Simulation crashes when vehicles exits

[EmilyBourne]

When running a simulations, a segfault occurs when a vehicle exits. Backtrace shows that the problem is in :
Veins::ChannelAccess::calculatePropagationDelay

Presumably the simulation continues to attempt to pass messages to/from the vehicle after it has been deleted, resulting in an invalid pointer.

Bug is quickly reproducible by running the example provided with only 5 cars (change 195 to 5 in /extern/veins/examples/veings/erlangen.rou.xml, this allows the bug to appear after around 10 seconds. The full simulation is much slower)

[EmilyBourne]

I have found a fix for this issue. In BasicNodeManager.h the following line needs to be added:
#include "veins/base/connectionManager/BaseConnectionManager.h"

and BaseConnectionManager* cc; needs to be added to the class.

In BasicNodeManager.cc the following lines need to be added:
#include "veins/base/utils/FindModule.h"

In initialize:
cc = FindModule<BaseConnectionManager*>::findGlobalModule();

In removeVehicle:
cModule* mod = getNodeModule(id);
if (!mod) error("no vehicle with Id \"%s\" found", id.c_str());
cModule* nic = mod->getSubmodule("nic");
if (cc && nic) {
cc->unregisterNic(nic);
}

[EmilyBourne]

This solution is not a complete fix. It also gives a segfault when finish() is called after the last vehicle exits. I cannot find why though given that the steps added are the same as those carried out by a normal veins simulation which presumably does not give this behavior.

[riebl]

Thank you for reporting this issue. It is fixed in the current master branch.
Please note, there is still a bug in OMNeT++ regarding the drawing of bubbles used by the ExampleService (bubbles are not removed when source module is removed). However, it runs fine with Cmdenv.