| /* |
| * Copyright (C) 2013 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.android.server; |
| |
| import android.os.Handler; |
| import android.os.Looper; |
| import android.os.Process; |
| import android.os.Trace; |
| |
| import com.android.internal.annotations.VisibleForTesting; |
| |
| /** |
| * Shared singleton thread for showing UI. This is a foreground thread, and in |
| * additional should not have operations that can take more than a few ms scheduled |
| * on it to avoid UI jank. |
| */ |
| public final class UiThread extends ServiceThread { |
| private static final long SLOW_DISPATCH_THRESHOLD_MS = 100; |
| private static final long SLOW_DELIVERY_THRESHOLD_MS = 200; |
| private static UiThread sInstance; |
| private static Handler sHandler; |
| |
| private UiThread() { |
| super("android.ui", Process.THREAD_PRIORITY_FOREGROUND, false /*allowIo*/); |
| } |
| |
| @Override |
| public void run() { |
| // Make sure UiThread is in the fg stune boost group |
| Process.setThreadGroup(Process.myTid(), Process.THREAD_GROUP_TOP_APP); |
| super.run(); |
| } |
| |
| private static void ensureThreadLocked() { |
| if (sInstance == null) { |
| sInstance = new UiThread(); |
| sInstance.start(); |
| final Looper looper = sInstance.getLooper(); |
| looper.setTraceTag(Trace.TRACE_TAG_SYSTEM_SERVER); |
| looper.setSlowLogThresholdMs( |
| SLOW_DISPATCH_THRESHOLD_MS, SLOW_DELIVERY_THRESHOLD_MS); |
| sHandler = new Handler(sInstance.getLooper()); |
| } |
| } |
| |
| public static UiThread get() { |
| synchronized (UiThread.class) { |
| ensureThreadLocked(); |
| return sInstance; |
| } |
| } |
| |
| public static Handler getHandler() { |
| synchronized (UiThread.class) { |
| ensureThreadLocked(); |
| return sHandler; |
| } |
| } |
| |
| /** |
| * Disposes current ui thread if it's initialized. Should only be used in tests to set up a |
| * new environment. |
| */ |
| @VisibleForTesting |
| public static void dispose() { |
| synchronized (UiThread.class) { |
| if (sInstance == null) { |
| return; |
| } |
| |
| getHandler().runWithScissors(sInstance::quit, 0 /* timeout */); |
| sInstance = null; |
| } |
| } |
| } |