/*

 * Copyright (c) 2014, 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,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

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

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package jdk.jfr.event.runtime;

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import java.nio.ByteBuffer;

import java.nio.channels.FileChannel;

import java.util.List;

import jdk.jfr.Recording;

import jdk.jfr.consumer.RecordedClassLoader;

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

 * @library /test/lib /test/jdk

 * @build jdk.jfr.event.runtime.TestClasses

 * @run main/othervm jdk.jfr.event.runtime.TestClassLoaderStatsEvent

 */

public class TestClassLoaderStatsEvent {

    private final static String EVENT_NAME = EventNames.ClassLoaderStatistics;

    private final static String CLASS_LOADER_NAME = "MyDummyClassLoader";

    private final static String CLASSLOADER_TYPE_NAME = "jdk.jfr.event.runtime.TestClassLoaderStatsEvent$DummyClassLoader";

    public static DummyClassLoader dummyloader;

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

        createDummyClassLoader(CLASS_LOADER_NAME);

        Recording recording = new Recording();

        recording.enable(EVENT_NAME);

        recording.start();

        recording.stop();

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

        Events.hasEvents(consumer);

        boolean isAnyFound = false;

        for (RecordedEvent event : consumer) {

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

            if (Events.assertField(event, "classLoader").getValue() == null) {

                continue;

            }

            RecordedClassLoader recordedClassLoader = event.getValue("classLoader");

            if (CLASSLOADER_TYPE_NAME.equals(recordedClassLoader.getType().getName())) {

                Asserts.assertEquals(CLASS_LOADER_NAME, recordedClassLoader.getName(),

                    "Expected class loader name " + CLASS_LOADER_NAME + ", got name " + recordedClassLoader.getName());

                Events.assertField(event, "classCount").equal(1L);

                Events.assertField(event, "chunkSize").above(1L);

                Events.assertField(event, "blockSize").above(1L);

                isAnyFound = true;

            }

        }

        Asserts.assertTrue(isAnyFound, "No events found");

    }

    private static void createDummyClassLoader(String name) throws Throwable {

        dummyloader = new DummyClassLoader(name);

        Class<?> c = Class.forName(TestClass.class.getName(), true, dummyloader);

        if (c.getClassLoader() != dummyloader) {

            throw new RuntimeException("TestClass defined by wrong classloader: " + c.getClassLoader());

        }

    }

    public static class DummyClassLoader extends ClassLoader {

        static ByteBuffer readClassFile(String name) {

            String testClasses = System.getProperty("test.classes");

            File f = new File(testClasses, name);

            try (FileInputStream fin = new FileInputStream(f)) {

                FileChannel fc = fin.getChannel();

                return fc.map(FileChannel.MapMode.READ_ONLY, 0, fc.size());

            } catch (IOException e) {

                throw new RuntimeException("Can't open file: " + f, e);

            }

        }

        protected Class<?> loadClass(String name, boolean resolve) throws ClassNotFoundException {

            Class<?> c;

            if (TestClass.class.getName().equals(name)) {

                c = findClass(name);

                if (resolve) {

                    resolveClass(c);

                }

            } else {

                c = super.loadClass(name, resolve);

            }

            return c;

        }

        protected Class<?> findClass(String name) throws ClassNotFoundException {

            if (!TestClass.class.getName().equals(name)) {

                throw new ClassNotFoundException("Unexpected class: " + name);

            }

            return defineClass(name, readClassFile(TestClass.class.getName().replace(".", File.separator) + ".class"), null);

        }

        public DummyClassLoader(String name) {

            super(name, ClassLoader.getSystemClassLoader());

        }

    }

}