1 /*

     2  * Copyright (c) 2013, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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

    21  * questions.

    22  */

    23 

    24 /*

    25  * @test

    26  * @bug 8021820

    27  * @summary The total number of file descriptors is limited to

    28  * 1024(FDSET_SIZE) on MacOSX (the size of fd array passed to select()

    29  * call in java.net classes is limited to this value).

    30  * @run main/othervm SelectFdsLimit

    31  * @author aleksej.efimov@oracle.com

    32  */

    33 

    34 import java.io.File;

    35 import java.io.FileInputStream;

    36 import java.io.FileNotFoundException;

    37 import java.io.IOException;

    38 import java.io.InputStream;

    39 import java.net.ServerSocket;

    40 import java.net.SocketTimeoutException;

    41 

    42 

    43 /*

    44  * Test must be run in othervm mode to ensure that all files

    45  * opened by openFiles() are closed propertly.

    46 */

    47 public class SelectFdsLimit {

    48     static final int FDTOOPEN = 1023;

    49     static final String TESTFILE = "testfile";

    50     static FileInputStream [] testFIS;

    51 

    52     static void prepareTestEnv() throws IOException {

    53             File fileToCreate = new File(TESTFILE);

    54             if (!fileToCreate.exists())

    55                 if (!fileToCreate.createNewFile())

    56                     throw new RuntimeException("Can't create test file");

    57     }

    58 

    59     //If there will be some problem (i.e. ulimits on number of opened files will fail)

    60     //then this method will fail with exception and test will be considered as

    61     //failed. But allocated fds will be released because the test is executed by

    62     //dedicated VM (@run main/othervm).

    63     static void openFiles(int fn, File f) throws FileNotFoundException, IOException {

    64         testFIS = new FileInputStream[FDTOOPEN];

    65         for (;;) {

    66             if (0 == fn)

    67                 break;

    68             FileInputStream fis = new FileInputStream(f);

    69             testFIS[--fn] = fis;

    70         }

    71     }

    72 

    73     public static void main(String [] args) throws IOException, FileNotFoundException {

    74 

    75         //The bug 8021820 is a Mac specific and because of that test will pass on all

    76         //other platforms

    77         if (!System.getProperty("os.name").contains("OS X")) {

    78            return;

    79         }

    80 

    81         //Create test directory with test files

    82         prepareTestEnv();

    83 

    84         //Consume FD ids for this java process to overflow the 1024

    85         openFiles(FDTOOPEN,new File(TESTFILE));

    86 

    87         //Wait for incoming connection and make the select() used in java.net

    88         //classes fail the limitation on FDSET_SIZE

    89         ServerSocket socket = new ServerSocket(0);

    90 

    91         //Set the minimal timeout, no one is

    92         //going to connect to this server socket

    93         socket.setSoTimeout(1);

    94 

    95         // The accept() call will throw SocketException if the

    96         // select() has failed due to limitation on fds size,

    97         // indicating test failure. A SocketTimeoutException

    98         // is expected, so it is caught and ignored, and the test

    99         // passes.

   100         try {

   101            socket.accept();

   102         } catch (SocketTimeoutException e) { }

   103     }

   104 }