1 /*
   2  * Copyright (c) 2001, 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 
  26 package sun.nio.ch;
  27 
  28 import sun.misc.*;
  29 
  30 
  31 /**
  32  * Manipulates a native array of pollfd structs.
  33  *
  34  * @author Mike McCloskey
  35  * @since 1.4
  36  */
  37 
  38 abstract class AbstractPollArrayWrapper {
  39 
  40     // Event masks
  41     static final short POLLIN       = 0x0001;
  42     static final short POLLOUT      = 0x0004;
  43     static final short POLLERR      = 0x0008;
  44     static final short POLLHUP      = 0x0010;
  45     static final short POLLNVAL     = 0x0020;
  46     static final short POLLREMOVE   = 0x0800;
  47 
  48     // Miscellaneous constants
  49     static final short SIZE_POLLFD   = 8;
  50     static final short FD_OFFSET     = 0;
  51     static final short EVENT_OFFSET  = 4;
  52     static final short REVENT_OFFSET = 6;
  53 
  54     // The poll fd array
  55     protected AllocatedNativeObject pollArray;
  56 
  57     // Number of valid entries in the pollArray
  58     protected int totalChannels = 0;
  59 
  60     // Base address of the native pollArray
  61     protected long pollArrayAddress;
  62 
  63     // Access methods for fd structures
  64     int getEventOps(int i) {
  65         int offset = SIZE_POLLFD * i + EVENT_OFFSET;
  66         return pollArray.getShort(offset);
  67     }
  68 
  69     int getReventOps(int i) {
  70         int offset = SIZE_POLLFD * i + REVENT_OFFSET;
  71         return pollArray.getShort(offset);
  72     }
  73 
  74     int getDescriptor(int i) {
  75         int offset = SIZE_POLLFD * i + FD_OFFSET;
  76         return pollArray.getInt(offset);
  77     }
  78 
  79     void putEventOps(int i, int event) {
  80         int offset = SIZE_POLLFD * i + EVENT_OFFSET;
  81         pollArray.putShort(offset, (short)event);
  82     }
  83 
  84     void putReventOps(int i, int revent) {
  85         int offset = SIZE_POLLFD * i + REVENT_OFFSET;
  86         pollArray.putShort(offset, (short)revent);
  87     }
  88 
  89     void putDescriptor(int i, int fd) {
  90         int offset = SIZE_POLLFD * i + FD_OFFSET;
  91         pollArray.putInt(offset, fd);
  92     }
  93 
  94 }