xref: /petsc/src/dm/impls/da/dadist.c (revision d71ae5a4db6382e7f06317b8d368875286fe9008)

/*
  Code for manipulating distributed regular arrays in parallel.
*/

#include <petsc/private/dmdaimpl.h> /*I   "petscdmda.h"   I*/

PetscErrorCode VecDuplicate_MPI_DA(Vec g, Vec *gg)
{
  DM          da;
  PetscLayout map;

  PetscFunctionBegin;
  PetscCall(VecGetDM(g, &da));
  PetscCall(DMCreateGlobalVector(da, gg));
  PetscCall(VecGetLayout(g, &map));
  PetscCall(VecSetLayout(*gg, map));
  PetscFunctionReturn(0);
}

PetscErrorCode DMCreateGlobalVector_DA(DM da, Vec *g)
{
  DM_DA *dd = (DM_DA *)da->data;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(da, DM_CLASSID, 1);
  PetscValidPointer(g, 2);
  PetscCall(VecCreate(PetscObjectComm((PetscObject)da), g));
  PetscCall(VecSetSizes(*g, dd->Nlocal, PETSC_DETERMINE));
  PetscCall(VecSetBlockSize(*g, dd->w));
  PetscCall(VecSetType(*g, da->vectype));
  if (dd->Nlocal < da->bind_below) {
    PetscCall(VecSetBindingPropagates(*g, PETSC_TRUE));
    PetscCall(VecBindToCPU(*g, PETSC_TRUE));
  }
  PetscCall(VecSetDM(*g, da));
  PetscCall(VecSetLocalToGlobalMapping(*g, da->ltogmap));
  PetscCall(VecSetOperation(*g, VECOP_VIEW, (void (*)(void))VecView_MPI_DA));
  PetscCall(VecSetOperation(*g, VECOP_LOAD, (void (*)(void))VecLoad_Default_DA));
  PetscCall(VecSetOperation(*g, VECOP_DUPLICATE, (void (*)(void))VecDuplicate_MPI_DA));
  PetscFunctionReturn(0);
}

/*@
   DMDACreateNaturalVector - Creates a parallel PETSc vector that
   will hold vector values in the natural numbering, rather than in
   the PETSc parallel numbering associated with the DMDA.

   Collective

   Input Parameter:
.  da - the distributed array

   Output Parameter:
.  g - the distributed global vector

   Level: developer

   Note:
   The output parameter, g, is a regular PETSc vector that should be destroyed
   with a call to VecDestroy() when usage is finished.

   The number of local entries in the vector on each process is the same
   as in a vector created with DMCreateGlobalVector().

.seealso: `DMCreateLocalVector()`, `VecDuplicate()`, `VecDuplicateVecs()`,
          `DMDACreate1d()`, `DMDACreate2d()`, `DMDACreate3d()`, `DMGlobalToLocalBegin()`,
          `DMGlobalToLocalEnd()`, `DMLocalToGlobalBegin()`
@*/
PetscErrorCode DMDACreateNaturalVector(DM da, Vec *g)
{
  PetscInt cnt;
  DM_DA   *dd = (DM_DA *)da->data;

  PetscFunctionBegin;
  PetscValidHeaderSpecificType(da, DM_CLASSID, 1, DMDA);
  PetscValidPointer(g, 2);
  if (dd->natural) {
    PetscCall(PetscObjectGetReference((PetscObject)dd->natural, &cnt));
    if (cnt == 1) { /* object is not currently used by anyone */
      PetscCall(PetscObjectReference((PetscObject)dd->natural));
      *g = dd->natural;
    } else PetscCall(VecDuplicate(dd->natural, g));
  } else { /* create the first version of this guy */
    PetscCall(VecCreate(PetscObjectComm((PetscObject)da), g));
    PetscCall(VecSetSizes(*g, dd->Nlocal, PETSC_DETERMINE));
    PetscCall(VecSetBlockSize(*g, dd->w));
    PetscCall(VecSetType(*g, da->vectype));
    PetscCall(PetscObjectReference((PetscObject)*g));

    dd->natural = *g;
  }
  PetscFunctionReturn(0);
}