1 /*
2 * Copyright (c) 2017, 2021, Red Hat, Inc. All rights reserved.
3 * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 /*
27 * @test id=passive
28 * @summary Test Shenandoah string deduplication implementation
29 * @key randomness
30 * @requires vm.gc.Shenandoah
31 * @library /test/lib
32 * @modules java.base/jdk.internal.misc:open
33 * @modules java.base/java.lang:open
34 * java.management
35 *
36 * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
37 * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=passive
38 * -XX:+ShenandoahDegeneratedGC -DGCCount=1
39 * TestStringDedup
40 *
41 * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
42 * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=passive
43 * -XX:-ShenandoahDegeneratedGC -DGCCount=1
44 * TestStringDedup
45 */
46
47 /*
48 * @test id=default
49 * @summary Test Shenandoah string deduplication implementation
50 * @key randomness
51 * @requires vm.gc.Shenandoah
52 * @library /test/lib
53 * @modules java.base/java.lang:open
54 * java.management
55 *
56 * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
57 * -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive -XX:StringDeduplicationAgeThreshold=3
58 * TestStringDedup
59 *
60 * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
61 * -XX:+UseShenandoahGC -XX:StringDeduplicationAgeThreshold=3
62 * TestStringDedup
63 *
64 * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
65 * -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=compact -XX:StringDeduplicationAgeThreshold=3
66 * TestStringDedup
67 */
68
69 /*
70 * @test id=generational
71 * @summary Test Shenandoah string deduplication implementation
72 * @key randomness
73 * @requires vm.gc.Shenandoah
74 * @library /test/lib
75 * @modules java.base/java.lang:open
76 * java.management
77 *
78 * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
79 * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=generational -XX:StringDeduplicationAgeThreshold=3
80 * TestStringDedup
81 */
82
83 import java.lang.reflect.*;
84 import java.util.*;
85 import jdk.test.lib.Utils;
86
87 public class TestStringDedup {
88 private static Field valueField;
89
90 private static final int UniqueStrings = 20;
91 // How many GC cycles are needed to complete deduplication.
92 private static final int GCCount = Integer.getInteger("GCCount", 3);
93
94 static {
95 try {
96 valueField = String.class.getDeclaredField("value");
97 valueField.setAccessible(true);
98 } catch (Exception e) {
99 throw new RuntimeException(e);
100 }
101 }
102
103 private static Object getValue(String string) {
104 try {
105 return valueField.get(string);
106 } catch (Exception e) {
107 throw new RuntimeException(e);
108 }
109 }
110
111 static class StringAndId {
112 private String str;
113 private int id;
114
115 public StringAndId(String str, int id) {
116 this.str = str;
117 this.id = id;
118 }
119
120 public String str() {
121 return str;
122 }
123
124 public int id() {
125 return id;
126 }
127 }
128
129 private static void generateStrings(ArrayList<StringAndId> strs, int unique_strs) {
130 Random rn = Utils.getRandomInstance();
131 for (int u = 0; u < unique_strs; u++) {
132 int n = rn.nextInt() % 10;
133 n = Math.max(n, 2);
134 for (int index = 0; index < n; index++) {
135 strs.add(new StringAndId("Unique String " + u, u));
136 }
137 }
138 }
139
140 private static int verifyDedepString(ArrayList<StringAndId> strs) {
141 HashMap<Object, StringAndId> seen = new HashMap<>();
142 int total = 0;
143 int dedup = 0;
144
145 for (StringAndId item : strs) {
146 total++;
147 StringAndId existing_item = seen.get(getValue(item.str()));
148 if (existing_item == null) {
149 seen.put(getValue(item.str()), item);
150 } else {
151 if (item.id() != existing_item.id() ||
152 !item.str().equals(existing_item.str())) {
153 System.out.println("StringDedup error:");
154 System.out.println("String: " + item.str() + " != " + existing_item.str());
155 throw new RuntimeException("StringDedup Test failed");
156 } else {
157 dedup++;
158 }
159 }
160 }
161 return (total - dedup);
162 }
163
164 public static void main(String[] args) {
165 ArrayList<StringAndId> astrs = new ArrayList<>();
166 generateStrings(astrs, UniqueStrings);
167 for (int count = 0; count < GCCount; count ++) {
168 System.gc();
169 }
170
171 int unique_count = 0;
172 for (int waitCount = 0; waitCount < 3; waitCount ++) {
173 // Let concurrent string dedup thread to run
174 try {
175 Thread.sleep(1000);
176 } catch (InterruptedException e) {
177 }
178
179 // All deduplicated, done.
180 unique_count = verifyDedepString(astrs);
181 if ( unique_count == UniqueStrings) {
182 return;
183 }
184 }
185
186 throw new RuntimeException("Expecting " + UniqueStrings + " unique strings, but got " + unique_count);
187 }
188 }