Re: [certi-dev] CERTI deadlock

[Eric Noulard]

2012/6/5 Michael Raab <address@hidden>:
> Hello Eric,
>
> please find attached the code snippets. Passive federate code is copied from
> my application.
> Active federate code is included in another library to which I do not have
> access at the moment, but I think the attached code should fit the library
> implementation.
>
> Passive Observer:
> while (true)
> {
>    this->_rtiAmb->tick(0.1f, 0.5f);
>
>    RTIfedTime mnet;
>    this->_rtiAmb->queryLBTS(mnet);
>
>    // update progress...
>
>    Thread.Sleep(10);
> }

This code seems multithreaded.
Do you have multiple thread accessing RTIambassador object concurrenlty?
If this is the case, this is currently not supported by CERTI.

You may use multithreaded code but currently the federate have to ensure
that no concurrent access to RTIambassador is done.


> //////////////////////////////////////////////////////
>
> Active Federate:
> while (true)
> {
>    // query simulations next event time
>    float nextTime = this->getNextTime();
>
>    RTIfedTime reqTime( nextTime );
>    this->_rtiAmb->nextEventRequest( reqTime );
>    this->_nextEventRequestPending = true;

I would have set "this->_nextEventRequestPending" to true
**before** sending the NER but this shouldn't be an issue
unless another thread using the same RTIA is ticking concurrently
in that case you will have a race on  "this->_nextEventRequestPending".

>    while( this->_rtiAmb->tick( 0.0, 0.2 ) );
>    {
>         if(!this->_nextEventRequestPending)
>          break;
>    }
> }
>
> Anything obviously?

When your federation is stucked, are your active federate stuck in this loop?

Other questions:

Are you using 1.3 or 1516 interface?

What are the value of the lookahead of your active federates?

When you finally kill the stucked federation what are the messages statistics
of each RTIA in terms of number of messages?
(in particular what is the number of NULL messages)

Could you try to run with
CERTI_USE_NULL_PRIME_MESSAGE_PROTOCOL set to ON ?


-- 
Erk
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