Delete not zeroing

ROOT
1

Bonjour,

Maybe a CINT feature in compiled code…
I would like to know if there some cases in which after a deleting an object the pointer is not set to NULL.

I have a rather complicated piece of code in which I perform some fits of histograms in a TTree. I create a TF1 from a “standard” fitting routine, and re-use the TF1 for the following events. If the fit fails, I delete the T1F and recall the initial routine.

But my output looks like this:

   :

Current pos = 656
Fitting function deleted 0x987b7c8
Current pos = 657

*** Break *** segmentation violation
Generating stack trace…
:

The code generating this looks like this:

            if( EdgePos>EDGE_POS_XMIN && EdgePos<EDGE_POS_XMAX ){
                ....
            } else {
                  delete CollBhEdge_X; // redo next time! 
                  cout << "Fitting function deleted " << CollBhEdge_X << endl;
            }

as you can see the delete did not zero the pointer, but did delete the object. During the next loop, having a non zero pointer on a delete object I get the crash.

Do you have any hint ? Should I send a coredump ?
Until I understand what is going on I will zero it by hand, but I feel a bit uncomfortable about the stability of my code.

merci d’avance, Vincent.

2

Vincent,

It is your responsability to reset pointers t0 0 when objects are deleted.
ROOT takes care of deleting objects deleted from the table
of CINT objects (created via the interpreter).

Rene

3

Bonjour René,

Effectively, that’s what I found out after your reply.

I thought the zeroing was the standard behavior, and I was conforted in this by the fact that CINT does the zeroing. Yet another difference in compiled vs interpreted code, so to say.

Bonne fêtes to everyone.

Vincent.