1 /*

     2  * Copyright (c) 2002, 2010, 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 /* @test

    25  * @bug 4639943

    26  * @summary  Checks that Windows behavior matches Solaris for

    27  *           various read/select combinations.

    28  * @author kladko

    29  */

    30 

    31 import java.nio.ByteBuffer;

    32 import java.nio.channels.Selector;

    33 import java.nio.channels.SelectionKey;

    34 import java.nio.channels.SocketChannel;

    35 

    36 public class SelectAfterRead {

    37 

    38     private static final int TIMEOUT = 1000;

    39 

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

    41 

    42         // server: accept connection and write one byte

    43         try (ByteServer server = new ByteServer();

    44              SocketChannel sc = SocketChannel.open(server.address())) {

    45 

    46             server.acceptConnection();

    47             server.write(1);

    48 

    49             try (Selector sel = Selector.open()) {

    50                 sc.read(ByteBuffer.allocate(1));

    51                 sc.configureBlocking(false);

    52                 sc.register(sel, SelectionKey.OP_READ);

    53                 // previously on Windows select would select channel here, although there was

    54                 // nothing to read

    55                 if (sel.selectNow() != 0)

    56                     throw new Exception("Select returned nonzero value");

    57             }

    58         }

    59 

    60         // Now we will test a two reads combination

    61         // server: accept connection and write two bytes

    62         try (ByteServer server = new ByteServer();

    63              SocketChannel sc = SocketChannel.open(server.address())) {

    64 

    65             server.acceptConnection();

    66             server.write(2);

    67 

    68             try (Selector sel = Selector.open()) {

    69                 sc.configureBlocking(false);

    70                 sc.register(sel, SelectionKey.OP_READ);

    71                 if (sel.select(TIMEOUT) != 1)

    72                     throw new Exception("One selected key expected");

    73                 sel.selectedKeys().clear();

    74                 // previously on Windows a channel would get selected only once

    75                 if (sel.selectNow() != 1)

    76                     throw new Exception("One selected key expected");

    77                 // Previously on Windows two consequent reads would cause select()

    78                 // to select a channel, although there was nothing remaining to

    79                 // read in the channel

    80                 if (sc.read(ByteBuffer.allocate(1)) != 1)

    81                     throw new Exception("One byte expected");

    82                 if (sc.read(ByteBuffer.allocate(1)) != 1)

    83                     throw new Exception("One byte expected");

    84                 if (sel.selectNow() != 0)

    85                     throw new Exception("Select returned nonzero value");

    86             }

    87         }

    88     }

    89 }