1 /*
2 * Copyright (c) 2017, 2018, Red Hat, Inc. 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
25 /*
26 * @test TestStringDedupStress
27 * @summary Test Shenandoah string deduplication implementation
28 * @key randomness
29 * @requires vm.gc.Shenandoah & !vm.graal.enabled
30 * @library /test/lib
31 * @modules java.base/jdk.internal.misc:open
32 * @modules java.base/java.lang:open
33 * java.management
34 *
35 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
36 * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=passive
37 * -XX:+ShenandoahDegeneratedGC
38 * TestStringDedupStress
39 *
40 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
41 * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=passive
42 * -XX:-ShenandoahDegeneratedGC
43 * TestStringDedupStress
44 */
45
46 /*
47 * @test TestStringDedupStress
48 * @summary Test Shenandoah string deduplication implementation
49 * @key randomness
50 * @requires vm.gc.Shenandoah & !vm.graal.enabled
51 * @library /test/lib
52 * @modules java.base/jdk.internal.misc:open
53 * @modules java.base/java.lang:open
54 * java.management
55 *
56 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
57 * -XX:+UseShenandoahGC
58 * -DtargetStrings=3000000
59 * TestStringDedupStress
60 *
61 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
62 * -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive
63 * -DtargetStrings=2000000
64 * TestStringDedupStress
65 *
66 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
67 * -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive
68 * -XX:+ShenandoahOOMDuringEvacALot
69 * -DtargetStrings=2000000
70 * TestStringDedupStress
71 *
72 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
73 * -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=compact
74 * TestStringDedupStress
75 */
76
77 /*
78 * @test TestStringDedupStress
79 * @summary Test Shenandoah string deduplication implementation
80 * @key randomness
81 * @requires vm.gc.Shenandoah & !vm.graal.enabled
82 * @library /test/lib
83 * @modules java.base/jdk.internal.misc:open
84 * @modules java.base/java.lang:open
85 * java.management
86 *
87 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
88 * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=iu
89 * TestStringDedupStress
90 *
91 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
92 * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=iu -XX:ShenandoahGCHeuristics=aggressive
93 * -DtargetStrings=2000000
94 * TestStringDedupStress
95 *
96 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
97 * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=iu
98 * -XX:+ShenandoahOOMDuringEvacALot
99 * -DtargetStrings=2000000
100 * TestStringDedupStress
101 *
102 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
103 * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=iu -XX:ShenandoahGCHeuristics=aggressive
104 * -XX:+ShenandoahOOMDuringEvacALot
105 * -DtargetStrings=2000000
106 * TestStringDedupStress
107 */
108
109 import java.lang.management.*;
110 import java.lang.reflect.*;
111 import java.util.*;
112 import jdk.test.lib.Utils;
113
114 import sun.misc.*;
115
116 public class TestStringDedupStress {
117 private static Field valueField;
118 private static Unsafe unsafe;
119
120 private static final int TARGET_STRINGS = Integer.getInteger("targetStrings", 2_500_000);
121 private static final long MAX_REWRITE_GC_CYCLES = 6;
122 private static final long MAX_REWRITE_TIME = 30*1000; // ms
123
124 private static final int UNIQUE_STRINGS = 20;
125
126 static {
127 try {
128 Field field = Unsafe.class.getDeclaredField("theUnsafe");
129 field.setAccessible(true);
130 unsafe = (Unsafe) field.get(null);
131
132 valueField = String.class.getDeclaredField("value");
133 valueField.setAccessible(true);
134 } catch (Exception e) {
135 throw new RuntimeException(e);
136 }
137 }
138
139 private static Object getValue(String string) {
140 try {
141 return valueField.get(string);
142 } catch (Exception e) {
143 throw new RuntimeException(e);
144 }
145 }
146
147 static class StringAndId {
148 private String str;
149 private int id;
150
151 public StringAndId(String str, int id) {
152 this.str = str;
153 this.id = id;
154 }
155
156 public String str() {
157 return str;
158 }
159
160 public int id() {
161 return id;
162 }
163 }
164
165 // Generate uniqueStrings number of strings
166 private static void generateStrings(ArrayList<StringAndId> strs, int uniqueStrings) {
167 Random rn = Utils.getRandomInstance();
168 for (int u = 0; u < uniqueStrings; u++) {
169 int n = rn.nextInt(uniqueStrings);
170 strs.add(new StringAndId("Unique String " + n, n));
171 }
172 }
173
174 private static int verifyDedupString(ArrayList<StringAndId> strs) {
175 Map<Object, StringAndId> seen = new HashMap<>(TARGET_STRINGS*2);
176 int total = 0;
177 int dedup = 0;
178
179 for (StringAndId item : strs) {
180 total++;
181 StringAndId existingItem = seen.get(getValue(item.str()));
182 if (existingItem == null) {
183 seen.put(getValue(item.str()), item);
184 } else {
185 if (item.id() != existingItem.id() ||
186 !item.str().equals(existingItem.str())) {
187 System.out.println("StringDedup error:");
188 System.out.println("id: " + item.id() + " != " + existingItem.id());
189 System.out.println("or String: " + item.str() + " != " + existingItem.str());
190 throw new RuntimeException("StringDedup Test failed");
191 } else {
192 dedup++;
193 }
194 }
195 }
196 System.out.println("Dedup: " + dedup + "/" + total + " unique: " + (total - dedup));
197 return (total - dedup);
198 }
199
200 static volatile ArrayList<StringAndId> astrs = new ArrayList<>();
201 static GarbageCollectorMXBean gcCycleMBean;
202
203 public static void main(String[] args) {
204 Random rn = Utils.getRandomInstance();
205
206 for (GarbageCollectorMXBean bean : ManagementFactory.getGarbageCollectorMXBeans()) {
207 if ("Shenandoah Cycles".equals(bean.getName())) {
208 gcCycleMBean = bean;
209 break;
210 }
211 }
212
213 if (gcCycleMBean == null) {
214 throw new RuntimeException("Can not find Shenandoah GC cycle mbean");
215 }
216
217 // Generate roughly TARGET_STRINGS strings, only UNIQUE_STRINGS are unique
218 int genIters = TARGET_STRINGS / UNIQUE_STRINGS;
219 for (int index = 0; index < genIters; index++) {
220 generateStrings(astrs, UNIQUE_STRINGS);
221 }
222
223 long cycleBeforeRewrite = gcCycleMBean.getCollectionCount();
224 long timeBeforeRewrite = System.currentTimeMillis();
225
226 long loop = 1;
227 while (true) {
228 int arrSize = astrs.size();
229 int index = rn.nextInt(arrSize);
230 StringAndId item = astrs.get(index);
231 int n = rn.nextInt(UNIQUE_STRINGS);
232 item.str = "Unique String " + n;
233 item.id = n;
234
235 if (loop++ % 1000 == 0) {
236 // enough GC cycles for rewritten strings to be deduplicated
237 if (gcCycleMBean.getCollectionCount() - cycleBeforeRewrite >= MAX_REWRITE_GC_CYCLES) {
238 break;
239 }
240
241 // enough time is spent waiting for GC to happen
242 if (System.currentTimeMillis() - timeBeforeRewrite >= MAX_REWRITE_TIME) {
243 break;
244 }
245 }
246 }
247 verifyDedupString(astrs);
248 }
249 }