///LA TODO Protection ?? What if several subscribers at the same time
        /// Not needed since all calls go through the participant which is synched
        public ISendDataHandler GetSendDataHandler(Topic t, Participant participant)
        {
            // In the case that we use the same port for several topics, we need to find the sender for the transport::address::port used
            string key = t.GetTransport() + "::" + t.GetDomainAddress() + "::" + t.GetPort();

            if (SendDataHandlers.ContainsKey(key))
            {
                return(SendDataHandlers[key]);
            }

            try
            {
                // Get the local interface, doing a translation from subnet if necessary
                string localIF = Domain.DoSubnetTranslation(participant.getDomain().GetLocalInterface());

                ISendDataHandler sender = null;
                if (t.GetTransport().Equals(Topic.TRANSPORT_MC))
                {
                    sender = new McSendDataHandler(t, localIF);
                }
                else if (t.GetTransport().Equals(Topic.TRANSPORT_TCP))
                {
                    sender = new TcpSendDataHandler(t, localIF);
                }
                if (sender != null)
                {
                    SendDataHandlers.Add(key, sender);
                    return(sender);
                }

                // We don't want to add the udp handler to the handler list, so handle this last
                if (t.GetTransport().Equals(Topic.TRANSPORT_UDP))
                {
                    if (udpSendDataHandler == null)
                    {
                        // We have only one sender for all topics, so use the domain value for buffer size
                        udpSendDataHandler = new McUdpSendDataHandler(
                            participant.getDomain().GetOutSocketBufferSize(),
                            localIF);

                        // Setup a listener on the participant info data published by participants on our domain.
                        // We use the information for topics with UDP as transport, to know the destination for UDP sends
                        // ie. we extract ip and port from the information and add it to our McUdpSendDataHandler
                        partInfoListener = new ParticipantInfoDataListener(participant, udpSendDataHandler);

                        partInfoSub = new Subscriber(participant.CreateParticipantInfoTopic());
                        partInfoSub.newDataDefault += new NewDataDefaultEventHandler(partInfoListener.SubscriberNewData);
                        partInfoSub.Start();
                    }
                    return(udpSendDataHandler);
                }

                throw new CommException("No such Transport " + t.GetTransport());
            }
            catch (System.IO.IOException ex)
            {
                throw new CommException("Error creating SendDataHandler. IOException -->" + ex.Message);
            }
        }
        /// Protection is not needed since all calls go through the participant which is synched
        public ReceiveDataHandler GetReceiveDataHandler(Topic top, Participant participant)
        {
            // In the case that we use the same port for several topics, we need to find the receiver for the transport::address::port used
            string key = MakeKey(top);

            if (ReceiveDataHandlers.ContainsKey(key))
            {
                ReceiveDataHandler rdh = ReceiveDataHandlers[key];

                // Check if any of the topics have a sample size larger than MAX_SEGMENT_SIZE
                // This will lead to a problem when using the same port, if samples becomes > MAX_SEGMENT_SIZE
                if ((rdh.GetSampleMaxSize() > Globals.MAX_SEGMENT_SIZE) || (top.GetSampleMaxSize() > Globals.MAX_SEGMENT_SIZE))
                {
                    if (top.GetTransport().Equals(Topic.TRANSPORT_UDP))
                    {
                        Logger.ExceptionLogger.LogMessage("Warning: UDP transport is used with Topics with 'sampleMaxSize' > " + Globals.MAX_SEGMENT_SIZE);
                    }
                    else
                    {
                        Logger.ExceptionLogger.LogMessage("Warning: Same port (" + top.GetPort() + ") is used with Topics with 'sampleMaxSize' > " + Globals.MAX_SEGMENT_SIZE);
                    }
                }
                return(rdh);
            }

            // Get the local interface, doing a translation from subnet if necessary
            string localIF = Domain.DoSubnetTranslation(participant.getDomain().GetLocalInterface());

            // Didn't exist, create one if transport is known
            if ((top.GetTransport().Equals(Topic.TRANSPORT_MC)) || (top.GetTransport().Equals(Topic.TRANSPORT_TCP)))
            {
                ReceiveDataHandlers.Add(key,
                                        new ReceiveDataHandler(top, participant, ReceiverFactory.CreateReceiver(top, localIF)));
                return(ReceiveDataHandlers[key]);
            }
            else if (top.GetTransport().Equals(Topic.TRANSPORT_UDP))
            {
                IReceiver rec = ReceiverFactory.CreateReceiver(top, localIF);
                ReceiveDataHandlers.Add(key, new ReceiveDataHandler(top, participant, rec));

                participant.SetUdpTransportInfo(((UdpReceiver)rec).IP, ((UdpReceiver)rec).Port);

                return(ReceiveDataHandlers[key]);
            }
            return(null);
        }