Originally posted by: Falcon_G

Hi everybody

Let say I get he memory usage of IloEnv  using getMemoryUsage().

I have the following situation:

1. empty model. MemUsage::16896

2. variables added: MemUsage::915728 (number of vars 14140)

3. objectuve function expression (not obj itself) is created : MemUsage::1142024

4. some constraints are added to an IlorangeArray:  MemUsage::1302856

5. some iloexpr are created and put in an array  (32200 precisely): MemUsage::5092792

6.  If I just decide to make a test, after following I can have :MemUsage::4982792

  model.end();
  model = IloModel(env);
  model.add(m_rng_design);

7. adding IloObj and IloCplex does not occupy more memory and memory remains the same.

8.               IloExpr tmp = cx + lag;
                  obj.setExpr(tmp);
                  tmp.end();
turns :MemUsage::5212352

NOW: if I invoke:

  cplex.clearModel();
  cplex.end();
  model.remove(obj);
  obj.getExpr().end();

 

it comes back to the more or less same MemUsage::4982792.

BUT if I inolve IloCPlex::Solve()

Then memory usage becomes  :MemUsage::5556752

and with all:

  cplex.clearModel();
  cplex.end();
  model.remove(obj);
  obj.getExpr().end();

it becomes MemUsage::5209432

and never goes back to MemUsage::4982792.

 

I have no idea where this memory is occupied.

Moreover, I seek solution NOT proposing to use IloEnv::end().

I appreciate any constructive comment.

Thank you in avance

 

 

 

 

 

 

 

 

 

 

#CPLEXOptimizers
#DecisionOptimization

Off the top of my head I don't see where memory could go. One idea for debugging this is to use IloIterator along with getMemoryUsage(). Using IloIterator<IloExtractable> you should be able to iterate over all extractables created for the IloEnv instance and these extractables should constitute the memory usage returned by getMemoryUsage(). Using IloExtractable::getId() you can create a list/set of extractables that exist at a certain point. If you store this set/list every time you invoke getMemoryUsage() then you can easily figure out which extractables were created/deleted between two snapshots. Maybe this can tell you where memory goes? I know it will be cumbersome but is the best I can think of at the moment.

#CPLEXOptimizers
#DecisionOptimization