1 /*
 2  * Copyright (c) 2020, 2023, Oracle and/or its affiliates. All rights reserved.
 3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 4  *
 5  * This code is free software; you can redistribute it and/or modify it
 6  * under the terms of the GNU General Public License version 2 only, as
 7  * published by the Free Software Foundation.
 8  *
 9  * This code is distributed in the hope that it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12  * version 2 for more details (a copy is included in the LICENSE file that
13  * accompanied this code).
14  *
15  * You should have received a copy of the GNU General Public License version
16  * 2 along with this work; if not, write to the Free Software Foundation,
17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18  *
19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20  * or visit www.oracle.com if you need additional information or have any
21  * questions.
22  */
23 
24 /*
25  * @test
26  * @summary Stress test timed park when pinned
27  * @requires vm.debug != true
28  * @run main PinALot 500000
29  */
30 
31 /*
32  * @test
33  * @requires vm.debug == true
34  * @run main/othervm/timeout=300 PinALot 200000
35  */
36 
37 import java.time.Duration;
38 import java.time.Instant;
39 import java.util.concurrent.atomic.AtomicInteger;
40 import java.util.concurrent.locks.LockSupport;
41 
42 public class PinALot {
43 
44     static final Object lock = new Object();
45 
46     public static void main(String[] args) throws Exception {
47         int iterations = 1_000_000;
48         if (args.length > 0) {
49             iterations = Integer.parseInt(args[0]);
50         }
51         final int ITERATIONS = iterations;
52 
53         AtomicInteger count = new AtomicInteger();
54 
55         Thread thread = Thread.ofVirtual().start(() -> {
56             synchronized (lock) {
57                 while (count.incrementAndGet() < ITERATIONS) {
58                     LockSupport.parkNanos(1);
59                 }
60             }
61         });
62 
63         boolean terminated;
64         do {
65             terminated = thread.join(Duration.ofSeconds(1));
66             System.out.println(Instant.now() + " => " + count.get());
67         } while (!terminated);
68 
69         int countValue = count.get();
70         if (countValue != ITERATIONS) {
71             throw new RuntimeException("count = " + countValue);
72         }
73     }
74 }