/*

 * Copyright (c) 2019, 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.

 *

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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

import java.io.File;

import java.net.URL;

import java.net.URLClassLoader;

import sun.hotspot.WhiteBox;

public class HelloUnload {

    private static String className = "CustomLoadee";

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

        if (args.length != 3) {

            throw new RuntimeException("Unexpected number of arguments: expected 3, actual " + args.length);

        }

        String path = args[0];

        URL url = new File(path).toURI().toURL();

        URL[] urls = new URL[] {url};

        System.out.println(path);

        System.out.println(url);

        // unload the custom class loader

        boolean doUnload = false;

        if (args[1].equals("true")) {

            doUnload = true;

        } else if (args[1].equals("false")) {

            doUnload = false;

        } else {

            throw new RuntimeException("args[1] can only be either \"true\" or \"false\", actual " + args[1]);

        }

        // should the CustomLoadee class be in the shared archive

        boolean inArchive = false;

        if (args[2].equals("true")) {

            inArchive = true;

        } else if (args[2].equals("false")) {

            inArchive = false;

        } else {

            throw new RuntimeException("args[2] can only be either \"true\" or \"false\", actual " + args[1]);

        }

        URLClassLoader urlClassLoader =

            new URLClassLoader("HelloClassLoader", urls, null);

        Class c = Class.forName(className, true, urlClassLoader);

        System.out.println(c);

        System.out.println(c.getClassLoader());

        Object o = c.newInstance();

        // [1] Check that CustomLoadee is defined by the correct loader

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

            throw new RuntimeException("c.getClassLoader() == " + c.getClassLoader() +

                                       ", expected == " + urlClassLoader);

        }

        // [2] Check that CustomLoadee is loaded from shared archive.

        WhiteBox wb = WhiteBox.getWhiteBox();

        if(wb.isSharedClass(HelloUnload.class)) {

            if (inArchive && !wb.isSharedClass(c)) {

                throw new RuntimeException("wb.isSharedClass(c) should be true");

            }

        }

        ClassUnloadCommon.failIf(!wb.isClassAlive(className), "should be live here");

        if (doUnload) {

            String loaderName = urlClassLoader.getName();

            int loadedRefcount = wb.getSymbolRefcount(loaderName);

            System.out.println("Refcount of symbol " + loaderName + " is " + loadedRefcount);

            urlClassLoader = null; c = null; o = null;

            ClassUnloadCommon.triggerUnloading();

            System.out.println("Is CustomLoadee alive? " + wb.isClassAlive(className));

            ClassUnloadCommon.failIf(wb.isClassAlive(className), "should have been unloaded");

            int unloadedRefcount = wb.getSymbolRefcount(loaderName);

            System.out.println("Refcount of symbol " + loaderName + " is " + unloadedRefcount);

            // refcount of a permanent symbol will not be decremented

            if (loadedRefcount != 65535) {

                ClassUnloadCommon.failIf(unloadedRefcount != (loadedRefcount - 1), "Refcount must be decremented");

            }

        }

    }

}