1 /*
2 * Copyright (c) 2017, 2018, Red Hat, Inc. All rights reserved.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation.
7 *
8 * This code is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
11 * version 2 for more details (a copy is included in the LICENSE file that
12 * accompanied this code).
13 *
14 * You should have received a copy of the GNU General Public License version
15 * 2 along with this work; if not, write to the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
17 *
18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
19 * or visit www.oracle.com if you need additional information or have any
20 * questions.
21 *
22 */
23
24 /*
25 * @test TestStringDedupStress
26 * @summary Test Shenandoah string deduplication implementation
27 * @key gc
28 * @requires vm.gc.Shenandoah
29 * @library /test/lib
30 * @modules java.base/jdk.internal.misc:open
31 * @modules java.base/java.lang:open
32 * java.management
33 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
34 * -DtargetStrings=3000000
35 * TestStringDedupStress
36 *
37 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
38 * -XX:ShenandoahGCHeuristics=aggressive -DtargetStrings=2000000
39 * TestStringDedupStress
40 *
41 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
42 * -XX:ShenandoahGCHeuristics=aggressive -XX:+ShenandoahOOMDuringEvacALot -DtargetStrings=2000000
43 * TestStringDedupStress
44 *
45 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
46 * -XX:ShenandoahGCHeuristics=static -DtargetStrings=4000000
47 * TestStringDedupStress
48 *
49 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
50 * -XX:ShenandoahGCHeuristics=compact
51 * TestStringDedupStress
52 *
53 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
54 * -XX:ShenandoahGCHeuristics=passive -XX:+ShenandoahDegeneratedGC -DtargetOverwrites=40000000
55 * TestStringDedupStress
56 *
57 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
58 * -XX:ShenandoahGCHeuristics=passive -XX:-ShenandoahDegeneratedGC -DtargetOverwrites=40000000
59 * TestStringDedupStress
60 *
61 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
62 * -XX:ShenandoahGCHeuristics=traversal
63 * TestStringDedupStress
64 *
65 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
66 * -XX:ShenandoahUpdateRefsEarly=off -DtargetStrings=3000000
67 * TestStringDedupStress
68 *
69 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
70 * -XX:ShenandoahGCHeuristics=compact -XX:ShenandoahUpdateRefsEarly=off -DtargetStrings=2000000
71 * TestStringDedupStress
72 *
73 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
74 * -XX:ShenandoahGCHeuristics=aggressive -XX:ShenandoahUpdateRefsEarly=off -DtargetStrings=2000000
75 * TestStringDedupStress
76 *
77 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
78 * -XX:ShenandoahGCHeuristics=static -XX:ShenandoahUpdateRefsEarly=off -DtargetOverwrites=4000000
79 * TestStringDedupStress
80 *
81 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
82 * -XX:ShenandoahGCHeuristics=aggressive -XX:ShenandoahUpdateRefsEarly=off -XX:+ShenandoahOOMDuringEvacALot -DtargetStrings=2000000
83 * TestStringDedupStress
84 *
85 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
86 * -XX:ShenandoahGCHeuristics=traversal -XX:+ShenandoahOOMDuringEvacALot -DtargetStrings=2000000
87 * TestStringDedupStress
88 */
89
90 import java.lang.management.*;
91 import java.lang.reflect.*;
92 import java.util.*;
93
94 import sun.misc.*;
95
96 public class TestStringDedupStress {
97 private static Field valueField;
98 private static Unsafe unsafe;
99
100 private static long TARGET_STRINGS = Long.getLong("targetStrings", 2_500_000);
101 private static long TARGET_OVERWRITES = Long.getLong("targetOverwrites", 600_000);
102 private static final long MAX_REWRITE_GC_CYCLES = 6;
103
104 private static final int UNIQUE_STRINGS = 20;
105
106 static {
107 try {
108 Field field = Unsafe.class.getDeclaredField("theUnsafe");
109 field.setAccessible(true);
110 unsafe = (Unsafe) field.get(null);
111
112 valueField = String.class.getDeclaredField("value");
113 valueField.setAccessible(true);
114 } catch (Exception e) {
115 throw new RuntimeException(e);
116 }
117 }
118
119 private static Object getValue(String string) {
120 try {
121 return valueField.get(string);
122 } catch (Exception e) {
123 throw new RuntimeException(e);
124 }
125 }
126
127 static class StringAndId {
128 private String str;
129 private int id;
130
131 public StringAndId(String str, int id) {
132 this.str = str;
133 this.id = id;
134 }
135
136 public String str() {
137 return str;
138 }
139
140 public int id() {
141 return id;
142 }
143 }
144
145 // Generate uniqueStrings number of strings
146 private static void generateStrings(ArrayList<StringAndId> strs, int uniqueStrings) {
147 Random rn = new Random();
148 for (int u = 0; u < uniqueStrings; u++) {
149 int n = rn.nextInt(uniqueStrings);
150 strs.add(new StringAndId("Unique String " + n, n));
151 }
152 }
153
154 private static int verifyDedepString(ArrayList<StringAndId> strs) {
155 HashMap<Object, StringAndId> seen = new HashMap<>();
156 int total = 0;
157 int dedup = 0;
158
159 for (StringAndId item : strs) {
160 total++;
161 StringAndId existingItem = seen.get(getValue(item.str()));
162 if (existingItem == null) {
163 seen.put(getValue(item.str()), item);
164 } else {
165 if (item.id() != existingItem.id() ||
166 !item.str().equals(existingItem.str())) {
167 System.out.println("StringDedup error:");
168 System.out.println("id: " + item.id() + " != " + existingItem.id());
169 System.out.println("or String: " + item.str() + " != " + existingItem.str());
170 throw new RuntimeException("StringDedup Test failed");
171 } else {
172 dedup++;
173 }
174 }
175 }
176 System.out.println("Dedup: " + dedup + "/" + total + " unique: " + (total - dedup));
177 return (total - dedup);
178 }
179
180 static volatile ArrayList<StringAndId> astrs = new ArrayList<>();
181 static GarbageCollectorMXBean gcCycleMBean;
182
183 public static void main(String[] args) {
184 Random rn = new Random();
185
186 for (GarbageCollectorMXBean bean : ManagementFactory.getGarbageCollectorMXBeans()) {
187 if ("Shenandoah Cycles".equals(bean.getName())) {
188 gcCycleMBean = bean;
189 break;
190 }
191 }
192
193 if (gcCycleMBean == null) {
194 throw new RuntimeException("Can not find Shenandoah GC cycle mbean");
195 }
196
197 // Generate roughly TARGET_STRINGS strings, only UNIQUE_STRINGS are unique
198 long genIters = TARGET_STRINGS / UNIQUE_STRINGS;
199 for (long index = 0; index < genIters; index++) {
200 generateStrings(astrs, UNIQUE_STRINGS);
201 }
202
203 long cycleBeforeRewrite = gcCycleMBean.getCollectionCount();
204
205 for (long loop = 1; loop < TARGET_OVERWRITES; loop++) {
206 int arrSize = astrs.size();
207 int index = rn.nextInt(arrSize);
208 StringAndId item = astrs.get(index);
209 int n = rn.nextInt(UNIQUE_STRINGS);
210 item.str = "Unique String " + n;
211 item.id = n;
212
213 if (loop % 1000 == 0) {
214 // enough GC cycles for rewritten strings to be deduplicated
215 if (gcCycleMBean.getCollectionCount() - cycleBeforeRewrite >= MAX_REWRITE_GC_CYCLES) {
216 break;
217 }
218 }
219 }
220 verifyDedepString(astrs);
221 }
222 }