/*
 * Copyright (c) 2008, 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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 * questions.
 */

package sun.nio.ch;

import java.nio.channels.spi.AsynchronousChannelProvider;
import java.security.AccessController;
import sun.security.action.GetPropertyAction;

/**
 * Creates this platform's default asynchronous channel provider
 */

public class DefaultAsynchronousChannelProvider {

    /**
     * Prevent instantiation.
     */
    private DefaultAsynchronousChannelProvider() { }

    @SuppressWarnings("unchecked")
    private static AsynchronousChannelProvider createProvider(String cn) {
        Class<AsynchronousChannelProvider> c;
        try {
            c = (Class<AsynchronousChannelProvider>)Class.forName(cn);
        } catch (ClassNotFoundException x) {
            throw new AssertionError(x);
        }
        try {
            return c.newInstance();
        } catch (IllegalAccessException | InstantiationException x) {
            throw new AssertionError(x);
        }

    }

    /**
     * Returns the default AsynchronousChannelProvider.
     */
    public static AsynchronousChannelProvider create() {
        String osname = AccessController
            .doPrivileged(new GetPropertyAction("os.name"));
        if (osname.equals("SunOS"))
            return createProvider("sun.nio.ch.SolarisAsynchronousChannelProvider");
        if (osname.equals("Linux"))
            return createProvider("sun.nio.ch.LinuxAsynchronousChannelProvider");
        if (osname.contains("OS X"))
            return createProvider("sun.nio.ch.BsdAsynchronousChannelProvider");
        if (osname.equals("AIX"))
            return createProvider("sun.nio.ch.AixAsynchronousChannelProvider");
        throw new InternalError("platform not recognized");
    }
}