[petsc-users] PETSC_NULL_OBJECT gets corrupt after call to MatNestGetISs in fortran

[Barry Smith]

   Thanks for reporting this. Currently the Fortran stub for this function is generated automatically which means it does not have the logic for handling a PETSC_NULL_OBJECT argument.

    Satish, could you please see if you can add a custom fortran stub for this function in maint?

  Thanks

   Barry



> On Feb 12, 2015, at 3:02 AM, Klaij, Christiaan <C.Klaij at marin.nl> wrote:
> 
> Using petsc-3.5.3, I noticed that PETSC_NULL_OBJECT gets corrupt after calling MatNestGetISs in fortran. Here's a small example:
> 
> $ cat fieldsplittry2.F90
> program fieldsplittry2
> 
>  use petscksp
>  implicit none
> #include <finclude/petsckspdef.h>
> 
>  PetscErrorCode :: ierr
>  PetscInt       :: size,i,j,start,end,n=4,numsplit=1
>  PetscScalar    :: zero=0.0,one=1.0
>  Vec            :: diag3,x,b
>  Mat            :: A,subA(4),myS
>  PC             :: pc,subpc(2)
>  KSP            :: ksp,subksp(2)
>  IS             :: isg(2)
> 
>  call PetscInitialize(PETSC_NULL_CHARACTER,ierr); CHKERRQ(ierr)
>  call MPI_Comm_size(PETSC_COMM_WORLD,size,ierr); CHKERRQ(ierr);
> 
>  ! vectors
>  call VecCreateMPI(MPI_COMM_WORLD,3*n,PETSC_DECIDE,diag3,ierr); CHKERRQ(ierr)
>  call VecSet(diag3,one,ierr); CHKERRQ(ierr)
> 
>  call VecCreateMPI(MPI_COMM_WORLD,4*n,PETSC_DECIDE,x,ierr); CHKERRQ(ierr)
>  call VecSet(x,zero,ierr); CHKERRQ(ierr)
> 
>  call VecDuplicate(x,b,ierr); CHKERRQ(ierr)
>  call VecSet(b,one,ierr); CHKERRQ(ierr)
> 
>  ! matrix a00
>  call MatCreateAIJ(MPI_COMM_WORLD,3*n,3*n,PETSC_DECIDE,PETSC_DECIDE,1,PETSC_NULL_INTEGER,0,PETSC_NULL_INTEGER,subA(1),ierr);CHKERRQ(ierr)
>  call MatDiagonalSet(subA(1),diag3,INSERT_VALUES,ierr);CHKERRQ(ierr)
>  call MatAssemblyBegin(subA(1),MAT_FINAL_ASSEMBLY,ierr);CHKERRQ(ierr)
>  call MatAssemblyEnd(subA(1),MAT_FINAL_ASSEMBLY,ierr);CHKERRQ(ierr)
> 
>  ! matrix a01
>  call MatCreateAIJ(MPI_COMM_WORLD,3*n,n,PETSC_DECIDE,PETSC_DECIDE,1,PETSC_NULL_INTEGER,1,PETSC_NULL_INTEGER,subA(2),ierr);CHKERRQ(ierr)
>  call MatGetOwnershipRange(subA(2),start,end,ierr);CHKERRQ(ierr);
>  do i=start,end-1
>     j=mod(i,size*n)
>     call MatSetValue(subA(2),i,j,one,INSERT_VALUES,ierr);CHKERRQ(ierr)
>  end do
>  call MatAssemblyBegin(subA(2),MAT_FINAL_ASSEMBLY,ierr);CHKERRQ(ierr)
>  call MatAssemblyEnd(subA(2),MAT_FINAL_ASSEMBLY,ierr);CHKERRQ(ierr)
> 
>  ! matrix a10
>  call  MatTranspose(subA(2),MAT_INITIAL_MATRIX,subA(3),ierr);CHKERRQ(ierr)
> 
>  ! matrix a11 (empty)
>  call MatCreateAIJ(MPI_COMM_WORLD,n,n,PETSC_DECIDE,PETSC_DECIDE,0,PETSC_NULL_INTEGER,0,PETSC_NULL_INTEGER,subA(4),ierr);CHKERRQ(ierr)
>  call MatAssemblyBegin(subA(4),MAT_FINAL_ASSEMBLY,ierr);CHKERRQ(ierr)
>  call MatAssemblyEnd(subA(4),MAT_FINAL_ASSEMBLY,ierr);CHKERRQ(ierr)
> 
>  ! nested mat [a00,a01;a10,a11]
>  call MatCreateNest(MPI_COMM_WORLD,2,PETSC_NULL_OBJECT,2,PETSC_NULL_OBJECT,subA,A,ierr);CHKERRQ(ierr)
>  call MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY,ierr);CHKERRQ(ierr)
>  call MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY,ierr);CHKERRQ(ierr)
> print *, PETSC_NULL_OBJECT
>  call MatNestGetISs(A,isg,PETSC_NULL_OBJECT,ierr);CHKERRQ(ierr);
> print *, PETSC_NULL_OBJECT
> 
>  call PetscFinalize(ierr)
> 
> end program fieldsplittry2
> $ ./fieldsplittry2
>                     0
>              39367824
> $
> 
> 
> dr. ir. Christiaan Klaij
> CFD Researcher
> Research & Development
> E mailto:C.Klaij at marin.nl
> T +31 317 49 33 44
> 
> 
> MARIN
> 2, Haagsteeg, P.O. Box 28, 6700 AA Wageningen, The Netherlands
> T +31 317 49 39 11, F +31 317 49 32 45, I www.marin.nl
>