1 /*
2 * Copyright (c) 2017, 2018, 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 TestStringDedup
27 * @summary Test Shenandoah string deduplication implementation
28 * @key gc
29 * @requires vm.gc.Shenandoah & !vm.graal.enabled
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
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
43 * TestStringDedup
44 */
45
46 /*
47 * @test TestStringDedup
48 * @summary Test Shenandoah string deduplication implementation
49 * @key gc
50 * @requires vm.gc.Shenandoah & !vm.graal.enabled
51 * @library /test/lib
52 * @modules java.base/jdk.internal.misc:open
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
58 * TestStringDedup
59 *
60 * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
61 * -XX:+UseShenandoahGC
62 * TestStringDedup
63 *
64 * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
65 * -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=compact
66 * TestStringDedup
67 */
68
69 import java.lang.reflect.*;
70 import java.util.*;
71
72 import sun.misc.*;
73
74 public class TestStringDedup {
75 private static Field valueField;
76 private static Unsafe unsafe;
77
78 private static final int UniqueStrings = 20;
79
80 static {
81 try {
82 Field field = Unsafe.class.getDeclaredField("theUnsafe");
83 field.setAccessible(true);
84 unsafe = (Unsafe) field.get(null);
85
86 valueField = String.class.getDeclaredField("value");
87 valueField.setAccessible(true);
88 } catch (Exception e) {
89 throw new RuntimeException(e);
90 }
91 }
92
93 private static Object getValue(String string) {
94 try {
95 return valueField.get(string);
96 } catch (Exception e) {
97 throw new RuntimeException(e);
98 }
99 }
100
101 static class StringAndId {
102 private String str;
103 private int id;
104
105 public StringAndId(String str, int id) {
106 this.str = str;
107 this.id = id;
108 }
109
110 public String str() {
111 return str;
112 }
113
114 public int id() {
115 return id;
116 }
117 }
118
119 private static void generateStrings(ArrayList<StringAndId> strs, int unique_strs) {
120 Random rn = new Random();
121 for (int u = 0; u < unique_strs; u++) {
122 int n = rn.nextInt() % 10;
123 n = Math.max(n, 2);
124 for (int index = 0; index < n; index++) {
125 strs.add(new StringAndId("Unique String " + u, u));
126 }
127 }
128 }
129
130 private static int verifyDedepString(ArrayList<StringAndId> strs) {
131 HashMap<Object, StringAndId> seen = new HashMap<>();
132 int total = 0;
133 int dedup = 0;
134
135 for (StringAndId item : strs) {
136 total++;
137 StringAndId existing_item = seen.get(getValue(item.str()));
138 if (existing_item == null) {
139 seen.put(getValue(item.str()), item);
140 } else {
141 if (item.id() != existing_item.id() ||
142 !item.str().equals(existing_item.str())) {
143 System.out.println("StringDedup error:");
144 System.out.println("String: " + item.str() + " != " + existing_item.str());
145 throw new RuntimeException("StringDedup Test failed");
146 } else {
147 dedup++;
148 }
149 }
150 }
151 System.out.println("Dedup: " + dedup + "/" + total + " unique: " + (total - dedup));
152 return (total - dedup);
153 }
154
155 public static void main(String[] args) {
156 ArrayList<StringAndId> astrs = new ArrayList<>();
157 generateStrings(astrs, UniqueStrings);
158 System.gc();
159 System.gc();
160 System.gc();
161 System.gc();
162 System.gc();
163
164 if (verifyDedepString(astrs) != UniqueStrings) {
165 // Can not guarantee all strings are deduplicated, there can
166 // still have pending items in queues.
167 System.out.println("Not all strings are deduplicated");
168 }
169 }
170 }