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 8003985
44 * @summary Support Contended Annotation - JEP 142
45 * @modules java.base/jdk.internal.misc
46 * @modules java.base/jdk.internal.vm.annotation
47 * @run main/othervm -XX:-RestrictContended Basic
48 */
49 public class Basic {
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.getDeclaredField(field1);
85 Field f2 = klass.getDeclaredField(field2);
86
87 if (isStatic(f1) != isStatic(f2)) {
88 return true; // these guys are in naturally disjoint locations
89 }
90
91 int diff = offset(f1) - offset(f2);
92 if (diff < 0) {
93 // f1 is first
94 return (offset(f2) - (offset(f1) + getSize(f1))) > 64;
95 } else {
96 // f2 is first
97 return (offset(f1) - (offset(f2) + getSize(f2))) > 64;
98 }
99 }
100
101 public static boolean isPadded(Class klass, String field1) throws Exception {
102 Field f1 = klass.getDeclaredField(field1);
103
104 if (isStatic(f1)) {
105 return offset(f1) > 128 + 64;
106 }
107
108 return offset(f1) > 64;
109 }
110
111 public static boolean sameLayout(Class klass1, Class klass2) throws Exception {
112 for (Field f1 : klass1.getDeclaredFields()) {
113 Field f2 = klass2.getDeclaredField(f1.getName());
114 if (offset(f1) != offset(f2)) {
115 return false;
116 }
117 }
118
119 for (Field f2 : klass1.getDeclaredFields()) {
120 Field f1 = klass2.getDeclaredField(f2.getName());
121 if (offset(f1) != offset(f2)) {
122 return false;
123 }
124 }
125
126 return true;
127 }
128
129 public static boolean isStatic(Field field) {
130 return Modifier.isStatic(field.getModifiers());
131 }
132
133 public static int offset(Field field) {
134 if (isStatic(field)) {
135 return (int) U.staticFieldOffset(field);
136 } else {
137 return (int) U.objectFieldOffset(field);
138 }
139 }
140
141 public static int getSize(Field field) {
142 Class type = field.getType();
143 if (type == byte.class) { return 1; }
144 if (type == boolean.class) { return 1; }
145 if (type == short.class) { return 2; }
146 if (type == char.class) { return 2; }
147 if (type == int.class) { return 4; }
148 if (type == float.class) { return 4; }
149 if (type == long.class) { return 8; }
150 if (type == double.class) { return 8; }
151 return ADDRESS_SIZE;
152 }
153
154 public static void main(String[] args) throws Exception {
155 boolean endResult = true;
156
157 // --------------- INSTANCE FIELDS ---------------------
158
159 if (arePaddedPairwise(Test1.class, "int1", "int2") ||
160 isPadded(Test1.class, "int1") ||
161 isPadded(Test1.class, "int2")) {
162 System.err.println("Test1 failed");
163 endResult &= false;
164 }
165
166 if (!arePaddedPairwise(Test2.class, "int1", "int2") ||
167 !isPadded(Test2.class, "int1") ||
168 isPadded(Test2.class, "int2")) {
169 System.err.println("Test2 failed");
170 endResult &= false;
171 }
172
173 if (!arePaddedPairwise(Test3.class, "int1", "int2") ||
174 !isPadded(Test3.class, "int1") ||
175 !isPadded(Test3.class, "int2")) {
176 System.err.println("Test3 failed");
177 endResult &= false;
178 }
179
180 if (arePaddedPairwise(Test4.class, "int1", "int2") ||
181 !isPadded(Test4.class, "int1") ||
182 !isPadded(Test4.class, "int2")) {
183 System.err.println("Test4 failed");
184 endResult &= false;
185 }
186
187 if (!arePaddedPairwise(Test5.class, "int1", "int2") ||
188 !isPadded(Test5.class, "int1") ||
189 !isPadded(Test5.class, "int2")) {
190 System.err.println("Test5 failed");
191 endResult &= false;
192 }
193
194 if (!arePaddedPairwise(Test6.class, "int1", "int2") ||
195 !isPadded(Test6.class, "int1") ||
196 !isPadded(Test6.class, "int2")) {
197 System.err.println("Test6 failed");
198 endResult &= false;
199 }
200
201 if (arePaddedPairwise(Test7.class, "int1", "int2") ||
202 !isPadded(Test7.class, "int1") ||
203 !isPadded(Test7.class, "int2")) {
204 System.err.println("Test7 failed");
205 endResult &= false;
206 }
207
208 if (!arePaddedPairwise(Test8.class, "int1", "int2") ||
209 !isPadded(Test8.class, "int1") ||
210 !isPadded(Test8.class, "int2")) {
211 System.err.println("Test8 failed");
212 endResult &= false;
213 }
214
215 if (!arePaddedPairwise(Test9.class, "int1", "int2") ||
216 !isPadded(Test9.class, "int1") ||
217 !isPadded(Test9.class, "int2")) {
218 System.err.println("Test9 failed");
219 endResult &= false;
220 }
221
222 if (!sameLayout(Test4.class, Test7.class)) {
223 System.err.println("Test4 and Test7 have different layouts");
224 endResult &= false;
225 }
226
227 if (!sameLayout(Test5.class, Test6.class)) {
228 System.err.println("Test5 and Test6 have different layouts");
229 endResult &= false;
230 }
231
232 if (!sameLayout(Test8.class, Test9.class)) {
233 System.err.println("Test8 and Test9 have different layouts");
234 endResult &= false;
235 }
236
237 System.out.println(endResult ? "Test PASSES" : "Test FAILS");
238 if (!endResult) {
239 throw new Error("Test failed");
240 }
241 }
242
243 // ----------------------------------- INSTANCE FIELDS -----------------------------------------
244
245 // naturally packed
246 public static class Test1 {
247 private int int1;
248 private int int2;
249 }
250
251 // int1 is padded
252 public static class Test2 {
253 @Contended private int int1;
254 private int int2;
255 }
256
257 // both fields are padded
258 public static class Test3 {
259 @Contended private int int1;
260 @Contended private int int2;
261 }
262
263 // fields are padded in the singular group
264 public static class Test4 {
265 @Contended("sameGroup") private int int1;
266 @Contended("sameGroup") private int int2;
267 }
268
269 // fields are padded in disjoint groups
270 public static class Test5 {
271 @Contended("diffGroup1") private int int1;
272 @Contended("diffGroup2") private int int2;
273 }
274
275 // fields are padded in disjoint groups
276 public static class Test6 {
277 @Contended private int int1;
278 @Contended("diffGroup2") private int int2;
279 }
280
281 // fields are padded in the singular group
282 @Contended
283 public static class Test7 {
284 private int int1;
285 private int int2;
286 }
287
288 // all fields are padded as the group, and one field is padded specifically
289 @Contended
290 public static class Test8 {
291 @Contended private int int1;
292 private int int2;
293 }
294
295 // all fields are padded as the group, and one field is padded specifically
296 @Contended
297 public static class Test9 {
298 @Contended("group") private int int1;
299 private int int2;
300 }
301
302 }
303