Java example source code file (StartStopTest.java)

This example Java source code file (StartStopTest.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

bye, create, double, exception, flags, integer, management, maximum, monitors, objectname, observedobject, pool, size, startstoptest, string

The StartStopTest.java Java example source code

/*
 * Copyright (c) 2005, 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.
 */

/*
 * @test
 * @bug 6222826
 * @summary Test that tasks are cancelled properly when
 *          monitors are started and stopped in a loop.
 * @author Luis-Miguel Alventosa
 * @run clean StartStopTest
 * @run build StartStopTest
 * @run main/othervm/timeout=300 StartStopTest 1
 * @run main/othervm/timeout=300 StartStopTest 2
 * @run main/othervm/timeout=300 StartStopTest 3
 * @run main/othervm/timeout=300 -Djmx.x.monitor.maximum.pool.size=5 StartStopTest 1
 * @run main/othervm/timeout=300 -Djmx.x.monitor.maximum.pool.size=5 StartStopTest 2
 * @run main/othervm/timeout=300 -Djmx.x.monitor.maximum.pool.size=5 StartStopTest 3
 * @run main/othervm/timeout=300 -Djmx.x.monitor.maximum.pool.size=-5 StartStopTest 1
 * @run main/othervm/timeout=300 -Djmx.x.monitor.maximum.pool.size=-5 StartStopTest 2
 * @run main/othervm/timeout=300 -Djmx.x.monitor.maximum.pool.size=-5 StartStopTest 3
 */

import java.util.concurrent.atomic.AtomicInteger;
import javax.management.MBeanServer;
import javax.management.MBeanServerFactory;
import javax.management.Notification;
import javax.management.NotificationListener;
import javax.management.ObjectName;
import javax.management.monitor.CounterMonitor;
import javax.management.monitor.GaugeMonitor;
import javax.management.monitor.Monitor;
import javax.management.monitor.MonitorNotification;
import javax.management.monitor.StringMonitor;

public class StartStopTest {

    static int maxPoolSize;
    static final AtomicInteger counter = new AtomicInteger();

    // MBean class
    public class ObservedObject implements ObservedObjectMBean {
        public boolean called = false;
        public Integer getInteger() {
            task("Integer");
            return 0;
        }
        public Double getDouble() {
            task("Double");
            return 0.0;
        }
        public String getString() {
            task("String");
            return "";
        }
        private void task(String prop) {
            called = true;
            final int c = counter.incrementAndGet();
            echo("\tTASK [" + c + "] in get" + prop);
        }
    }

    // MBean interface
    public interface ObservedObjectMBean {
        public Integer getInteger();
        public Double getDouble();
        public String getString();
    }

    /**
     * Run test
     */
    public int runTest(int monitorType) throws Exception {

        int nTasks = maxPoolSize + 2;
        ObjectName[] mbeanNames = new ObjectName[nTasks];
        ObservedObject[] monitored = new ObservedObject[nTasks];
        ObjectName[] monitorNames = new ObjectName[nTasks];
        Monitor[] monitor = new Monitor[nTasks];
        String[] attributes = { "Integer", "Double", "String" };

        try {
            echo(">>> CREATE MBeanServer");
            MBeanServer server = MBeanServerFactory.newMBeanServer();

            String domain = server.getDefaultDomain();

            for (int i = 0; i < nTasks; i++) {
                mbeanNames[i] =
                    new ObjectName(":type=ObservedObject,instance=" + (i + 1));
                monitored[i] = new ObservedObject();
                echo(">>> CREATE ObservedObject = " + mbeanNames[i].toString());
                server.registerMBean(monitored[i], mbeanNames[i]);
                switch (monitorType) {
                case 1:
                    monitorNames[i] = new ObjectName(":type=CounterMonitor," +
                                                     "instance=" + (i + 1));
                    monitor[i] = new CounterMonitor();
                    break;
                case 2:
                    monitorNames[i] = new ObjectName(":type=GaugeMonitor," +
                                                     "instance=" + (i + 1));
                    monitor[i] = new GaugeMonitor();
                    break;
                case 3:
                    monitorNames[i] = new ObjectName(":type=StringMonitor," +
                                                     "instance=" + (i + 1));
                    monitor[i] = new StringMonitor();
                    break;
                default:
                    echo("Unsupported monitor type");
                    return 1;
                }
                echo(">>> CREATE Monitor = " + monitorNames[i].toString());
                server.registerMBean(monitor[i], monitorNames[i]);
                monitor[i].addObservedObject(mbeanNames[i]);
                monitor[i].setObservedAttribute(attributes[monitorType-1]);
                monitor[i].setGranularityPeriod(50);
            }

            for (int j = 0; j < 2; j++) {
                echo(">>> Start MONITORS");
                for (int i = 0; i < nTasks; i++)
                    monitor[i].start();
                echo(">>> MONITORS started");
                Thread.sleep(500);
                echo(">>> Check FLAGS true");
                for (int i = 0; i < nTasks; i++)
                    if (!monitored[i].called) {
                        echo("KO: At least one attribute was not called");
                        return 1;
                    }
                echo(">>> FLAGS checked true");
                echo(">>> Stop MONITORS");
                for (int i = 0; i < nTasks; i++)
                    monitor[i].stop();
                echo(">>> MONITORS stopped");
                Thread.sleep(500);
                echo(">>> Set FLAGS to false");
                for (int i = 0; i < nTasks; i++)
                    monitored[i].called = false;
                echo(">>> FLAGS set to false");
                echo(">>> Check FLAGS remain false");
                for (int i = 0; i < nTasks; i++)
                    if (monitored[i].called) {
                        echo("KO: At least one attribute " +
                             "continued to get called");
                        return 1;
                    }
                echo(">>> FLAGS checked false");
            }
        } finally {
            for (int i = 0; i < nTasks; i++)
                if (monitor[i] != null)
                    monitor[i].stop();
        }

        return 0;
    }

    /*
     * Print message
     */
    private static void echo(String message) {
        System.out.println(message);
    }

    /*
     * Standalone entry point.
     *
     * Run the test and report to stdout.
     */
    public static void main (String args[]) throws Exception {
        Integer size = Integer.getInteger("jmx.x.monitor.maximum.pool.size");
        if (size == null) {
            maxPoolSize = 10;
            echo(">>> MAXIMUM POOL SIZE = 10 [default value]");
        } else {
            maxPoolSize = size.intValue() < 1 ? 1 : size.intValue();
            echo(">>> MAXIMUM POOL SIZE = " + maxPoolSize);
        }
        StartStopTest test = new StartStopTest();
        int error = test.runTest(Integer.parseInt(args[0]));
        if (error > 0) {
            echo(">>> Unhappy Bye, Bye!");
            throw new IllegalStateException(
                "Test FAILED: Unexpected Maximum Pool Size Overflow!");
        } else {
            echo(">>> Happy Bye, Bye!");
        }
    }
}