/*

 * 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.Map.Entry;

import java.util.Iterator;

import java.util.Set;

import java.util.HashSet;

import java.util.HashMap;

import java.nio.ByteBuffer;

import java.nio.channels.SelectionKey;

import java.nio.channels.ClosedChannelException;

import java.nio.channels.NotYetBoundException;

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.NotificationHandler;

import com.sun.nio.sctp.MessageInfo;

import com.sun.nio.sctp.SctpChannel;

import com.sun.nio.sctp.SctpMultiChannel;

import com.sun.nio.sctp.SctpSocketOption;

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

/**

 * An implementation of SctpMultiChannel

 */

public class SctpMultiChannelImpl extends SctpMultiChannel

    implements SelChImpl

{

    private final FileDescriptor fd;

    private final int fdVal;

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

    private volatile long receiverThread = 0;

    private volatile long senderThread = 0;

    /* Lock held by current receiving thread */

    private final Object receiveLock = new Object();

    /* Lock held by current sending thread */

    private final Object sendLock = new Object();

    /* 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,

        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 */

    /* Keeps a map of addresses to association, and visa versa */

    private HashMap<SocketAddress, Association> addressMap =

                         new HashMap<SocketAddress, Association>();

    private HashMap<Association, Set<SocketAddress>> associationMap =

                         new HashMap<Association, Set<SocketAddress>>();

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

    /* If an association has been shutdown mark it for removal after

     * the user handler has been invoked */

    private final ThreadLocal<Association> associationToRemove =

        new ThreadLocal<Association>() {

             @Override protected Association initialValue() {

                 return null;

            }

    };

    /* A notification handler cannot invoke receive */

    private final ThreadLocal<Boolean> receiveInvoked =

        new ThreadLocal<Boolean>() {

             @Override protected Boolean initialValue() {

                 return Boolean.FALSE;

            }

    };

    public SctpMultiChannelImpl(SelectorProvider provider)

            throws IOException {

        //TODO: update provider, remove public modifier

        super(provider);

        this.fd = SctpNet.socket(false /*one-to-many*/);

        this.fdVal = IOUtil.fdVal(fd);

    }

    @Override

    public SctpMultiChannel bind(SocketAddress local, int backlog)

            throws IOException {

        synchronized (receiveLock) {

            synchronized (sendLock) {

                synchronized (stateLock) {

                    ensureOpen();

                    if (isBound())

                        SctpNet.throwAlreadyBoundException();

                    InetSocketAddress isa = (local == null) ?

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

                    SecurityManager sm = System.getSecurityManager();

                    if (sm != null)

                        sm.checkListen(isa.getPort());

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

                    InetSocketAddress boundIsa = Net.localAddress(fd);

                    port = boundIsa.getPort();

                    localAddresses.add(isa);

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

                        wildcard = true;

                    SctpNet.listen(fdVal, backlog < 1 ? 50 : backlog);

                }

            }

        }

        return this;

    }

    @Override

    public SctpMultiChannel bindAddress(InetAddress address)

            throws IOException {

        return bindUnbindAddress(address, true);

    }

    @Override

    public SctpMultiChannel unbindAddress(InetAddress address)

            throws IOException {

        return bindUnbindAddress(address, false);

    }

    private SctpMultiChannel 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;

    }

    @Override

    public Set<Association> associations()

            throws ClosedChannelException, NotYetBoundException {

        synchronized (stateLock) {

            if (!isOpen())

                throw new ClosedChannelException();

            if (!isBound())

                throw new NotYetBoundException();

            return Collections.unmodifiableSet(associationMap.keySet());

        }

    }

    private boolean isBound() {

        synchronized (stateLock) {

            return port == -1 ? false : true;

        }

    }

    private void ensureOpen() throws IOException {

        synchronized (stateLock) {

            if (!isOpen())

                throw new ClosedChannelException();

        }

    }

    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

    protected void implConfigureBlocking(boolean block) throws IOException {

        IOUtil.configureBlocking(fd, block);

    }

    @Override

    public void implCloseSelectableChannel() throws IOException {

        synchronized (stateLock) {

            SctpNet.preClose(fdVal);

            if (receiverThread != 0)

                NativeThread.signal(receiverThread);

            if (senderThread != 0)

                NativeThread.signal(senderThread);

            if (!isRegistered())

                kill();

        }

    }

    @Override

    public FileDescriptor getFD() {

        return fd;

    }

    @Override

    public int getFDVal() {

        return fdVal;

    }

    /**

     * Translates native poll revent ops into a ready operation ops

     */

    private boolean translateReadyOps(int ops, int initialOps,

                                      SelectionKeyImpl sk) {

        int intOps = sk.nioInterestOps();

        int oldOps = sk.nioReadyOps();

        int newOps = initialOps;

        if ((ops & PollArrayWrapper.POLLNVAL) != 0) {

            /* This should only happen if this channel is pre-closed while a

             * selection operation is in progress

             * ## Throw an error if this channel has not been pre-closed */

            return false;

        }

        if ((ops & (PollArrayWrapper.POLLERR

                    | PollArrayWrapper.POLLHUP)) != 0) {

            newOps = intOps;

            sk.nioReadyOps(newOps);

            return (newOps & ~oldOps) != 0;

        }

        if (((ops & PollArrayWrapper.POLLIN) != 0) &&

            ((intOps & SelectionKey.OP_READ) != 0))

            newOps |= SelectionKey.OP_READ;

        if (((ops & PollArrayWrapper.POLLOUT) != 0) &&

            ((intOps & SelectionKey.OP_WRITE) != 0))

            newOps |= SelectionKey.OP_WRITE;

        sk.nioReadyOps(newOps);

        return (newOps & ~oldOps) != 0;

    }

    @Override

    public boolean translateAndUpdateReadyOps(int ops, SelectionKeyImpl sk) {

        return translateReadyOps(ops, sk.nioReadyOps(), sk);

    }

    @Override

    public boolean translateAndSetReadyOps(int ops, SelectionKeyImpl sk) {

        return translateReadyOps(ops, 0, sk);

    }

    @Override

    public void translateAndSetInterestOps(int ops, SelectionKeyImpl sk) {

        int newOps = 0;

        if ((ops & SelectionKey.OP_READ) != 0)

            newOps |= PollArrayWrapper.POLLIN;

        if ((ops & SelectionKey.OP_WRITE) != 0)

            newOps |= PollArrayWrapper.POLLOUT;

        sk.selector.putEventOps(sk, newOps);

    }

    @Override

    public void kill() throws IOException {

        synchronized (stateLock) {

            if (state == ChannelState.KILLED)

                return;

            if (state == ChannelState.UNINITIALIZED) {

                state = ChannelState.KILLED;

                return;

            }

            assert !isOpen() && !isRegistered();

            /* Postpone the kill if there is a thread sending or receiving. */

            if (receiverThread == 0 && senderThread == 0) {

                SctpNet.close(fdVal);

                state = ChannelState.KILLED;

            } else {

                state = ChannelState.KILLPENDING;

            }

        }

    }

    @Override

    public <T> SctpMultiChannel setOption(SctpSocketOption<T> name,

                                          T value,

                                          Association association)

            throws IOException {

        if (name == null)

            throw new NullPointerException();

        if (!(supportedOptions().contains(name)))

            throw new UnsupportedOperationException("'" + name + "' not supported");

        synchronized (stateLock) {

            if (association != null && (name.equals(SCTP_PRIMARY_ADDR) ||

                    name.equals(SCTP_SET_PEER_PRIMARY_ADDR))) {

                checkAssociation(association);

            }

            if (!isOpen())

                throw new ClosedChannelException();

            int assocId = association == null ? 0 : association.associationID();

            SctpNet.setSocketOption(fdVal, name, value, assocId);

        }

        return this;

    }

    @Override

    @SuppressWarnings("unchecked")

    public <T> T getOption(SctpSocketOption<T> name, Association association)

            throws IOException {

        if (name == null)

            throw new NullPointerException();

        if (!supportedOptions().contains(name))

            throw new UnsupportedOperationException("'" + name + "' not supported");

        synchronized (stateLock) {

            if (association != null && (name.equals(SCTP_PRIMARY_ADDR) ||

                    name.equals(SCTP_SET_PEER_PRIMARY_ADDR))) {

                checkAssociation(association);

            }

            if (!isOpen())

                throw new ClosedChannelException();

            int assocId = association == null ? 0 : association.associationID();

            return (T)SctpNet.getSocketOption(fdVal, name, assocId);

        }

    }

    private static class DefaultOptionsHolder {

        static final Set<SctpSocketOption<?>> defaultOptions = defaultOptions();

        private static Set<SctpSocketOption<?>> defaultOptions() {

            HashSet<SctpSocketOption<?>> set = new HashSet<SctpSocketOption<?>>(10);

            set.add(SCTP_DISABLE_FRAGMENTS);

            set.add(SCTP_EXPLICIT_COMPLETE);

            set.add(SCTP_FRAGMENT_INTERLEAVE);

            set.add(SCTP_INIT_MAXSTREAMS);

            set.add(SCTP_NODELAY);

            set.add(SCTP_PRIMARY_ADDR);

            set.add(SCTP_SET_PEER_PRIMARY_ADDR);

            set.add(SO_SNDBUF);

            set.add(SO_RCVBUF);

            set.add(SO_LINGER);

            return Collections.unmodifiableSet(set);

        }

    }

    @Override

    public final Set<SctpSocketOption<?>> supportedOptions() {

        return DefaultOptionsHolder.defaultOptions;

    }

    @Override

    public <T> MessageInfo receive(ByteBuffer buffer,

                                   T attachment,

                                   NotificationHandler<T> handler)

            throws IOException {

        if (buffer == null)

            throw new IllegalArgumentException("buffer cannot be null");

        if (buffer.isReadOnly())

            throw new IllegalArgumentException("Read-only buffer");

        if (receiveInvoked.get())

            throw new IllegalReceiveException(

                    "cannot invoke receive from handler");

        receiveInvoked.set(Boolean.TRUE);

        try {

            SctpResultContainer resultContainer = new SctpResultContainer();

            do {

                resultContainer.clear();

                synchronized (receiveLock) {

                    ensureOpen();

                    if (!isBound())

                        throw new NotYetBoundException();

                    int n = 0;

                    try {

                        begin();

                        synchronized (stateLock) {

                            if(!isOpen())

                                return null;

                            receiverThread = NativeThread.current();

                        }

                        do {

                            n = receive(fdVal, buffer, resultContainer);

                        } while ((n == IOStatus.INTERRUPTED) && isOpen());

                    } finally {

                        receiverCleanup();

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

                        assert IOStatus.check(n);

                    }

                    if (!resultContainer.isNotification()) {

                        /* message or nothing */

                        if (resultContainer.hasSomething()) {

                            /* Set the association before returning */

                            SctpMessageInfoImpl info =

                                    resultContainer.getMessageInfo();

                            info.setAssociation(lookupAssociation(info.

                                    associationID()));

                            SecurityManager sm = System.getSecurityManager();

                            if (sm != null) {

                                InetSocketAddress isa  = (InetSocketAddress)info.address();

                                if (!addressMap.containsKey(isa)) {

                                    /* must be a new association */

                                    try {

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

                                                       isa.getPort());

                                    } catch (SecurityException se) {

                                        buffer.clear();

                                        throw se;

                                    }

                                }

                            }

                            assert info.association() != null;

                            return info;

                        } else  {

                          /* Non-blocking may return null if nothing available*/

                            return null;

                        }