1/*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package dalvik.system;
18
19import java.io.FileDescriptor;
20import java.net.Socket;
21import java.net.SocketException;
22
23/**
24 * Callbacks for socket assignment and reassignment.
25 *
26 * @hide
27 */
28public abstract class SocketTagger {
29
30    private static SocketTagger tagger = new SocketTagger() {
31        @Override public void tag(FileDescriptor socketDescriptor) throws SocketException {}
32        @Override public void untag(FileDescriptor socketDescriptor) throws SocketException {}
33    };
34
35    /**
36     * Notified when {@code socketDescriptor} is either assigned to the current
37     * thread. The socket is either newly connected or reused from a connection
38     * pool. Implementations of this method should be thread-safe.
39     */
40    public abstract void tag(FileDescriptor socketDescriptor) throws SocketException;
41
42    /**
43     * Notified when {@code socketDescriptor} is released from the current
44     * thread to a connection pool. Implementations of this method should be
45     * thread-safe.
46     *
47     * <p><strong>Note:</strong> this method will not be invoked when the socket
48     * is closed.
49     */
50    public abstract void untag(FileDescriptor socketDescriptor) throws SocketException;
51
52    public final void tag(Socket socket) throws SocketException {
53        if (!socket.isClosed()) {
54            tag(socket.getFileDescriptor$());
55        }
56    }
57
58    public final void untag(Socket socket) throws SocketException {
59        if (!socket.isClosed()) {
60            untag(socket.getFileDescriptor$());
61        }
62    }
63
64    /**
65     * Sets this process' socket tagger to {@code tagger}.
66     */
67    public static synchronized void set(SocketTagger tagger) {
68        if (tagger == null) {
69            throw new NullPointerException("tagger == null");
70        }
71        SocketTagger.tagger = tagger;
72    }
73
74    /**
75     * Returns this process socket tagger.
76     */
77    public static synchronized SocketTagger get() {
78        return tagger;
79    }
80}
81