1 /*
2 * Copyright (c) 2024, 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 id=timeout
26 * @summary Stress test timed-Object.wait
27 * @run main/othervm TimedWaitALot 200
28 */
29
30 /*
31 * @test id=timeout-notify
32 * @summary Test timed-Object.wait where the waiting thread is awakened with Object.notify
33 * at around the same time that the timeout expires.
34 * @run main/othervm TimedWaitALot 200 true false
35 */
36
37 /*
38 * @test id=timeout-interrupt
39 * @summary Test timed-Object.wait where the waiting thread is awakened with Thread.interrupt
40 * at around the same time that the timeout expires.
41 * @run main/othervm TimedWaitALot 200 false true
42 */
43
44 /*
45 * @test id=timeout-notify-interrupt
46 * @summary Test timed-Object.wait where the waiting thread is awakened with Object.notify
47 * and Thread.interrupt at around the same time that the timeout expires.
48 * @run main/othervm TimedWaitALot 100 true true
49 */
50
51 import java.time.Instant;
52 import java.util.concurrent.Executors;
53 import java.util.concurrent.SynchronousQueue;
54 import java.util.concurrent.ThreadLocalRandom;
55
56 public class TimedWaitALot {
57 public static void main(String[] args) throws Exception {
58 int iterations = Integer.parseInt(args[0]);
59 boolean notify = args.length >= 2 && "true".equals(args[1]);
60 boolean interrupt = args.length >=3 && "true".equals(args[2]);
61
62 // test all timeouts concurrently
63 int[] timeouts = { 10, 20, 50, 100 };
64 for (int i = 1; i <= iterations; i++) {
65 System.out.println(Instant.now() + " => " + i + " of " + iterations);
66 test(notify, interrupt, timeouts);
67 }
68 }
69
70 /**
71 * Start a first virtual thread to wait in Object.wait(millis).
72 * If {@code notify} is true, start a virtual thread to use Object.notifyAll at around
73 * the same time that the timeout expires.
74 * If {@code interrupt} is true, start virtual thread to interrupts the first virtual
75 * thread at around the same time as the timeout expires.
76 */
77 static void test(boolean notify, boolean interrupt, int... timeouts) throws Exception {
78 try (var executor = Executors.newVirtualThreadPerTaskExecutor()) {
79 for (int timeout : timeouts) {
80 var queue = new SynchronousQueue<Thread>();
81 var lock = new Object();
82
83 // virtual thread waits with Object.wait(timeout)
84 executor.submit(() -> {
85 queue.put(Thread.currentThread());
86 synchronized (lock) {
87 lock.wait(timeout);
88 }
89 return null;
90 });
91
92 // wait for thread to start
93 Thread thread = queue.take();
94
95 // start thread to Object.notifyAll at around time that the timeout expires
96 if (notify) {
97 if (ThreadLocalRandom.current().nextBoolean()) {
98 synchronized (lock) {
99 sleepLessThan(timeout);
100 lock.notifyAll();
101 }
102 } else {
103 sleepLessThan(timeout);
104 synchronized (lock) {
105 lock.notifyAll();
106 }
107 }
108 }
109
110 // start thread to interrupt first thread at around time that the timeout expires
111 if (interrupt) {
112 executor.submit(() -> {
113 sleepLessThan(timeout);
114 thread.interrupt();
115 return null;
116 });
117 }
118 }
119 }
120 }
121
122 /**
123 * Sleeps for just less than the given timeout, in millis.
124 */
125 private static void sleepLessThan(long timeout) throws InterruptedException {
126 int delta = ThreadLocalRandom.current().nextInt(10);
127 Thread.sleep(timeout - delta);
128 }
129 }