1 /*
2 * Copyright (c) 2017, 2021, Red Hat, Inc. All rights reserved.
3 * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 /*
27 * @test id=passive
28 * @summary Test Shenandoah string deduplication implementation
29 * @key randomness
30 * @requires vm.gc.Shenandoah
31 * @library /test/lib
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 id=generational
48 * @summary Test Shenandoah string deduplication implementation
49 * @key randomness
50 * @requires vm.gc.Shenandoah
51 * @library /test/lib
52 * @modules java.base/java.lang:open
53 * java.management
54 *
55 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
56 * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=generational
57 * -XX:+ShenandoahDegeneratedGC
58 * -DtargetStrings=3000000
59 * TestStringDedupStress
60 */
61
62 /*
63 * @test id=default
64 * @summary Test Shenandoah string deduplication implementation
65 * @key randomness
66 * @requires vm.gc.Shenandoah
67 * @library /test/lib
68 * @modules java.base/java.lang:open
69 * java.management
70 *
71 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
72 * -XX:+UseShenandoahGC
73 * -DtargetStrings=3000000
74 * TestStringDedupStress
75 *
76 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
77 * -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive
78 * -DtargetStrings=2000000
79 * TestStringDedupStress
80 *
81 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
82 * -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive
83 * -XX:+ShenandoahOOMDuringEvacALot
84 * -DtargetStrings=2000000
85 * TestStringDedupStress
86 *
87 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
88 * -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=compact
89 * TestStringDedupStress
90 */
91
92 /*
93 * @test id=iu
94 * @summary Test Shenandoah string deduplication implementation
95 * @key randomness
96 * @requires vm.gc.Shenandoah
97 * @library /test/lib
98 * @modules java.base/java.lang:open
99 * java.management
100 *
101 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
102 * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=iu
103 * TestStringDedupStress
104 *
105 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
106 * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=iu -XX:ShenandoahGCHeuristics=aggressive
107 * -DtargetStrings=2000000
108 * TestStringDedupStress
109 *
110 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
111 * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=iu
112 * -XX:+ShenandoahOOMDuringEvacALot
113 * -DtargetStrings=2000000
114 * TestStringDedupStress
115 *
116 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
117 * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=iu -XX:ShenandoahGCHeuristics=aggressive
118 * -XX:+ShenandoahOOMDuringEvacALot
119 * -DtargetStrings=2000000
120 * TestStringDedupStress
121 */
122
123 import java.lang.management.*;
124 import java.lang.reflect.*;
125 import java.util.*;
126 import jdk.test.lib.Utils;
127
128 public class TestStringDedupStress {
129 private static Field valueField;
130
131 private static final int TARGET_STRINGS = Integer.getInteger("targetStrings", 2_500_000);
132 private static final long MAX_REWRITE_GC_CYCLES = 6;
133 private static final long MAX_REWRITE_TIME_NS = 30L * 1_000_000_000L; // 30s in ns
134
135 private static final int UNIQUE_STRINGS = 20;
136
137 static {
138 try {
139 valueField = String.class.getDeclaredField("value");
140 valueField.setAccessible(true);
141 } catch (Exception e) {
142 throw new RuntimeException(e);
143 }
144 }
145
146 private static Object getValue(String string) {
147 try {
148 return valueField.get(string);
149 } catch (Exception e) {
150 throw new RuntimeException(e);
151 }
152 }
153
154 static class StringAndId {
155 private String str;
156 private int id;
157
158 public StringAndId(String str, int id) {
159 this.str = str;
160 this.id = id;
161 }
162
163 public String str() {
164 return str;
165 }
166
167 public int id() {
168 return id;
169 }
170 }
171
172 // Generate uniqueStrings number of strings
173 private static void generateStrings(ArrayList<StringAndId> strs, int uniqueStrings) {
174 Random rn = Utils.getRandomInstance();
175 for (int u = 0; u < uniqueStrings; u++) {
176 int n = rn.nextInt(uniqueStrings);
177 strs.add(new StringAndId("Unique String " + n, n));
178 }
179 }
180
181 private static int verifyDedupString(ArrayList<StringAndId> strs) {
182 Map<Object, StringAndId> seen = new HashMap<>(TARGET_STRINGS*2);
183 int total = 0;
184 int dedup = 0;
185
186 for (StringAndId item : strs) {
187 total++;
188 StringAndId existingItem = seen.get(getValue(item.str()));
189 if (existingItem == null) {
190 seen.put(getValue(item.str()), item);
191 } else {
192 if (item.id() != existingItem.id() ||
193 !item.str().equals(existingItem.str())) {
194 System.out.println("StringDedup error:");
195 System.out.println("id: " + item.id() + " != " + existingItem.id());
196 System.out.println("or String: " + item.str() + " != " + existingItem.str());
197 throw new RuntimeException("StringDedup Test failed");
198 } else {
199 dedup++;
200 }
201 }
202 }
203 System.out.println("Dedup: " + dedup + "/" + total + " unique: " + (total - dedup));
204 return (total - dedup);
205 }
206
207 static volatile ArrayList<StringAndId> astrs = new ArrayList<>();
208 static GarbageCollectorMXBean gcCycleMBean;
209
210 public static void main(String[] args) {
211 Random rn = Utils.getRandomInstance();
212
213 for (GarbageCollectorMXBean bean : ManagementFactory.getGarbageCollectorMXBeans()) {
214 if ("Shenandoah Cycles".equals(bean.getName())) {
215 gcCycleMBean = bean;
216 break;
217 }
218 }
219
220 if (gcCycleMBean == null) {
221 throw new RuntimeException("Can not find Shenandoah GC cycle mbean");
222 }
223
224 // Generate roughly TARGET_STRINGS strings, only UNIQUE_STRINGS are unique
225 int genIters = TARGET_STRINGS / UNIQUE_STRINGS;
226 for (int index = 0; index < genIters; index++) {
227 generateStrings(astrs, UNIQUE_STRINGS);
228 }
229
230 long cycleBeforeRewrite = gcCycleMBean.getCollectionCount();
231 long timeBeforeRewriteNanos = System.nanoTime();
232
233 long loop = 1;
234 while (true) {
235 int arrSize = astrs.size();
236 int index = rn.nextInt(arrSize);
237 StringAndId item = astrs.get(index);
238 int n = rn.nextInt(UNIQUE_STRINGS);
239 item.str = "Unique String " + n;
240 item.id = n;
241
242 if (loop++ % 1000 == 0) {
243 // enough GC cycles for rewritten strings to be deduplicated
244 if (gcCycleMBean.getCollectionCount() - cycleBeforeRewrite >= MAX_REWRITE_GC_CYCLES) {
245 break;
246 }
247
248 // enough time is spent waiting for GC to happen
249 if (System.nanoTime() - timeBeforeRewriteNanos >= MAX_REWRITE_TIME_NS) {
250 break;
251 }
252 }
253 }
254 verifyDedupString(astrs);
255 }
256 }