/* * Copyright (c) 2008, 2009, 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.nio.channels.*;import java.net.InetAddress;import java.net.NetworkInterface;import java.io.IOException;import java.util.HashSet; /** * MembershipKey implementation. */ class MembershipKeyImpl    extends MembershipKey{    private final MulticastChannel ch;    private final InetAddress group;    private final NetworkInterface interf;    private final InetAddress source;     // true when key is valid    private volatile boolean valid = true;     // lock used when creating or accessing blockedSet    private Object stateLock = new Object();     // set of source addresses that are blocked    private HashSet<InetAddress> blockedSet;     private MembershipKeyImpl(MulticastChannel ch,                              InetAddress group,                              NetworkInterface interf,                              InetAddress source)    {        this.ch = ch;        this.group = group;        this.interf = interf;        this.source = source;    }     /**     * MembershipKey will additional context for IPv4 membership     */    static class Type4 extends MembershipKeyImpl {        private final int groupAddress;        private final int interfAddress;        private final int sourceAddress;         Type4(MulticastChannel ch,              InetAddress group,              NetworkInterface interf,              InetAddress source,              int groupAddress,              int interfAddress,              int sourceAddress)        {            super(ch, group, interf, source);            this.groupAddress = groupAddress;            this.interfAddress = interfAddress;            this.sourceAddress = sourceAddress;        }         int groupAddress() {            return groupAddress;        }         int interfaceAddress() {            return interfAddress;        }         int source() {            return sourceAddress;        }    }     /**     * MembershipKey will additional context for IPv6 membership     */    static class Type6 extends MembershipKeyImpl {        private final byte[] groupAddress;        private final int index;        private final byte[] sourceAddress;         Type6(MulticastChannel ch,              InetAddress group,              NetworkInterface interf,              InetAddress source,              byte[] groupAddress,              int index,              byte[] sourceAddress)        {            super(ch, group, interf, source);            this.groupAddress = groupAddress;            this.index = index;            this.sourceAddress = sourceAddress;        }         byte[] groupAddress() {            return groupAddress;        }         int index() {            return index;        }         byte[] source() {            return sourceAddress;        }    }     public boolean isValid() {        return valid;    }     // package-private    void invalidate() {        valid = false;    }     public void drop() {        // delegate to channel        ((DatagramChannelImpl)ch).drop(this);    }     @Override    public MulticastChannel channel() {        return ch;    }     @Override    public InetAddress group() {        return group;    }     @Override    public NetworkInterface networkInterface() {        return interf;    }     @Override    public InetAddress sourceAddress() {        return source;    }     @Override    public MembershipKey block(InetAddress toBlock)        throws IOException    {        if (source != null)            throw new IllegalStateException("key is source-specific");         synchronized (stateLock) {            if ((blockedSet != null) && blockedSet.contains(toBlock)) {                // already blocked, nothing to do                return this;            }             ((DatagramChannelImpl)ch).block(this, toBlock);             // created blocked set if required and add source address            if (blockedSet == null)                blockedSet = new HashSet<InetAddress>();            blockedSet.add(toBlock);        }        return this;    }     @Override    public MembershipKey unblock(InetAddress toUnblock) {        synchronized (stateLock) {            if ((blockedSet == null) || !blockedSet.contains(toUnblock))                throw new IllegalStateException("not blocked");             ((DatagramChannelImpl)ch).unblock(this, toUnblock);             blockedSet.remove(toUnblock);        }        return this;    }     @Override    public String toString() {        StringBuilder sb = new StringBuilder(64);        sb.append('<');        sb.append(group.getHostAddress());        sb.append(',');        sb.append(interf.getName());        if (source != null) {            sb.append(',');            sb.append(source.getHostAddress());        }        sb.append('>');        return sb.toString();    }}