1 /* 2 * Copyright (c) 2022, 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 virtual threads with a variation of the Skynet 1M benchmark 27 * @requires vm.continuations 28 * @run main/othervm/timeout=300 -Xmx1400m Skynet 29 */ 30 31 /* 32 * @test 33 * @requires vm.debug == true & vm.continuations 34 * @requires vm.gc.Z 35 * @run main/othervm/timeout=300 -XX:+UnlockDiagnosticVMOptions 36 * -XX:+ZVerifyOops -XX:ZCollectionInterval=0.01 -Xmx1400m Skynet 37 */ 38 39 import java.util.concurrent.BlockingQueue; 40 import java.util.concurrent.SynchronousQueue; 41 import java.util.concurrent.ThreadFactory; 42 43 public class Skynet { 44 public static void main(String[] args) { 45 int iterations = (args.length > 0) ? Integer.parseInt(args[0]) : 10; 46 for (int i = 0; i < iterations; i++) { 47 skynet(1_000_000, 499999500000L); 48 } 49 } 50 51 static void skynet(int num, long expected) { 52 long start = System.currentTimeMillis(); 53 var chan = new Channel<Long>(); 54 55 Thread.startVirtualThread(() -> skynet(chan, 0, num, 10)); 56 57 long sum = chan.receive(); 58 long end = System.currentTimeMillis(); 59 System.out.format("Result: %d in %s ms%n", sum, (end-start)); 60 if (sum != expected) 61 throw new AssertionError("unexpected result!"); 62 } 63 64 static void skynet(Channel<Long> result, int num, int size, int div) { 65 if (size == 1) { 66 result.send((long)num); 67 } else { 68 var chan = new Channel<Long>(); 69 for (int i = 0; i < div; i++) { 70 int subNum = num + i * (size / div); 71 Thread.startVirtualThread(() -> skynet(chan, subNum, size / div, div)); 72 } 73 long sum = 0; 74 for (int i = 0; i < div; i++) { 75 sum += chan.receive(); 76 } 77 result.send(sum); 78 } 79 } 80 81 static class Channel<T> { 82 private final BlockingQueue<T> q; 83 84 Channel() { 85 q = new SynchronousQueue<>(); 86 } 87 88 void send(T e) { 89 boolean interrupted = false; 90 while (true) { 91 try { 92 q.put(e); 93 break; 94 } catch (InterruptedException x) { 95 interrupted = true; 96 } 97 } 98 if (interrupted) 99 Thread.currentThread().interrupt(); 100 } 101 102 T receive() { 103 boolean interrupted = false; 104 T e; 105 while (true) { 106 try { 107 e = q.take(); 108 break; 109 } catch (InterruptedException x) { 110 interrupted = true; 111 } 112 } 113 if (interrupted) 114 Thread.currentThread().interrupt(); 115 return e; 116 } 117 } 118 }