1 /*
2  * Copyright (C) 2023 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.rkpdapp;
18 
19 import java.util.concurrent.ExecutorService;
20 import java.util.concurrent.LinkedBlockingQueue;
21 import java.util.concurrent.ThreadPoolExecutor;
22 import java.util.concurrent.TimeUnit;
23 
24 /**
25  * This class provides a global thread pool to RKPD app.
26  */
27 public class ThreadPool {
28     public static final int NUMBER_OF_THREADS = 4;
29     /*
30      * This thread pool has a minimum of 0 threads and a maximum of up to 4. If
31      * a thread is idle for more than 60 seconds, it is terminated. RKPD is idle
32      * most of the time. So, this way we can don't keep unused threads around.
33      */
34     public static final ExecutorService EXECUTOR;
35 
36     static {
37         ThreadPoolExecutor executor =
38                 new ThreadPoolExecutor(/*corePoolSize=*/ NUMBER_OF_THREADS,
39                     /*maximumPoolSize=*/ NUMBER_OF_THREADS,
40                     /*keepAliveTime=*/ 60L, /*unit=*/ TimeUnit.SECONDS,
41                     /*workQueue=*/ new LinkedBlockingQueue<Runnable>());
42         executor.allowCoreThreadTimeOut(true);
43         EXECUTOR = executor;
44     }
45 }
46