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  * @modules java.base/jdk.internal.misc
  30  * @run main/othervm -XX:-UseOnStackReplacement -XX:-BackgroundCompilation TestUnsafeUnalignedMismatchedAccesses
  31  * @run main/othervm -XX:-UseOnStackReplacement -XX:-BackgroundCompilation -XX:+UnlockDiagnosticVMOptions -XX:-UseUnalignedAccesses TestUnsafeUnalignedMismatchedAccesses
  32  *
  33  */
  34 
  35 import java.lang.reflect.*;
  36 import jdk.internal.misc.Unsafe;
  37 
  38 public class TestUnsafeUnalignedMismatchedAccesses {
  39 
  40     private static final Unsafe UNSAFE;
  41 
  42     static {
  43         try {
  44             Field unsafeField = Unsafe.class.getDeclaredField("theUnsafe");
  45             unsafeField.setAccessible(true);
  46             UNSAFE = (Unsafe) unsafeField.get(null);
  47         }
  48         catch (Exception e) {
  49             throw new AssertionError(e);
  50         }
  51     }
  52 
  53     static void test1(byte[] array) {
  54         array[0] = 0;
  55         UNSAFE.putIntUnaligned(array, UNSAFE.ARRAY_BYTE_BASE_OFFSET, 0);
  56         array[0] = 0;
  57     }
  58 
  59     static void test2(byte[] array) {
  60         array[0] = 0;
  61         UNSAFE.putIntUnaligned(array, UNSAFE.ARRAY_BYTE_BASE_OFFSET+1, 0);
  62         array[0] = 0;
  63     }
  64 
  65     static void test3(byte[] array) {
  66         array[0] = 0;
  67         UNSAFE.putIntUnaligned(array, UNSAFE.ARRAY_BYTE_BASE_OFFSET+2, 0);
  68         array[0] = 0;
  69     }
  70 
  71     static void test4(byte[] array) {
  72         array[0] = 0;
  73         UNSAFE.putIntUnaligned(array, UNSAFE.ARRAY_BYTE_BASE_OFFSET+3, 0);
  74         array[0] = 0;
  75     }
  76 
  77     static void test5(byte[] array) {
  78         array[0] = 0;
  79         UNSAFE.putInt(array, UNSAFE.ARRAY_BYTE_BASE_OFFSET, 0);
  80         array[0] = 0;
  81     }
  82 
  83     // unaligned access and non escaping allocation
  84     static void test6() {
  85         byte[] array = new byte[10];
  86         UNSAFE.putIntUnaligned(array, UNSAFE.ARRAY_BYTE_BASE_OFFSET+1, -1);
  87         array[0] = 0;
  88     }
  89 
  90     // unaligned access and non escaping allocation
  91     static int test7() {
  92         byte[] array = new byte[10];
  93         UNSAFE.putIntUnaligned(array, UNSAFE.ARRAY_BYTE_BASE_OFFSET+1, -1);
  94         array[0] = 0;
  95         array[2] = 0;
  96         return array[0] + array[1] + array[2] + array[3] + array[4];
  97     }
  98 
  99     // unaligned access with vectorization
 100     static void test8(int[] src1, int[] src2, int[] dst) {
 101         for (int i = 0; i < dst.length-1; i++) {
 102             int res = src1[i] + src2[i];
 103             UNSAFE.putIntUnaligned(dst, UNSAFE.ARRAY_INT_BASE_OFFSET + i*4+1, res);
 104         }
 105     }
 106 
 107     static public void main(String[] args) throws Exception {
 108         byte[] byte_array = new byte[100];
 109         int[] int_array = new int[100];
 110         Object[] obj_array = new Object[100];
 111         TestUnsafeUnalignedMismatchedAccesses test = new TestUnsafeUnalignedMismatchedAccesses();
 112         for (int i = 0; i < 20000; i++) {
 113             test1(byte_array);
 114             test2(byte_array);
 115             test3(byte_array);
 116             test4(byte_array);
 117             test5(byte_array);
 118             test6();
 119             test7();
 120             test8(int_array, int_array, int_array);
 121         }
 122     }
 123 }