Index: java/com/l2jserver/gameserver/instancemanager/AntiFeedManager.java
===================================================================
--- java/com/l2jserver/gameserver/instancemanager/AntiFeedManager.java  (revision 5453)
+++ java/com/l2jserver/gameserver/instancemanager/AntiFeedManager.java  (working copy)
@@ -14,6 +14,9 @@
  */
 package com.l2jserver.gameserver.instancemanager;

+import gnu.trove.TIntObjectHashMap;
+import gnu.trove.TObjectProcedure;
+
 import java.util.Map;

 import javolution.util.FastMap;
@@ -26,7 +29,8 @@
 public class AntiFeedManager
 {
    private Map<Integer,Long> _lastDeathTimes;
-
+   private TIntObjectHashMap<Map<Integer, Integer>> _eventIPs;
+
    public static final AntiFeedManager getInstance()
    {
        return SingletonHolder._instance;
@@ -35,6 +39,7 @@
    private AntiFeedManager()
    {
        _lastDeathTimes = new FastMap<Integer,Long>().shared();
+       _eventIPs = new TIntObjectHashMap<Map<Integer, Integer>>();
    }

    /**
@@ -96,7 +101,153 @@
    {
        _lastDeathTimes.clear();
    }
-
+
+   /**
+    * Register new event for dualbox check.
+    * Should be called only once.
+    * @param eventId
+    */
+   public final void registerEvent(int eventId)
+   {
+       if (!_eventIPs.containsKey(eventId))
+           _eventIPs.put(eventId, new FastMap<Integer, Integer>());
+   }
+
+   /**
+    * If number of all simultaneous connections from player's IP address lower than max
+    * then increment connection count and return true.
+    * Returns false if number of all simultaneous connections from player's IP address
+    * higher than max.
+    * @param eventId
+    * @param player
+    * @param max
+    * @return
+    */
+   public final boolean tryAddPlayer(int eventId, L2PcInstance player, int max)
+   {
+       if (_eventIPs.isEmpty())
+           return false;
+
+       final Map<Integer, Integer> event = _eventIPs.get(eventId);
+       if (event == null)
+           return false; // no such event registered
+
+       final L2GameClient client = player.getClient();
+       if (client == null || client.isDetached())
+           return false; // unable to determine IP address
+
+       final Integer addrHash = Integer.valueOf(client.getConnection().getInetAddress().hashCode());
+       Integer number;
+       synchronized (event)
+       {
+           number = event.get(addrHash);
+           if (number == null)
+           {
+               number = new Integer(0);
+               event.put(addrHash, number);
+           }
+       }
+
+       synchronized (number)
+       {
+           if (number < max)
+           {
+               number++;
+               return true;
+           }
+       }
+       return false;
+   }
+
+   /**
+    * Decreasing number of active connection from player's IP address
+    * Returns true if success and false if any problem detected.
+    * @param eventId
+    * @param player
+    * @return
+    */
+   public final boolean removePlayer(int eventId, L2PcInstance player)
+   {
+       if (_eventIPs.isEmpty())
+           return false;
+
+       final Map<Integer, Integer> event = _eventIPs.get(eventId);
+       if (event == null)
+           return false; // no such event registered
+
+       final L2GameClient client = player.getClient();
+       if (client == null || client.isDetached())
+           return false; // unable to determine IP address
+
+       final Integer addrHash = Integer.valueOf(client.getConnection().getInetAddress().hashCode());
+       Integer number = event.get(addrHash);
+       if (number == null)
+           return false; // address not registered
+
+       synchronized (number)
+       {
+           if (number > 0)
+           {
+               number--;
+               return true;
+           }
+           return false; // all boxes connected from this IP already removed
+       }
+   }
+
+   /**
+    * Remove player connection IP address from all registered events lists.
+    * @param player
+    */
+   public final void disconnectPlayer(L2PcInstance player)
+   {
+       if (_eventIPs.isEmpty())
+           return;
+
+       final L2GameClient client = player.getClient();
+       if (client == null || client.isDetached())
+           return;
+
+       final Integer addrHash = Integer.valueOf(client.getConnection().getInetAddress().hashCode());
+       _eventIPs.forEachValue(new DisconnectProcedure(addrHash));
+   }
+
+   /**
+    * Clear all entries for this eventId.
+    * @param eventId
+    */
+   public final void clear(int eventId)
+   {
+       final Map<Integer, Integer> event = _eventIPs.get(eventId);
+       if (event != null)
+           event.clear();
+   }
+
+   private final class DisconnectProcedure implements TObjectProcedure<Map<Integer, Integer>>
+   {
+       private final Integer _addrHash;
+
+       public DisconnectProcedure(Integer hash)
+       {
+           _addrHash = hash;
+       }
+
+       @Override
+       public final boolean execute(Map<Integer, Integer> event)
+       {
+           Integer number = event.get(_addrHash);
+           if (number != null)
+           {
+               synchronized (number)
+               {
+                   if (number > 0)
+                       number--;
+               }
+           }
+           return true;
+       }
+   }
+
    @SuppressWarnings("synthetic-access")
    private static class SingletonHolder
    {