/*

 * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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package sun.nio.ch;

import sun.misc.*;

/**

 * Manipulates a native array of pollfd structs.

 *

 * @author Mike McCloskey

 * @since 1.4

 */

public abstract class AbstractPollArrayWrapper {

    // Miscellaneous constants

    static final short SIZE_POLLFD   = 8;

    static final short FD_OFFSET     = 0;

    static final short EVENT_OFFSET  = 4;

    static final short REVENT_OFFSET = 6;

    // The poll fd array

    protected AllocatedNativeObject pollArray;

    // Number of valid entries in the pollArray

    protected int totalChannels = 0;

    // Base address of the native pollArray

    protected long pollArrayAddress;

    // Access methods for fd structures

    int getEventOps(int i) {

        int offset = SIZE_POLLFD * i + EVENT_OFFSET;

        return pollArray.getShort(offset);

    }

    int getReventOps(int i) {

        int offset = SIZE_POLLFD * i + REVENT_OFFSET;

        return pollArray.getShort(offset);

    }

    int getDescriptor(int i) {

        int offset = SIZE_POLLFD * i + FD_OFFSET;

        return pollArray.getInt(offset);

    }

    void putEventOps(int i, int event) {

        int offset = SIZE_POLLFD * i + EVENT_OFFSET;

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

    }

    void putReventOps(int i, int revent) {

        int offset = SIZE_POLLFD * i + REVENT_OFFSET;

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

    }

    void putDescriptor(int i, int fd) {

        int offset = SIZE_POLLFD * i + FD_OFFSET;

        pollArray.putInt(offset, fd);

    }

}