/*
 * Copyright (c) 2007, 2018, 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 java.net;

import java.io.IOException;
import java.io.FileDescriptor;
import sun.net.ResourceManager;

/*
 * This class defines the plain SocketImpl that is used when
 * the System property java.net.preferIPv4Stack is set to true.
 *
 * @author Chris Hegarty
 */

class TwoStacksPlainSocketImpl extends AbstractPlainSocketImpl {

    // true if this socket is exclusively bound
    private final boolean exclusiveBind;

    // emulates SO_REUSEADDR when exclusiveBind is true
    private boolean isReuseAddress;

    static {
        initProto();
    }

    public TwoStacksPlainSocketImpl(boolean exclBind) {
        exclusiveBind = exclBind;
    }

    public TwoStacksPlainSocketImpl(FileDescriptor fd, boolean exclBind) {
        this.fd = fd;
        exclusiveBind = exclBind;
    }

    public Object getOption(int opt) throws SocketException {
        if (isClosedOrPending()) {
            throw new SocketException("Socket Closed");
        }
        if (opt == SO_BINDADDR) {
            InetAddressContainer in = new InetAddressContainer();
            socketGetOption(opt, in);
            return in.addr;
        } else if (opt == SO_REUSEADDR && exclusiveBind) {
            // SO_REUSEADDR emulated when using exclusive bind
            return isReuseAddress;
        } else if (opt == SO_REUSEPORT) {
            // SO_REUSEPORT is not supported on Windows.
            throw new UnsupportedOperationException("unsupported option");
        } else
            return super.getOption(opt);
    }

    @Override
    void socketBind(InetAddress address, int port) throws IOException {
        socketBind(address, port, exclusiveBind);
    }

    @Override
    void socketSetOption(int opt, boolean on, Object value)
        throws SocketException
    {
        // SO_REUSEADDR emulated when using exclusive bind
        if (opt == SO_REUSEADDR && exclusiveBind)
            isReuseAddress = on;
        else if (opt == SO_REUSEPORT) {
            // SO_REUSEPORT is not supported on Windows.
            throw new UnsupportedOperationException("unsupported option");
        }
        else
            socketNativeSetOption(opt, on, value);
    }

    /**
     * Closes the socket.
     */
    @Override
    protected void close() throws IOException {
        synchronized(fdLock) {
            if (fd != null) {
                if (!stream) {
                    ResourceManager.afterUdpClose();
                }
                if (fdUseCount == 0) {
                    if (closePending) {
                        return;
                    }
                    closePending = true;
                    socketClose();
                    fd = null;
                    return;
                } else {
                    /*
                     * If a thread has acquired the fd and a close
                     * isn't pending then use a deferred close.
                     * Also decrement fdUseCount to signal the last
                     * thread that releases the fd to close it.
                     */
                    if (!closePending) {
                        closePending = true;
                        fdUseCount--;
                        socketClose();
                    }
                }
            }
        }
    }

    /* Native methods */

    static native void initProto();

    native void socketCreate(boolean stream) throws IOException;

    native void socketConnect(InetAddress address, int port, int timeout)
        throws IOException;

    native void socketBind(InetAddress address, int port, boolean exclBind)
        throws IOException;

    native void socketListen(int count) throws IOException;

    native void socketAccept(SocketImpl s) throws IOException;

    native int socketAvailable() throws IOException;

    native void socketClose0(boolean useDeferredClose) throws IOException;

    native void socketShutdown(int howto) throws IOException;

    native void socketNativeSetOption(int cmd, boolean on, Object value)
        throws SocketException;

    native int socketGetOption(int opt, Object iaContainerObj) throws SocketException;

    native void socketSendUrgentData(int data) throws IOException;
}