On the C side of anything called by Fortran you must declare it as PC *pc
rather than pc and then get the PC inside for example
void pcasmfreespace_(PC *inpc)
{
PC pc = *inpc;
....
On Aug 25, 2011, at 1:29 PM, Gaetan Kenway wrote:
> Hello
>
> I've managed to get the c-function for freeing preconditioner memory written.
> The contents of my new 'pcasmfreespace.c' is below:
>
> #include <private/pcimpl.h> /*I "petscpc.h" I*/
>
> typedef struct {
> PetscInt n, n_local, n_local_true;
> PetscInt overlap; /* overlap requested by user */
> KSP *ksp; /* linear solvers for each block */
> VecScatter *restriction; /* mapping from global to subregion */
> VecScatter *localization; /* mapping from overlapping to
> non-overlapping subregion */
> VecScatter *prolongation; /* mapping from subregion to global */
> Vec *x,*y,*y_local; /* work vectors */
> IS *is; /* index set that defines each overlapping
> subdomain */
> IS *is_local; /* index set that defines each
> non-overlapping subdomain, may be NULL */
> Mat *mat,*pmat; /* mat is not currently used */
> PCASMType type; /* use reduced interpolation, restriction or
> both */
> PetscInt type_set; /* if user set this value (so won't change it
> for symmetric problems) */
> PetscInt same_local_solves; /* flag indicating whether all local solvers
> are same */
> PetscInt sort_indices; /* flag to sort subdomain indices */
> } PC_ASM;
>
> void pcasmfreespace_(PC pc)
> {
>
> PC_ASM *osm = (PC_ASM*)pc->data;
> PetscErrorCode ierr;
>
> if (osm->pmat) {
> if (osm->n_local_true > 0) {
> ierr = MatDestroyMatrices(osm->n_local_true,&osm->pmat);CHKERRQ(ierr);
> }
> osm->pmat = 0;
> }
>
> if (pc->pmat) {ierr = MatDestroy(pc->pmat);CHKERRQ(ierr); pc->pmat = 0;}
>
> }
>
> Note the underscore as I'm trying to call it from Fortran. When I call it
> from fortran, I use:
>
> call pcasmfreespace(global_pc)
>
> This calls, the function, ok, but (according to Valgrind) I have an invalid
> read on the line containing:
>
> if (osm->pmat){
>
> I suspect this is something to do with passing the fortran "pointer" of the
> PC to c, or something along this lines. Is there anything else special you
> have to do to pass the "fortran" petsc objects to c?
>
> Thanks
>
> Gaetan
>
>
> Message: 2
> Date: Sun, 21 Aug 2011 17:22:28 -0500
> From: Barry Smith <bsmith at mcs.anl.gov>
> Subject: Re: [petsc-users] Freeing Preconditioner Matrix Space
> To: PETSc users list <petsc-users at mcs.anl.gov>
> Message-ID: <953121EF-B6AC-42EE-87BE-D4402C121652 at mcs.anl.gov>
> Content-Type: text/plain; charset=us-ascii
>
>
> You don't need to put that in the PETSc source. Just built it in the same
> directory you build your application and link it in like any of your
> application code. You will need to stick
> #include <private/pcimpl.h> /*I "petscpc.h" I*/
>
> typedef struct {
> PetscInt n, n_local, n_local_true;
> PetscInt overlap; /* overlap requested by user */
> KSP *ksp; /* linear solvers for each block */
> VecScatter *restriction; /* mapping from global to subregion */
> VecScatter *localization; /* mapping from overlapping to
> non-overlapping subregion */
> VecScatter *prolongation; /* mapping from subregion to global */
> Vec *x,*y,*y_local; /* work vectors */
> IS *is; /* index set that defines each overlapping
> subdomain */
> IS *is_local; /* index set that defines each
> non-overlapping subdomain, may be NULL */
> Mat *mat,*pmat; /* mat is not currently used */
> PCASMType type; /* use reduced interpolation, restriction or
> both */
> PetscBool type_set; /* if user set this value (so won't change
> it for symmetric problems) */
> PetscBool same_local_solves; /* flag indicating whether all local solvers
> are same */
> PetscBool sort_indices; /* flag to sort subdomain indices */
> } PC_ASM;
>
> before the subroutine.
>
> Barry
>
> On Aug 21, 2011, at 3:24 PM, Gaetan Kenway wrote:
>
> > Hello
> >
> > I am attempting to implement a "hack" that was posted on the list a while
> > back. I'm working with the adjoint linear system solver for a CFD solver.
> > I'm using the ASM (or Block Jacobi) preconditioner with ILU(p) on each of
> > the sub-domains. I use a different Preconditioner matrix (Pmat) than the
> > actual jacobian. What I want to do is destroy the Pmat memory after the ILU
> > factorization is performed. The hack that was posted is copied below:
> > PCASMFreeSpace(PC pc)
> > {
> > PC_ASM *osm = (PC_ASM*)pc->data;
> > PetscErrorCode ierr;
> >
> > if (osm->pmat) {
> > if (osm->n_local_true > 0) {
> >
> > ierr = MatDestroyMatrices(osm->n_
> local_true,&osm->pmat);CHKERRQ(ierr);
> > }
> > osm->pmat = 0;
> > }
> > if (pc->pmat) {ierr = MatDestroy(pc->pmat);CHKERRQ(ierr); pc->pmat = 0;}
> >
> > return 0;
> > }
> >
> > However, I've had no luck actually getting the function compiled into
> > petsc. There are no erorrs reported with i type "make" in the asm
> > directory, but when I try to use the function in my application it can't
> > find the symbol while linking. Where does it go in the asm.c file? Does it
> > use "static PetscErrorCode" or "PetscErrorCode PETSCKSP_DLLEXPORT"? Does it
> > have to be added to the .h include files? What has to be done for it work
> > with Fortran?
> >
> > Any suggestions would be greatly appreciated. This represents a
> > significant chunk of my application's memory (10%-30%) and as such its too
> > much to ignore. Also is there any chance something like this would make
> > it into an actual PETSc release?
> >
> > Gaetan
> >
>
>
