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