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 * Copyright (c) 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.lang.reflect.Array;

import java.util.ArrayList;

import java.util.HashSet;

import java.util.List;

import java.util.Set;

import java.util.concurrent.Callable;

import jdk.jfr.Recording;

import jdk.jfr.consumer.RecordedEvent;

import jdk.jfr.consumer.RecordedObject;

import jdk.jfr.internal.test.WhiteBox;

import jdk.test.lib.jfr.EventNames;

import jdk.test.lib.jfr.Events;

/**

 * @test

 * @key jfr

 * @requires vm.hasJFR

 * @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.TestObjectDescription

 */

public class TestObjectDescription {

    private static final int OBJECT_DESCRIPTION_MAX_SIZE = 100;

    private static final String CLASS_NAME = TestClassLoader.class.getName() + "$TestClass";

    public static List<?> leaks;

    public final static class MyThreadGroup extends ThreadGroup {

        public final static String NAME = "My Thread Group";

        public MyThreadGroup(String name) {

            super(name);

        }

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

        byte[] bytes = new byte[10];

    }

    public final static class MyThread extends Thread {

        public final static String NAME = "My Thread";

        public MyThread() {

            super(NAME);

        }

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

        byte[] bytes = new byte[10];

    }

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

        WhiteBox.setWriteAllObjectSamples(true);

        testThreadGroupName();

        testThreadName();

        testClassName();

        testSize();

        testEllipsis();

    }

    private static void testThreadName() throws Exception {

        asseertObjectDescription(() -> {

            List<MyThread> threads = new ArrayList<>(OldObjects.MIN_SIZE);

            for (int i = 0; i < OldObjects.MIN_SIZE; i++) {

                threads.add(new MyThread());

            }

            return threads;

        }, "Thread Name: " + MyThread.NAME);

    }

    private static void testThreadGroupName() throws Exception {

        asseertObjectDescription(() -> {

            List<MyThreadGroup> groups = new ArrayList<>(OldObjects.MIN_SIZE);

            for (int i = 0; i < OldObjects.MIN_SIZE; i++) {

                groups.add(new MyThreadGroup("My Thread Group"));

            }

            return groups;

        }, "Thread Group: " + "My Thread Group");

    }

    private static void testClassName() throws Exception {

        asseertObjectDescription(() -> {

            TestClassLoader testClassLoader = new TestClassLoader();

            List<Object> classObjects = new ArrayList<>(OldObjects.MIN_SIZE);

            for (Class<?> clazz : testClassLoader.loadClasses(OldObjects.MIN_SIZE / 20)) {

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

                for (int i = 0; i < 20; i++) {

                    Object classArray = Array.newInstance(clazz, 20);

                    Array.set(classArray, i, clazz.newInstance());

                    classObjects.add(classArray);

                }

            }

            return classObjects;

        }, "Class Name: " + CLASS_NAME);

    }

    private static void testSize() throws Exception {

        asseertObjectDescription(() -> {

            List<Object> arrayLists = new ArrayList<>(OldObjects.MIN_SIZE);

            for (int i = 0; i < OldObjects.MIN_SIZE; i++) {

                List<Object> arrayList = new ArrayList<>();

                arrayList.add(new Object());

                arrayList.add(new Object());

                arrayList.add(new Object());

                arrayLists.add(arrayList);

            }

            return arrayLists;

        }, "Size: 3");

    }

    private static void testEllipsis() throws Exception {

        asseertObjectDescription(() -> {

            StringBuilder sb = new StringBuilder();

            for (int i = 0; i < 2 * OBJECT_DESCRIPTION_MAX_SIZE; i++) {

                sb.append("x");

            }

            String threadName = sb.toString();

            List<Thread> threads = new ArrayList<>();

            for (int i = 0; i < OldObjects.MIN_SIZE; i++) {

                threads.add(new Thread(threadName));

            }

            return threads;

        }, "xxx...");

    }

    private static void asseertObjectDescription(Callable<List<?>> callable, String text) throws Exception {

        int iteration = 1;

        while (true) {

            try (Recording recording = new Recording()) {

                System.out.println("Iteration: " + iteration);

                recording.enable(EventNames.OldObjectSample).withoutStackTrace().with("cutoff", "infinity");

                recording.start();

                leaks = null;

                System.gc();

                leaks = callable.call();

                recording.stop();

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

                Set<String> objectDescriptions = extractObjectDecriptions(events);

                for (String s : objectDescriptions) {

                    if (s.contains(text)) {

                        printDescriptions(objectDescriptions);

                        return;

                    }

                }

                System.out.println("Could not find object description containing text \"" + text + "\"");

                printDescriptions(objectDescriptions);

                System.out.println();

                iteration++;

            }

        }

    }

    private static void printDescriptions(Set<String> objectDescriptions) {

        System.out.println("Found descriptions:");

        for (String t : objectDescriptions) {

            System.out.println(t);

        }

    }

    private static Set<String> extractObjectDecriptions(List<RecordedEvent> events) {

        Set<String> objectDescriptions = new HashSet<>();

        for (RecordedEvent e : events) {

            objectDescriptions.addAll(extractObjectDescriptions(e.getValue("object")));

        }

        return objectDescriptions;

    }

    private static Set<String> extractObjectDescriptions(RecordedObject o) {

        Set<Long> visited = new HashSet<>();

        Set<String> descriptions = new HashSet<>();

        while (o != null) {

            Long memoryAddress = o.getValue("address");

            if (visited.contains(memoryAddress)) {

                return descriptions;

            }

            visited.add(memoryAddress);

            String od = o.getValue("description");

            if (od != null) {

                descriptions.add(od);

            }

            RecordedObject referrer = o.getValue("referrer");

            o = referrer != null ? referrer.getValue("object") : null;

        }

        return descriptions;

    }

}