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