I cannot remember why I selected -2 as the initial value for PETSc objects in
Fortran. Probably because it would ensure a dramatic crash if you used
an object without initializing it from Fortran.
It could be changing
config/BuildSystem/config/compilersFortran.py:
self.addDefine('FORTRAN_TYPE_INITIALIZE', ' = -2')
to 0 would mean that if you called destroy on the object and never created it
everything would be fine; so you would not need to use any special code to
check.
Would that be a better model?
Barry
> On Feb 2, 2021, at 2:34 PM, Mark Adams <[email protected]> wrote:
>
> Thanks Randy, that makes sense.
> Mark
>
> On Tue, Feb 2, 2021 at 3:27 PM Randall Mackie <[email protected]
> <mailto:[email protected]>> wrote:
> Hi Mark,
>
> I don’t know what the XGC code is, but the way I do this in my Fortran code
> is that I initialize all objects I later want to destroy, for example:
>
> mat11=PETSC_NULL_MAT
> vec1=PETSC_NULL_VEC
>
> etc
>
> Then I check and destroy like:
>
> if (mat11 /= PETSC_NULL_MAT) call MatDestroy(mat11, ierr)
>
> etc.
>
> Hope this helps,
>
> Randy
>
>
> > On Feb 2, 2021, at 12:17 PM, Mark Adams <[email protected]
> > <mailto:[email protected]>> wrote:
> >
> > Satish, a few years ago you helped us transition the XGC Fortran code from
> > v3.7.7 and we seemed to have regressed.
> >
> > As I recall we removed the initialization of Mats (for example) in XGC.
> > PETSc seems to initialize them with -2 in Fortran (Albert, cc'ed, verified
> > this today) and I recall that from our previous conversation. As I look at
> > the code now Fortran MatDestroy just goes straight to C, which would
> > explain our crashes when we MatDestroy an uninitialized (-2) Mat.
> >
> > What is the correct way to delete with initializing Fortran objects?
> >
> > Thanks,
> > Mark
> >
> >
>
