sirius::mpi::Grid Class Reference

MPI grid interface. More...

#include <mpi_grid.hpp>

Public Member Functions
	Grid (std::vector< int > dimensions__, Communicator const &parent_communicator__)
int	num_dimensions () const
	Actual number of grid dimensions. More...
auto const &	communicator (int directions__=0xFF) const

Private Member Functions
int	valid_directions (int directions__) const
	Return valid directions for the current grid dimensionality. More...
void	initialize ()
	Initialize the grid. More...
	Grid (Grid const &src)=delete
Grid &	operator= (Grid const &src)=delete

Private Attributes
std::vector< int >	dimensions_
	Dimensions of the grid. More...
Communicator const &	parent_communicator_
	Parent communicator. More...
Communicator	base_grid_communicator_
	Grid communicator of the enrire grid returned by MPI_Cart_create. More...
std::vector< Communicator >	communicators_
	Grid communicators. More...

Detailed Description

MPI grid interface.

The following terminology is used. Suppose we have a 4x5 grid of MPI ranks. We say it's a two-dimensional grid with the first dimension of the size 4 and the second dimensoion of the size 5. The actual number of grid dimensions is two, however we may also consider the grid as being a D-dimensional (D >= 2) with implicit dimension sizes equal to one, e.g. 4x5 := 4x5x1x1x1... The communication happens along single or multiple directions along the grid dimensions. We specify directions wth bits, eg. directions=00000101 reads as "communication along 1-st and 3-rd dimensions".

Communication along dimension d0 (between ranks of d0).

In the provided example the corresponding communicator is MPI_grid::communicator(1 << d0), where d0 is the integer index of dimension.

Definition at line 46 of file mpi_grid.hpp.

Constructor & Destructor Documentation

Grid()

sirius::mpi::Grid::Grid ( std::vector< int >  dimensions__, Communicator const &  parent_communicator__  )

inline

Definition at line 128 of file mpi_grid.hpp.

Member Function Documentation

valid_directions()

int sirius::mpi::Grid::valid_directions ( int  directions__ ) const

inlineprivate

Return valid directions for the current grid dimensionality.

Definition at line 64 of file mpi_grid.hpp.

initialize()

void sirius::mpi::Grid::initialize ( )

inlineprivate

Initialize the grid.

Definition at line 70 of file mpi_grid.hpp.

num_dimensions()

int sirius::mpi::Grid::num_dimensions ( ) const

inline

Actual number of grid dimensions.

Definition at line 136 of file mpi_grid.hpp.

communicator()

auto const & sirius::mpi::Grid::communicator ( int  directions__ = 0xFF ) const

inline

Definition at line 141 of file mpi_grid.hpp.

Member Data Documentation

dimensions_

std::vector<int> sirius::mpi::Grid::dimensions_

private

Dimensions of the grid.

Definition at line 50 of file mpi_grid.hpp.

parent_communicator_

Communicator const& sirius::mpi::Grid::parent_communicator_

private

Parent communicator.

Definition at line 53 of file mpi_grid.hpp.

base_grid_communicator_

Communicator sirius::mpi::Grid::base_grid_communicator_

private

Grid communicator of the enrire grid returned by MPI_Cart_create.

Definition at line 56 of file mpi_grid.hpp.

communicators_

std::vector<Communicator> sirius::mpi::Grid::communicators_

private

Grid communicators.

Grid comminicators are built for all possible combinations of directions, i.e. 001, 010, 011, etc. First communicator is the trivial "self" communicator; the last communicator handles the entire grid.

Definition at line 61 of file mpi_grid.hpp.

---

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

• mpi_grid.hpp