[Clp] potential memory leak in CLP with CBC trunk

[Kish Shen]

Hi,

I am now able to compile the latest trunk version of Cbc/Clp with gcc 
3.3 after my post about it yesterday. Thanks to Michael Hennebry and 
John Forrest for their help!

I ran valgrind with this latest download, and I am still seeing the same 
memory leak. I should have made clear in my previous message that I 
carefully checked that delete was done for all the pointers to the COIN 
solvers, in this case to OsiClpSolverInterface.

The only line of code I comment out between the two versions is the call 
to initialSolve()

	    lpd->lp->Solver->initialSolve();

where lpd->lp->Solver is a OsiClpSolverInterface *, which is allocated 
with a new:

     lp->Solver = new OsiXxxSolverInterface();

(OsiXxxSolverInterface is typdef'ed to OsiClpSolverInterface for the 
Cbc/Clp version here).

and Solver is deleted before the end of the program:

	delete lp->Solver;

With the initialSolve() line, I get the following leak summary,

==9960== LEAK SUMMARY:
==9960==    definitely lost: 0 bytes in 0 blocks.
==9960==      possibly lost: 0 bytes in 0 blocks.
==9960==    still reachable: 6,912 bytes in 3 blocks.
==9960==         suppressed: 0 bytes in 0 blocks.

but with the initialSolve() line commented out, I get:

==9993== LEAK SUMMARY:
==9993==    definitely lost: 0 bytes in 0 blocks.
==9993==      possibly lost: 0 bytes in 0 blocks.
==9993==    still reachable: 1,280 bytes in 1 blocks.
==9993==         suppressed: 0 bytes in 0 blocks.

I don't quite understand why these blocks are shown as reachable -- 
Solver, which is the only pointer in my code to the OsiClpSolver 
interface, is deleted (but I assume the delete method does not delete 
the 2 blocks that are allocated when initialSolve() is called). These 
blocks do show up as definitely lost in the real code I am using (rather 
than the simplified version I am compiling here).

Cheers,

Kish


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