/*

 * 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package sun.nio.ch;

import sun.misc.*;

/**

 * Manipulates a native array of pollfd structs on Solaris:

 *

 * typedef struct pollfd {

 *    int fd;

 *    short events;

 *    short revents;

 * } pollfd_t;

 *

 * @author Mike McCloskey

 * @since 1.4

 */

public class PollArrayWrapper extends AbstractPollArrayWrapper {

    public static final short POLLCONN = POLLOUT;

    // File descriptor to write for interrupt

    int interruptFD;

    PollArrayWrapper(int newSize) {

        newSize = (newSize + 1) * SIZE_POLLFD;

        pollArray = new AllocatedNativeObject(newSize, false);

        pollArrayAddress = pollArray.address();

        totalChannels = 1;

    }

    void initInterrupt(int fd0, int fd1) {

        interruptFD = fd1;

        putDescriptor(0, fd0);

        putEventOps(0, POLLIN);

        putReventOps(0, 0);

    }

    void release(int i) {

        return;

    }

    void free() {

        pollArray.free();

    }

    /**

     * Prepare another pollfd struct for use.

     */

    void addEntry(SelChImpl sc) {

        putDescriptor(totalChannels, IOUtil.fdVal(sc.getFD()));

        putEventOps(totalChannels, 0);

        putReventOps(totalChannels, 0);

        totalChannels++;

    }

    /**

     * Writes the pollfd entry from the source wrapper at the source index

     * over the entry in the target wrapper at the target index. The source

     * array remains unchanged unless the source array and the target are

     * the same array.

     */

    static void replaceEntry(PollArrayWrapper source, int sindex,

                      PollArrayWrapper target, int tindex) {

        target.putDescriptor(tindex, source.getDescriptor(sindex));

        target.putEventOps(tindex, source.getEventOps(sindex));

        target.putReventOps(tindex, source.getReventOps(sindex));

    }

    /**

     * Grows the pollfd array to a size that will accommodate newSize

     * pollfd entries. This method does no checking of the newSize

     * to determine if it is in fact bigger than the old size: it

     * always reallocates an array of the new size.

     */

    void grow(int newSize) {

        // create new array

        PollArrayWrapper temp = new PollArrayWrapper(newSize);

        // Copy over existing entries

        for (int i=0; i<totalChannels; i++)

            replaceEntry(this, i, temp, i);

        // Swap new array into pollArray field

        pollArray.free();

        pollArray = temp.pollArray;

        pollArrayAddress = pollArray.address();

    }

    int poll(int numfds, int offset, long timeout) {

        return poll0(pollArrayAddress + (offset * SIZE_POLLFD),

                     numfds, timeout);

    }

    public void interrupt() {

        interrupt(interruptFD);

    }

    private native int poll0(long pollAddress, int numfds, long timeout);

    private static native void interrupt(int fd);

}