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 TestShenandoahStringDedup.java
26 * @summary Test Shenandoah string deduplication implementation
27 * @key gc
28 * @library /test/lib
29 * @modules java.base/jdk.internal.misc:open
30 * @modules java.base/java.lang:open
31 * java.management
32 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
33 * -DtargetStrings=3000000
34 * ShenandoahStrDedupStress
35 *
36 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
37 * -XX:ShenandoahGCHeuristics=aggressive -DtargetStrings=2000000
38 * ShenandoahStrDedupStress
39 *
40 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
41 * -XX:ShenandoahGCHeuristics=aggressive -XX:+ShenandoahOOMDuringEvacALot -DtargetStrings=2000000
42 * ShenandoahStrDedupStress
43 *
44 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
45 * -XX:ShenandoahGCHeuristics=static -DtargetStrings=4000000
46 * ShenandoahStrDedupStress
47 *
48 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
49 * -XX:ShenandoahGCHeuristics=compact
50 * ShenandoahStrDedupStress
51 *
52 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
53 * -XX:ShenandoahGCHeuristics=passive -XX:+ShenandoahDegeneratedGC -DtargetOverwrites=40000000
54 * ShenandoahStrDedupStress
55 *
56 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
57 * -XX:ShenandoahGCHeuristics=passive -XX:-ShenandoahDegeneratedGC -DtargetOverwrites=40000000
58 * ShenandoahStrDedupStress
59 *
60 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
61 * -XX:ShenandoahGCHeuristics=traversal
62 * ShenandoahStrDedupStress
63 *
64 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
65 * -XX:ShenandoahUpdateRefsEarly=off -DtargetStrings=3000000
66 * ShenandoahStrDedupStress
67 *
68 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
69 * -XX:ShenandoahGCHeuristics=compact -XX:ShenandoahUpdateRefsEarly=off -DtargetStrings=2000000
70 * ShenandoahStrDedupStress
71 *
72 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
73 * -XX:ShenandoahGCHeuristics=aggressive -XX:ShenandoahUpdateRefsEarly=off -DtargetStrings=2000000
74 * ShenandoahStrDedupStress
75 *
76 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
77 * -XX:ShenandoahGCHeuristics=static -XX:ShenandoahUpdateRefsEarly=off -DtargetOverwrites=4000000
78 * ShenandoahStrDedupStress
79 *
80 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
81 * -XX:ShenandoahGCHeuristics=aggressive -XX:ShenandoahUpdateRefsEarly=off -XX:+ShenandoahOOMDuringEvacALot -DtargetStrings=2000000
82 * ShenandoahStrDedupStress
83 *
84 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx512M -Xlog:gc+stats
85 * -XX:ShenandoahGCHeuristics=traversal -XX:+ShenandoahOOMDuringEvacALot -DtargetStrings=2000000
86 * ShenandoahStrDedupStress
87 */
88
89 import java.lang.management.*;
90 import java.lang.reflect.*;
91 import java.util.*;
92 import sun.misc.*;
93
94 public class ShenandoahStrDedupStress {
95 private static Field valueField;
96 private static Unsafe unsafe;
97
98 private static long TARGET_STRINGS = Long.getLong("targetStrings", 2_500_000);
99 private static long TARGET_OVERWRITES = Long.getLong("targetOverwrites", 600_000);
100 private static final long MAX_REWRITE_GC_CYCLES = 6;
101
102 private static final int UNIQUE_STRINGS = 20;
103 static {
104 try {
105 Field field = Unsafe.class.getDeclaredField("theUnsafe");
106 field.setAccessible(true);
107 unsafe = (Unsafe)field.get(null);
108
109 valueField = String.class.getDeclaredField("value");
110 valueField.setAccessible(true);
111 } catch (Exception e) {
112 throw new RuntimeException(e);
113 }
114 }
115
116 private static Object getValue(String string) {
117 try {
118 return valueField.get(string);
119 } catch (Exception e) {
120 throw new RuntimeException(e);
121 }
122 }
123
124 static class StringAndId {
125 private String str;
126 private int id;
127 public StringAndId(String str, int id) {
128 this.str = str;
129 this.id = id;
130 }
131
132 public String str() { return str; }
133 public int id() { return id; }
134 }
135
136 // Generate uniqueStrings number of strings
137 private static void generateStrings(ArrayList<StringAndId> strs, int uniqueStrings) {
138 Random rn = new Random();
139 for (int u = 0; u < uniqueStrings; u ++) {
140 int n = rn.nextInt(uniqueStrings);
141 strs.add(new StringAndId("Unique String " + n, n));
142 }
143 }
144
145 private static int verifyDedepString(ArrayList<StringAndId> strs) {
146 HashMap<Object, StringAndId> seen = new HashMap<>();
147 int total = 0;
148 int dedup = 0;
149
150 for (StringAndId item : strs) {
151 total ++;
152 StringAndId existingItem = seen.get(getValue(item.str()));
153 if (existingItem == null) {
154 seen.put(getValue(item.str()), item);
155 } else {
156 if (item.id() != existingItem.id() ||
157 !item.str().equals(existingItem.str())) {
158 System.out.println("StringDedup error:");
159 System.out.println("id: " + item.id() + " != " + existingItem.id());
160 System.out.println("or String: " + item.str() + " != " + existingItem.str());
161 throw new RuntimeException("StringDedup Test failed");
162 } else {
163 dedup ++;
164 }
165 }
166 }
167 System.out.println("Dedup: " + dedup + "/" + total + " unique: " + (total - dedup));
168 return (total - dedup);
169 }
170
171 static volatile ArrayList<StringAndId> astrs = new ArrayList<>();
172 static GarbageCollectorMXBean gcCycleMBean;
173
174 public static void main(String[] args) {
175 Random rn = new Random();
176
177 for (GarbageCollectorMXBean bean : ManagementFactory.getGarbageCollectorMXBeans()) {
178 if ("Shenandoah Cycles".equals(bean.getName())) {
179 gcCycleMBean = bean;
180 break;
181 }
182 }
183
184 if (gcCycleMBean == null) {
185 throw new RuntimeException("Can not find Shenandoah GC cycle mbean");
186 }
187
188 // Generate roughly TARGET_STRINGS strings, only UNIQUE_STRINGS are unique
189 long genIters = TARGET_STRINGS / UNIQUE_STRINGS;
190 for(long index = 0; index < genIters; index ++) {
191 generateStrings(astrs, UNIQUE_STRINGS);
192 }
193
194 long cycleBeforeRewrite = gcCycleMBean.getCollectionCount();
195
196 for (long loop = 1; loop < TARGET_OVERWRITES; loop ++) {
197 int arrSize = astrs.size();
198 int index = rn.nextInt(arrSize);
199 StringAndId item = astrs.get(index);
200 int n = rn.nextInt(UNIQUE_STRINGS);
201 item.str = "Unique String " + n;
202 item.id = n;
203
204 if (loop % 1000 == 0) {
205 // enough GC cycles for rewritten strings to be deduplicated
206 if (gcCycleMBean.getCollectionCount() - cycleBeforeRewrite >= MAX_REWRITE_GC_CYCLES) {
207 break;
208 }
209 }
210 }
211 verifyDedepString(astrs);
212 }
213 }