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
30 /*
31 * @test id=generational
32 * @requires vm.gc.Shenandoah
33 * @summary Confirm that card marking and remembered set scanning do not crash.
34 * @library /testlibrary /test/lib /
35 * @build jdk.test.whitebox.WhiteBox
36 * @run driver jdk.test.lib.helpers.ClassFileInstaller jdk.test.whitebox.WhiteBox
37 * @run main/othervm -Xbootclasspath/a:.
38 * -XX:+IgnoreUnrecognizedVMOptions
39 * -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI
40 * -XX:+UnlockExperimentalVMOptions
41 * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=generational
42 * gc.shenandoah.generational.TestSimpleGenerational
43 */
44 public class TestSimpleGenerational {
45 private static WhiteBox WB = WhiteBox.getWhiteBox();
46 private static final int RANDOM_SEED = 46;
47 // Sequence of random numbers should end with same value
48 private static final int EXPECTED_LAST_RANDOM = 136227050;
49
50
51 public static class Node {
52 private static final int NEIGHBOR_COUNT = 5;
53 private static final int INT_ARRAY_SIZE = 8;
54 private static final Random RANDOM = new Random(RANDOM_SEED);
55
56 private int val;
57 private Object objectField;
58
59 // Each Node instance holds references to two "private" arrays.
60 // One array holds raw seething bits (primitive integers) and the other
61 // holds references.
62
63 private int[] intsField;
64 private Node [] neighbors;
65
66 public Node(int val) {
67 this.val = val;
68 this.objectField = new Object();
69 this.intsField = new int[INT_ARRAY_SIZE];
70 this.intsField[0] = 0xca;
71 this.intsField[1] = 0xfe;
72 this.intsField[2] = 0xba;
73 this.intsField[3] = 0xbe;
74 this.intsField[4] = 0xba;
75 this.intsField[5] = 0xad;
76 this.intsField[6] = 0xba;
77 this.intsField[7] = 0xbe;
78
79 this.neighbors = new Node[NEIGHBOR_COUNT];
80 }
81
82 public int value() {
83 return val;
84 }
85
86 // Copy each neighbor of n into a new node's neighbor array.
87 // Then overwrite arbitrarily selected neighbor with newly allocated
88 // leaf node.
89 public static Node upheaval(Node n) {
90 int firstValue = RANDOM.nextInt(Integer.MAX_VALUE);
91 Node result = new Node(firstValue);
92 if (n != null) {
93 for (int i = 0; i < NEIGHBOR_COUNT; i++) {
94 result.neighbors[i] = n.neighbors[i];
95 }
96 }
97 int secondValue = RANDOM.nextInt(Integer.MAX_VALUE);
98 int overwriteIndex = firstValue % NEIGHBOR_COUNT;
99 result.neighbors[overwriteIndex] = new Node(secondValue);
100 return result;
101 }
102 }
103
104 public static void main(String args[]) throws Exception {
105 Node n = null;
106
107 if (!WB.getBooleanVMFlag("UseShenandoahGC") || !WB.getStringVMFlag("ShenandoahGCMode").equals("generational")) {
108 throw new IllegalStateException("Command-line options not honored!");
109 }
110
111 for (int count = 10000; count > 0; count--) {
112 n = Node.upheaval(n);
113 }
114
115 System.out.println("Expected Last Random: [" + n.value() + "]");
116 if (n.value() != EXPECTED_LAST_RANDOM) {
117 throw new IllegalStateException("Random number sequence ended badly!");
118 }
119 }
120 }