/*

 * 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.  Sun designates this

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

 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

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 */

package sun.nio.ch;

import java.io.IOException;

import java.nio.channels.*;

import java.nio.channels.spi.*;

import java.util.*;

import sun.misc.*;

/**

 * An implementation of Selector for Solaris.

 */

class PollSelectorImpl

    extends AbstractPollSelectorImpl

{

    // File descriptors used for interrupt

    private int fd0;

    private int fd1;

    // Lock for interrupt triggering and clearing

    private Object interruptLock = new Object();

    private boolean interruptTriggered = false;

    /**

     * Package private constructor called by factory method in

     * the abstract superclass Selector.

     */

    PollSelectorImpl(SelectorProvider sp) {

        super(sp, 1, 1);

        int[] fdes = new int[2];

        IOUtil.initPipe(fdes, false);

        fd0 = fdes[0];

        fd1 = fdes[1];

        pollWrapper = new PollArrayWrapper(INIT_CAP);

        pollWrapper.initInterrupt(fd0, fd1);

        channelArray = new SelectionKeyImpl[INIT_CAP];

    }

    protected int doSelect(long timeout)

        throws IOException

    {

        if (channelArray == null)

            throw new ClosedSelectorException();

        processDeregisterQueue();

        try {

            begin();

            pollWrapper.poll(totalChannels, 0, timeout);

        } finally {

            end();

        }

        processDeregisterQueue();

        int numKeysUpdated = updateSelectedKeys();

        if (pollWrapper.getReventOps(0) != 0) {

            // Clear the wakeup pipe

            pollWrapper.putReventOps(0, 0);

            synchronized (interruptLock) {

                IOUtil.drain(fd0);

                interruptTriggered = false;

            }

        }

        return numKeysUpdated;

    }

    protected void implCloseInterrupt() throws IOException {

        // prevent further wakeup

        synchronized (interruptLock) {

            interruptTriggered = true;

        }

        fd0 = -1;

        fd1 = -1;

        pollWrapper.release(0);

    }

    public Selector wakeup() {

        synchronized (interruptLock) {

            if (!interruptTriggered) {

                pollWrapper.interrupt();

                interruptTriggered = true;

            }

        }

        return this;

    }

}