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 17 package android.net; 18 19 import android.os.HandlerThread; 20 import 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 */ 29 public 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 ConnectivityThread()39 private ConnectivityThread() { 40 super("ConnectivityThread"); 41 } 42 createInstance()43 private static ConnectivityThread createInstance() { 44 ConnectivityThread t = new ConnectivityThread(); 45 t.start(); 46 return t; 47 } 48 get()49 public static ConnectivityThread get() { 50 return Singleton.INSTANCE; 51 } 52 getInstanceLooper()53 public static Looper getInstanceLooper() { 54 return Singleton.INSTANCE.getLooper(); 55 } 56 } 57