psblas3/base/internals/psi_fnd_owner.F90

!   
!                Parallel Sparse BLAS  version 3.5
!      (C) Copyright 2006-2018
!        Salvatore Filippone    
!        Alfredo Buttari      
!   
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!   
!   
!
! File: psi_fnd_owner.f90
!
! Subroutine: psi_fnd_owner
!   Figure out who owns  global indices. 
! 
! Arguments: 
!    nv       - integer                 Number of indices required on  the calling
!                                       process 
!    idx(:)   - integer                 Required indices on the calling process.
!                                       Note: the indices should be unique!
!    iprc(:)  - integer(psb_ipk_), allocatable    Output: process identifiers for
!                                       the corresponding
!                                       indices
!    desc_a   - type(psb_desc_type).    The communication descriptor.        
!    info     - integer.                return code.
! 
subroutine psi_fnd_owner(nv,idx,iprc,desc,info)
  use psb_desc_mod
  use psb_serial_mod
  use psb_const_mod
  use psb_error_mod
  use psb_penv_mod
  use psb_realloc_mod
  use psi_mod, psb_protect_name => psi_fnd_owner
#ifdef MPI_MOD
  use mpi
#endif

  implicit none 
#ifdef MPI_H
  include 'mpif.h'
#endif
  integer(psb_ipk_), intent(in)      :: nv
  integer(psb_lpk_), intent(in)      :: idx(:)
  integer(psb_ipk_), allocatable, intent(out) ::  iprc(:)
  type(psb_desc_type), intent(inout) :: desc
  integer(psb_ipk_), intent(out)     :: info


  integer(psb_ipk_), allocatable :: hsz(:),hidx(:),helem(:),hproc(:),&
       & sdsz(:),sdidx(:), rvsz(:), rvidx(:),answers(:,:),idxsrch(:,:)

  integer(psb_ipk_) :: i,n_row,n_col,err_act,ih,icomm,hsize,ip,isz,k,j,&
       & last_ih, last_j
  type(psb_ctxt_type) :: ctxt
  integer(psb_ipk_)   :: np,me
  logical, parameter  :: gettime=.false.
  real(psb_dpk_)      :: t0, t1, t2, t3, t4, tamx, tidx
  character(len=20)   :: name

  info = psb_success_
  name = 'psi_fnd_owner'
  call psb_erractionsave(err_act)

  ctxt   = desc%get_context()
  icomm   = desc%get_mpic()
  n_row   = desc%get_local_rows()
  n_col   = desc%get_local_cols()


  ! check on blacs grid 
  call psb_info(ctxt, me, np)

  if (np == -1) then
    info = psb_err_context_error_
    call psb_errpush(info,name)
    goto 9999
  endif

  if (nv < 0 ) then
    info = psb_err_context_error_
    call psb_errpush(info,name)
    goto 9999
  endif

  if (.not.(desc%is_ok())) then 
    call psb_errpush(psb_err_from_subroutine_,name,a_err='invalid desc')
    goto 9999      
  end if

  call desc%fnd_owner(idx(1:nv),iprc,info)
  
  if (info /= psb_success_) then 
    call psb_errpush(psb_err_from_subroutine_,name,a_err='desc%fnd_owner') 
    goto 9999      
  end if
  call psb_erractionrestore(err_act)
  return

9999 call psb_error_handler(ctxt,err_act)

  return

end subroutine psi_fnd_owner