafe = Unsafe.class.getDeclaredField("theUnsafe");
59 unsafe.setAccessible(true);
60 U = (Unsafe) unsafe.get(null);
61 } catch (NoSuchFieldException | IllegalAccessException e) {
62 throw new IllegalStateException(e);
63 }
64
65 // When running with CompressedOops on 64-bit platform, the address size
66 // reported by Unsafe is still 8, while the real reference fields are 4 bytes long.
67 // Try to guess the reference field size with this naive trick.
68 try {
69 long off1 = U.objectFieldOffset(CompressedOopsClass.class.getField("obj1"));
70 long off2 = U.objectFieldOffset(CompressedOopsClass.class.getField("obj2"));
71 ADDRESS_SIZE = (int) Math.abs(off2 - off1);
72 HEADER_SIZE = (int) Math.min(off1, off2);
73 } catch (NoSuchFieldException e) {
74 ADDRESS_SIZE = -1;
75 }
76 }
77
78 static class CompressedOopsClass {
79 public Object obj1;
80 public Object obj2;
81 }
82
83 public static boolean arePaddedPairwise(Class klass, String field1, String field2) throws Exception {
84 Field f1 = klass.getField(field1);
85 Field f2 = klass.getField(field2);
86
87 int diff = offset(f1) - offset(f2);
88 if (diff < 0) {
89 // f1 is first
90 return (offset(f2) - (offset(f1) + getSize(f1))) > 64;
91 } else {
92 // f2 is first
93 return (offset(f1) - (offset(f2) + getSize(f2))) > 64;
94 }
95 }
96
97 public static boolean sameLayout(Class klass1, Class klass2) throws Exception {
98 for (Field f1 : klass1.getDeclaredFields()) {
99 Field f2 = klass2.getDeclaredField(f1.getName());
100 if (offset(f1) != offset(f2)) {
101 return false;
102 }
103 }
104
105 for (Field f2 : klass1.getDeclaredFields()) {
106 Field f1 = klass2.getDeclaredField(f2.getName());
107 if (offset(f1) != offset(f2)) {
108 return false;
109 }
110 }
111
112 return true;
113 }
114
115 public static boolean isStatic(Field field) {
116 return Modifier.isStatic(field.getModifiers());
117 }
118
119 public static int offset(Field field) {
120 if (isStatic(field)) {
121 return (int) U.staticFieldOffset(field);
122 } else {
123 return (int) U.objectFieldOffset(field);
124 }
125 }
126
127 public static int getSize(Field field) {
128 Class type = field.getType();
129 if (type == byte.class) { return 1; }
130 if (type == boolean.class) { return 1; }
131 if (type == short.class) { return 2; }
132 if (type == char.class) { return 2; }
133 if (type == int.class) { return 4; }
134 if (type == float.class) { return 4; }
135 if (type == long.class) { return 8; }
136 if (type == double.class) { return 8; }
137 return ADDRESS_SIZE;
138 }
139
140 public static void main(String[] args) throws Exception {
141 boolean endResult = true;
142
143 if (!arePaddedPairwise(R1.class, "int1", "int2")) {
144 System.err.println("R1 failed");
145 endResult &= false;
146 }
147
148 if (!arePaddedPairwise(R2.class, "int1", "int2")) {
149 System.err.println("R2 failed");
150 endResult &= false;
151 }
152
153 if (!arePaddedPairwise(R3.class, "int1", "int2")) {
154 System.err.println("R3 failed");
155 endResult &= false;
156 }
157
158 System.out.println(endResult ? "Test PASSES" : "Test FAILS");
159 if (!endResult) {
160 throw new Error("Test failed");
161 }
162 }
163
164 public static class R1 {
165 @Contended
166 public int int1;
167 @Contended
168 public int int2;
169 }
170
171 public static class R2 {
172 @Contended("")
173 public int int1;
174 @Contended("")
175 public int int2;
176 }
177
178 public static class R3 {
179 @Contended()
180 public int int1;
181 @Contended()
182 public int int2;
183 }
184
185 }
186