shshahma@8655: /*
shshahma@8655:  * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
shshahma@8655:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
shshahma@8655:  *
shshahma@8655:  * This code is free software; you can redistribute it and/or modify it
shshahma@8655:  * under the terms of the GNU General Public License version 2 only, as
shshahma@8655:  * published by the Free Software Foundation.  Oracle designates this
shshahma@8655:  * particular file as subject to the "Classpath" exception as provided
shshahma@8655:  * by Oracle in the LICENSE file that accompanied this code.
shshahma@8655:  *
shshahma@8655:  * This code is distributed in the hope that it will be useful, but WITHOUT
shshahma@8655:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
shshahma@8655:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
shshahma@8655:  * version 2 for more details (a copy is included in the LICENSE file that
shshahma@8655:  * accompanied this code).
shshahma@8655:  *
shshahma@8655:  * You should have received a copy of the GNU General Public License version
shshahma@8655:  * 2 along with this work; if not, write to the Free Software Foundation,
shshahma@8655:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
shshahma@8655:  *
shshahma@8655:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
shshahma@8655:  * or visit www.oracle.com if you need additional information or have any
shshahma@8655:  * questions.
shshahma@8655:  */
shshahma@8655: 
shshahma@8655: /*
shshahma@8655:  * @test
shshahma@8655:  * @bug 8155781
shshahma@8655:  * @modules java.base/jdk.internal.misc
shshahma@8655:  *
shshahma@8655:  * @run main/bootclasspath/othervm -XX:+IgnoreUnrecognizedVMOptions -XX:+UnlockDiagnosticVMOptions
shshahma@8655:  *                                 -XX:-TieredCompilation -Xbatch
shshahma@8655:  *                                 -XX:CompileCommand=dontinline,compiler.unsafe.OpaqueAccesses::test*
shshahma@8655:  *                                 compiler.unsafe.OpaqueAccesses
shshahma@8655:  */
shshahma@8655: package compiler.unsafe;
shshahma@8655: 
shshahma@8655: import sun.misc.Unsafe;
shshahma@8655: 
shshahma@8655: import java.lang.reflect.Field;
shshahma@8655: 
shshahma@8655: public class OpaqueAccesses {
shshahma@8655:     private static final Unsafe UNSAFE = Unsafe.getUnsafe();
shshahma@8655: 
shshahma@8655:     private static final Object INSTANCE = new OpaqueAccesses();
shshahma@8655: 
shshahma@8655:     private static final Object[] ARRAY = new Object[10];
shshahma@8655: 
shshahma@8655:     private static final long F_OFFSET;
shshahma@8655:     private static final long E_OFFSET;
shshahma@8655: 
shshahma@8655:     static {
shshahma@8655:         try {
shshahma@8655:             Field field = OpaqueAccesses.class.getDeclaredField("f");
shshahma@8655:             F_OFFSET = UNSAFE.objectFieldOffset(field);
shshahma@8655: 
shshahma@8655:             E_OFFSET = UNSAFE.arrayBaseOffset(ARRAY.getClass());
shshahma@8655:         } catch (NoSuchFieldException e) {
shshahma@8655:             throw new Error(e);
shshahma@8655:         }
shshahma@8655:     }
shshahma@8655: 
shshahma@8655:     private Object f = new Object();
shshahma@8655: 
shshahma@8655:     static Object testFixedOffsetField(Object o) {
shshahma@8655:         return UNSAFE.getObject(o, F_OFFSET);
shshahma@8655:     }
shshahma@8655: 
shshahma@8655:     static int testFixedOffsetHeader0(Object o) {
shshahma@8655:         return UNSAFE.getInt(o, 0);
shshahma@8655:     }
shshahma@8655: 
shshahma@8655:     static int testFixedOffsetHeader4(Object o) {
shshahma@8655:         return UNSAFE.getInt(o, 4);
shshahma@8655:     }
shshahma@8655: 
shshahma@8655:     static Object testFixedBase(long off) {
shshahma@8655:         return UNSAFE.getObject(INSTANCE, off);
shshahma@8655:     }
shshahma@8655: 
shshahma@8655:     static Object testOpaque(Object o, long off) {
shshahma@8655:         return UNSAFE.getObject(o, off);
shshahma@8655:     }
shshahma@8655: 
shshahma@8655:     static int testFixedOffsetHeaderArray0(Object[] arr) {
shshahma@8655:         return UNSAFE.getInt(arr, 0);
shshahma@8655:     }
shshahma@8655: 
shshahma@8655:     static int testFixedOffsetHeaderArray4(Object[] arr) {
shshahma@8655:         return UNSAFE.getInt(arr, 4);
shshahma@8655:     }
shshahma@8655: 
shshahma@8655:     static Object testFixedOffsetArray(Object[] arr) {
shshahma@8655:         return UNSAFE.getObject(arr, E_OFFSET);
shshahma@8655:     }
shshahma@8655: 
shshahma@8655:     static Object testFixedBaseArray(long off) {
shshahma@8655:         return UNSAFE.getObject(ARRAY, off);
shshahma@8655:     }
shshahma@8655: 
shshahma@8655:     static Object testOpaqueArray(Object[] o, long off) {
shshahma@8655:         return UNSAFE.getObject(o, off);
shshahma@8655:     }
shshahma@8655: 
shshahma@8655:     static final long ADDR = UNSAFE.allocateMemory(10);
shshahma@8655:     static boolean flag;
shshahma@8655: 
shshahma@8655:     static int testMixedAccess() {
shshahma@8655:         flag = !flag;
shshahma@8655:         Object o = (flag ? INSTANCE : null);
shshahma@8655:         long off = (flag ? F_OFFSET : ADDR);
shshahma@8655:         return UNSAFE.getInt(o, off);
shshahma@8655:     }
shshahma@8655: 
shshahma@8655:     public static void main(String[] args) {
shshahma@8655:         for (int i = 0; i < 20_000; i++) {
shshahma@8655:             // Instance
shshahma@8655:             testFixedOffsetField(INSTANCE);
shshahma@8655:             testFixedOffsetHeader0(INSTANCE);
shshahma@8655:             testFixedOffsetHeader4(INSTANCE);
shshahma@8655:             testFixedBase(F_OFFSET);
shshahma@8655:             testOpaque(INSTANCE, F_OFFSET);
shshahma@8655:             testMixedAccess();
shshahma@8655: 
shshahma@8655:             // Array
shshahma@8655:             testFixedOffsetHeaderArray0(ARRAY);
shshahma@8655:             testFixedOffsetHeaderArray4(ARRAY);
shshahma@8655:             testFixedOffsetArray(ARRAY);
shshahma@8655:             testFixedBaseArray(E_OFFSET);
shshahma@8655:             testOpaqueArray(ARRAY, E_OFFSET);
shshahma@8655:         }
shshahma@8655:         System.out.println("TEST PASSED");
shshahma@8655:     }
shshahma@8655: }