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 package com.android.settings.utils; 17 18 import android.os.Looper; 19 20 public class ThreadUtils { 21 private static volatile Thread sMainThread; 22 23 /** 24 * Returns true if the current thread is the UI thread. 25 */ isMainThread()26 public static boolean isMainThread() { 27 if (sMainThread == null) { 28 sMainThread = Looper.getMainLooper().getThread(); 29 } 30 return Thread.currentThread() == sMainThread; 31 } 32 33 /** 34 * Checks that the current thread is the UI thread. Otherwise throws an exception. 35 */ ensureMainThread()36 public static void ensureMainThread() { 37 if (!isMainThread()) { 38 throw new RuntimeException("Must be called on the UI thread"); 39 } 40 } 41 42 } 43