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 8003985
44 * @summary Support Contended Annotation - JEP 142
45 * @modules java.base/sun.misc
46 * @run main/othervm -XX:-RestrictContended Basic
47 */
48 public class Basic {
49
50 private static final Unsafe U;
51 private static int ADDRESS_SIZE;
52 private static int HEADER_SIZE;
53
54 static {
55 // steal Unsafe
56 try {
57 Field unsafe = Unsafe.class.getDeclaredField("theUnsafe");
58 unsafe.setAccessible(true);
59 U = (Unsafe) unsafe.get(null);
60 } catch (NoSuchFieldException | IllegalAccessException e) {
61 throw new IllegalStateException(e);
62 }
63
64 // When running with CompressedOops on 64-bit platform, the address size
65 // reported by Unsafe is still 8, while the real reference fields are 4 bytes long.
66 // Try to guess the reference field size with this naive trick.
67 try {
68 long off1 = U.objectFieldOffset(CompressedOopsClass.class.getField("obj1"));
69 long off2 = U.objectFieldOffset(CompressedOopsClass.class.getField("obj2"));
70 ADDRESS_SIZE = (int) Math.abs(off2 - off1);
71 HEADER_SIZE = (int) Math.min(off1, off2);
72 } catch (NoSuchFieldException e) {
73 ADDRESS_SIZE = -1;
74 }
75 }
76
77 static class CompressedOopsClass {
78 public Object obj1;
79 public Object obj2;
80 }
81
82 public static boolean arePaddedPairwise(Class klass, String field1, String field2) throws Exception {
83 Field f1 = klass.getDeclaredField(field1);
84 Field f2 = klass.getDeclaredField(field2);
85
86 if (isStatic(f1) != isStatic(f2)) {
87 return true; // these guys are in naturally disjoint locations
88 }
89
90 int diff = offset(f1) - offset(f2);
91 if (diff < 0) {
92 // f1 is first
93 return (offset(f2) - (offset(f1) + getSize(f1))) > 64;
94 } else {
95 // f2 is first
96 return (offset(f1) - (offset(f2) + getSize(f2))) > 64;
97 }
98 }
99
100 public static boolean isPadded(Class klass, String field1) throws Exception {
101 Field f1 = klass.getDeclaredField(field1);
102
103 if (isStatic(f1)) {
104 return offset(f1) > 128 + 64;
105 }
106
107 return offset(f1) > 64;
108 }
109
110 public static boolean sameLayout(Class klass1, Class klass2) throws Exception {
111 for (Field f1 : klass1.getDeclaredFields()) {
112 Field f2 = klass2.getDeclaredField(f1.getName());
113 if (offset(f1) != offset(f2)) {
114 return false;
115 }
116 }
117
118 for (Field f2 : klass1.getDeclaredFields()) {
119 Field f1 = klass2.getDeclaredField(f2.getName());
120 if (offset(f1) != offset(f2)) {
121 return false;
122 }
123 }
124
125 return true;
126 }
127
128 public static boolean isStatic(Field field) {
129 return Modifier.isStatic(field.getModifiers());
130 }
131
132 public static int offset(Field field) {
133 if (isStatic(field)) {
134 return (int) U.staticFieldOffset(field);
135 } else {
136 return (int) U.objectFieldOffset(field);
137 }
138 }
139
140 public static int getSize(Field field) {
141 Class type = field.getType();
142 if (type == byte.class) { return 1; }
143 if (type == boolean.class) { return 1; }
144 if (type == short.class) { return 2; }
145 if (type == char.class) { return 2; }
146 if (type == int.class) { return 4; }
147 if (type == float.class) { return 4; }
148 if (type == long.class) { return 8; }
149 if (type == double.class) { return 8; }
150 return ADDRESS_SIZE;
151 }
152
153 public static void main(String[] args) throws Exception {
154 boolean endResult = true;
155
156 // --------------- INSTANCE FIELDS ---------------------
157
158 if (arePaddedPairwise(Test1.class, "int1", "int2") ||
159 isPadded(Test1.class, "int1") ||
160 isPadded(Test1.class, "int2")) {
161 System.err.println("Test1 failed");
162 endResult &= false;
163 }
164
165 if (!arePaddedPairwise(Test2.class, "int1", "int2") ||
166 !isPadded(Test2.class, "int1") ||
167 isPadded(Test2.class, "int2")) {
168 System.err.println("Test2 failed");
169 endResult &= false;
170 }
171
172 if (!arePaddedPairwise(Test3.class, "int1", "int2") ||
173 !isPadded(Test3.class, "int1") ||
174 !isPadded(Test3.class, "int2")) {
175 System.err.println("Test3 failed");
176 endResult &= false;
177 }
178
179 if (arePaddedPairwise(Test4.class, "int1", "int2") ||
180 !isPadded(Test4.class, "int1") ||
181 !isPadded(Test4.class, "int2")) {
182 System.err.println("Test4 failed");
183 endResult &= false;
184 }
185
186 if (!arePaddedPairwise(Test5.class, "int1", "int2") ||
187 !isPadded(Test5.class, "int1") ||
188 !isPadded(Test5.class, "int2")) {
189 System.err.println("Test5 failed");
190 endResult &= false;
191 }
192
193 if (!arePaddedPairwise(Test6.class, "int1", "int2") ||
194 !isPadded(Test6.class, "int1") ||
195 !isPadded(Test6.class, "int2")) {
196 System.err.println("Test6 failed");
197 endResult &= false;
198 }
199
200 if (arePaddedPairwise(Test7.class, "int1", "int2") ||
201 !isPadded(Test7.class, "int1") ||
202 !isPadded(Test7.class, "int2")) {
203 System.err.println("Test7 failed");
204 endResult &= false;
205 }
206
207 if (!arePaddedPairwise(Test8.class, "int1", "int2") ||
208 !isPadded(Test8.class, "int1") ||
209 !isPadded(Test8.class, "int2")) {
210 System.err.println("Test8 failed");
211 endResult &= false;
212 }
213
214 if (!arePaddedPairwise(Test9.class, "int1", "int2") ||
215 !isPadded(Test9.class, "int1") ||
216 !isPadded(Test9.class, "int2")) {
217 System.err.println("Test9 failed");
218 endResult &= false;
219 }
220
221 if (!sameLayout(Test4.class, Test7.class)) {
222 System.err.println("Test4 and Test7 have different layouts");
223 endResult &= false;
224 }
225
226 if (!sameLayout(Test5.class, Test6.class)) {
227 System.err.println("Test5 and Test6 have different layouts");
228 endResult &= false;
229 }
230
231 if (!sameLayout(Test8.class, Test9.class)) {
232 System.err.println("Test8 and Test9 have different layouts");
233 endResult &= false;
234 }
235
236 System.out.println(endResult ? "Test PASSES" : "Test FAILS");
237 if (!endResult) {
238 throw new Error("Test failed");
239 }
240 }
241
242 // ----------------------------------- INSTANCE FIELDS -----------------------------------------
243
244 // naturally packed
245 public static class Test1 {
246 private int int1;
247 private int int2;
248 }
249
250 // int1 is padded
251 public static class Test2 {
252 @Contended private int int1;
253 private int int2;
254 }
255
256 // both fields are padded
257 public static class Test3 {
258 @Contended private int int1;
259 @Contended private int int2;
260 }
261
262 // fields are padded in the singular group
263 public static class Test4 {
264 @Contended("sameGroup") private int int1;
265 @Contended("sameGroup") private int int2;
266 }
267
268 // fields are padded in disjoint groups
269 public static class Test5 {
270 @Contended("diffGroup1") private int int1;
271 @Contended("diffGroup2") private int int2;
272 }
273
274 // fields are padded in disjoint groups
275 public static class Test6 {
276 @Contended private int int1;
277 @Contended("diffGroup2") private int int2;
278 }
279
280 // fields are padded in the singular group
281 @Contended
282 public static class Test7 {
283 private int int1;
284 private int int2;
285 }
286
287 // all fields are padded as the group, and one field is padded specifically
288 @Contended
289 public static class Test8 {
290 @Contended private int int1;
291 private int int2;
292 }
293
294 // all fields are padded as the group, and one field is padded specifically
295 @Contended
296 public static class Test9 {
297 @Contended("group") private int int1;
298 private int int2;
299 }
300
301 }
302