1/*
2 * Copyright (c) 2006, 2012, 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
26package java.io;
27
28/**
29 * Context during upcalls from object stream to class-defined
30 * readObject/writeObject methods.
31 * Holds object currently being deserialized and descriptor for current class.
32 *
33 * This context keeps track of the thread it was constructed on, and allows
34 * only a single call of defaultReadObject, readFields, defaultWriteObject
35 * or writeFields which must be invoked on the same thread before the class's
36 * readObject/writeObject method has returned.
37 * If not set to the current thread, the getObj method throws NotActiveException.
38 */
39final class SerialCallbackContext {
40    private final Object obj;
41    private final ObjectStreamClass desc;
42    /**
43     * Thread this context is in use by.
44     * As this only works in one thread, we do not need to worry about thread-safety.
45     */
46    private Thread thread;
47
48    public SerialCallbackContext(Object obj, ObjectStreamClass desc) {
49        this.obj = obj;
50        this.desc = desc;
51        this.thread = Thread.currentThread();
52    }
53
54    public Object getObj() throws NotActiveException {
55        checkAndSetUsed();
56        return obj;
57    }
58
59    public ObjectStreamClass getDesc() {
60        return desc;
61    }
62
63    private void checkAndSetUsed() throws NotActiveException {
64        if (thread != Thread.currentThread()) {
65             throw new NotActiveException(
66              "not in readObject invocation or fields already read");
67        }
68        thread = null;
69    }
70
71    public void setUsed() {
72        thread = null;
73    }
74}
75