Dianne Hackborn | 8d044e8 | 2013-04-30 17:24:15 -0700 | [diff] [blame] | 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; |
Jeff Sharkey | 74cd3de | 2016-04-06 17:40:54 -0600 | [diff] [blame] | 20 | import android.os.Trace; |
Dianne Hackborn | 8d044e8 | 2013-04-30 17:24:15 -0700 | [diff] [blame] | 21 | |
| 22 | /** |
| 23 | * Shared singleton thread for showing UI. This is a foreground thread, and in |
| 24 | * additional should not have operations that can take more than a few ms scheduled |
| 25 | * on it to avoid UI jank. |
| 26 | */ |
Jeff Brown | 4ccb823 | 2014-01-16 22:16:42 -0800 | [diff] [blame] | 27 | public final class UiThread extends ServiceThread { |
Dianne Hackborn | 8d044e8 | 2013-04-30 17:24:15 -0700 | [diff] [blame] | 28 | private static UiThread sInstance; |
| 29 | private static Handler sHandler; |
| 30 | |
| 31 | private UiThread() { |
Jeff Brown | 4ccb823 | 2014-01-16 22:16:42 -0800 | [diff] [blame] | 32 | super("android.ui", android.os.Process.THREAD_PRIORITY_FOREGROUND, false /*allowIo*/); |
Dianne Hackborn | 8d044e8 | 2013-04-30 17:24:15 -0700 | [diff] [blame] | 33 | } |
| 34 | |
| 35 | private static void ensureThreadLocked() { |
| 36 | if (sInstance == null) { |
| 37 | sInstance = new UiThread(); |
| 38 | sInstance.start(); |
Jeff Sharkey | 74cd3de | 2016-04-06 17:40:54 -0600 | [diff] [blame] | 39 | sInstance.getLooper().setTraceTag(Trace.TRACE_TAG_ACTIVITY_MANAGER); |
Dianne Hackborn | 8d044e8 | 2013-04-30 17:24:15 -0700 | [diff] [blame] | 40 | sHandler = new Handler(sInstance.getLooper()); |
Dianne Hackborn | 8d044e8 | 2013-04-30 17:24:15 -0700 | [diff] [blame] | 41 | } |
| 42 | } |
| 43 | |
| 44 | public static UiThread get() { |
| 45 | synchronized (UiThread.class) { |
| 46 | ensureThreadLocked(); |
| 47 | return sInstance; |
| 48 | } |
| 49 | } |
| 50 | |
| 51 | public static Handler getHandler() { |
| 52 | synchronized (UiThread.class) { |
| 53 | ensureThreadLocked(); |
| 54 | return sHandler; |
| 55 | } |
| 56 | } |
| 57 | } |