/*

 * Copyright (c) 2015, 2018, 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.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * 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,

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 *

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package jdk.jfr.event.oldobject;

import java.util.ArrayList;

import java.util.List;

import jdk.jfr.Recording;

import jdk.jfr.consumer.RecordedEvent;

import jdk.jfr.internal.test.WhiteBox;

import jdk.test.lib.jfr.EventNames;

import jdk.test.lib.jfr.Events;

/*

 * @test

 * @key jfr

 * @requires vm.gc == "null"

 * @library /test/lib /test/jdk

 * @modules jdk.jfr/jdk.jfr.internal.test

 * @run main/othervm -XX:TLABSize=2k jdk.jfr.event.oldobject.TestCircularReference

 */

public class TestCircularReference {

    static class TestCircularReferrer {

        // Allocate array to trigger sampling code path for interpreter / c1

        final byte[] leak = new byte[1_0000_000];

        TestCircularReferrer reference;

        public void setReference(TestCircularReferrer reference) {

            this.reference = reference;

        }

    }

    public final static List<Object> referenceHolder = new ArrayList<>(OldObjects.MIN_SIZE);

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

        WhiteBox.setWriteAllObjectSamples(true);

        try (Recording r = new Recording()) {

            r.enable(EventNames.OldObjectSample).with("cutoff", "infinity").withStackTrace();

            r.start();

            TestCircularReferrer a = new TestCircularReferrer();

            TestCircularReferrer b = new TestCircularReferrer();

            TestCircularReferrer c = new TestCircularReferrer();

            a.setReference(b);

            b.setReference(c);

            c.setReference(a);

            referenceHolder.add(a);

            TestCircularReferrer selfReflector = new TestCircularReferrer();

            selfReflector.setReference(selfReflector);

            referenceHolder.add(selfReflector);

            r.stop();

            List<RecordedEvent> events = Events.fromRecording(r);

            if (events.isEmpty()) {

                throw new AssertionError("Expected Old Object Sample events!");

            }

        }

    }

}