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 import java.lang.reflect.*;
69 import java.util.*;
70 import jdk.test.lib.Utils;
71
72 public class TestStringDedup {
73 private static Field valueField;
74
75 private static final int UniqueStrings = 20;
76 // How many GC cycles are needed to complete deduplication.
77 private static final int GCCount = Integer.getInteger("GCCount", 3);
78
79 static {
80 try {
81 valueField = String.class.getDeclaredField("value");
82 valueField.setAccessible(true);
83 } catch (Exception e) {
84 throw new RuntimeException(e);
85 }
86 }
87
88 private static Object getValue(String string) {
89 try {
90 return valueField.get(string);
91 } catch (Exception e) {
92 throw new RuntimeException(e);
93 }
94 }
95
96 static class StringAndId {
97 private String str;
98 private int id;
99
100 public StringAndId(String str, int id) {
101 this.str = str;
102 this.id = id;
103 }
104
105 public String str() {
106 return str;
107 }
108
109 public int id() {
110 return id;
111 }
112 }
113
114 private static void generateStrings(ArrayList<StringAndId> strs, int unique_strs) {
115 Random rn = Utils.getRandomInstance();
116 for (int u = 0; u < unique_strs; u++) {
117 int n = rn.nextInt() % 10;
118 n = Math.max(n, 2);
119 for (int index = 0; index < n; index++) {
120 strs.add(new StringAndId("Unique String " + u, u));
121 }
122 }
123 }
124
125 private static int verifyDedepString(ArrayList<StringAndId> strs) {
126 HashMap<Object, StringAndId> seen = new HashMap<>();
127 int total = 0;
128 int dedup = 0;
129
130 for (StringAndId item : strs) {
131 total++;
132 StringAndId existing_item = seen.get(getValue(item.str()));
133 if (existing_item == null) {
134 seen.put(getValue(item.str()), item);
135 } else {
136 if (item.id() != existing_item.id() ||
137 !item.str().equals(existing_item.str())) {
138 System.out.println("StringDedup error:");
139 System.out.println("String: " + item.str() + " != " + existing_item.str());
140 throw new RuntimeException("StringDedup Test failed");
141 } else {
142 dedup++;
143 }
144 }
145 }
146 return (total - dedup);
147 }
148
149 public static void main(String[] args) {
150 ArrayList<StringAndId> astrs = new ArrayList<>();
151 generateStrings(astrs, UniqueStrings);
152 for (int count = 0; count < GCCount; count ++) {
153 System.gc();
154 }
155
156 int unique_count = 0;
157 for (int waitCount = 0; waitCount < 3; waitCount ++) {
158 // Let concurrent string dedup thread to run
159 try {
160 Thread.sleep(1000);
161 } catch (InterruptedException e) {
162 }
163
164 // All deduplicated, done.
165 unique_count = verifyDedepString(astrs);
166 if ( unique_count == UniqueStrings) {
167 return;
168 }
169 }
170
171 throw new RuntimeException("Expecting " + UniqueStrings + " unique strings, but got " + unique_count);
172 }
173 }