/*

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 * 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.

 *

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/*

 * @test

 * @bug 6760712

 * @summary test the connector server option that causes it not to prevent the

 * VM from exiting

 * @author Shanliang JIANG, Eamonn McManus

 * @modules java.management

 * @run main/othervm DaemonRMIExporterTest

 */

import java.util.Arrays;

import java.util.Collections;

import java.util.HashSet;

import java.util.Map;

import java.util.Set;

import javax.management.MBeanServerFactory;

import javax.management.remote.JMXConnector;

import javax.management.remote.JMXConnectorFactory;

import javax.management.remote.JMXServiceURL;

import javax.management.remote.JMXConnectorServer;

import javax.management.remote.JMXConnectorServerFactory;

// Test the connector server option that causes it not to prevent the VM

// from exiting.  It's tricky to test exactly that, though possible.  If

// we're being run from within jtreg, then jtreg has threads of its own

// that will prevent the VM from exiting.  What's more it will kill all

// threads that the test created as soon as the main method returns,

// including the ones that would prevent the VM from exiting without the

// special option.

// Here we check that the test code does not create

// any permanent non-daemon threads, by recording the initial set of

// non-daemon threads (including at least one from jtreg), doing our stuff,

// then waiting for there to be no non-daemon threads that were not in

// the initial set.

public class DaemonRMIExporterTest {

    public static void main(String[] args) throws Exception {

        Set<Thread> initialNonDaemonThreads = getNonDaemonThreads();

        JMXServiceURL addr = new JMXServiceURL("rmi", null, 0);

        System.out.println("DaemonRMIExporterTest: Creating a RMIConnectorServer on " + addr);

        Map<String, ?> env =

            Collections.singletonMap("jmx.remote.x.daemon", "true");

        JMXConnectorServer server =

                JMXConnectorServerFactory.newJMXConnectorServer(addr,

                env,

                MBeanServerFactory.createMBeanServer());

        server.start();

        System.out.println("DaemonRMIExporterTest: Started the server on " + server.getAddress());

        System.out.println("DaemonRMIExporterTest: Connecting a client to the server ...");

        final JMXConnector conn = JMXConnectorFactory.connect(server.getAddress());

        conn.getMBeanServerConnection().getDefaultDomain();

        System.out.println("DaemonRMIExporterTest: Closing the client ...");

        conn.close();

        System.out.println("DaemonRMIExporterTest No more user code to execute, the VM should " +

                "exit normally, otherwise will be blocked forever if the bug is not fixed.");

        long deadline = System.currentTimeMillis() + 10000;

        ok: {

            while (System.currentTimeMillis() < deadline) {

                Set<Thread> nonDaemonThreads = getNonDaemonThreads();

                nonDaemonThreads.removeAll(initialNonDaemonThreads);

                if (nonDaemonThreads.isEmpty())

                    break ok;

                System.out.println("Non-daemon threads: " + nonDaemonThreads);

                try {

                    Thread.sleep(500);

                } catch (InterruptedException e) {

                    throw new AssertionError(e);

                }

            }

            throw new Exception("TEST FAILED: non-daemon threads remain");

        }

        System.out.println("TEST PASSED");

    }

    private static Set<Thread> getNonDaemonThreads() {

        ThreadGroup tg = Thread.currentThread().getThreadGroup();

        while (tg.getParent() != null)

            tg = tg.getParent();

        Thread[] threads = null;

        for (int size = 10; size < 10000; size *= 2) {

            threads = new Thread[size];

            int n = tg.enumerate(threads, true);

            if (n < size) {

                threads = Arrays.copyOf(threads, n);

                break;

            }

        }

        Set<Thread> ndThreads = new HashSet<Thread>();

        for (Thread t : threads) {

            if (!t.isDaemon())

                ndThreads.add(t);

        }

        return ndThreads;

    }

}