1 /*
2 * Copyright (c) 2017, 2021, 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 id=passive
27 * @summary Test Shenandoah string deduplication implementation
28 * @key randomness
29 * @requires vm.gc.Shenandoah
30 * @library /test/lib
31 * @modules java.base/java.lang:open
32 * java.management
33 *
34 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
35 * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=passive
36 * -XX:+ShenandoahDegeneratedGC
37 * TestStringDedupStress
38 *
39 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
40 * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=passive
41 * -XX:-ShenandoahDegeneratedGC
42 * TestStringDedupStress
43 */
44
45 /*
46 * @test id=default
47 * @summary Test Shenandoah string deduplication implementation
48 * @key randomness
49 * @requires vm.gc.Shenandoah
50 * @library /test/lib
51 * @modules java.base/java.lang:open
52 * java.management
53 *
54 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
55 * -XX:+UseShenandoahGC
56 * -DtargetStrings=3000000
57 * TestStringDedupStress
58 *
59 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
60 * -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive
61 * -DtargetStrings=2000000
62 * TestStringDedupStress
63 *
64 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
65 * -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive
66 * -XX:+ShenandoahOOMDuringEvacALot
67 * -DtargetStrings=2000000
68 * TestStringDedupStress
69 *
70 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
71 * -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=compact
72 * TestStringDedupStress
73 */
74
75 /*
76 * @test id=iu
77 * @summary Test Shenandoah string deduplication implementation
78 * @key randomness
79 * @requires vm.gc.Shenandoah
80 * @library /test/lib
81 * @modules java.base/java.lang:open
82 * java.management
83 *
84 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
85 * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=iu
86 * TestStringDedupStress
87 *
88 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
89 * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=iu -XX:ShenandoahGCHeuristics=aggressive
90 * -DtargetStrings=2000000
91 * TestStringDedupStress
92 *
93 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
94 * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=iu
95 * -XX:+ShenandoahOOMDuringEvacALot
96 * -DtargetStrings=2000000
97 * TestStringDedupStress
98 *
99 * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
100 * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=iu -XX:ShenandoahGCHeuristics=aggressive
101 * -XX:+ShenandoahOOMDuringEvacALot
102 * -DtargetStrings=2000000
103 * TestStringDedupStress
104 */
105
106 import java.lang.management.*;
107 import java.lang.reflect.*;
108 import java.util.*;
109 import jdk.test.lib.Utils;
110
111 public class TestStringDedupStress {
112 private static Field valueField;
113
114 private static final int TARGET_STRINGS = Integer.getInteger("targetStrings", 2_500_000);
115 private static final long MAX_REWRITE_GC_CYCLES = 6;
116 private static final long MAX_REWRITE_TIME = 30*1000; // ms
117
118 private static final int UNIQUE_STRINGS = 20;
119
120 static {
121 try {
122 valueField = String.class.getDeclaredField("value");
123 valueField.setAccessible(true);
124 } catch (Exception e) {
125 throw new RuntimeException(e);
126 }
127 }
128
129 private static Object getValue(String string) {
130 try {
131 return valueField.get(string);
132 } catch (Exception e) {
133 throw new RuntimeException(e);
134 }
135 }
136
137 static class StringAndId {
138 private String str;
139 private int id;
140
141 public StringAndId(String str, int id) {
142 this.str = str;
143 this.id = id;
144 }
145
146 public String str() {
147 return str;
148 }
149
150 public int id() {
151 return id;
152 }
153 }
154
155 // Generate uniqueStrings number of strings
156 private static void generateStrings(ArrayList<StringAndId> strs, int uniqueStrings) {
157 Random rn = Utils.getRandomInstance();
158 for (int u = 0; u < uniqueStrings; u++) {
159 int n = rn.nextInt(uniqueStrings);
160 strs.add(new StringAndId("Unique String " + n, n));
161 }
162 }
163
164 private static int verifyDedupString(ArrayList<StringAndId> strs) {
165 Map<Object, StringAndId> seen = new HashMap<>(TARGET_STRINGS*2);
166 int total = 0;
167 int dedup = 0;
168
169 for (StringAndId item : strs) {
170 total++;
171 StringAndId existingItem = seen.get(getValue(item.str()));
172 if (existingItem == null) {
173 seen.put(getValue(item.str()), item);
174 } else {
175 if (item.id() != existingItem.id() ||
176 !item.str().equals(existingItem.str())) {
177 System.out.println("StringDedup error:");
178 System.out.println("id: " + item.id() + " != " + existingItem.id());
179 System.out.println("or String: " + item.str() + " != " + existingItem.str());
180 throw new RuntimeException("StringDedup Test failed");
181 } else {
182 dedup++;
183 }
184 }
185 }
186 System.out.println("Dedup: " + dedup + "/" + total + " unique: " + (total - dedup));
187 return (total - dedup);
188 }
189
190 static volatile ArrayList<StringAndId> astrs = new ArrayList<>();
191 static GarbageCollectorMXBean gcCycleMBean;
192
193 public static void main(String[] args) {
194 Random rn = Utils.getRandomInstance();
195
196 for (GarbageCollectorMXBean bean : ManagementFactory.getGarbageCollectorMXBeans()) {
197 if ("Shenandoah Cycles".equals(bean.getName())) {
198 gcCycleMBean = bean;
199 break;
200 }
201 }
202
203 if (gcCycleMBean == null) {
204 throw new RuntimeException("Can not find Shenandoah GC cycle mbean");
205 }
206
207 // Generate roughly TARGET_STRINGS strings, only UNIQUE_STRINGS are unique
208 int genIters = TARGET_STRINGS / UNIQUE_STRINGS;
209 for (int index = 0; index < genIters; index++) {
210 generateStrings(astrs, UNIQUE_STRINGS);
211 }
212
213 long cycleBeforeRewrite = gcCycleMBean.getCollectionCount();
214 long timeBeforeRewrite = System.currentTimeMillis();
215
216 long loop = 1;
217 while (true) {
218 int arrSize = astrs.size();
219 int index = rn.nextInt(arrSize);
220 StringAndId item = astrs.get(index);
221 int n = rn.nextInt(UNIQUE_STRINGS);
222 item.str = "Unique String " + n;
223 item.id = n;
224
225 if (loop++ % 1000 == 0) {
226 // enough GC cycles for rewritten strings to be deduplicated
227 if (gcCycleMBean.getCollectionCount() - cycleBeforeRewrite >= MAX_REWRITE_GC_CYCLES) {
228 break;
229 }
230
231 // enough time is spent waiting for GC to happen
232 if (System.currentTimeMillis() - timeBeforeRewrite >= MAX_REWRITE_TIME) {
233 break;
234 }
235 }
236 }
237 verifyDedupString(astrs);
238 }
239 }