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