/*

 * Copyright (c) 2015, 2016, 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.

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 */

/*

 * @test TestDisableExplicitGC

 * @requires vm.opt.DisableExplicitGC == null

 * @summary Verify GC behavior with DisableExplicitGC flag.

 * @library /test/lib

 * @modules java.base/jdk.internal.misc

 * @modules jdk.management/com.sun.management.internal

 * @run main/othervm                             -Xlog:gc=debug TestDisableExplicitGC

 * @run main/othervm/fail -XX:+DisableExplicitGC -Xlog:gc=debug TestDisableExplicitGC

 * @run main/othervm      -XX:-DisableExplicitGC -Xlog:gc=debug TestDisableExplicitGC

 */

import java.lang.management.GarbageCollectorMXBean;

import java.util.List;

import static jdk.test.lib.Asserts.*;

public class TestDisableExplicitGC {

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

        List<GarbageCollectorMXBean> list = java.lang.management.ManagementFactory.getGarbageCollectorMXBeans();

        long collectionCountBefore = getCollectionCount(list);

        System.gc();

        long collectionCountAfter = getCollectionCount(list);

        assertLT(collectionCountBefore, collectionCountAfter);

    }

    private static long getCollectionCount(List<GarbageCollectorMXBean> list) {

        int collectionCount = 0;

        for (GarbageCollectorMXBean gcMXBean : list) {

            collectionCount += gcMXBean.getCollectionCount();

        }

        return collectionCount;

    }

}