[Cbc] Problem in CbcCompareUser/invalid heap

[Lou Hafer]

Folks,

     If it's windows, this is a long-standing issue. Debug builds in 
Visual Studio were unusable because the VS heap implementation checks 
for violations of the heap conditions in debug builds. Cbc did not 
properly rebuild the heap after changing the evaluation function. I 
fixed this in r1506 because I needed to work with a windows debug build 
but quite possibly it's broken again.

     The key point is that the heap must be rebuilt when the evaluation 
function changes. Otherwise it's a bomb waiting to go off.

     John's observation about using drand as the return value is 
interesting. Begs the question of whether the overhead of maintaining 
the heap is really worth it.

                                              Lou



On 14/11/12 12:43 AM, John Forrest wrote:
> Haroldo,
>
> Using which compiler do you have problems with CbcCompareDefault - or is
> it with CbcCompareUser?
>
> If it is gcc then I am totally mystified as I changed CbcCompareDefault
> to do
>
>     return (drand48()<0.5);
>
> and my runs were fine (not even much slower!).
> 1506
> So is just with Windows or Intel?
>
> John Forrest