1 /*
2 * Copyright Amazon.com Inc. or its affiliates. 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 package gc.shenandoah.generational;
26
27 import jdk.test.whitebox.WhiteBox;
28 import java.util.Random;
29 import java.util.HashMap;
30
31 /*
32 * To avoid the risk of false regressions identified by this test, the heap
33 * size is set artificially high. Though this test is known to run reliably
34 * in 66 MB heap, the heap size for this test run is currently set to 256 MB.
35 */
36
37 /*
38 * @test TestConcurrentEvac
39 * @requires vm.gc.Shenandoah
40 * @summary Confirm that card marking and remembered set scanning do not crash.
41 * @library /testlibrary /test/lib /
42 * @build jdk.test.whitebox.WhiteBox
43 * @run driver jdk.test.lib.helpers.ClassFileInstaller jdk.test.whitebox.WhiteBox
44 * @run main/othervm -Xbootclasspath/a:.
45 * -Xms256m -Xmx256m
46 * -XX:+IgnoreUnrecognizedVMOptions
47 * -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI
48 * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=generational
49 * -XX:NewRatio=1 -XX:+UnlockExperimentalVMOptions
50 * -XX:ShenandoahGuaranteedGCInterval=3000
51 * -XX:-UseDynamicNumberOfGCThreads -XX:-ShenandoahPacing
52 * gc.shenandoah.generational.TestConcurrentEvac
53 */
54
55 public class TestConcurrentEvac {
56 private static WhiteBox wb = WhiteBox.getWhiteBox();
57
58 static private final int SeedForRandom = 46;
59 // Sequence of random numbers should end with same value
60
61 // Smaller table will cause creation of more old-gen garbage
62 // as previous entries in table are overwritten with new values.
63 static private final int TableSize = 53;
64 static private final int MaxStringLength = 47;
65 static private final int SentenceLength = 5;
66
67 static private Random random = new Random(SeedForRandom);
68
69 public static class Node {
70 static private final int NeighborCount = 48;
71 static private final int ChildOverwriteCount = 32;
72 static private final int IntArraySize = 128;
73
74 private String name;
75
76 // Each Node instance holds an array containing all substrings of
77 // its name
78
79 // This array has entries from 0 .. (name.length() - 1).
80 // num_substrings[i] represents the number of substrings that
81 // correspond to a name of length i+1.
82 private static int [] num_substrings;
83
84 static {
85 // Initialize num_substrings.
86 // For a name of length N, there are
87 // N substrings of length 1
88 // N-1 substrings of length 2
89 // N-2 substrings of length 3
90 // ...
91 // 1 substring of length N
92 // Note that:
93 // num_substrings[0] = 1
94 // num_substrings[1] = 3
95 // num_substrings[i] = (i+1)+num_substrings[i-1]
96
97 num_substrings = new int[MaxStringLength];
98 num_substrings[0] = 1;
99 for (int i = 1; i < MaxStringLength; i++)
100 num_substrings[i] = (i+1)+num_substrings[i-1];
101 }
102
103 private String [] substrings;
104 private Node [] neighbors;
105
106 public Node(String name) {
107 this.name = name;
108 this.substrings = new String[num_substrings[name.length() - 1]];
109
110 int index = 0;
111 for (int substring_length = 1;
112 substring_length <= name.length(); substring_length++) {
113 for (int offset = 0;
114 offset + substring_length <= name.length(); offset++) {
115 this.substrings[index++] = name.substring(offset,
116 offset + substring_length);
117 }
118 }
119 }
120
121 public String value() {
122 return name;
123 }
124
125 public String arbitrary_substring() {
126 int index = TestConcurrentEvac.randomUnsignedInt() % substrings.length;
127 return substrings[index];
128 }
129 }
130
131
132 // Return random int between 1 and MaxStringLength inclusive
133 static int randomStringLength() {
134 int length = randomUnsignedInt();
135 length %= (MaxStringLength - 1);
136 length += 1;
137 return length;
138 }
139
140 static String randomCharacter() {
141 int index = randomUnsignedInt() % 52;
142 return ("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ".
143 substring(index, index+1));
144 }
145
146 static String randomString() {
147 int length = randomStringLength();
148 String result = new String(); // make the compiler work for this garbage...
149 for (int i = 0; i < length; i++)
150 result += randomCharacter();
151 return result;
152 }
153
154 static int randomUnsignedInt() {
155 int result = random.nextInt();
156 if (result < 0) result = -result;
157 if (result < 0) result = 0;
158 return result;
159 }
160
161 static int randomIndex() {
162 int index = randomUnsignedInt();
163 index %= TableSize;
164 return index;
165 }
166
167 public static void main(String args[]) throws Exception {
168 HashMap<Integer, Node> table = new HashMap<Integer, Node>(TableSize);
169
170 if (!wb.getBooleanVMFlag("UseShenandoahGC") ||
171 !wb.getStringVMFlag("ShenandoahGCMode").equals("generational"))
172 throw new IllegalStateException("Command-line options not honored!");
173
174 for (int count = java.lang.Integer.MAX_VALUE/1024; count >= 0; count--) {
175 int index = randomIndex();
176 String name = randomString();
177 table.put(index, new Node(name));
178 }
179
180 String conclusion = "";
181
182 for (int i = 0; i < SentenceLength; i++) {
183 Node a_node = table.get(randomIndex());
184 if (a_node == null)
185 i--;
186 else {
187 String a_string = a_node.arbitrary_substring();
188 conclusion += a_string;
189 conclusion += " ";
190 }
191 }
192 conclusion = conclusion.substring(0, conclusion.length() - 1);
193
194 System.out.println("Conclusion is [" + conclusion + "]");
195
196 if (!conclusion.equals("cTy cTykJ kAkKAOWYEHbxFCmRIlyk xjYMdNmtAQXNGdIc sqHKsWnJIP"))
197 throw new IllegalStateException("Random sequence of words did not end well!");
198
199 }
200 }
201