1 /*
2  * Copyright (C) 2020 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 import java.util.concurrent.atomic.AtomicInteger;
17 
18 public class Main {
19 
20   private static class LazyGrandChildThread implements Runnable {
21     @Override
run()22     public void run() {}
23   }
24 
25   private static class ChildThread implements Runnable {
26     @Override
run()27     public void run() {
28       // Allocate memory forcing GCs and fork children.
29       for (int i = 0; i < 100; ++i) {
30         int [][] a = new int[10][];
31         for (int j = 0; j < 10; ++j) {
32           a[j] = new int[50000 * j + 20];
33           a[j][17] = 1;
34         }
35         Thread t = new Thread(new LazyGrandChildThread());
36         t.start();
37         int sum = 0;
38         // Make it hard to optimize out the arrays.
39         for (int j = 0; j < 10; ++j) {
40           sum += a[j][16] /* = 0 */ + a[j][17] /* = 1 */;
41         }
42         if (sum != 10) {
43           System.out.println("Bad result! Was " + sum);
44         }
45         try {
46           t.join();
47         } catch (InterruptedException e) {
48           System.out.println("Interrupted by " + e);
49         }
50       }
51       System.out.println("Child finished");
52     }
53   }
54 
main(String[] args)55   public static void main(String[] args) {
56     System.out.println("Main Started");
57     new Thread(new ChildThread()).start();
58     System.out.println("Main Finished");
59   }
60 }
61