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