PetscObjectReference

Indicates to any PetscObject that it is being referenced by another PetscObject. This increases the reference count for that object by one.

#include "petsc.h"    
int PetscObjectReference(PetscObject obj)

Collective on PetscObject

obj -the PETSc object. This must be cast with (PetscObject), for example, PetscObjectReference((PetscObject)mat);