1 /*
2  * Copyright (C) 2021 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.server.connectivity.mdns;
18 
19 import android.annotation.NonNull;
20 
21 import com.android.server.connectivity.mdns.util.MdnsUtils;
22 
23 import java.util.Set;
24 import java.util.concurrent.ScheduledExecutorService;
25 import java.util.concurrent.ScheduledThreadPoolExecutor;
26 
27 /**
28  * This class provides {@link ScheduledExecutorService} instances to {@link MdnsServiceTypeClient}
29  * instances, and provides method to shutdown all the created executors.
30  */
31 public class ExecutorProvider {
32 
33     private final Set<ScheduledExecutorService> serviceTypeClientSchedulerExecutors =
34             MdnsUtils.newSet();
35 
36     /** Returns a new {@link ScheduledExecutorService} instance. */
newServiceTypeClientSchedulerExecutor()37     public ScheduledExecutorService newServiceTypeClientSchedulerExecutor() {
38         // TODO: actually use a pool ?
39         ScheduledExecutorService executor = new ScheduledThreadPoolExecutor(1);
40         serviceTypeClientSchedulerExecutors.add(executor);
41         return executor;
42     }
43 
44     /** Shuts down all the created {@link ScheduledExecutorService} instances. */
shutdownAll()45     public void shutdownAll() {
46         for (ScheduledExecutorService executor : serviceTypeClientSchedulerExecutors) {
47             if (executor.isShutdown()) {
48                 continue;
49             }
50             executor.shutdownNow();
51         }
52         serviceTypeClientSchedulerExecutors.clear();
53     }
54 
55     /**
56      * Shutdown one executor service and remove the executor service from the set.
57      * @param executorService the executorService to be shutdown
58      */
shutdownExecutorService(@onNull ScheduledExecutorService executorService)59     public void shutdownExecutorService(@NonNull ScheduledExecutorService executorService) {
60         if (!executorService.isShutdown()) {
61             executorService.shutdownNow();
62         }
63         serviceTypeClientSchedulerExecutors.remove(executorService);
64     }
65 }