Is it possible to use HYPRE_ParVector references without memory leaks?

[thartland]

Is it possible to use HYPRE_ParVector references without memory leaks?

[liruipeng]

Hi @thartland If you only call HYPRE_ParVectorDestroy to free the object of IJVecotr, it is expected to have memory leak from the other parts of IJVector. HYPRE_IJVectorDestroy free them as well. I don't see the reason why you can't call HYPRE_IJVectorDestroy on IJ_grad. Maybe I missed something. If you have to call HYPRE_ParVectorDestroy to free the parvector, the way I guess is to manipulate the IJ structure, after HYPRE_IJVectorGetObject, by setting

hypre_IJVectorObject(vector) = NULL

or something like that, so you can call HYPRE_IJVectorDestroy to free the IJVector but keep the ParVector.

[rfalgout]

We have reference counters in some of the matrix/vector objects in hypre. I wonder if we should expose this to users somehow so they can create persistent references to objects and better manage memory. The simplest thing we could do for now is implement a GetObjectRef call for all matrices and vectors. This would maintain backward compatibility and I think it would help Tucker out. Basically, this call (instead of GetObject) would return an object that must be freed separately at some point. So here both the IJDestroy and the ParDestroy would have to be called (in any order).

[thartland]

Thanks everyone for the quick responses! I am glad to know that it wasn't something obvious that I missed. Before your team invests the time into this effort let me communicate a bit more with my team to further clarify needs, I'll follow up in the next few days.

[thartland]

I did a slight redesign of my code to avoid memory leaks. Thank you for clarifying how these objects work, that information was useful to me.