| /* |
| * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* |
| * @test |
| * @bug 8016474 |
| * @summary The bug only happens with C1 and G1 using a different ObjectAlignmentInBytes than KlassAlignmentInBytes (which is 8) |
| * @run main/othervm -Xbatch -XX:+IgnoreUnrecognizedVMOptions -XX:ObjectAlignmentInBytes=32 GetUnsafeObjectG1PreBarrier |
| */ |
| |
| import java.lang.reflect.Field; |
| |
| import sun.misc.Unsafe; |
| |
| public class GetUnsafeObjectG1PreBarrier { |
| private static final Unsafe unsafe; |
| private static final int N = 100_000; |
| |
| static { |
| try { |
| Field theUnsafe = Unsafe.class.getDeclaredField("theUnsafe"); |
| theUnsafe.setAccessible(true); |
| unsafe = (Unsafe) theUnsafe.get(null); |
| } catch (NoSuchFieldException | IllegalAccessException e) { |
| throw new IllegalStateException(e); |
| } |
| } |
| |
| public Object a; |
| |
| public static void main(String[] args) throws Throwable { |
| new GetUnsafeObjectG1PreBarrier(); |
| } |
| |
| public GetUnsafeObjectG1PreBarrier() throws Throwable { |
| doit(); |
| } |
| |
| private void doit() throws Throwable { |
| Field field = GetUnsafeObjectG1PreBarrier.class.getField("a"); |
| long fieldOffset = unsafe.objectFieldOffset(field); |
| |
| for (int i = 0; i < N; i++) { |
| readField(this, fieldOffset); |
| } |
| } |
| |
| private void readField(Object o, long fieldOffset) { |
| unsafe.getObject(o, fieldOffset); |
| } |
| } |