LTE: Segmentation fault

[Peter Riedemann]

Hi,
I'm working inside of a project which uses ns-3.22. In the project code there is one node which has an application server and there are some other nodes which have an application client. My task is to realise some topologies (e.g. dsl, lte, plc topology) so that the server and the clients can communicate to each other using a realistic topology. I've realised a dsl topology and a plc topology. For both the simulator runs fines. I've realised a lte topology, too. Once I run the simulator using the lte topology, I've got an segmentation fault during the simulation. It doesn't matter if I use ns-3.24.1. The same error occurs. Running the simulator with gdb shows the following:

Program received signal SIGSEGV, Segmentation fault.
0x00007fffefb8ceba in ns3::EventImpl* ns3::MakeEvent<void (ns3::Application::*)(), ns3::Application*>(void (ns3::Application::*)(), ns3::Application*)::EventMemberImpl0::Notify() (this=0x92c5b0) at ./ns3/make-event.h:323
323          (EventMemberImplObjTraits<OBJ>::GetReference (m_obj).*m_function)();

The simulator initialize the server and the clients correctly and then it terminates at any time. But it happens before the a package will be send.
To identify the error I've created a simple example with an UDP Echo Server and some UDP Echo Clients using the same lte topology. However, in this case the simulator runs fine and all messages will be transfered. So I don't know how to fix the problem. Because the simulator runs fine with other network topologies I think the error has to be existent in the lte topology.

Can you please look at my example code and check if there is a error or missing code part? I've attached the example and you can just copy the file into the scratch folder to run it,

Thanks,
Peter

[Tommaso Pecorella]

Hi,

the error could be in your applications. Without them it's next to impossible to do a guess.

I'd use the debugger tho. The line you posted is only the very last of the backtrack. If you go deeper in the stack you'll find the offending one, or at least the type of event that was supposed to be executed.

Most probably you scheduled an event for a non-existent object, or something similar.

Have fun debugging.

T

[Biljana Bojović]

Hi Peter, did you solve this issue?

[Biljana Bojović]

I have run the script that you shared and I do not get any error. I get the following output:

IP: 176.0.0.1
At time 2s client sent 1472 bytes to 176.0.0.2 port 8080
At time 2.01494s server received 1472 bytes from 7.0.0.6 port 49153
At time 2.01494s server sent 1472 bytes to 7.0.0.6 port 49153
At time 2.02s client received 1472 bytes from 176.0.0.2 port 8080
At time 4s client sent 1472 bytes to 176.0.0.2 port 8080
At time 4.01394s server received 1472 bytes from 7.0.0.6 port 49153
At time 4.01394s server sent 1472 bytes to 7.0.0.6 port 49153
At time 4.019s client received 1472 bytes from 176.0.0.2 port 8080
At time 6s client sent 1472 bytes to 176.0.0.2 port 8080
At time 6.01394s server received 1472 bytes from 7.0.0.6 port 49153
At time 6.01394s server sent 1472 bytes to 7.0.0.6 port 49153
At time 6.019s client received 1472 bytes from 176.0.0.2 port 8080
At time 8s client sent 1472 bytes to 176.0.0.2 port 8080
At time 8.01394s server received 1472 bytes from 7.0.0.6 port 49153
At time 8.01394s server sent 1472 bytes to 7.0.0.6 port 49153
At time 8.019s client received 1472 bytes from 176.0.0.2 port 8080
At time 10s client sent 1472 bytes to 176.0.0.2 port 8080
At time 10.0139s server received 1472 bytes from 7.0.0.6 port 49153
At time 10.0139s server sent 1472 bytes to 7.0.0.6 port 49153
At time 10.019s client received 1472 bytes from 176.0.0.2 port 8080

Can you please share the script with which I could reproduce the segmentation fault?