1 /* 2 * Copyright (c) 2020, 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 26 * @summary Stress test Thread.yield 27 * @requires vm.debug != true 28 * @run main YieldALot 500000 29 */ 30 31 /* 32 * @test 33 * @requires vm.debug == true 34 * @run main YieldALot 200000 35 */ 36 37 import java.time.Duration; 38 import java.time.Instant; 39 import java.util.concurrent.atomic.AtomicInteger; 40 41 public class YieldALot { 42 43 public static void main(String[] args) throws Exception { 44 int iterations; 45 if (args.length > 0) { 46 iterations = Integer.parseInt(args[0]); 47 } else { 48 iterations = 1_000_000; 49 } 50 51 AtomicInteger count = new AtomicInteger(); 52 Thread thread = Thread.ofVirtual().start(() -> { 53 while (count.incrementAndGet() < iterations) { 54 Thread.yield(); 55 } 56 }); 57 58 boolean terminated; 59 do { 60 terminated = thread.join(Duration.ofSeconds(1)); 61 System.out.println(Instant.now() + " => " + count.get() + " of " + iterations); 62 } while (!terminated); 63 64 int countValue = count.get(); 65 if (countValue != iterations) { 66 throw new RuntimeException("Thread terminated, count=" + countValue); 67 } 68 } 69 }