/* * Copyright (c) 2020 Alibaba Group Holding Limited. All Rights Reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Alibaba designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. */ /* * @test * @summary T12212948 * @requires os.family == "linux" * @library /lib/testlibrary * @run main/othervm -XX:+UnlockExperimentalVMOptions -XX:+EnableCoroutine -XX:+UseWispMonitor -Dcom.alibaba.wisp.transparentWispSwitch=true LazyUnparkBugTest */ public class LazyUnparkBugTest { private static volatile Object thunk = null; public static void test() throws Exception { thunk = null; Thread t1 = new Thread(() -> { try { synchronized (LazyUnparkBugTest.class) { Thread.sleep(1_000L); } Object o; do { o = thunk; } while (o == null); } catch (Exception e) { e.printStackTrace(); } }); Thread t2 = new Thread(() -> { try { Thread.sleep(5_0L); synchronized (LazyUnparkBugTest.class) { System.out.println("in t2"); } } catch (Exception e) { e.printStackTrace(); } thunk = new Object(); }); t1.start(); t2.start(); t1.join(); t2.join(); } public static void main(String[] args) throws Exception { long begin = System.currentTimeMillis(); test(); long end = System.currentTimeMillis(); System.out.println("cost : " + (end - begin) + " ms"); if ((end - begin) > 2000) { throw new Error("this is bug " + (end - begin)); } } }