/*
 * Copyright (c) 2011, 2013 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.*;

public class RedefineBigClassApp {
    /**
     * Memory leak is assumed, if application consumes more than specified amount of memory during its execution.
     * The number is given in Kb.
     */
    private static final long MEM_LEAK_THRESHOLD = 32 * 1024; // 32Mb

    public static void main(String[] args) throws Exception {
        System.out.println("Creating instance of " +
            RedefineBigClassAgent.clz);
        RedefineBigClassAgent.clz.newInstance();

        long vMemBefore = getVMemSize();
        int count = 0;
        while (!RedefineBigClassAgent.doneRedefining) {
            System.out.println("App loop count: " + ++count);
            try {
                Thread.sleep(10 * 1000);
            } catch (InterruptedException ie) {
            }
        }
        System.out.println("App looped  " + count + " times.");

        long vMemAfter = getVMemSize();
        if (vMemBefore == 0 || vMemAfter == 0) {
            System.err.println("WARNING: Cannot perform memory leak detection on this OS");
        } else {
            long vMemDelta = vMemAfter - vMemBefore;
            if (vMemDelta > MEM_LEAK_THRESHOLD) {
                System.err.println("FAIL: Virtual memory usage increased by " + vMemDelta + "Kb " +
                        "(greater than " + MEM_LEAK_THRESHOLD + "Kb)");
                System.exit(1);
            }
            System.err.println("PASS: Virtual memory usage increased by " + vMemDelta + "Kb " +
                    "(not greater than " + MEM_LEAK_THRESHOLD + "Kb)");
        }
        System.exit(0);
    }

    /**
     * Return size of virtual memory allocated to the process in Kb.
     * Linux specific. On other platforms and in case of any errors return 0.
     */
    private static long getVMemSize() {

        // Refer to the Linux proc(5) man page for details about /proc/self/stat file
        //
        // In short, this file contains status information about the current process
        // written in one line. The fields are separated with spaces.
        // The 23rd field is defined as 'vsize %lu   Virtual memory size in bytes'

        try (FileReader fileReader = new FileReader("/proc/self/stat");
             BufferedReader bufferedReader = new BufferedReader(fileReader)) {
            String line = bufferedReader.readLine();
            return Long.parseLong(line.split(" ")[22]) / 1024;
        } catch (Exception ex) {}
        return 0;
    }
}