1 /*
2 * Copyright (c) 2021, Amazon, 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 package gc.shenandoah.generational;
26
27 import sun.hotspot.WhiteBox;
28 import java.util.Random;
29
30 /*
31 * @test TestSimpleGenerational
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 sun.hotspot.WhiteBox
36 * @run driver jdk.test.lib.helpers.ClassFileInstaller sun.hotspot.WhiteBox
37 * @run main/othervm -Xbootclasspath/a:.
38 * -XX:+IgnoreUnrecognizedVMOptions
39 * -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI
40 * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=generational
41 * gc.shenandoah.generational.TestSimpleGenerational
42 */
43 public class TestSimpleGenerational {
44 private static WhiteBox wb = WhiteBox.getWhiteBox();
45 static private final int SeedForRandom = 46;
46 // Sequence of random numbers should end with same value
47 private static int ExpectedLastRandom = 272454100;
48
49
50 public static class Node {
51 static private final int NeighborCount = 5;
52 static private final int IntArraySize = 8;
53 static private Random random = new Random(SeedForRandom);
54
55 private int val;
56 private Object field_o;
57
58 // Each Node instance holds references to two "private" arrays.
59 // One array holds raw seething bits (primitive integers) and the
60 // holds references.
61
62 private int[] field_ints;
63 private Node [] neighbors;
64
65 public Node(int val) {
66 this.val = val;
67 this.field_o = new Object();
68 this.field_ints = new int[IntArraySize];
69 this.field_ints[0] = 0xca;
70 this.field_ints[1] = 0xfe;
71 this.field_ints[2] = 0xba;
72 this.field_ints[3] = 0xbe;
73 this.field_ints[4] = 0xba;
74 this.field_ints[5] = 0xad;
75 this.field_ints[6] = 0xba;
76 this.field_ints[7] = 0xbe;
77
78 this.neighbors = new Node[NeighborCount];
79 }
80
81 public int value() {
82 return val;
83 }
84
85 // Copy each neighbor of n into a new node's neighbor array.
86 // Then overwrite arbitrarily selected neighbor with newly allocated
87 // leaf node.
88 public static Node upheaval(Node n) {
89 int first_val = random.nextInt();
90 if (first_val < 0) first_val = -first_val;
91 if (first_val < 0) first_val = 0;
92 Node result = new Node(first_val);
93 if (n != null) {
94 for (int i = 0; i < NeighborCount; i++)
95 result.neighbors[i] = n.neighbors[i];
96 }
97 int second_val = random.nextInt();
98 if (second_val < 0) second_val = -second_val;
99 if (second_val < 0) second_val = 0;
100
101 int overwrite_index = first_val % NeighborCount;
102 result.neighbors[overwrite_index] = new Node(second_val);
103 return result;
104 }
105 }
106
107 public static void main(String args[]) throws Exception {
108 Node n = null;
109
110 if (!wb.getBooleanVMFlag("UseShenandoahGC") ||
111 !wb.getStringVMFlag("ShenandoahGCMode").equals("generational"))
112 throw new IllegalStateException("Command-line options not honored!");
113
114 for (int count = 10000; count > 0; count--) {
115 n = Node.upheaval(n);
116 }
117
118 if (n.value() != ExpectedLastRandom)
119 throw new IllegalStateException("Random number sequence ended badly!");
120
121 }
122
123 }
124