GetPutByte.java revision 10551:b64432bae527 
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 * @test
26 * @summary Verify behaviour of Unsafe.get/putByte
27 * @library /testlibrary
28 * @modules java.base/jdk.internal.misc
29 *          java.management
30 * @run main GetPutByte
31 */
32
33import java.lang.reflect.Field;
34import jdk.test.lib.*;
35import sun.misc.Unsafe;
36import static jdk.test.lib.Asserts.*;
37
38public class GetPutByte {
39    public static void main(String args[]) throws Exception {
40        Unsafe unsafe = Utils.getUnsafe();
41        Test t = new Test();
42        Field field = Test.class.getField("b");
43
44        long offset = unsafe.objectFieldOffset(field);
45        assertEquals((byte)0, unsafe.getByte(t, offset));
46        unsafe.putByte(t, offset, (byte)1);
47        assertEquals((byte)1, unsafe.getByte(t, offset));
48
49        long address = unsafe.allocateMemory(8);
50        unsafe.putByte(address, (byte)2);
51        assertEquals((byte)2, unsafe.getByte(address));
52        unsafe.freeMemory(address);
53
54        byte arrayByte[] = { -1, 0, 1, 2 };
55        int scale = unsafe.arrayIndexScale(arrayByte.getClass());
56        offset = unsafe.arrayBaseOffset(arrayByte.getClass());
57        for (int i = 0; i < arrayByte.length; i++) {
58            assertEquals(unsafe.getByte(arrayByte, offset), arrayByte[i]);
59            offset += scale;
60        }
61    }
62
63    static class Test {
64        public byte b = 0;
65    }
66}
67