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