/*

 * Copyright 2006 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

/*

 * @test

 * @summary configuring unconnected Socket before passing to implAccept can cause fd leak

 * @bug 6368984

 * @author Edward Wang

 */

import java.io.*;

import java.net.*;

public class AcceptCauseFileDescriptorLeak {

    private static final int REPS = 1000;

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

        final ServerSocket ss = new ServerSocket(0) {

            public Socket accept() throws IOException {

                Socket s = new Socket() { };

                s.setSoTimeout(10000);

                implAccept(s);

                return s;

            }

        };

        Thread t = new Thread(new Runnable() {

            public void run() {

                try {

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

                        (new Socket("localhost", ss.getLocalPort())).close();

                    }

                } catch (IOException e) {

                    e.printStackTrace();

                }

            }

        });

        t.start();

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

            ss.accept().close();

        }

        ss.close();

        t.join();

        //

        // The threshold 20 below is a little arbitrary. The point here is that

        // the remaining open file descriptors should be constant independent

        // of REPS.

        //

        if (countOpenFD() > 20) {

            throw new RuntimeException("File descriptor leak detected.");

        }

    }

    /*

     * Actually, this approach to count open file descriptors only

     * works for Solaris/Linux. On Windows platform, this method

     * will simply return zero. So the test will always be passed

     * on Windows, too.

     */

    private static int countOpenFD() {

        File dirOfFD = new File("/proc/self/fd");

        File[] fds = dirOfFD.listFiles();

        if (fds != null)

            return fds.length;

        else

            return 0;

    }

}