1 /* 2 * Copyright (c) 2015, 2016, 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 Verifies the behaviour of Unsafe.fieldOffset 27 * @library /test/lib 28 * @modules java.base/jdk.internal.misc 29 * java.management 30 * @run main FieldOffset 31 */ 32 33 import java.lang.reflect.Field; 34 import jdk.internal.misc.Unsafe; 35 import java.lang.reflect.*; 36 import static jdk.test.lib.Asserts.*; 37 38 public class FieldOffset { 39 public static void main(String args[]) throws Exception { 40 Unsafe unsafe = Unsafe.getUnsafe(); 41 Field[] fields = Test.class.getDeclaredFields(); 42 43 for (int i = 0; i < fields.length; i++) { 44 long offset = unsafe.objectFieldOffset(fields[i]); 45 // Ensure we got a valid offset value back 46 assertNotEquals(offset, unsafe.INVALID_FIELD_OFFSET); 47 48 // Make sure the field offset is unique 49 for (int j = 0; j < i; j++) { 50 assertNotEquals(offset, unsafe.objectFieldOffset(fields[j])); 51 } 52 } 53 54 fields = StaticTest.class.getDeclaredFields(); 55 for (int i = 0; i < fields.length; i++) { 56 long offset = unsafe.staticFieldOffset(fields[i]); 57 // Ensure we got a valid offset value back 58 assertNotEquals(offset, unsafe.INVALID_FIELD_OFFSET); 59 60 // Make sure the field offset is unique 61 for (int j = 0; j < i; j++) { 62 assertNotEquals(offset, unsafe.staticFieldOffset(fields[j])); 63 } 64 } 65 66 } 67 68 class Test { 69 boolean booleanField; 70 byte byteField; 71 char charField; 72 double doubleField; 73 float floatField; 74 int intField; 75 long longField; 76 Object objectField; 77 short shortField; 78 } 79 80 static class StaticTest { 81 static boolean booleanField; 82 static byte byteField; 83 static char charField; 84 static double doubleField; 85 static float floatField; 86 static int intField; 87 static long longField; 88 static Object objectField; 89 static short shortField; 90 } 91 92 }