Error while Implementing setDisallowed setAllowed for Sumo and Veins?

Question

I am trying to implement a TraCi command for mysumo scenario (traci.lane.setDisallowed) while using veins. I created a new command in the TraciCommandInterface.cpp like:

void TraCICommandInterface::Lane::setDisallowed(std::list<std::string> disallowedClasses)
{
    TraCIBuffer buf = connection->query(CMD_SET_LANE_VARIABLE, TraCIBuffer() << LANE_DISALLOWED << laneId << TYPE_STRINGLIST << disallowedClasses);
    ASSERT(buf.eof());
}

and called like:

std::list<std::string> disallowedClasses = {"all"};
if (simTime()==20) {
    TraCICommandInterface* cInt = getCommandInterface();
    cInt->lane("ed_1_0").setDisallowed(disallowedClasses);
}

The problem is that i get the error: Answered with error to command 0xc3: Wrong position in requestMessage after dispatching command 195. Expected command length was 38 but 18 Bytes were read.

Is there something wrong with the way i implemented the command? Any suggestions why this problems occurs?

score 1 · Accepted Answer · answered Dec 09 '20 at 13:39

As of Veins 5.0, TraCIBuffer only has a few overloads for C++ data types, notably for std::string, simtime_t, and TraCICoord (see here). All other types are sent as stored in memory (by casting to char*) (see here) - certainly not a good idea for std::list.

For copy/paste-able code for how to serialize a std::list<std::string> to a binary blob representing the TYPE_STRINGLIST SUMO/TraCI expects, see the code of TraCICommandInterface::Vehicle::changeVehicleRoute(const std::list<std::string>& edges), available here.

Error while Implementing setDisallowed setAllowed for Sumo and Veins?

1 Answers1