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.concurrent.LinkedBlockingQueue; 23 import java.util.concurrent.ThreadFactory; 24 import java.util.concurrent.ThreadPoolExecutor; 25 import java.util.concurrent.TimeUnit; 26 import java.util.concurrent.atomic.AtomicInteger; 27 28 /** 29 * Various different executors used in Launcher 30 */ 31 public class Executors { 32 33 private static final int POOL_SIZE = 34 Math.max(Runtime.getRuntime().availableProcessors(), 2); 35 private static final int KEEP_ALIVE = 1; 36 37 /** 38 * An {@link ThreadPoolExecutor} to be used with async task with no limit on the queue size. 39 */ 40 public static final ThreadPoolExecutor THREAD_POOL_EXECUTOR = new ThreadPoolExecutor( 41 POOL_SIZE, POOL_SIZE, KEEP_ALIVE, TimeUnit.SECONDS, new LinkedBlockingQueue<>()); 42 43 /** 44 * Returns the executor for running tasks on the main thread. 45 */ 46 public static final LooperExecutor MAIN_EXECUTOR = 47 new LooperExecutor(Looper.getMainLooper()); 48 49 /** 50 * A background executor for using time sensitive actions where user is waiting for response. 51 */ 52 public static final LooperExecutor UI_HELPER_EXECUTOR = 53 new LooperExecutor( 54 createAndStartNewLooper("UiThreadHelper", Process.THREAD_PRIORITY_FOREGROUND)); 55 56 /** 57 * Utility method to get a started handler thread statically 58 */ createAndStartNewLooper(String name)59 public static Looper createAndStartNewLooper(String name) { 60 return createAndStartNewLooper(name, Process.THREAD_PRIORITY_DEFAULT); 61 } 62 63 /** 64 * Utility method to get a started handler thread statically with the provided priority 65 */ createAndStartNewLooper(String name, int priority)66 public static Looper createAndStartNewLooper(String name, int priority) { 67 HandlerThread thread = new HandlerThread(name, priority); 68 thread.start(); 69 return thread.getLooper(); 70 } 71 72 /** 73 * Executor used for running Launcher model related tasks (eg loading icons or updated db) 74 */ 75 public static final LooperExecutor MODEL_EXECUTOR = 76 new LooperExecutor(createAndStartNewLooper("launcher-loader")); 77 78 /** 79 * A simple ThreadFactory to set the thread name and priority when used with executors. 80 */ 81 public static class SimpleThreadFactory implements ThreadFactory { 82 83 private final int mPriority; 84 private final String mNamePrefix; 85 86 private final AtomicInteger mCount = new AtomicInteger(0); 87 SimpleThreadFactory(String namePrefix, int priority)88 public SimpleThreadFactory(String namePrefix, int priority) { 89 mNamePrefix = namePrefix; 90 mPriority = priority; 91 } 92 93 @Override newThread(Runnable runnable)94 public Thread newThread(Runnable runnable) { 95 Thread t = new Thread(() -> { 96 Process.setThreadPriority(mPriority); 97 runnable.run(); 98 }, mNamePrefix + mCount.incrementAndGet()); 99 return t; 100 } 101 } 102 } 103