1 /*
   2  * Copyright (c) 2015, Oracle and/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 /**
  26  * @test
  27  * @bug 8136473
  28  * @summary Mismatched stores on same slice possible with Unsafe.Put*Unaligned methods
  29  * @run main/othervm -XX:-UseOnStackReplacement -XX:-BackgroundCompilation TestUnsafeUnalignedMismatchedAccesses
  30  * @run main/othervm -XX:-UseOnStackReplacement -XX:-BackgroundCompilation -XX:+UnlockDiagnosticVMOptions -XX:-UseUnalignedAccesses TestUnsafeUnalignedMismatchedAccesses
  31  *
  32  */
  33 
  34 import java.lang.reflect.*;
  35 import jdk.internal.misc.Unsafe;
  36 
  37 public class TestUnsafeUnalignedMismatchedAccesses {
  38 
  39     private static final Unsafe UNSAFE;
  40 
  41     static {
  42         try {
  43             Field unsafeField = Unsafe.class.getDeclaredField("theUnsafe");
  44             unsafeField.setAccessible(true);
  45             UNSAFE = (Unsafe) unsafeField.get(null);
  46         }
  47         catch (Exception e) {
  48             throw new AssertionError(e);
  49         }
  50     }
  51 
  52     static void test1(byte[] array) {
  53         array[0] = 0;
  54         UNSAFE.putIntUnaligned(array, UNSAFE.ARRAY_BYTE_BASE_OFFSET, 0);
  55         array[0] = 0;
  56     }
  57 
  58     static void test2(byte[] array) {
  59         array[0] = 0;
  60         UNSAFE.putIntUnaligned(array, UNSAFE.ARRAY_BYTE_BASE_OFFSET+1, 0);
  61         array[0] = 0;
  62     }
  63 
  64     static void test3(byte[] array) {
  65         array[0] = 0;
  66         UNSAFE.putIntUnaligned(array, UNSAFE.ARRAY_BYTE_BASE_OFFSET+2, 0);
  67         array[0] = 0;
  68     }
  69 
  70     static void test4(byte[] array) {
  71         array[0] = 0;
  72         UNSAFE.putIntUnaligned(array, UNSAFE.ARRAY_BYTE_BASE_OFFSET+3, 0);
  73         array[0] = 0;
  74     }
  75 
  76     static void test5(byte[] array) {
  77         array[0] = 0;
  78         UNSAFE.putInt(array, UNSAFE.ARRAY_BYTE_BASE_OFFSET, 0);
  79         array[0] = 0;
  80     }
  81 
  82     // unaligned access and non escaping allocation
  83     static void test6() {
  84         byte[] array = new byte[10];
  85         UNSAFE.putIntUnaligned(array, UNSAFE.ARRAY_BYTE_BASE_OFFSET+1, -1);
  86         array[0] = 0;
  87     }
  88 
  89     // unaligned access and non escaping allocation
  90     static int test7() {
  91         byte[] array = new byte[10];
  92         UNSAFE.putIntUnaligned(array, UNSAFE.ARRAY_BYTE_BASE_OFFSET+1, -1);
  93         array[0] = 0;
  94         array[2] = 0;
  95         return array[0] + array[1] + array[2] + array[3] + array[4];
  96     }
  97 
  98     // unaligned access with vectorization
  99     static void test8(int[] src1, int[] src2, int[] dst) {
 100         for (int i = 0; i < dst.length-1; i++) {
 101             int res = src1[i] + src2[i];
 102             UNSAFE.putIntUnaligned(dst, UNSAFE.ARRAY_INT_BASE_OFFSET + i*4+1, res);
 103         }
 104     }
 105 
 106     static public void main(String[] args) throws Exception {
 107         byte[] byte_array = new byte[100];
 108         int[] int_array = new int[100];
 109         Object[] obj_array = new Object[100];
 110         TestUnsafeUnalignedMismatchedAccesses test = new TestUnsafeUnalignedMismatchedAccesses();
 111         for (int i = 0; i < 20000; i++) {
 112             test1(byte_array);
 113             test2(byte_array);
 114             test3(byte_array);
 115             test4(byte_array);
 116             test5(byte_array);
 117             test6();
 118             test7();
 119             test8(int_array, int_array, int_array);
 120         }
 121     }
 122 }