[Help-glpk] Error detected in file glplib10.c at line 109

[Antonello Lobianco]

Hello.. 
    I am trying to parallelise the Qt/C++ code of  multi agent model representing farmers.
For the time being I'm using only 1 thread as I got from this list that glpk is, at the present time, not  re-entrant.

The funny(!) side is that when I use the new code (see down), even if it use only **1** working threads, the unpatched version of glpk crash.
I used then the doc example and I was able to receive the following error message when crashing:

Assertion failed: xlcmp(env->t_last, t) <= 0
Error detected in file glplib10.c at line 109

Is it a glpk bug or something I am doing seriously very wrong ??

Regards,
   Antonello

Glpk wrapper code:

> void
> Manager_agents::aFunction(){
>     int nThreads = 1; // nThreads = 1, as for now glpk in not reendrant
>     for (int i=0; i < nThreads; i++){ 
>         ThreadClass* wThread = new ThreadClass;
>         wThreads.push_back(wThread);
>
>     }
>     vector<double> outputs (agents.size(), ((double)0));
>     for (uint y=0;y<agents.size();y++){
>         volatile bool assigned = false;
>         while(!assigned) {
>             for (uint z=0;z<wThreads.size();z++){
>
>                 if (!wThreads[z]->isRunning()){
>                     wThreads[z]->assignJob(agents[y]); // this is run serialised in the main working thread !
>                     wThreads[z]->start(); // parallel threads
>
>                     assigned = true;
>                 }
>             }
>         }
>     }
>
>     // Be sure that all threads have ended their last job before continue..
>     for (int z=0; z <wThreads.size(); z++){
>
>         wThreads[z]->wait();
>     }
>     for ( int z=0; z< agents.size(); z++){
>         outputs[z] = agents->getOutput();
>     }
> }
>
> Manager_farmers_threads::Manager_farmers_threads(){
>
> }
>
> void
> Manager_farmers_threads::run(){
>     agent->solve(); // -> call the PDF documentation example (content of the main function)
> }
>
> void
> Manager_farmers_threads::assignJob(Agent_space* agent_h){
>
>     agent =  agent_h;
>     agent -> cachedOutput = 0;
> } 

model output:

[...]

> z = 733.333; x1 = 33.3333; x2 = 66.6667; x3 = 0
> *     0: obj =   0.000000000e+00  infeas =  0.000e+00 (0)
>
> *     2: obj =   7.333333333e+02  infeas =  0.000e+00 (0)
> OPTIMAL SOLUTION FOUND
>
> z = 733.333; x1 = 33.3333; x2 = 66.6667; x3 = 0
> *     0: obj =   0.000000000e+00  infeas =  0.000e+00 (0)
> *     2: obj =   7.333333333e+02  infeas =  0.000e+00 (0)
>
> OPTIMAL SOLUTION FOUND
>
> z = 733.333; x1 = 33.3333; x2 = 66.6667; x3 = 0
> *     0: obj =   0.000000000e+00  infeas =  0.000e+00 (0)
> *     2: obj =   7.333333333e+02  infeas =  0.000e+00 (0)
> OPTIMAL SOLUTION FOUND
>
> z = 733.333; x1 = 33.3333; x2 = 66.6667; x3 = 0
> *     0: obj =   0.000000000e+00  infeas =  0.000e+00 (0)
> *     2: obj =   7.333333333e+02  infeas =  0.000e+00 (0)
> OPTIMAL SOLUTION FOUND
>
> z = 733.333; x1 = 33.3333; x2 = 66.6667; x3 = 0
>
> Assertion failed: xlcmp(env->t_last, t) <= 0
> Error detected in file glplib10.c at line 109


-- 
Antonello Lobianco
Assegnista di Ricerca
Dipartimento di Economia, Università Politecnica delle Marche

Progetto "RegMAS per il Piceno" (Fondazione CARISAP)
Tel: +39.071.2207116
Email: address@hidden