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