[sumo-dev] possible multi QThread safety violation on single sink loopde

[Richter Gerald <Gerald.Richter@xxxxxxxxx>]

Hi,

I got a scenario and execution scripts using a traci runner
where threads were set to 4.
While rebuilding and configuring this, I set loopdetector output file 
identical
for all the instantE1 detectors.

running the runner.py script from an ipython3 shell
repeatedly for different seeds,
apparently there is a thread race going on,
because traci server crashes indeterministically with
FatalTraCIError: connection closed by SUMO

* this did not occur before the single loopdetector output file
* it ceases to be a problem when threads are set to 1

and debugging into this state gives a lot of pouring QThread messages.

so right now I am not sure if it is the thread-twitchyness of ipython,
or something else... testing with
* python3 shell, 4 threads: crashes
* python3 shell, 1 threads: all fine

is this a known phenomenon?

cheers,
Gerald