1/*
2 * Copyright (C) 2016 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 android.net;
18
19import android.os.HandlerThread;
20import android.os.Looper;
21
22/**
23 * Shared singleton connectivity thread for the system.  This is a thread for
24 * connectivity operations such as AsyncChannel connections to system services.
25 * Various connectivity manager objects can use this singleton as a common
26 * resource for their handlers instead of creating separate threads of their own.
27 * @hide
28 */
29public final class ConnectivityThread extends HandlerThread {
30
31    // A class implementing the lazy holder idiom: the unique static instance
32    // of ConnectivityThread is instantiated in a thread-safe way (guaranteed by
33    // the language specs) the first time that Singleton is referenced in get()
34    // or getInstanceLooper().
35    private static class Singleton {
36        private static final ConnectivityThread INSTANCE = createInstance();
37    }
38
39    private ConnectivityThread() {
40        super("ConnectivityThread");
41    }
42
43    private static ConnectivityThread createInstance() {
44        ConnectivityThread t = new ConnectivityThread();
45        t.start();
46        return t;
47    }
48
49    public static ConnectivityThread get() {
50        return Singleton.INSTANCE;
51    }
52
53    public static Looper getInstanceLooper() {
54        return Singleton.INSTANCE.getLooper();
55    }
56}
57