1 /*
   2  * Copyright (c) 2017, 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.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 package sun.nio.ch;
  26 
  27 import java.io.IOException;
  28 
  29 import static sun.nio.ch.KQueue.EV_ADD;
  30 import static sun.nio.ch.KQueue.EV_DELETE;
  31 import static sun.nio.ch.KQueue.EV_ONESHOT;
  32 
  33 
  34 /**
  35  * Poller implementation based on the kqueue facility.
  36  */
  37 
  38 class KQueuePoller extends Poller {
  39     private static final int MAX_EVENTS_TO_POLL = 512;
  40 
  41     private final int kqfd;
  42     private final int filter;
  43     private final long address;
  44 
  45     KQueuePoller(int filter) throws IOException {
  46         this.kqfd = KQueue.create();
  47         this.filter = filter;
  48         this.address = KQueue.allocatePollArray(MAX_EVENTS_TO_POLL);
  49     }
  50 
  51     @Override
  52     protected void implRegister(int fdVal) {
  53         int err = KQueue.register(kqfd, fdVal, filter, (EV_ADD|EV_ONESHOT));
  54         if (err != 0)
  55             throw new InternalError("kevent failed: " + err);
  56     }
  57 
  58     @Override
  59     protected boolean implDeregister(int fdVal) {
  60         int err = KQueue.register(kqfd, fdVal, filter, EV_DELETE);
  61         return (err == 0);
  62     }
  63 
  64     @Override
  65     public void run() {
  66         try {
  67             for (;;) {
  68                 int n = KQueue.poll(kqfd, address, MAX_EVENTS_TO_POLL, -1L);
  69                 while (n-- > 0) {
  70                     long keventAddress = KQueue.getEvent(address, n);
  71                     int fdVal = KQueue.getDescriptor(keventAddress);
  72                     polled(fdVal);
  73                 }
  74             }
  75         } catch (Throwable t) {
  76             t.printStackTrace();
  77         }
  78     }
  79 }