1 /* 2 * Copyright (c) 2019, Red Hat, 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 * @test TestUnsafeOffheapSwap 26 * @summary Miscompilation in Unsafe off-heap swap routines 27 * @key gc 28 * @requires vm.gc.Shenandoah & !vm.graal.enabled 29 * @modules java.base/jdk.internal.misc:+open 30 * 31 * @run main/othervm -XX:-UseOnStackReplacement -XX:-BackgroundCompilation -XX:-TieredCompilation 32 * -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC 33 * TestUnsafeOffheapSwap 34 */ 35 36 import java.util.*; 37 import jdk.internal.misc.Unsafe; 38 39 public class TestUnsafeOffheapSwap { 40 41 static final int SIZE = 10000; 42 static final long SEED = 1; 43 44 static final jdk.internal.misc.Unsafe UNSAFE = Unsafe.getUnsafe(); 45 static final int SCALE = UNSAFE.ARRAY_INT_INDEX_SCALE; 46 47 static Memory mem; 48 static int[] arr; 49 50 public static void main(String[] args) throws Exception { 51 // Bug is exposed when memory.addr is not known statically 52 mem = new Memory(SIZE*SCALE); 53 arr = new int[SIZE]; 54 55 for (int i = 0; i < 10; i++) { 56 test(); 57 } 58 } 59 60 static void test() { 61 Random rnd = new Random(SEED); 62 for (int i = 0; i < SIZE; i++) { 63 int value = rnd.nextInt(); 64 mem.setInt(i, value); 65 arr[i] = value; 66 } 67 68 for (int i = 0; i < SIZE; i++) { 69 if (arr[i] != mem.getInt(i)) { 70 throw new IllegalStateException("TESTBUG: Values mismatch before swaps"); 71 } 72 } 73 74 for (int i = 1; i < SIZE; i++) { 75 mem.swap(i - 1, i); 76 int tmp = arr[i - 1]; 77 arr[i - 1] = arr[i]; 78 arr[i] = tmp; 79 } 80 81 for (int i = 0; i < SIZE; i++) { 82 if (arr[i] != mem.getInt(i)) { 83 throw new IllegalStateException("Values mismatch after swaps"); 84 } 85 } 86 } 87 88 static class Memory { 89 private final long addr; 90 91 Memory(int size) { 92 addr = UNSAFE.allocateMemory(size); 93 } 94 95 public int getInt(int idx) { 96 return UNSAFE.getInt(addr + idx*SCALE); 97 } 98 99 public void setInt(int idx, int val) { 100 UNSAFE.putInt(addr + idx*SCALE, val); 101 } 102 103 public void swap(int a, int b) { 104 int tmp = getInt(a); 105 setInt(a, getInt(b)); 106 setInt(b, tmp); 107 } 108 } 109 }