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 & !vm.graal.enabled
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 -Xmx1g -Xlog:gc+stats
34 * -DtargetStrings=3000000
35 * -Xlog:gc
36 * TestStringDedupStress
37 *
38 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g -Xlog:gc+stats
39 * -XX:ShenandoahGCHeuristics=aggressive -DtargetStrings=2000000
40 * -Xlog:gc
41 * TestStringDedupStress
42 *
43 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g -Xlog:gc+stats
44 * -XX:ShenandoahGCHeuristics=aggressive -XX:+ShenandoahOOMDuringEvacALot -DtargetStrings=2000000
45 * -Xlog:gc
46 * TestStringDedupStress
47 *
48 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g -Xlog:gc+stats
49 * -XX:ShenandoahGCHeuristics=static -DtargetStrings=4000000
50 * -Xlog:gc
51 * TestStringDedupStress
52 *
53 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g -Xlog:gc+stats
54 * -XX:ShenandoahGCHeuristics=compact
55 * -Xlog:gc
56 * TestStringDedupStress
57 *
58 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g -Xlog:gc+stats
59 * -XX:ShenandoahGCHeuristics=passive -XX:+ShenandoahDegeneratedGC
60 * -Xlog:gc
61 * TestStringDedupStress
62 *
63 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g -Xlog:gc+stats
64 * -XX:ShenandoahGCHeuristics=passive -XX:-ShenandoahDegeneratedGC
65 * -Xlog:gc
66 * TestStringDedupStress
67 *
68 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g -Xlog:gc+stats
69 * -XX:ShenandoahGCHeuristics=traversal
70 * -Xlog:gc
71 * TestStringDedupStress
72 *
73 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g -Xlog:gc+stats
74 * -XX:ShenandoahUpdateRefsEarly=off -DtargetStrings=3000000
75 * -Xlog:gc
76 * TestStringDedupStress
77 *
78 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g -Xlog:gc+stats
79 * -XX:ShenandoahGCHeuristics=compact -XX:ShenandoahUpdateRefsEarly=off -DtargetStrings=2000000
80 * -Xlog:gc
81 * TestStringDedupStress
82 *
83 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g -Xlog:gc+stats
84 * -XX:ShenandoahGCHeuristics=aggressive -XX:ShenandoahUpdateRefsEarly=off -DtargetStrings=2000000
85 * -Xlog:gc
86 * TestStringDedupStress
87 *
88 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g -Xlog:gc+stats
89 * -XX:ShenandoahGCHeuristics=static -XX:ShenandoahUpdateRefsEarly=off
90 * -Xlog:gc
91 * TestStringDedupStress
92 *
93 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g -Xlog:gc+stats
94 * -XX:ShenandoahGCHeuristics=aggressive -XX:ShenandoahUpdateRefsEarly=off -XX:+ShenandoahOOMDuringEvacALot -DtargetStrings=2000000
95 * -Xlog:gc
96 * TestStringDedupStress
97 *
98 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g -Xlog:gc+stats
99 * -XX:ShenandoahGCHeuristics=traversal -XX:+ShenandoahOOMDuringEvacALot -DtargetStrings=2000000
100 * -Xlog:gc
101 * TestStringDedupStress
102 */
103
104 import java.lang.management.*;
105 import java.lang.reflect.*;
106 import java.util.*;
107
108 import sun.misc.*;
109
110 public class TestStringDedupStress {
111 private static Field valueField;
112 private static Unsafe unsafe;
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 Field field = Unsafe.class.getDeclaredField("theUnsafe");
123 field.setAccessible(true);
124 unsafe = (Unsafe) field.get(null);
125
126 valueField = String.class.getDeclaredField("value");
127 valueField.setAccessible(true);
128 } catch (Exception e) {
129 throw new RuntimeException(e);
130 }
131 }
132
133 private static Object getValue(String string) {
134 try {
135 return valueField.get(string);
136 } catch (Exception e) {
137 throw new RuntimeException(e);
138 }
139 }
140
141 static class StringAndId {
142 private String str;
143 private int id;
144
145 public StringAndId(String str, int id) {
146 this.str = str;
147 this.id = id;
148 }
149
150 public String str() {
151 return str;
152 }
153
154 public int id() {
155 return id;
156 }
157 }
158
159 // Generate uniqueStrings number of strings
160 private static void generateStrings(ArrayList<StringAndId> strs, int uniqueStrings) {
161 Random rn = new Random();
162 for (int u = 0; u < uniqueStrings; u++) {
163 int n = rn.nextInt(uniqueStrings);
164 strs.add(new StringAndId("Unique String " + n, n));
165 }
166 }
167
168 private static int verifyDedupString(ArrayList<StringAndId> strs) {
169 Map<Object, StringAndId> seen = new HashMap<>(TARGET_STRINGS*2);
170 int total = 0;
171 int dedup = 0;
172
173 for (StringAndId item : strs) {
174 total++;
175 StringAndId existingItem = seen.get(getValue(item.str()));
176 if (existingItem == null) {
177 seen.put(getValue(item.str()), item);
178 } else {
179 if (item.id() != existingItem.id() ||
180 !item.str().equals(existingItem.str())) {
181 System.out.println("StringDedup error:");
182 System.out.println("id: " + item.id() + " != " + existingItem.id());
183 System.out.println("or String: " + item.str() + " != " + existingItem.str());
184 throw new RuntimeException("StringDedup Test failed");
185 } else {
186 dedup++;
187 }
188 }
189 }
190 System.out.println("Dedup: " + dedup + "/" + total + " unique: " + (total - dedup));
191 return (total - dedup);
192 }
193
194 static volatile ArrayList<StringAndId> astrs = new ArrayList<>();
195 static GarbageCollectorMXBean gcCycleMBean;
196
197 public static void main(String[] args) {
198 Random rn = new Random();
199
200 for (GarbageCollectorMXBean bean : ManagementFactory.getGarbageCollectorMXBeans()) {
201 if ("Shenandoah Cycles".equals(bean.getName())) {
202 gcCycleMBean = bean;
203 break;
204 }
205 }
206
207 if (gcCycleMBean == null) {
208 throw new RuntimeException("Can not find Shenandoah GC cycle mbean");
209 }
210
211 // Generate roughly TARGET_STRINGS strings, only UNIQUE_STRINGS are unique
212 int genIters = TARGET_STRINGS / UNIQUE_STRINGS;
213 for (int index = 0; index < genIters; index++) {
214 generateStrings(astrs, UNIQUE_STRINGS);
215 }
216
217 long cycleBeforeRewrite = gcCycleMBean.getCollectionCount();
218 long timeBeforeRewrite = System.currentTimeMillis();
219
220 long loop = 1;
221 while (true) {
222 int arrSize = astrs.size();
223 int index = rn.nextInt(arrSize);
224 StringAndId item = astrs.get(index);
225 int n = rn.nextInt(UNIQUE_STRINGS);
226 item.str = "Unique String " + n;
227 item.id = n;
228
229 if (loop++ % 1000 == 0) {
230 // enough GC cycles for rewritten strings to be deduplicated
231 if (gcCycleMBean.getCollectionCount() - cycleBeforeRewrite >= MAX_REWRITE_GC_CYCLES) {
232 break;
233 }
234
235 // enough time is spent waiting for GC to happen
236 if (System.currentTimeMillis() - timeBeforeRewrite >= MAX_REWRITE_TIME) {
237 break;
238 }
239 }
240 }
241 verifyDedupString(astrs);
242 }
243 }