1 /* 2 * Copyright (C) 2008 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.launcher3.util; 17 18 import android.os.HandlerThread; 19 import android.os.Looper; 20 import android.os.Process; 21 22 import java.util.Map; 23 import java.util.concurrent.ConcurrentHashMap; 24 import java.util.concurrent.ExecutorService; 25 import java.util.concurrent.LinkedBlockingQueue; 26 import java.util.concurrent.ThreadFactory; 27 import java.util.concurrent.ThreadPoolExecutor; 28 import java.util.concurrent.TimeUnit; 29 import java.util.concurrent.atomic.AtomicInteger; 30 31 /** 32 * Various different executors used in Launcher 33 */ 34 public class Executors { 35 36 private static final int POOL_SIZE = 37 Math.max(Runtime.getRuntime().availableProcessors(), 2); 38 private static final int KEEP_ALIVE = 1; 39 40 /** Dedicated executor instances for work depending on other packages. */ 41 private static final Map<String, LooperExecutor> PACKAGE_EXECUTORS = new ConcurrentHashMap<>(); 42 43 /** 44 * An {@link ThreadPoolExecutor} to be used with async task with no limit on the queue size. 45 */ 46 public static final ThreadPoolExecutor THREAD_POOL_EXECUTOR = new ThreadPoolExecutor( 47 POOL_SIZE, POOL_SIZE, KEEP_ALIVE, TimeUnit.SECONDS, new LinkedBlockingQueue<>()); 48 49 /** 50 * Returns the executor for running tasks on the main thread. 51 */ 52 public static final LooperExecutor MAIN_EXECUTOR = 53 new LooperExecutor(Looper.getMainLooper()); 54 55 /** 56 * A background executor for using time sensitive actions where user is waiting for response. 57 */ 58 public static final LooperExecutor UI_HELPER_EXECUTOR = 59 new LooperExecutor( 60 createAndStartNewLooper("UiThreadHelper", Process.THREAD_PRIORITY_FOREGROUND)); 61 62 63 /** A background executor to preinflate views. */ 64 public static final ExecutorService VIEW_PREINFLATION_EXECUTOR = 65 java.util.concurrent.Executors.newSingleThreadExecutor(); 66 67 /** 68 * Utility method to get a started handler thread statically 69 */ createAndStartNewLooper(String name)70 public static Looper createAndStartNewLooper(String name) { 71 return createAndStartNewLooper(name, Process.THREAD_PRIORITY_DEFAULT); 72 } 73 74 /** 75 * Utility method to get a started handler thread statically with the provided priority 76 */ createAndStartNewLooper(String name, int priority)77 public static Looper createAndStartNewLooper(String name, int priority) { 78 HandlerThread thread = new HandlerThread(name, priority); 79 thread.start(); 80 return thread.getLooper(); 81 } 82 83 /** 84 * Executor used for running Launcher model related tasks (eg loading icons or updated db) 85 */ 86 public static final LooperExecutor MODEL_EXECUTOR = 87 new LooperExecutor(createAndStartNewLooper("launcher-loader")); 88 89 /** 90 * Returns and caches a single thread executor for a given package. 91 * 92 * @param packageName Package associated with the executor. 93 */ getPackageExecutor(String packageName)94 public static LooperExecutor getPackageExecutor(String packageName) { 95 return PACKAGE_EXECUTORS.computeIfAbsent( 96 packageName, p -> new LooperExecutor( 97 createAndStartNewLooper(p, Process.THREAD_PRIORITY_DEFAULT))); 98 } 99 100 /** 101 * A simple ThreadFactory to set the thread name and priority when used with executors. 102 */ 103 public static class SimpleThreadFactory implements ThreadFactory { 104 105 private final int mPriority; 106 private final String mNamePrefix; 107 108 private final AtomicInteger mCount = new AtomicInteger(0); 109 SimpleThreadFactory(String namePrefix, int priority)110 public SimpleThreadFactory(String namePrefix, int priority) { 111 mNamePrefix = namePrefix; 112 mPriority = priority; 113 } 114 115 @Override newThread(Runnable runnable)116 public Thread newThread(Runnable runnable) { 117 Thread t = new Thread(() -> { 118 Process.setThreadPriority(mPriority); 119 runnable.run(); 120 }, mNamePrefix + mCount.incrementAndGet()); 121 return t; 122 } 123 } 124 } 125