/*
 * Copyright (c) 2020, 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.io.FileInputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;

public class LoadLibrary {

    public static String testClasses;

    public static void runTest() throws Exception {
        // create a classloader and load a class that loads a library.
        MyClassLoader myLoader = new MyClassLoader();
        Class<?> c = Class.forName("LoadLibraryClass", true, myLoader);
    }

    public static void main(String[] args) throws Exception {
        testClasses = args[0];
        runTest();
        ClassUnloadCommon.triggerUnloading();
    }

    public static class MyClassLoader extends ClassLoader {

        public static final String CLASS_NAME = "LoadLibraryClass";

        static ByteBuffer readClassFile(String name) {
            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: " + name +
                                           ", exception: " + e.toString());
            }
        }

        protected Class<?> loadClass(String name, boolean resolve)
            throws ClassNotFoundException {
            Class<?> c;
            if (!"LoadLibraryClass".equals(name)) {
                c = super.loadClass(name, resolve);
            } else {
                // should not delegate to the system class loader
                c = findClass(name);
                if (resolve) {
                    resolveClass(c);
                }
            }
            return c;
        }

        protected Class<?> findClass(String name) throws ClassNotFoundException {
            if (!"LoadLibraryClass".equals(name)) {
                throw new ClassNotFoundException("Unexpected class: " + name);
            }
            return defineClass(name, readClassFile(name + ".class"), null);
        }
    } // MyClassLoader

}


class LoadLibraryClass {
    static {
        System.loadLibrary("LoadLibraryClass");
        nTest();
    }
    native static void nTest();
}