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 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g
29 * -verbose:gc
30 * -DtargetStrings=3000000
31 * TestStringDedupStress
32 *
33 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g
34 * -XX:ShenandoahGCHeuristics=aggressive -DtargetStrings=2000000
35 * -verbose:gc
36 * TestStringDedupStress
37 *
38 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g
39 * -XX:ShenandoahGCHeuristics=aggressive -XX:+ShenandoahOOMDuringEvacALot -DtargetStrings=2000000
40 * -verbose:gc
41 * TestStringDedupStress
42 *
43 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g
44 * -XX:ShenandoahGCHeuristics=static -DtargetStrings=4000000
45 * -verbose:gc
46 * TestStringDedupStress
47 *
48 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g
49 * -XX:ShenandoahGCHeuristics=compact
50 * -verbose:gc
51 * TestStringDedupStress
52 *
53 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g
54 * -XX:ShenandoahGCMode=passive -XX:+ShenandoahDegeneratedGC -DtargetOverwrites=40000000
55 * -verbose:gc
56 * TestStringDedupStress
57 *
58 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g
59 * -XX:ShenandoahGCMode=passive -XX:-ShenandoahDegeneratedGC -DtargetOverwrites=40000000
60 * -verbose:gc
61 * TestStringDedupStress
62 *
63 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g
64 * -XX:ShenandoahUpdateRefsEarly=off -DtargetStrings=3000000
65 * -verbose:gc
66 * TestStringDedupStress
67 *
68 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g
69 * -XX:ShenandoahGCHeuristics=compact -XX:ShenandoahUpdateRefsEarly=off -DtargetStrings=2000000
70 * -verbose:gc
71 * TestStringDedupStress
72 *
73 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g
74 * -XX:ShenandoahGCHeuristics=aggressive -XX:ShenandoahUpdateRefsEarly=off -DtargetStrings=2000000
75 * -verbose:gc
76 * TestStringDedupStress
77 *
78 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g
79 * -XX:ShenandoahGCHeuristics=static -XX:ShenandoahUpdateRefsEarly=off -DtargetOverwrites=4000000
80 * -verbose:gc
81 * TestStringDedupStress
82 *
83 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g
84 * -XX:ShenandoahGCHeuristics=aggressive -XX:ShenandoahUpdateRefsEarly=off -XX:+ShenandoahOOMDuringEvacALot -DtargetStrings=2000000
85 * -verbose:gc
86 * TestStringDedupStress
87 *
88 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g
89 * -XX:ShenandoahGCMode=traversal
90 * -verbose:gc
91 * TestStringDedupStress
92 *
93 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g
94 * -XX:ShenandoahGCMode=traversal -XX:ShenandoahGCHeuristics=aggressive -DtargetStrings=2000000
95 * -verbose:gc
96 * TestStringDedupStress
97 *
98 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g
99 * -XX:ShenandoahGCMode=traversal
100 * -XX:+ShenandoahOOMDuringEvacALot
101 * -DtargetStrings=2000000
102 * -verbose:gc
103 * TestStringDedupStress
104 *
105 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx1g
106 * -XX:ShenandoahGCMode=traversal -XX:ShenandoahGCHeuristics=aggressive
107 * -XX:+ShenandoahOOMDuringEvacALot
108 * -DtargetStrings=2000000
109 * -verbose:gc
110 * TestStringDedupStress
111 */
112
113 import java.lang.management.*;
114 import java.lang.reflect.*;
115 import java.util.*;
116
117 import sun.misc.*;
118
119 public class TestStringDedupStress {
120 private static Field valueField;
121 private static Unsafe unsafe;
122
123 private static final int TARGET_STRINGS = Integer.getInteger("targetStrings", 2_500_000);
124 private static final long MAX_REWRITE_GC_CYCLES = 6;
125 private static final long MAX_REWRITE_TIME = 30*1000; // ms
126
127 private static final int UNIQUE_STRINGS = 20;
128
129 static {
130 try {
131 Field field = Unsafe.class.getDeclaredField("theUnsafe");
132 field.setAccessible(true);
133 unsafe = (Unsafe) field.get(null);
134
135 valueField = String.class.getDeclaredField("value");
136 valueField.setAccessible(true);
137 } catch (Exception e) {
138 throw new RuntimeException(e);
139 }
140 }
141
142 private static Object getValue(String string) {
143 try {
144 return valueField.get(string);
145 } catch (Exception e) {
146 throw new RuntimeException(e);
147 }
148 }
149
150 static class StringAndId {
151 private String str;
152 private int id;
153
154 public StringAndId(String str, int id) {
155 this.str = str;
156 this.id = id;
157 }
158
159 public String str() {
160 return str;
161 }
162
163 public int id() {
164 return id;
165 }
166 }
167
168 // Generate uniqueStrings number of strings
169 private static void generateStrings(ArrayList<StringAndId> strs, int uniqueStrings) {
170 Random rn = new Random();
171 for (int u = 0; u < uniqueStrings; u++) {
172 int n = rn.nextInt(uniqueStrings);
173 strs.add(new StringAndId("Unique String " + n, n));
174 }
175 }
176
177 private static int verifyDedupString(ArrayList<StringAndId> strs) {
178 Map<Object, StringAndId> seen = new HashMap<>(TARGET_STRINGS*2);
179 int total = 0;
180 int dedup = 0;
181
182 for (StringAndId item : strs) {
183 total++;
184 StringAndId existingItem = seen.get(getValue(item.str()));
185 if (existingItem == null) {
186 seen.put(getValue(item.str()), item);
187 } else {
188 if (item.id() != existingItem.id() ||
189 !item.str().equals(existingItem.str())) {
190 System.out.println("StringDedup error:");
191 System.out.println("id: " + item.id() + " != " + existingItem.id());
192 System.out.println("or String: " + item.str() + " != " + existingItem.str());
193 throw new RuntimeException("StringDedup Test failed");
194 } else {
195 dedup++;
196 }
197 }
198 }
199 System.out.println("Dedup: " + dedup + "/" + total + " unique: " + (total - dedup));
200 return (total - dedup);
201 }
202
203 static volatile ArrayList<StringAndId> astrs = new ArrayList<>();
204 static GarbageCollectorMXBean gcCycleMBean;
205
206 public static void main(String[] args) {
207 Random rn = new Random();
208
209 for (GarbageCollectorMXBean bean : ManagementFactory.getGarbageCollectorMXBeans()) {
210 if ("Shenandoah Cycles".equals(bean.getName())) {
211 gcCycleMBean = bean;
212 break;
213 }
214 }
215
216 if (gcCycleMBean == null) {
217 throw new RuntimeException("Can not find Shenandoah GC cycle mbean");
218 }
219
220 // Generate roughly TARGET_STRINGS strings, only UNIQUE_STRINGS are unique
221 int genIters = TARGET_STRINGS / UNIQUE_STRINGS;
222 for (int index = 0; index < genIters; index++) {
223 generateStrings(astrs, UNIQUE_STRINGS);
224 }
225
226 long cycleBeforeRewrite = gcCycleMBean.getCollectionCount();
227 long timeBeforeRewrite = System.currentTimeMillis();
228
229 long loop = 1;
230 while (true) {
231 int arrSize = astrs.size();
232 int index = rn.nextInt(arrSize);
233 StringAndId item = astrs.get(index);
234 int n = rn.nextInt(UNIQUE_STRINGS);
235 item.str = "Unique String " + n;
236 item.id = n;
237
238 if (loop++ % 1000 == 0) {
239 // enough GC cycles for rewritten strings to be deduplicated
240 if (gcCycleMBean.getCollectionCount() - cycleBeforeRewrite >= MAX_REWRITE_GC_CYCLES) {
241 break;
242 }
243
244 // enough time is spent waiting for GC to happen
245 if (System.currentTimeMillis() - timeBeforeRewrite >= MAX_REWRITE_TIME) {
246 break;
247 }
248 }
249 }
250 verifyDedupString(astrs);
251 }
252 }