1 /*
 2  * Copyright (c) 2001, 2021, 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.  Oracle designates this
 8  * particular file as subject to the "Classpath" exception as provided
 9  * by Oracle in the LICENSE file that accompanied this code.
10  *
11  * This code is distributed in the hope that it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14  * version 2 for more details (a copy is included in the LICENSE file that
15  * accompanied this code).
16  *
17  * You should have received a copy of the GNU General Public License version
18  * 2 along with this work; if not, write to the Free Software Foundation,
19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20  *
21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22  * or visit www.oracle.com if you need additional information or have any
23  * questions.
24  */
25 
26 package jdk.internal.reflect;
27 
28 import java.lang.reflect.Field;
29 import java.util.Set;
30 
31 /** Base class for jdk.internal.misc.Unsafe-based FieldAccessors for static
32     fields. The observation is that there are only nine types of
33     fields from the standpoint of reflection code: the eight primitive
34     types and Object. Using class Unsafe instead of generated
35     bytecodes saves memory and loading time for the
36     dynamically-generated FieldAccessors. */
37 
38 abstract class UnsafeStaticFieldAccessorImpl extends UnsafeFieldAccessorImpl {
39     static {
40         Reflection.registerFieldsToFilter(UnsafeStaticFieldAccessorImpl.class,
41                                           Set.of("base"));
42     }
43 
44     protected final Object base; // base
45 
46     UnsafeStaticFieldAccessorImpl(Field field) {
47         super(field);
48         base = unsafe.staticFieldBase(field);
49     }
50 }