1 /* 2 * Copyright (C) 2013 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 com.android.server; 18 19 import android.os.Handler; 20 import android.os.HandlerThread; 21 import android.os.StrictMode; 22 import android.util.Slog; 23 24 /** 25 * Shared singleton thread for showing UI. This is a foreground thread, and in 26 * additional should not have operations that can take more than a few ms scheduled 27 * on it to avoid UI jank. 28 */ 29 public final class UiThread extends HandlerThread { 30 private static UiThread sInstance; 31 private static Handler sHandler; 32 33 private UiThread() { 34 super("android.ui", android.os.Process.THREAD_PRIORITY_FOREGROUND); 35 } 36 37 private static void ensureThreadLocked() { 38 if (sInstance == null) { 39 sInstance = new UiThread(); 40 sInstance.start(); 41 sHandler = new Handler(sInstance.getLooper()); 42 sHandler.post(new Runnable() { 43 @Override 44 public void run() { 45 //Looper.myLooper().setMessageLogging(new LogPrinter( 46 // Log.VERBOSE, "WindowManagerPolicy", Log.LOG_ID_SYSTEM)); 47 android.os.Process.setCanSelfBackground(false); 48 49 // For debug builds, log event loop stalls to dropbox for analysis. 50 if (StrictMode.conditionallyEnableDebugLogging()) { 51 Slog.i("UiThread", "Enabled StrictMode logging for UI thread"); 52 } 53 } 54 }); 55 } 56 } 57 58 public static UiThread get() { 59 synchronized (UiThread.class) { 60 ensureThreadLocked(); 61 return sInstance; 62 } 63 } 64 65 public static Handler getHandler() { 66 synchronized (UiThread.class) { 67 ensureThreadLocked(); 68 return sHandler; 69 } 70 } 71 } 72
