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.tare;
18 
19 import android.os.Handler;
20 import android.os.HandlerExecutor;
21 import android.os.HandlerThread;
22 import android.os.Looper;
23 import android.os.Trace;
24 
25 import java.util.concurrent.Executor;
26 
27 /**
28  * Singleton thread for all of TARE.
29  *
30  * @see com.android.internal.os.BackgroundThread
31  */
32 final class TareHandlerThread extends HandlerThread {
33 
34     private static TareHandlerThread sInstance;
35     private static Executor sHandlerExecutor;
36     private static Handler sHandler;
37 
TareHandlerThread()38     private TareHandlerThread() {
39         super("tare");
40     }
41 
ensureThreadLocked()42     private static void ensureThreadLocked() {
43         if (sInstance == null) {
44             sInstance = new TareHandlerThread();
45             sInstance.start();
46             final Looper looper = sInstance.getLooper();
47             looper.setTraceTag(Trace.TRACE_TAG_SYSTEM_SERVER);
48             sHandler = new Handler(sInstance.getLooper());
49             sHandlerExecutor = new HandlerExecutor(sHandler);
50         }
51     }
52 
get()53     static TareHandlerThread get() {
54         synchronized (TareHandlerThread.class) {
55             ensureThreadLocked();
56         }
57         return sInstance;
58     }
59 
60     /** Returns the singleton handler executor for TareHandlerThread */
getExecutor()61     public static Executor getExecutor() {
62         synchronized (TareHandlerThread.class) {
63             ensureThreadLocked();
64             return sHandlerExecutor;
65         }
66     }
67 
68     /** Returns the singleton handler for TareHandlerThread. */
getHandler()69     public static Handler getHandler() {
70         synchronized (TareHandlerThread.class) {
71             ensureThreadLocked();
72         }
73         return sHandler;
74     }
75 }
76