1 /* 2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 3 * 4 * This code is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU General Public License version 2 only, as 6 * published by the Free Software Foundation. 7 * 8 * This code is distributed in the hope that it will be useful, but WITHOUT 9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 11 * version 2 for more details (a copy is included in the LICENSE file that 12 * accompanied this code). 13 * 14 * You should have received a copy of the GNU General Public License version 15 * 2 along with this work; if not, write to the Free Software Foundation, 16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 17 * 18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 19 * or visit www.oracle.com if you need additional information or have any 20 * questions. 21 */ 22 23 /* 24 * This file is available under and governed by the GNU General Public 25 * License version 2 only, as published by the Free Software Foundation. 26 * However, the following notice accompanied the original version of this 27 * file: 28 * 29 * Written by Martin Buchholz and Jason Mehrens with assistance from 30 * members of JCP JSR-166 Expert Group and released to the public 31 * domain, as explained at 32 * http://creativecommons.org/publicdomain/zero/1.0/ 33 */ 34 35 /* 36 * @test 37 * @summary Only one thread should be created when a thread needs to 38 * be kept alive to service a delayed task waiting in the queue. 39 * @library /test/lib 40 */ 41 42 import static java.util.concurrent.TimeUnit.MILLISECONDS; 43 44 import java.util.concurrent.ScheduledThreadPoolExecutor; 45 import java.util.concurrent.ThreadFactory; 46 import java.util.concurrent.atomic.AtomicLong; 47 import jdk.test.lib.Utils; 48 49 public class ThreadRestarts { 50 static final long LONG_DELAY_MS = Utils.adjustTimeout(10_000); 51 static final long FAR_FUTURE_MS = 10 * LONG_DELAY_MS; 52 53 public static void main(String[] args) throws Exception { 54 test(false); 55 test(true); 56 } 57 58 private static void test(boolean allowTimeout) throws Exception { 59 CountingThreadFactory ctf = new CountingThreadFactory(); 60 ScheduledThreadPoolExecutor stpe 61 = new ScheduledThreadPoolExecutor(10, ctf); 62 try { 63 // schedule a dummy task in the "far future" 64 Runnable nop = new Runnable() { public void run() {}}; 65 stpe.schedule(nop, FAR_FUTURE_MS, MILLISECONDS); 66 stpe.setKeepAliveTime(1L, MILLISECONDS); 67 stpe.allowCoreThreadTimeOut(allowTimeout); 68 MILLISECONDS.sleep(12L); 69 } finally { 70 stpe.shutdownNow(); 71 if (!stpe.awaitTermination(LONG_DELAY_MS, MILLISECONDS)) 72 throw new AssertionError("timed out"); 73 } 74 if (ctf.count.get() > 1) 75 throw new AssertionError( 76 String.format("%d threads created, 1 expected", 77 ctf.count.get())); 78 } 79 80 static class CountingThreadFactory implements ThreadFactory { 81 final AtomicLong count = new AtomicLong(0L); 82 83 public Thread newThread(Runnable r) { 84 count.getAndIncrement(); 85 Thread t = new Thread(r); 86 t.setDaemon(true); 87 return t; 88 } 89 } 90 }