1 /*
2 * Copyright (c) 2013, 2016, 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 jdk.internal.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.misc
47 * @modules java.base/jdk.internal.vm.annotation
48 * @run main/othervm -XX:-RestrictContended DefaultValue
49 */
50 public class DefaultValue {
51
52 private static final Unsafe U;
53 private static int ADDRESS_SIZE;
54 private static int HEADER_SIZE;
55
56 static {
57 // steal Unsafe
58 try {
59 Field unsafe = Unsafe.class.getDeclaredField("theUnsafe");
60 unsafe.setAccessible(true);
61 U = (Unsafe) unsafe.get(null);
62 } catch (NoSuchFieldException | IllegalAccessException e) {
63 throw new IllegalStateException(e);
64 }
65
66 // When running with CompressedOops on 64-bit platform, the address size
67 // reported by Unsafe is still 8, while the real reference fields are 4 bytes long.
68 // Try to guess the reference field size with this naive trick.
69 try {
70 long off1 = U.objectFieldOffset(CompressedOopsClass.class.getField("obj1"));
71 long off2 = U.objectFieldOffset(CompressedOopsClass.class.getField("obj2"));
72 ADDRESS_SIZE = (int) Math.abs(off2 - off1);
73 HEADER_SIZE = (int) Math.min(off1, off2);
74 } catch (NoSuchFieldException e) {
75 ADDRESS_SIZE = -1;
76 }
77 }
78
79 static class CompressedOopsClass {
80 public Object obj1;
81 public Object obj2;
82 }
83
84 public static boolean arePaddedPairwise(Class klass, String field1, String field2) throws Exception {
85 Field f1 = klass.getField(field1);
86 Field f2 = klass.getField(field2);
87
88 int diff = offset(f1) - offset(f2);
89 if (diff < 0) {
90 // f1 is first
91 return (offset(f2) - (offset(f1) + getSize(f1))) > 64;
92 } else {
93 // f2 is first
94 return (offset(f1) - (offset(f2) + getSize(f2))) > 64;
95 }
96 }
97
98 public static boolean sameLayout(Class klass1, Class klass2) throws Exception {
99 for (Field f1 : klass1.getDeclaredFields()) {
100 Field f2 = klass2.getDeclaredField(f1.getName());
101 if (offset(f1) != offset(f2)) {
102 return false;
103 }
104 }
105
106 for (Field f2 : klass1.getDeclaredFields()) {
107 Field f1 = klass2.getDeclaredField(f2.getName());
108 if (offset(f1) != offset(f2)) {
109 return false;
110 }
111 }
112
113 return true;
114 }
115
116 public static boolean isStatic(Field field) {
117 return Modifier.isStatic(field.getModifiers());
118 }
119
120 public static int offset(Field field) {
121 if (isStatic(field)) {
122 return (int) U.staticFieldOffset(field);
123 } else {
124 return (int) U.objectFieldOffset(field);
125 }
126 }
127
128 public static int getSize(Field field) {
129 Class type = field.getType();
130 if (type == byte.class) { return 1; }
131 if (type == boolean.class) { return 1; }
132 if (type == short.class) { return 2; }
133 if (type == char.class) { return 2; }
134 if (type == int.class) { return 4; }
135 if (type == float.class) { return 4; }
136 if (type == long.class) { return 8; }
137 if (type == double.class) { return 8; }
138 return ADDRESS_SIZE;
139 }
140
141 public static void main(String[] args) throws Exception {
142 boolean endResult = true;
143
144 if (!arePaddedPairwise(R1.class, "int1", "int2")) {
145 System.err.println("R1 failed");
146 endResult &= false;
147 }
148
149 if (!arePaddedPairwise(R2.class, "int1", "int2")) {
150 System.err.println("R2 failed");
151 endResult &= false;
152 }
153
154 if (!arePaddedPairwise(R3.class, "int1", "int2")) {
155 System.err.println("R3 failed");
156 endResult &= false;
157 }
158
159 System.out.println(endResult ? "Test PASSES" : "Test FAILS");
160 if (!endResult) {
161 throw new Error("Test failed");
162 }
163 }
164
165 public static class R1 {
166 @Contended
167 public int int1;
168 @Contended
169 public int int2;
170 }
171
172 public static class R2 {
173 @Contended("")
174 public int int1;
175 @Contended("")
176 public int int2;
177 }
178
179 public static class R3 {
180 @Contended()
181 public int int1;
182 @Contended()
183 public int int2;
184 }
185
186 }
187