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.test.lib.unsafe.UnsafeHelper; 35 import jdk.internal.misc.Unsafe; 36 import java.lang.reflect.*; 37 import static jdk.test.lib.Asserts.*; 38 39 public class FieldOffset { 40 public static void main(String args[]) throws Exception { 41 Unsafe unsafe = UnsafeHelper.getUnsafe(); 42 Field[] fields = Test.class.getDeclaredFields(); 43 44 for (int i = 0; i < fields.length; i++) { 45 long offset = unsafe.objectFieldOffset(fields[i]); 46 // Ensure we got a valid offset value back 47 assertNotEquals(offset, unsafe.INVALID_FIELD_OFFSET); 48 49 // Make sure the field offset is unique 50 for (int j = 0; j < i; j++) { 51 assertNotEquals(offset, unsafe.objectFieldOffset(fields[j])); 52 } 53 } 54 55 fields = StaticTest.class.getDeclaredFields(); 56 for (int i = 0; i < fields.length; i++) { 57 long offset = unsafe.staticFieldOffset(fields[i]); 58 // Ensure we got a valid offset value back 59 assertNotEquals(offset, unsafe.INVALID_FIELD_OFFSET); 60 61 // Make sure the field offset is unique 62 for (int j = 0; j < i; j++) { 63 assertNotEquals(offset, unsafe.staticFieldOffset(fields[j])); 64 } 65 } 66 67 } 68 69 class Test { 70 boolean booleanField; 71 byte byteField; 72 char charField; 73 double doubleField; 74 float floatField; 75 int intField; 76 long longField; 77 Object objectField; 78 short shortField; 79 } 80 81 static class StaticTest { 82 static boolean booleanField; 83 static byte byteField; 84 static char charField; 85 static double doubleField; 86 static float floatField; 87 static int intField; 88 static long longField; 89 static Object objectField; 90 static short shortField; 91 } 92 93 }