/*

 * Copyright (c) 2018, Red Hat, Inc. All rights reserved.

 *

 * 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 TestPauseNotifications

 * @summary Check that MX notifications are reported for all cycles

 * @key gc

 * @requires vm.gc.Shenandoah

 *

 * @run main/othervm -Xmx128m -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=passive       -XX:+ShenandoahDegeneratedGC TestPauseNotifications

 * @run main/othervm -Xmx128m -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=passive       -XX:-ShenandoahDegeneratedGC TestPauseNotifications

 *

 * @run main/othervm -Xmx128m -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive    TestPauseNotifications

 *

 * @run main/othervm -Xmx128m -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=adaptive      TestPauseNotifications

 * @run main/othervm -Xmx128m -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=static        TestPauseNotifications

 * @run main/othervm -Xmx128m -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=compact       TestPauseNotifications

 * @run main/othervm -Xmx128m -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=traversal     TestPauseNotifications

 */

import java.util.*;

import java.util.concurrent.atomic.*;

import javax.management.*;

import java.lang.management.*;

import javax.management.openmbean.*;

import com.sun.management.GarbageCollectionNotificationInfo;

public class TestPauseNotifications {

    static final long HEAP_MB = 128;                           // adjust for test configuration above

    static final long TARGET_MB = Long.getLong("target", 8_000); // 8 Gb allocation

    static volatile Object sink;

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

        final AtomicLong pausesDuration = new AtomicLong();

        final AtomicLong cyclesDuration = new AtomicLong();

        NotificationListener listener = new NotificationListener() {

            @Override

            public void handleNotification(Notification n, Object o) {

                if (n.getType().equals(GarbageCollectionNotificationInfo.GARBAGE_COLLECTION_NOTIFICATION)) {

                    GarbageCollectionNotificationInfo info = GarbageCollectionNotificationInfo.from((CompositeData) n.getUserData());

                    System.out.println(info.getGcInfo().toString());

                    System.out.println(info.getGcName());

                    System.out.println();

                    long d = info.getGcInfo().getDuration();

                    String name = info.getGcName();

                    if (name.contains("Shenandoah")) {

                        if (name.equals("Shenandoah Pauses")) {

                            pausesDuration.addAndGet(d);

                        } else if (name.equals("Shenandoah Cycles")) {

                            cyclesDuration.addAndGet(d);

                        } else {

                            throw new IllegalStateException("Unknown name: " + name);

                        }

                    }

                }

            }

        };

        for (GarbageCollectorMXBean bean : ManagementFactory.getGarbageCollectorMXBeans()) {

            ((NotificationEmitter) bean).addNotificationListener(listener, null, null);

        }

        final int size = 100_000;

        long count = TARGET_MB * 1024 * 1024 / (16 + 4 * size);

        for (int c = 0; c < count; c++) {

            sink = new int[size];

        }

        Thread.sleep(1000);

        long pausesActual = pausesDuration.get();

        long cyclesActual = cyclesDuration.get();

        long minExpected = 1;

        long maxExpected = Long.MAX_VALUE;

        {

            String msg = "Pauses expected = [" + minExpected + "; " + maxExpected + "], actual = " + pausesActual;

            if (minExpected < pausesActual && pausesActual < maxExpected) {

                System.out.println(msg);

            } else {

                throw new IllegalStateException(msg);

            }

        }

        {

            String msg = "Cycles expected = [" + minExpected + "; " + maxExpected + "], actual = " + cyclesActual;

            if (minExpected < cyclesActual && cyclesActual < maxExpected) {

                System.out.println(msg);

            } else {

                throw new IllegalStateException(msg);

            }

        }

        {

            String msg = "Cycle duration (" + cyclesActual + "), pause duration (" + pausesActual + ")";

            if (pausesActual < cyclesActual) {

                System.out.println(msg);

            } else {

                throw new IllegalStateException(msg);

            }

        }

    }

}