1 /*

     2  * Copyright 2006 Sun Microsystems, Inc.  All Rights Reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

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

    18  *

    19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

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

    21  * have any questions.

    22  */

    23 

    24 /*

    25  * @test

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

    27  * @bug 6368984

    28  * @author Edward Wang

    29  */

    30 

    31 import java.io.*;

    32 import java.net.*;

    33 

    34 public class AcceptCauseFileDescriptorLeak {

    35     private static final int REPS = 1000;

    36 

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

    38         final ServerSocket ss = new ServerSocket(0) {

    39             public Socket accept() throws IOException {

    40                 Socket s = new Socket() { };

    41                 s.setSoTimeout(10000);

    42                 implAccept(s);

    43                 return s;

    44             }

    45         };

    46         Thread t = new Thread(new Runnable() {

    47             public void run() {

    48                 try {

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

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

    51                     }

    52                 } catch (IOException e) {

    53                     e.printStackTrace();

    54                 }

    55             }

    56         });

    57         t.start();

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

    59             ss.accept().close();

    60         }

    61         ss.close();

    62         t.join();

    63 

    64         //

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

    66         // the remaining open file descriptors should be constant independent

    67         // of REPS.

    68         //

    69         if (countOpenFD() > 20) {

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

    71         }

    72     }

    73 

    74 

    75     /*

    76      * Actually, this approach to count open file descriptors only

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

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

    79      * on Windows, too.

    80      */

    81     private static int countOpenFD() {

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

    83         File[] fds = dirOfFD.listFiles();

    84 

    85         if (fds != null)

    86             return fds.length;

    87         else

    88             return 0;

    89     }

    90 }