1 /*

     2  * Copyright (c) 2018, 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 8201315

    26  * @summary Test that channels can be registered, interest ops can changed,

    27  *          and keys cancelled while a selection operation is in progress.

    28  */

    29 

    30 import java.io.IOException;

    31 import java.nio.channels.Pipe;

    32 import java.nio.channels.SelectionKey;

    33 import java.nio.channels.Selector;

    34 import java.util.concurrent.Callable;

    35 import java.util.concurrent.ExecutorService;

    36 import java.util.concurrent.Executors;

    37 import java.util.concurrent.Future;

    38 import java.util.concurrent.Phaser;

    39 

    40 public class RegisterDuringSelect {

    41 

    42     static Callable<Void> selectLoop(Selector sel, Phaser barrier) {

    43         return new Callable<Void>() {

    44             @Override

    45             public Void call() throws IOException {

    46                 for (;;) {

    47                     sel.select();

    48                     if (sel.isOpen()) {

    49                         barrier.arriveAndAwaitAdvance();

    50                     } else {

    51                         // closed

    52                         return null;

    53                     }

    54                 }

    55             }

    56         };

    57     }

    58     /**

    59      * Invoke register, interestOps, and cancel concurrently with a thread

    60      * doing a selection operation

    61      */

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

    63         Future<Void> result;

    64 

    65         ExecutorService pool = Executors.newFixedThreadPool(1);

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

    67             Phaser barrier = new Phaser(2);

    68 

    69             // submit task to do the select loop

    70             result = pool.submit(selectLoop(sel, barrier));

    71 

    72             Pipe p = Pipe.open();

    73             try {

    74                 Pipe.SourceChannel sc = p.source();

    75                 sc.configureBlocking(false);

    76 

    77                 System.out.println("register ...");

    78                 SelectionKey key = sc.register(sel, SelectionKey.OP_READ);

    79                 if (!sel.keys().contains(key))

    80                     throw new RuntimeException("key not in key set");

    81                 sel.wakeup();

    82                 barrier.arriveAndAwaitAdvance();

    83 

    84                 System.out.println("interestOps ...");

    85                 key.interestOps(0);

    86                 sel.wakeup();

    87                 barrier.arriveAndAwaitAdvance();

    88 

    89                 System.out.println("cancel ...");

    90                 key.cancel();

    91                 sel.wakeup();

    92                 barrier.arriveAndAwaitAdvance();

    93                 if (sel.keys().contains(key))

    94                     throw new RuntimeException("key not removed from key set");

    95 

    96             } finally {

    97                 p.source().close();

    98                 p.sink().close();

    99             }

   100 

   101         } finally {

   102             pool.shutdown();

   103         }

   104 

   105         // ensure selectLoop completes without exception

   106         result.get();

   107 

   108     }

   109 }