1 /*
2 * Copyright (c) 2017, 2021, Red Hat, Inc. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 /*
26 * @test id=passive
27 * @summary Test Shenandoah string deduplication implementation
28 * @key randomness
29 * @requires vm.gc.Shenandoah
30 * @library /test/lib
31 * @modules java.base/jdk.internal.misc:open
32 * @modules java.base/java.lang:open
33 * java.management
34 *
35 * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
36 * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=passive
37 * -XX:+ShenandoahDegeneratedGC -DGCCount=1
38 * TestStringDedup
39 *
40 * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
41 * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=passive
42 * -XX:-ShenandoahDegeneratedGC -DGCCount=1
43 * TestStringDedup
44 */
45
46 /*
47 * @test id=default
48 * @summary Test Shenandoah string deduplication implementation
49 * @key randomness
50 * @requires vm.gc.Shenandoah
51 * @library /test/lib
52 * @modules java.base/java.lang:open
53 * java.management
54 *
55 * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
56 * -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive -XX:StringDeduplicationAgeThreshold=3
57 * TestStringDedup
58 *
59 * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
60 * -XX:+UseShenandoahGC -XX:StringDeduplicationAgeThreshold=3
61 * TestStringDedup
62 *
63 * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
64 * -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=compact -XX:StringDeduplicationAgeThreshold=3
65 * TestStringDedup
66 */
67
68 /*
69 * @test id=generational
70 * @summary Test Shenandoah string deduplication implementation
71 * @key randomness
72 * @requires vm.gc.Shenandoah
73 * @library /test/lib
74 * @modules java.base/java.lang:open
75 * java.management
76 *
77 * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
78 * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=generational -XX:StringDeduplicationAgeThreshold=3
79 * TestStringDedup
80 */
81
82 import java.lang.reflect.*;
83 import java.util.*;
84 import jdk.test.lib.Utils;
85
86 public class TestStringDedup {
87 private static Field valueField;
88
89 private static final int UniqueStrings = 20;
90 // How many GC cycles are needed to complete deduplication.
91 private static final int GCCount = Integer.getInteger("GCCount", 3);
92
93 static {
94 try {
95 valueField = String.class.getDeclaredField("value");
96 valueField.setAccessible(true);
97 } catch (Exception e) {
98 throw new RuntimeException(e);
99 }
100 }
101
102 private static Object getValue(String string) {
103 try {
104 return valueField.get(string);
105 } catch (Exception e) {
106 throw new RuntimeException(e);
107 }
108 }
109
110 static class StringAndId {
111 private String str;
112 private int id;
113
114 public StringAndId(String str, int id) {
115 this.str = str;
116 this.id = id;
117 }
118
119 public String str() {
120 return str;
121 }
122
123 public int id() {
124 return id;
125 }
126 }
127
128 private static void generateStrings(ArrayList<StringAndId> strs, int unique_strs) {
129 Random rn = Utils.getRandomInstance();
130 for (int u = 0; u < unique_strs; u++) {
131 int n = rn.nextInt() % 10;
132 n = Math.max(n, 2);
133 for (int index = 0; index < n; index++) {
134 strs.add(new StringAndId("Unique String " + u, u));
135 }
136 }
137 }
138
139 private static int verifyDedepString(ArrayList<StringAndId> strs) {
140 HashMap<Object, StringAndId> seen = new HashMap<>();
141 int total = 0;
142 int dedup = 0;
143
144 for (StringAndId item : strs) {
145 total++;
146 StringAndId existing_item = seen.get(getValue(item.str()));
147 if (existing_item == null) {
148 seen.put(getValue(item.str()), item);
149 } else {
150 if (item.id() != existing_item.id() ||
151 !item.str().equals(existing_item.str())) {
152 System.out.println("StringDedup error:");
153 System.out.println("String: " + item.str() + " != " + existing_item.str());
154 throw new RuntimeException("StringDedup Test failed");
155 } else {
156 dedup++;
157 }
158 }
159 }
160 return (total - dedup);
161 }
162
163 public static void main(String[] args) {
164 ArrayList<StringAndId> astrs = new ArrayList<>();
165 generateStrings(astrs, UniqueStrings);
166 for (int count = 0; count < GCCount; count ++) {
167 System.gc();
168 }
169
170 int unique_count = 0;
171 for (int waitCount = 0; waitCount < 3; waitCount ++) {
172 // Let concurrent string dedup thread to run
173 try {
174 Thread.sleep(1000);
175 } catch (InterruptedException e) {
176 }
177
178 // All deduplicated, done.
179 unique_count = verifyDedepString(astrs);
180 if ( unique_count == UniqueStrings) {
181 return;
182 }
183 }
184
185 throw new RuntimeException("Expecting " + UniqueStrings + " unique strings, but got " + unique_count);
186 }
187 }