Hello Jakob, the error was caused when trying to access an empty result (no objects in range). Since a vehicle always has itself in range, the problem never occurred in the first case. It should be fixed in the latest development version 335d5a7. regards, Jakob
2018-01-05 9:44 GMT+01:00 Kaths, Jakob <[email protected]>: > Hi, > > > > I retried with today’s nightly snapshot (0_32_0_+0080-45b239f71c) and get > the same behavior, except I can now catch a tcpip::SocketException > (somehow didn’t work in my larger code) and avoid the crash. > > > > Maybe I got you wrong, but retrieving an empty vehicle subscription works > fine and without throwing an exception for me (I used the example you > provided with the Python test and with 100m radius, at times there are no > vehicles and no persons). When subscribing only to persons though, the > exception is thrown as soon as I retrieve the results with > “traci.simulation.getContextSubscriptionResults("ego");” when there is no > person around. > > So to me it seems that > > traci.simulation.subscribeContext(CMD_SUBSCRIBE_VEHICLE_CONTEXT, "ego", > startTime, endTime, CMD_GET_VEHICLE_VARIABLE, subscription_radius, > egoSubscriptionVarsVeh); > > and > > traci.simulation.subscribeContext(CMD_SUBSCRIBE_VEHICLE_CONTEXT, "ego", > startTime, endTime, CMD_GET_PERSON_VARIABLE, subscription_radius, > egoSubscriptionVarsPed); > > have a different behavior when there are no results. I’m not sure if > that’s intended, but it did confuse me since I thought I could just > exchange CMD_GET_VEHICLE_VARIABLE by CMD_GET_PERSON_VARIABLE. > > > > If you still need them, I would like to provide the stack traces, but I > don’t know how to create them unfortunately. Would StackWalker be the right > tool? > > > > Thanks > > > > Jakob > > > > > > > > *Von:* [email protected] [mailto:[email protected]] > *Im Auftrag von *Jakob Erdmann > *Gesendet:* Donnerstag, 4. Januar 2018 16:28 > > *An:* Sumo project User discussions <[email protected]> > *Betreff:* Re: [sumo-user] Context Subscription of a Vehicle to Values of > Persons (TraCI API C++) > > > > Possibly you are trying to retrieve context subscription results when > there aren't any. The client throws Exceptions without any error message > in this case (helpful messages added in the development version). This was > the only way I could reproduce an error. > > Please see if you get a better error with the development version. > Otherwise I need at least the stack traces from your crash (client and > server). > > > > regards, > > Jakob > > > > 2018-01-03 17:30 GMT+01:00 Kaths, Jakob <[email protected]>: > > Hey, > > > > thanks a lot for your answer. I checked the Python example and adapted it > to my needs and it worked. I then prepared the minimal example for C++ and > while doing that, I think I found the solution. However, I still didn’t > fully understand why… Maybe you could give me a little hint, just for > understanding. My subscription to both vehicles and persons around a > vehicle works fine now. If I only subscribe to persons though, the program > crashes straight after starting it. So, if I comment line 66 it crashes > (which is what I did in my not-minimal-example and why I asked for help), > if I comment line 67 it works and if I don’t comment either of those two > lines, it works, too. > > > > You can find the cpp-file here: > > https://syncandshare.lrz.de/dl/fiWxH8FERhgLwXaDorAyFmW1/SumoConnect.cpp > > > > Thanks for the amazing help here! > > > > Jakob Kaths > > > > > > *Von:* [email protected] [mailto:[email protected]] > *Im Auftrag von *Jakob Erdmann > *Gesendet:* Mittwoch, 20. Dezember 2017 09:32 > *An:* Sumo project User discussions <[email protected]> > *Betreff:* Re: [sumo-user] Context Subscription of a Vehicle to Values of > Persons (TraCI API C++) > > > > Hello, > > subscribing to persons around an object and subscribing to things around a > person should be working. (at least it does in our tests since version > 0.31.0). > > You may take a look at the tests at https://github.com/DLR-TS/ > sumo/tree/master/tests/complex/traci/contextSubscriptions > > Can send a small scenario where it fails for you? > > regards, > > Jakob > > > > 2017-12-19 17:59 GMT+01:00 Kaths, Jakob <[email protected]>: > > Hello! > > > > I was wondering if it’s possible to retrieve values of pedestrians in SUMO > by subscription. I know, that in Context Subscription in the Wiki ( > http://sumo.dlr.de/wiki/TraCI/Object_Context_Subscription) pedestrians > are not mentioned. However, I found the corresponding value > (CMD_GET_PERSON_VARIABLE 0xae) in the TraCIConstants.h and tried to > subscribe, but it failed. Is there a possibility to retrieve position, > angle, speed etc. from pedestrians via subscription without modelling them > as vehicles? If not, is this planned for the future or could you give a > hint of how to implement this? > > > > Thanks in advance! > > > Jakob > > > > > > -- > > Dipl.-Ing. Jakob Kaths > > > > Technische Universität München > Ingenieurfakultät Bau Geo Umwelt > Lehrstuhl für Verkehrstechnik > [email protected] > > > > > _______________________________________________ > sumo-user mailing list > [email protected] > To change your delivery options, retrieve your password, or unsubscribe > from this list, visit > https://dev.eclipse.org/mailman/listinfo/sumo-user > > > > > _______________________________________________ > sumo-user mailing list > [email protected] > To change your delivery options, retrieve your password, or unsubscribe > from this list, visit > https://dev.eclipse.org/mailman/listinfo/sumo-user > > > > _______________________________________________ > sumo-user mailing list > [email protected] > To change your delivery options, retrieve your password, or unsubscribe > from this list, visit > https://dev.eclipse.org/mailman/listinfo/sumo-user > >
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