dash::halo::StencilOperatorBoundary< StencilOperatorT > Class Template Reference

Proxy StencilOperator for boundary elements only. More...

#include <StencilOperator.h>

Public Types
using	Element_t = typename StencilOperatorT::Element_t
using	uindex_t = typename StencilOperatorT::uindex_t
using	ViewSpec_t = typename StencilOperatorT::ViewSpec_t
using	Coords_t = typename StencilOperatorT::Coords_t
using	iterator = typename StencilOperatorT::iterator_bnd
using	const_iterator = const iterator
using	BoundaryViews_t = typename StencilSpecViews_t::BoundaryViews_t
using	RegionCoords_t = RegionCoords< NumDimensions >

Public Member Functions
	StencilOperatorBoundary (const StencilOperatorT *stencil_op)
iterator	begin () noexcept
	Returns the begin iterator for all boundary elements. More...
const_iterator	begin () const noexcept
	Returns the begin const iterator for all boundary elements. More...
iterator	end () noexcept
	Returns the end iterator for all boundary elements. More...
const_iterator	end () const noexcept
	Returns the end const iterator for all boundary elements. More...
const BoundaryViews_t &	view () const
	Returns all boundary views including all boundary elements (no dublicates) Unlike the view methods in StencilOperator and StencilOperatorInner this method returns a container with views. More...
uindex_t	boundary_size () const
	Returns the number of all boundary elements (no dublicates) More...
template<typename BinaryFunc = internal::replace<Element_t>>
void	set_values_at (const Coords_t &coords, Element_t value, Element_t coefficient_center, BinaryFunc op=BinaryFunc())
	Modifies all stencil point elements and the center with halo check. More...
std::pair< iterator, iterator >	iterator_at (dim_t dim, RegionPos pos)
	Returns a pair of boundary iterators (first: begin, second: end) for a given dimension and RegionPos. More...
std::pair< iterator, iterator >	iterator_at (region_index_t index)
template<typename BinaryFunc = std::plus<Element_t>>
Element_t	get_value_at (const Coords_t &coords, Element_t coefficient_center, BinaryFunc op=BinaryFunc()) const
	Returns the result of the given operation done on all stencil point elements and the center. More...
template<typename Op >
void	update (Element_t *begin_dst, Op operation)
	Updates all boundary elements using a user-defined stencil operation. More...
template<typename Op >
void	update (const iterator &begin, const iterator &end, Element_t *begin_out, Op operation)
	Updates all boundary elements within a user defined range using a userdefined stencil operation. More...

Detailed Description

template<typename StencilOperatorT>
class dash::halo::StencilOperatorBoundary< StencilOperatorT >

Proxy StencilOperator for boundary elements only.

Definition at line 393 of file StencilOperator.h.

Member Function Documentation

begin() [1/2]

template<typename StencilOperatorT>

iterator dash::halo::StencilOperatorBoundary< StencilOperatorT >::begin ( )

inlinenoexcept

Returns the begin iterator for all boundary elements.

Definition at line 418 of file StencilOperator.h.

{ return _stencil_op->_bbegin; }

begin() [2/2]

template<typename StencilOperatorT>

const_iterator dash::halo::StencilOperatorBoundary< StencilOperatorT >::begin ( ) const

inlinenoexcept

Returns the begin const iterator for all boundary elements.

Definition at line 423 of file StencilOperator.h.

{ return _stencil_op->_bbegin; }

boundary_size()

template<typename StencilOperatorT>

uindex_t dash::halo::StencilOperatorBoundary< StencilOperatorT >::boundary_size ( ) const

inline

Returns the number of all boundary elements (no dublicates)

Definition at line 448 of file StencilOperator.h.

                                 {
    return _stencil_op->_spec_views.boundary_size();
  }

end() [1/2]

template<typename StencilOperatorT>

iterator dash::halo::StencilOperatorBoundary< StencilOperatorT >::end ( )

inlinenoexcept

Returns the end iterator for all boundary elements.

Definition at line 428 of file StencilOperator.h.

{ return _stencil_op->_bend; }

end() [2/2]

template<typename StencilOperatorT>

const_iterator dash::halo::StencilOperatorBoundary< StencilOperatorT >::end ( ) const

inlinenoexcept

Returns the end const iterator for all boundary elements.

Definition at line 433 of file StencilOperator.h.

{ return _stencil_op->_bend; }

get_value_at()

template<typename StencilOperatorT>

template<typename BinaryFunc = std::plus<Element_t>>

Element_t dash::halo::StencilOperatorBoundary< StencilOperatorT >::get_value_at ( const Coords_t &  coords, Element_t  coefficient_center, BinaryFunc  op = BinaryFunc()  ) const

inline

Returns the result of the given operation done on all stencil point elements and the center.

The stencil points are multiplied with their coefficent (StencilPoint) and the center is multiplied with the given center coefficient. Test and use of halo elements. -> useful only for elements with stencil points pointing to halo elements. (boundary elements)

Parameters

coords	center coordinate
coefficient	for center
op	operation to use (e.g. std::plus). default: std::plus

Definition at line 547 of file StencilOperator.h.

                                                                        {
    auto* center = _stencil_op->_local_memory + _stencil_op->get_offset(coords);
    Element_t value        = *center * coefficient_center;
    auto&    stencil_spec = _stencil_op->_stencil_spec;
    for(auto i = 0; i < NumStencilPoints; ++i) {
      bool halo           = false;
      auto coords_stencil = coords;

      for(auto d = 0; d < NumDimensions; ++d) {
        coords_stencil[d] += stencil_spec[i][d];
        if(coords_stencil[d] < 0
           || coords_stencil[d] >= _stencil_op->_view_local->extent(d))
          halo = true;
      }

      if(halo) {
        auto& halo_memory = *_stencil_op->_halo_memory;
        auto  index       = _stencil_op->_halo_block->index_at(
          *(_stencil_op->_view_local), coords_stencil);
        auto halomem_pos = halo_memory.first_element_at(index);

        halo_memory.to_halo_mem_coords(index, coords_stencil);
        auto offset = halo_memory.offset(index, coords_stencil);
        value = op(value, stencil_spec[i].coefficient() * halomem_pos[offset]);
      } else {
        auto stencil_point_value = center[_stencil_op->_stencil_offsets[i]];
        value = op(value, stencil_spec[i].coefficient() * stencil_point_value);
      }
    }

    return value;
  }

iterator_at()

template<typename StencilOperatorT>

std::pair<iterator, iterator> dash::halo::StencilOperatorBoundary< StencilOperatorT >::iterator_at ( dim_t  dim, RegionPos  pos  )

inline

Returns a pair of boundary iterators (first: begin, second: end) for a given dimension and RegionPos.

Iterators of higher dimensions will not iterate over elements which were already covered in lower dimensions. Using all iterators for all dimensions and RegionPos has the same effect as using bbegin and bend.

Definition at line 501 of file StencilOperator.h.

                                                                    {
    DASH_ASSERT_LT(dim, NumDimensions, "Given dimension to great");
    const auto&    bnd_views = _stencil_op->_spec_views.boundary_views();
    uindex_t offset = 0;
    auto           it_views  = std::begin(bnd_views);
    for(dim_t d = 0; d < dim; ++d, ++it_views)
      offset += it_views->size() + (++it_views)->size();

    if(pos == RegionPos::POST) {
      offset += it_views->size();
      ++it_views;
    }

    auto it_begin = _stencil_op->_bbegin + offset;

    return std::make_pair(it_begin, it_begin + it_views->size());
  }

set_values_at()

template<typename StencilOperatorT>

template<typename BinaryFunc = internal::replace<Element_t>>

void dash::halo::StencilOperatorBoundary< StencilOperatorT >::set_values_at ( const Coords_t &  coords, Element_t  value, Element_t  coefficient_center, BinaryFunc  op = BinaryFunc()  )

inline

Modifies all stencil point elements and the center with halo check.

If a stencil point points to a halo element or a non existing element no operation is performed for this one. The stencil points are multiplied with their coefficent (StencilPoint) and the center is multiplied with the given center coefficient. The results then modifies the center/stencil point elements via the given operation.

Parameters

coords	center coordinate
value	base value for all points
coefficient	for center
op	operation to use (e.g. std::plus). default: replace

Definition at line 467 of file StencilOperator.h.

                                                   {
    auto* center = _stencil_op->_local_memory + _stencil_op->get_offset(coords);

    *center = op(*center, coefficient_center * value);
    for(auto i = 0; i < NumStencilPoints; ++i) {
      bool halo = false;
      for(auto d = 0; d < NumDimensions; ++d) {
        auto coord_value = coords[d] + _stencil_op->_stencil_spec[i][d];
        if(coord_value < 0
           || coord_value >= _stencil_op->_view_local->extent(d)) {
          halo = true;
          break;
        }
      }

      if(halo)
        continue;

      auto& stencil_point_value = center[_stencil_op->_stencil_offsets[i]];
      stencil_point_value =
        op(stencil_point_value,
           _stencil_op->_stencil_spec[i].coefficient() * value);
    }
  }

update() [1/2]

template<typename StencilOperatorT>

template<typename Op >

void dash::halo::StencilOperatorBoundary< StencilOperatorT >::update ( Element_t *  begin_dst, Op  operation  )

inline

Updates all boundary elements using a user-defined stencil operation.

Parameters

begin_dst	Pointer to the beginning of the destination memory
operation	User-definied operation for updating all boundary elements

Definition at line 589 of file StencilOperator.h.

                                                  {
    update(begin(), end(), begin_dst, operation);
  }

update() [2/2]

template<typename StencilOperatorT>

template<typename Op >

void dash::halo::StencilOperatorBoundary< StencilOperatorT >::update ( const iterator &  begin, const iterator &  end, Element_t *  begin_out, Op  operation  )

inline

Updates all boundary elements within a user defined range using a userdefined stencil operation.

Parameters

begin	Iterator of the beginnning boundary data element
end	Iterator of the last boundary data element
begin_dst	Pointer to the beginning of the destination memory
operation	User-definied operation for updating all inner elements

Definition at line 604 of file StencilOperator.h.

                            {
    for(auto it = begin; it != end; ++it) {
      begin_out[it.lpos()] = operation(it);
    }
  }

view()

template<typename StencilOperatorT>

const BoundaryViews_t& dash::halo::StencilOperatorBoundary< StencilOperatorT >::view ( ) const

inline

Returns all boundary views including all boundary elements (no dublicates) Unlike the view methods in StencilOperator and StencilOperatorInner this method returns a container with views.

Definition at line 441 of file StencilOperator.h.

                                      {
    return _stencil_op->_spec_views.boundary_views();
  }

---

The documentation for this class was generated from the following file:

• /tmp/tmporruphar/dash/include/dash/halo/StencilOperator.h