1 /*

     2  * Copyright (c) 2001, 2012, 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 

    29 /**

    30  * Manipulates a native array of pollfd structs.

    31  *

    32  * @author Mike McCloskey

    33  * @since 1.4

    34  */

    35 

    36 public abstract class AbstractPollArrayWrapper {

    37 

    38     // Miscellaneous constants

    39     static final short SIZE_POLLFD   = 8;

    40     static final short FD_OFFSET     = 0;

    41     static final short EVENT_OFFSET  = 4;

    42     static final short REVENT_OFFSET = 6;

    43 

    44     // The poll fd array

    45     protected AllocatedNativeObject pollArray;

    46 

    47     // Number of valid entries in the pollArray

    48     protected int totalChannels = 0;

    49 

    50     // Base address of the native pollArray

    51     protected long pollArrayAddress;

    52 

    53     // Access methods for fd structures

    54     int getEventOps(int i) {

    55         int offset = SIZE_POLLFD * i + EVENT_OFFSET;

    56         return pollArray.getShort(offset);

    57     }

    58 

    59     int getReventOps(int i) {

    60         int offset = SIZE_POLLFD * i + REVENT_OFFSET;

    61         return pollArray.getShort(offset);

    62     }

    63 

    64     int getDescriptor(int i) {

    65         int offset = SIZE_POLLFD * i + FD_OFFSET;

    66         return pollArray.getInt(offset);

    67     }

    68 

    69     void putEventOps(int i, int event) {

    70         int offset = SIZE_POLLFD * i + EVENT_OFFSET;

    71         pollArray.putShort(offset, (short)event);

    72     }

    73 

    74     void putReventOps(int i, int revent) {

    75         int offset = SIZE_POLLFD * i + REVENT_OFFSET;

    76         pollArray.putShort(offset, (short)revent);

    77     }

    78 

    79     void putDescriptor(int i, int fd) {

    80         int offset = SIZE_POLLFD * i + FD_OFFSET;

    81         pollArray.putInt(offset, fd);

    82     }

    83 

    84 }