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 TestStringDedup
26 * @summary Test Shenandoah string deduplication implementation
27 * @key gc
28 * @requires vm.gc.Shenandoah
29 * @library /test/lib
30 * @modules java.base/jdk.internal.misc:open
31 * @modules java.base/java.lang:open
32 * java.management
33 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=passive -XX:+ShenandoahDegeneratedGC -XX:+UseStringDeduplication -Xmx256M -Xlog:gc+stats TestStringDedup
34 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=passive -XX:-ShenandoahDegeneratedGC -XX:+UseStringDeduplication -Xmx256M -Xlog:gc+stats TestStringDedup
35 *
36 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive -XX:+UseStringDeduplication -Xmx256M -Xlog:gc+stats TestStringDedup
37 *
38 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx256M -Xlog:gc+stats TestStringDedup
39 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=traversal -XX:+UseStringDeduplication -Xmx256M -Xlog:gc+stats TestStringDedup
40 *
41 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=compact -XX:+UseStringDeduplication -Xmx256M -Xlog:gc+stats TestStringDedup
42 */
43
44 import java.lang.reflect.*;
45 import java.util.*;
46
47 import sun.misc.*;
48
49 public class TestStringDedup {
50 private static Field valueField;
51 private static Unsafe unsafe;
52
53 private static final int UniqueStrings = 20;
54
55 static {
56 try {
57 Field field = Unsafe.class.getDeclaredField("theUnsafe");
58 field.setAccessible(true);
59 unsafe = (Unsafe) field.get(null);
60
61 valueField = String.class.getDeclaredField("value");
62 valueField.setAccessible(true);
63 } catch (Exception e) {
64 throw new RuntimeException(e);
65 }
66 }
67
68 private static Object getValue(String string) {
69 try {
70 return valueField.get(string);
71 } catch (Exception e) {
72 throw new RuntimeException(e);
73 }
74 }
75
76 static class StringAndId {
77 private String str;
78 private int id;
79
80 public StringAndId(String str, int id) {
81 this.str = str;
82 this.id = id;
83 }
84
85 public String str() {
86 return str;
87 }
88
89 public int id() {
90 return id;
91 }
92 }
93
94 private static void generateStrings(ArrayList<StringAndId> strs, int unique_strs) {
95 Random rn = new Random();
96 for (int u = 0; u < unique_strs; u++) {
97 int n = rn.nextInt() % 10;
98 n = Math.max(n, 2);
99 for (int index = 0; index < n; index++) {
100 strs.add(new StringAndId("Unique String " + u, u));
101 }
102 }
103 }
104
105 private static int verifyDedepString(ArrayList<StringAndId> strs) {
106 HashMap<Object, StringAndId> seen = new HashMap<>();
107 int total = 0;
108 int dedup = 0;
109
110 for (StringAndId item : strs) {
111 total++;
112 StringAndId existing_item = seen.get(getValue(item.str()));
113 if (existing_item == null) {
114 seen.put(getValue(item.str()), item);
115 } else {
116 if (item.id() != existing_item.id() ||
117 !item.str().equals(existing_item.str())) {
118 System.out.println("StringDedup error:");
119 System.out.println("String: " + item.str() + " != " + existing_item.str());
120 throw new RuntimeException("StringDedup Test failed");
121 } else {
122 dedup++;
123 }
124 }
125 }
126 System.out.println("Dedup: " + dedup + "/" + total + " unique: " + (total - dedup));
127 return (total - dedup);
128 }
129
130 public static void main(String[] args) {
131 ArrayList<StringAndId> astrs = new ArrayList<>();
132 generateStrings(astrs, UniqueStrings);
133 System.gc();
134 System.gc();
135 System.gc();
136 System.gc();
137 System.gc();
138
139 if (verifyDedepString(astrs) != UniqueStrings) {
140 // Can not guarantee all strings are deduplicated, there can
141 // still have pending items in queues.
142 System.out.println("Not all strings are deduplicated");
143 }
144 }
145 }