/*

 * Copyright 2001-2005 Sun Microsystems, Inc.  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.  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

 * have any questions.

 */

package sun.nio.ch;

import java.nio.channels.spi.SelectorProvider;

import java.security.AccessController;

import java.security.PrivilegedAction;

import sun.security.action.GetPropertyAction;

/**

 * Creates this platform's default SelectorProvider

 */

public class DefaultSelectorProvider {

    /**

     * Prevent instantiation.

     */

    private DefaultSelectorProvider() { }

    /**

     * Returns the default SelectorProvider.

     */

    public static SelectorProvider create() {

        String osname = AccessController.doPrivileged(

            new GetPropertyAction("os.name"));

        if ("SunOS".equals(osname)) {

            return new sun.nio.ch.DevPollSelectorProvider();

        }

        // use EPollSelectorProvider for Linux kernels >= 2.6

        if ("Linux".equals(osname)) {

            String osversion = AccessController.doPrivileged(

                new GetPropertyAction("os.version"));

            String[] vers = osversion.split("\\.", 0);

            if (vers.length >= 2) {

                try {

                    int major = Integer.parseInt(vers[0]);

                    int minor = Integer.parseInt(vers[1]);

                    if (major > 2 || (major == 2 && minor >= 6)) {

                        return new sun.nio.ch.EPollSelectorProvider();

                    }

                } catch (NumberFormatException x) {

                    // format not recognized

                }

            }

        }

        return new sun.nio.ch.PollSelectorProvider();

    }

}