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