void MulticastClientTransport::dropIdleTransports()
    {
        bringInNewTransports();

        Lock lock(mClientTransportsMutex);

        bool needToRemove = false;

        ClientTransportList::iterator iter;
        for (iter = mClientTransports.begin(); iter != mClientTransports.end(); ++iter)
        {
            RCF::ClientTransport & transport = ***iter;
            RcfSessionWeakPtr rcfSessionWeakPtr = transport.getRcfSession();
            if ( rcfSessionWeakPtr == RcfSessionWeakPtr() )
            {
                // HTTP/HTTPS connections do not hold on to the RcfSession and can't receive pings.
                continue;
            }
            RcfSessionPtr rcfSessionPtr = rcfSessionWeakPtr.lock();
            if (!rcfSessionPtr)
            {
                RCF_LOG_2() << "Dropping subscription. Subscriber has closed connection.";
                iter->reset();
                needToRemove = true;
            }
            else
            {
                boost::uint32_t pingIntervalMs = rcfSessionPtr->getPingIntervalMs();
                if (pingIntervalMs)
                {
                    RCF::Timer pingTimer( rcfSessionPtr->getPingTimestamp() );
                    if (pingTimer.elapsed(5000 + 2*pingIntervalMs))
                    {
                        std::string subscriberUrl = rcfSessionPtr->getClientAddress().string();
                        
                        RCF_LOG_2()(subscriberUrl)(pingIntervalMs) 
                            << "Dropping subscription. Subscriber has not sent pings within the expected ping interval.";

                        iter->reset();
                        needToRemove = true;
                    }
                }
            }
        }

        if (needToRemove)
        {
            eraseRemove(mClientTransports, ClientTransportAutoPtrPtr());
        }
    }
    void MulticastClientTransport::pingAllTransports()
    {
        bringInNewTransports();

        Lock lock(mClientTransportsMutex);

        if (!mMulticastTemp.get())
        {
            mMulticastTemp.reset( new MulticastClientTransport() );
        }

        MulticastClientTransport & multicastTemp = 
            static_cast<MulticastClientTransport &>(*mMulticastTemp);

        multicastTemp.mClientTransports.resize(0);

        ClientTransportList::iterator iter;
        for (iter = mClientTransports.begin(); iter != mClientTransports.end(); ++iter)
        {
            I_ClientTransport & transport = ***iter;
            RcfSessionPtr rcfSessionPtr = transport.getRcfSession().lock();
            if (rcfSessionPtr)
            {
                boost::uint32_t pingIntervalMs = rcfSessionPtr->getPingIntervalMs();
                if (pingIntervalMs)
                {
                    multicastTemp.mClientTransports.push_back(*iter);
                }
            }
        }

        RcfClient<I_Null> nullClient( mMulticastTemp );
        nullClient.getClientStub().ping(RCF::Oneway);
        mMulticastTemp.reset( nullClient.getClientStub().releaseTransport().release() );
        multicastTemp.mClientTransports.resize(0);
    }