/*

 * Copyright (c) 2009, 2010, 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 java.net.InetAddress;

import java.net.SocketAddress;

import java.net.SocketException;

import java.net.InetSocketAddress;

import java.io.FileDescriptor;

import java.io.IOException;

import java.util.Collections;

import java.util.Set;

import java.util.HashSet;

import java.nio.ByteBuffer;

import java.nio.channels.SelectionKey;

import java.nio.channels.ClosedChannelException;

import java.nio.channels.ConnectionPendingException;

import java.nio.channels.NoConnectionPendingException;

import java.nio.channels.AlreadyConnectedException;

import java.nio.channels.NotYetBoundException;

import java.nio.channels.NotYetConnectedException;

import java.nio.channels.spi.SelectorProvider;

import com.sun.nio.sctp.AbstractNotificationHandler;

import com.sun.nio.sctp.Association;

import com.sun.nio.sctp.AssociationChangeNotification;

import com.sun.nio.sctp.HandlerResult;

import com.sun.nio.sctp.IllegalReceiveException;

import com.sun.nio.sctp.InvalidStreamException;

import com.sun.nio.sctp.IllegalUnbindException;

import com.sun.nio.sctp.MessageInfo;

import com.sun.nio.sctp.NotificationHandler;

import com.sun.nio.sctp.SctpChannel;

import com.sun.nio.sctp.SctpSocketOption;

import sun.nio.ch.PollArrayWrapper;

import sun.nio.ch.SelChImpl;

import static sun.nio.ch.SctpResultContainer.SEND_FAILED;

import static sun.nio.ch.SctpResultContainer.ASSOCIATION_CHANGED;

import static sun.nio.ch.SctpResultContainer.PEER_ADDRESS_CHANGED;

import static sun.nio.ch.SctpResultContainer.SHUTDOWN;

/**

 * An implementation of an SctpChannel

 */

public class SctpChannelImpl extends SctpChannel

    implements SelChImpl

{

    private final FileDescriptor fd;

    private final int fdVal;

    /* IDs of native threads doing send and receivess, for signalling */

    private volatile long receiverThread = 0;

    private volatile long senderThread = 0;

    /* Lock held by current receiving or connecting thread */

    private final Object receiveLock = new Object();

    /* Lock held by current sending or connecting thread */

    private final Object sendLock = new Object();

    private final ThreadLocal<Boolean> receiveInvoked =

        new ThreadLocal<Boolean>() {

             @Override protected Boolean initialValue() {

                 return Boolean.FALSE;

            }

    };

    /* Lock held by any thread that modifies the state fields declared below

       DO NOT invoke a blocking I/O operation while holding this lock! */

    private final Object stateLock = new Object();

    private enum ChannelState {

        UNINITIALIZED,

        UNCONNECTED,

        PENDING,

        CONNECTED,

        KILLPENDING,

        KILLED,

    }

    /* -- The following fields are protected by stateLock -- */

    private ChannelState state = ChannelState.UNINITIALIZED;

    /* Binding; Once bound the port will remain constant. */

    int port = -1;

    private HashSet<InetSocketAddress> localAddresses = new HashSet<InetSocketAddress>();

    /* Has the channel been bound to the wildcard address */

    private boolean wildcard; /* false */

    //private InetSocketAddress remoteAddress = null;

    /* Input/Output open */

    private boolean readyToConnect;

    /* Shutdown */

    private boolean isShutdown;

    private Association association;

    private Set<SocketAddress> remoteAddresses = Collections.EMPTY_SET;

    /* -- End of fields protected by stateLock -- */

    /**

     * Constructor for normal connecting sockets

     */

    public SctpChannelImpl(SelectorProvider provider) throws IOException {

        //TODO: update provider remove public modifier

        super(provider);

        this.fd = SctpNet.socket(true);

        this.fdVal = IOUtil.fdVal(fd);

        this.state = ChannelState.UNCONNECTED;

    }

    /**

     * Constructor for sockets obtained from server sockets

     */

    public SctpChannelImpl(SelectorProvider provider, FileDescriptor fd)

         throws IOException {

        this(provider, fd, null);

    }

    /**

     * Constructor for sockets obtained from branching

     */

    public SctpChannelImpl(SelectorProvider provider,

                           FileDescriptor fd,

                           Association association)

            throws IOException {

        super(provider);

        this.fd = fd;

        this.fdVal = IOUtil.fdVal(fd);

        this.state = ChannelState.CONNECTED;

        port = (Net.localAddress(fd)).getPort();

        if (association != null) { /* branched */

            this.association = association;

        } else { /* obtained from server channel */

            /* Receive COMM_UP */

            ByteBuffer buf = Util.getTemporaryDirectBuffer(50);

            try {

                receive(buf, null, null, true);

            } finally {

                Util.releaseTemporaryDirectBuffer(buf);

            }

        }

    }

    /**

     * Binds the channel's socket to a local address.

     */

    @Override

    public SctpChannel bind(SocketAddress local) throws IOException {

        synchronized (receiveLock) {

            synchronized (sendLock) {

                synchronized (stateLock) {

                    ensureOpenAndUnconnected();

                    if (isBound())

                        SctpNet.throwAlreadyBoundException();

                    InetSocketAddress isa = (local == null) ?

                        new InetSocketAddress(0) : Net.checkAddress(local);

                    Net.bind(fd, isa.getAddress(), isa.getPort());

                    InetSocketAddress boundIsa = Net.localAddress(fd);

                    port = boundIsa.getPort();

                    localAddresses.add(isa);

                    if (isa.getAddress().isAnyLocalAddress())

                        wildcard = true;

                }

            }

        }

        return this;

    }

    @Override

    public SctpChannel bindAddress(InetAddress address)

            throws IOException {

        bindUnbindAddress(address, true);

        localAddresses.add(new InetSocketAddress(address, port));

        return this;

    }

    @Override

    public SctpChannel unbindAddress(InetAddress address)

            throws IOException {

        bindUnbindAddress(address, false);

        localAddresses.remove(new InetSocketAddress(address, port));

        return this;

    }

    private SctpChannel bindUnbindAddress(InetAddress address, boolean add)

            throws IOException {

        if (address == null)

            throw new IllegalArgumentException();

        synchronized (receiveLock) {

            synchronized (sendLock) {

                synchronized (stateLock) {

                    if (!isOpen())

                        throw new ClosedChannelException();

                    if (!isBound())

                        throw new NotYetBoundException();

                    if (wildcard)

                        throw new IllegalStateException(

                                "Cannot add or remove addresses from a channel that is bound to the wildcard address");

                    if (address.isAnyLocalAddress())

                        throw new IllegalArgumentException(

                                "Cannot add or remove the wildcard address");

                    if (add) {

                        for (InetSocketAddress addr : localAddresses) {

                            if (addr.getAddress().equals(address)) {

                                SctpNet.throwAlreadyBoundException();

                            }

                        }

                    } else { /*removing */

                        /* Verify that there is more than one address

                         * and that address is already bound */

                        if (localAddresses.size() <= 1)

                            throw new IllegalUnbindException("Cannot remove address from a channel with only one address bound");

                        boolean foundAddress = false;

                        for (InetSocketAddress addr : localAddresses) {

                            if (addr.getAddress().equals(address)) {

                                foundAddress = true;

                                break;

                            }

                        }

                        if (!foundAddress )

                            throw new IllegalUnbindException("Cannot remove address from a channel that is not bound to that address");

                    }

                    SctpNet.bindx(fdVal, new InetAddress[]{address}, port, add);

                    /* Update our internal Set to reflect the addition/removal */

                    if (add)

                        localAddresses.add(new InetSocketAddress(address, port));

                    else {

                        for (InetSocketAddress addr : localAddresses) {

                            if (addr.getAddress().equals(address)) {

                                localAddresses.remove(addr);

                                break;

                            }

                        }

                    }

                }

            }

        }

        return this;

    }

    private boolean isBound() {

        synchronized (stateLock) {

            return port == -1 ? false : true;

        }

    }

    private boolean isConnected() {

        synchronized (stateLock) {

            return (state == ChannelState.CONNECTED);

        }

    }

    private void ensureOpenAndUnconnected() throws IOException {

        synchronized (stateLock) {

            if (!isOpen())

                throw new ClosedChannelException();

            if (isConnected())

                throw new AlreadyConnectedException();

            if (state == ChannelState.PENDING)

                throw new ConnectionPendingException();

        }

    }

    private boolean ensureReceiveOpen() throws ClosedChannelException {

        synchronized (stateLock) {

            if (!isOpen())

                throw new ClosedChannelException();

            if (!isConnected())

                throw new NotYetConnectedException();

            else

                return true;

        }

    }

    private void ensureSendOpen() throws ClosedChannelException {

        synchronized (stateLock) {

            if (!isOpen())

                throw new ClosedChannelException();

            if (isShutdown)

                throw new ClosedChannelException();

            if (!isConnected())

                throw new NotYetConnectedException();

        }

    }

    private void receiverCleanup() throws IOException {

        synchronized (stateLock) {

            receiverThread = 0;

            if (state == ChannelState.KILLPENDING)

                kill();

        }

    }

    private void senderCleanup() throws IOException {

        synchronized (stateLock) {

            senderThread = 0;

            if (state == ChannelState.KILLPENDING)

                kill();

        }

    }

    @Override

    public Association association() throws ClosedChannelException {

        synchronized (stateLock) {

            if (!isOpen())

                throw new ClosedChannelException();

            if (!isConnected())

                return null;

            return association;

        }

    }

    @Override

    public boolean connect(SocketAddress endpoint) throws IOException {

        synchronized (receiveLock) {

            synchronized (sendLock) {

                ensureOpenAndUnconnected();

                InetSocketAddress isa = Net.checkAddress(endpoint);

                SecurityManager sm = System.getSecurityManager();

                if (sm != null)

                    sm.checkConnect(isa.getAddress().getHostAddress(),

                                    isa.getPort());

                synchronized (blockingLock()) {

                    int n = 0;

                    try {

                        try {

                            begin();

                            synchronized (stateLock) {

                                if (!isOpen()) {

                                    return false;

                                }

                                receiverThread = NativeThread.current();

                            }

                            for (;;) {

                                InetAddress ia = isa.getAddress();

                                if (ia.isAnyLocalAddress())

                                    ia = InetAddress.getLocalHost();

                                n = SctpNet.connect(fdVal, ia, isa.getPort());

                                if (  (n == IOStatus.INTERRUPTED)

                                      && isOpen())

                                    continue;

                                break;

                            }

                        } finally {

                            receiverCleanup();

                            end((n > 0) || (n == IOStatus.UNAVAILABLE));

                            assert IOStatus.check(n);

                        }

                    } catch (IOException x) {

                        /* If an exception was thrown, close the channel after

                         * invoking end() so as to avoid bogus

                         * AsynchronousCloseExceptions */

                        close();

                        throw x;

                    }

                    if (n > 0) {

                        synchronized (stateLock) {

                            /* Connection succeeded */

                            state = ChannelState.CONNECTED;

                            if (!isBound()) {

                                InetSocketAddress boundIsa =

                                        Net.localAddress(fd);

                                port = boundIsa.getPort();

                            }

                            /* Receive COMM_UP */

                            ByteBuffer buf = Util.getTemporaryDirectBuffer(50);

                            try {

                                receive(buf, null, null, true);

                            } finally {

                                Util.releaseTemporaryDirectBuffer(buf);

                            }

                            /* cache remote addresses */

                            try {

                                remoteAddresses = getRemoteAddresses();

                            } catch (IOException unused) { /* swallow exception */ }

                            return true;

                        }

                    } else  {

                        synchronized (stateLock) {

                            /* If nonblocking and no exception then connection

                             * pending; disallow another invocation */

                            if (!isBlocking())

                                state = ChannelState.PENDING;

                            else

                                assert false;

                        }

                    }

                }

                return false;

            }

        }

    }

    @Override

    public boolean connect(SocketAddress endpoint,

                           int maxOutStreams,

                           int maxInStreams)

            throws IOException {

        ensureOpenAndUnconnected();

        return setOption(SCTP_INIT_MAXSTREAMS, InitMaxStreams.

                create(maxInStreams, maxOutStreams)).connect(endpoint);

    }

    @Override

    public boolean isConnectionPending() {

        synchronized (stateLock) {

            return (state == ChannelState.PENDING);

        }

    }

    @Override

    public boolean finishConnect() throws IOException {

        synchronized (receiveLock) {

            synchronized (sendLock) {

                synchronized (stateLock) {

                    if (!isOpen())

                        throw new ClosedChannelException();

                    if (isConnected())

                        return true;

                    if (state != ChannelState.PENDING)

                        throw new NoConnectionPendingException();

                }

                int n = 0;

                try {

                    try {

                        begin();

                        synchronized (blockingLock()) {

                            synchronized (stateLock) {

                                if (!isOpen()) {

                                    return false;

                                }

                                receiverThread = NativeThread.current();

                            }

                            if (!isBlocking()) {

                                for (;;) {

                                    n = checkConnect(fd, false, readyToConnect);

                                    if (  (n == IOStatus.INTERRUPTED)

                                          && isOpen())

                                        continue;

                                    break;

                                }

                            } else {

                                for (;;) {

                                    n = checkConnect(fd, true, readyToConnect);

                                    if (n == 0) {

                                        // Loop in case of

                                        // spurious notifications

                                        continue;

                                    }

                                    if (  (n == IOStatus.INTERRUPTED)

                                          && isOpen())

                                        continue;

                                    break;

                                }

                            }

                        }

                    } finally {

                        synchronized (stateLock) {

                            receiverThread = 0;

                            if (state == ChannelState.KILLPENDING) {

                                kill();

                                /* poll()/getsockopt() does not report

                                 * error (throws exception, with n = 0)

                                 * on Linux platform after dup2 and

                                 * signal-wakeup. Force n to 0 so the

                                 * end() can throw appropriate exception */

                                n = 0;

                            }

                        }

                        end((n > 0) || (n == IOStatus.UNAVAILABLE));

                        assert IOStatus.check(n);

                    }

                } catch (IOException x) {

                    /* If an exception was thrown, close the channel after

                     * invoking end() so as to avoid bogus

                     * AsynchronousCloseExceptions */

                    close();

                    throw x;

                }

                if (n > 0) {

                    synchronized (stateLock) {

                        state = ChannelState.CONNECTED;

                        if (!isBound()) {

                            InetSocketAddress boundIsa =

                                    Net.localAddress(fd);

                            port = boundIsa.getPort();

                        }