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 * Copyright (c) 2013, 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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 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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package jdk.jfr.event.gc.detailed;

import java.time.Duration;

import java.util.List;

import java.util.Optional;

import java.util.Random;

import jdk.jfr.Recording;

import jdk.jfr.consumer.RecordedEvent;

import jdk.test.lib.Asserts;

import jdk.test.lib.jfr.EventNames;

import jdk.test.lib.jfr.Events;

/**

 * @test

 * @key jfr

 * @requires vm.hasJFR

 * @requires vm.gc == "G1" | vm.gc == null

 * @library /test/lib /test/jdk

 * @run main/othervm -XX:+UnlockExperimentalVMOptions -XX:-UseFastUnorderedTimeStamps -XX:G1HeapRegionSize=1m -Xmx64m -Xmn16m -XX:+UseG1GC jdk.jfr.event.gc.detailed.TestEvacuationInfoEvent

 */

public class TestEvacuationInfoEvent {

    private final static String EVENT_FAILED_NAME = EventNames.EvacuationFailed;

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

        final long g1HeapRegionSize = 1024 * 1024;

        Recording recording = new Recording();

        recording.enable(EVENT_INFO_NAME).withThreshold(Duration.ofMillis(0));

        recording.enable(EVENT_FAILED_NAME).withThreshold(Duration.ofMillis(0));

        recording.start();

        allocate();

        recording.stop();

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

        Asserts.assertFalse(events.isEmpty(), "No events found");

        for (RecordedEvent event : events) {

            if (!Events.isEventType(event, EVENT_INFO_NAME)) {

                continue;

            }

            System.out.println("Event: " + event);

            int setRegions = Events.assertField(event, "cSetRegions").atLeast(0).getValue();

            long setUsedAfter = Events.assertField(event, "cSetUsedAfter").atLeast(0L).getValue();

            long setUsedBefore = Events.assertField(event, "cSetUsedBefore").atLeast(setUsedAfter).getValue();

            int allocationRegions = Events.assertField(event, "allocationRegions").atLeast(0).getValue();

            long bytesCopied = Events.assertField(event, "bytesCopied").atLeast(0L).getValue();

            int regionsFreed = Events.assertField(event, "regionsFreed").atLeast(0).getValue();

            Asserts.assertEquals(allocRegionsUsedBefore + bytesCopied, allocRegionsUsedAfter, "allocRegionsUsedBefore + bytesCopied = allocRegionsUsedAfter");

            Asserts.assertGreaterThanOrEqual(setRegions, regionsFreed, "setRegions >= regionsFreed");

            Asserts.assertGreaterThanOrEqual(g1HeapRegionSize * allocationRegions, allocRegionsUsedAfter, "G1HeapRegionSize * allocationRegions >= allocationRegionsUsedAfter");

            Asserts.assertGreaterThanOrEqual(g1HeapRegionSize * setRegions, setUsedAfter, "G1HeapRegionSize * setRegions >= setUsedAfter");

            Asserts.assertGreaterThanOrEqual(g1HeapRegionSize * setRegions, setUsedBefore, "G1HeapRegionSize * setRegions >= setUsedBefore");

            Asserts.assertGreaterThanOrEqual(g1HeapRegionSize, allocRegionsUsedBefore, "G1HeapRegionSize >= allocRegionsUsedBefore");

            int gcId = Events.assertField(event, "gcId").getValue();

            boolean isEvacuationFailed = containsEvacuationFailed(events, gcId);

            if (isEvacuationFailed) {

                Asserts.assertGreaterThan(setUsedAfter, 0L, "EvacuationFailure -> setUsedAfter > 0");

                Asserts.assertGreaterThan(setRegions, regionsFreed, "EvacuationFailure -> setRegions > regionsFreed");

            } else {

                Asserts.assertEquals(setUsedAfter, 0L, "No EvacuationFailure -> setUsedAfter = 0");

                Asserts.assertEquals(setRegions, regionsFreed, "No EvacuationFailure -> setRegions = regionsFreed");

            }

        }

    }

    private static boolean containsEvacuationFailed(List<RecordedEvent> events, int gcId) {

        Optional<RecordedEvent> failedEvent = events.stream()

                                .filter(e -> Events.isEventType(e, EVENT_FAILED_NAME))

                                .filter(e -> gcId == (int)Events.assertField(e, "gcId").getValue())

                                .findAny();

        System.out.println("Failed event: " + (failedEvent.isPresent() ? failedEvent.get() : "None"));

        return failedEvent.isPresent();

    }

    public static DummyObject[] dummys = new DummyObject[6000];

        /**

         * Allocate memory to trigger garbage collections.

         * We want the allocated objects to have different life time, because we want both "young" and "old" objects.

         * This is done by keeping the objects in an array and step the current index by a small random number in the loop.

         * The loop will continue until we have allocated a fixed number of bytes.

         */

        private static void allocate() {

            Random r = new Random(0);

            long bytesToAllocate = 256 * 1024 * 1024;

            int currPos = 0;

            while (bytesToAllocate > 0) {

                int allocSize = 1000 + (r.nextInt(4000));

                bytesToAllocate -= allocSize;

                dummys[currPos] = new DummyObject(allocSize);

                // Skip a few positions to get different duration on the objects.

                currPos = (currPos + r.nextInt(20)) % dummys.length;

            }

            for (int c=0; c<dummys.length; c++) {

                dummys[c] = null;

            }

            System.gc();

        }

        public static class DummyObject {

            public byte[] payload;

            DummyObject(int size) {

            payload = new byte[size];

        }

    }

}