/* * Copyright (c) 2023, Oracle and/or its affiliates. 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. * * 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. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ import jdk.test.lib.process.OutputAnalyzer; import jdk.test.lib.Platform; import jdk.test.lib.process.ProcessTools; import java.lang.management.ManagementFactory; import java.lang.management.ThreadInfo; import java.lang.management.ThreadMXBean; /* * @test * @bug 8318757 * @summary Test concurrent monitor deflation by MonitorDeflationThread and thread dumping * @library /test/lib * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:GuaranteedAsyncDeflationInterval=2000 -XX:LockingMode=0 ConcurrentDeflation */ public class ConcurrentDeflation { public static final long TOTAL_RUN_TIME_NS = 10_000_000_000L; public static Object[] monitors = new Object[1000]; public static int monitorCount; public static void main(String[] args) throws Exception { Thread threadDumper = new Thread(() -> dumpThreads()); threadDumper.start(); Thread monitorCreator = new Thread(() -> createMonitors()); monitorCreator.start(); threadDumper.join(); monitorCreator.join(); } static private void dumpThreads() { ThreadMXBean threadBean = ManagementFactory.getThreadMXBean(); int dumpCount = 0; long startTime = System.nanoTime(); while (System.nanoTime() - startTime < TOTAL_RUN_TIME_NS) { threadBean.dumpAllThreads(true, false); dumpCount++; try { Thread.sleep(10); } catch (InterruptedException e) {} } System.out.println("Dumped all thread info " + dumpCount + " times"); } static private void createMonitors() { int index = 0; long startTime = System.nanoTime(); while (System.nanoTime() - startTime < TOTAL_RUN_TIME_NS) { index = index++ % 1000; monitors[index] = new Object(); synchronized (monitors[index]) { monitorCount++; } } System.out.println("Created " + monitorCount + " monitors"); } }