Void function creation

[Ma CAs]

Hello,

I am trying to calculate throughput and make void function so I could run it as Simulator::Schedule: 

void LTE (double starttime, double duration)

{

        Ptr<PacketSink> sink = serverApps.Get (0)->GetObject<PacketSink> ();

        double totalMbytes = sink->GetTotalRx ()/1000000;

        double lteThroughput = totalMbytes * 8.0 / (duration - starttime);

        std::cout <<"Total Mbytes: "<< totalMbytes <<"; Throughput " <<lteThroughput << " Mbps \t" << std::endl;

}

But I get problem with serverApps as it is not declarated. How could i do that in this function?

../scratch/lena-simple-epc.cc: In function ‘void LTE(double, double)’:

../scratch/lena-simple-epc.cc:43:32: error: ‘serverApps’ was not declared in this scope

         Ptr<PacketSink> sink = serverApps.Get (0)->GetObject<PacketSink> ();

                                ^~~~~~~~~~

../scratch/lena-simple-epc.cc:43:32: note: suggested alternative: ‘strverscmp’

         Ptr<PacketSink> sink = serverApps.Get (0)->GetObject<PacketSink> ();

                                ^~~~~~~~~~

                                strverscmp

../scratch/lena-simple-epc.cc:43:72: error: expected primary-expression before ‘>’ token

         Ptr<PacketSink> sink = serverApps.Get (0)->GetObject<PacketSink> ();

                                                                        ^

../scratch/lena-simple-epc.cc:43:75: error: expected primary-expression before ‘)’ token

         Ptr<PacketSink> sink = serverApps.Get (0)->GetObject<PacketSink> ();

                                                                           ^

[Adil Alsuhaim]

serverApps is created in another function (I am guessing in main), so it's outside the scope of this void function. 

In ns-3, all nodes are contained in a global list of nodes called NodeList. A Node can contain a list of applications (also a list of devices). PacketSink is an application (it's a subclass of ns3::Application). If you want to access all the PacketSink applications in all the nodes, you can do this:

for (uint32_t i=0 ; i < NodeList::GetNNodes(); i++)
{
  Ptr<Node> nodeI = NodeList::GetNode(i);
  for (uint32_t j=0 ; j < nodeI->GetNApplications(); j++)
  {
    Ptr<Application> appI = nodeI->GetApplication (j);
    if ( appI->GetInstanceTypeId () == PacketSink::GetTypeId ()) // checking before performing dynamic cast.
    {
      Ptr<PacketSink> sink = DynamicCast <PacketSink> (appI);
      //do what you need to do
    }
  }
}

If you're sure that node 0 contains only one application, the packet sink, then you can just do

Ptr<PacketSink> sink = DynamicCast<PacketSink> (NodeList::GetNode(0)->GetApplication(0));

Cheers,

Adil