I think originally PetscBag was this small lightweight thing that was not
"worthy" of being a full fledged object.
It will be slightly tricky (or at least nonstandard) to make PetscBag a
PETSc object because of
ierr = PetscMalloc(bagsize+sizeof(struct
_n_PetscBag)+sizeof(PetscScalar),bag);CHKERRQ(ierr);
ierr = PetscMemzero(*bag,bagsize+sizeof(struct
_n_PetscBag)+sizeof(PetscScalar));CHKERRQ(ierr);
(*bag)->bagsize = bagsize+sizeof(struct
_n_PetscBag)+sizeof(PetscScalar);
(*bag)->bagcomm = comm;
(*bag)->structlocation = (void*)(((char*)(*bag)) +
sizeof(PetscScalar)*(sizeof(struct _n_PetscBag)/sizeof(PetscScalar)) +
sizeof(PetscScalar));
while for PETSc objects
PetscErrorCode PetscObjectCreate(MPI_Comm comm, PetscObject *obj)
{
GenericObject o;
PetscErrorCode ierr;
PetscFunctionBegin;
PetscValidPointer(obj,2);
#if !defined(PETSC_USE_DYNAMIC_LIBRARIES)
ierr = PetscSysInitializePackage(PETSC_NULL);CHKERRQ(ierr);
#endif
ierr =
PetscHeaderCreate(o,_p_GenericObject,-1,PETSC_OBJECT_CLASSID,0,"PetscObject",comm,PetscObjectDestroy_GenericObject,0);CHKERRQ(ierr);
#define PetscHeaderCreate(h,tp,pops,cook,t,class_name,com,des,vie) \
(PetscNew(struct tp,&(h)) || \
PetscNew(PetscOps,&(((PetscObject)(h))->bops)) || \
PetscNew(pops,&((h)->ops)) || \
PetscHeaderCreate_Private((PetscObject)h,cook,t,class_name,com,(PetscObjectFunction)des,(PetscObjectViewerFunction)vie)
|| \
PetscLogObjectCreate(h) || \
PetscLogObjectMemory(h, sizeof(struct tp) + sizeof(PetscOps) + sizeof(pops)))
The "size" of the malloced space is funky in the PetscBag case so you cannot
directly do the PetscHeaderCreate() to create the PetscBag.
At this time I vote that you add the PetscBagSetOptionsPrefix() directly for
Bags and do not turn the Bag into a real PetscObject.
Barry
On Apr 8, 2011, at 12:29 PM, Ethan Coon wrote:
>
> I'm using a couple of bags in an application, and that application is in
> turn being used in a domain-decomposition algorithm with multiple
> domains (each an instance of the application). So I'd like to set the
> options prefix of the bag, so that each application instance has its own
> prefix and can be used with the same options "database." Currently
> PetscBag passes PETSC_NULL for the prefix.
>
> To fix this, it looks like the best option would be to have a
> PetscBagSetOptionsPrefix() in the same mold as everything else. I added
> this, and then found out that PetscBag isn't a PetscObject, in the sense
> that it has no header or CLASS_ID (so PetscObjectSetOptionsPrefix()
> doesn't work on a bag).
>
> Is this the best way forward, to make PetscBag a PetscObject, with
> CLASS_ID, etc? And if so, is there a good example of this that I should
> follow to do so?
>
> Thanks,
>
> Ethan
>
>
>
>
> --
> ------------------------------------
> Ethan Coon
> Post-Doctoral Researcher
> Applied Mathematics - T-5
> Los Alamos National Laboratory
> 505-665-8289
>
> http://www.ldeo.columbia.edu/~ecoon/
> ------------------------------------
>
