2-dimensional MPI process grid. More...

#include <grid.hh>

Public Member Functions
	grid ()
	Create a new grid object. Does not initialize any BLACS or MPI data.

	grid (const gridshape gridtype)
	Create a new grid object by initializing a new BLACS process grid. More...

void	set (const int blacs_context)
	Create a grid object from an existing BLACS process grid. More...

void	exit ()
	Exits the BLACS grid, but does not shutdown BLACS/MPI.

void	finalize (const bool mpi_continue=false)
	Shuts down BLACS, and optionally MPI. More...

void	printf (const int row, const int col, const char *fmt,...) const
	Helper wrapper around the C standard I/O 'printf()' function. Conceptually similar to guarding a normal 'printf()' function with a check for 'row==myrow() && col==mycol()'. More...

void	info () const
	Print some brief information about the BLACS grid. The printing is done by row 0 and col 0.

bool	rank0 () const
	Check if the executing process is rank 0, i.e., if the process row and column are 0.

bool	ingrid () const
	Check if the executing process is in the grid, i.e., if neither the process row nor column are -1.

void	barrier (const char scope='A') const
	Execute a barrier across the specified scope of the BLACS grid. More...

bool	valid_grid () const
	Is the BLACS grid valid?


void	send (const int m, const int n, const int *x, const int rdest=0, const int cdest=0) const
	Point-to-point send. Should be matched by a corresponding 'recv' call. More...

void	send (const int m, const int n, const float *x, const int rdest=0, const int cdest=0) const

void	send (const int m, const int n, const double *x, const int rdest=0, const int cdest=0) const

void	send (const int m, const int n, const int ldx, const int *x, const int rdest=0, const int cdest=0) const

void	send (const int m, const int n, const int ldx, const float *x, const int rdest=0, const int cdest=0) const

void	send (const int m, const int n, const int ldx, const double *x, const int rdest=0, const int cdest=0) const


void	recv (const int m, const int n, int *x, const int rsrc=0, const int csrc=0) const
	Point-to-point receive. Should be matched by a corresponding 'send' call. More...

void	recv (const int m, const int n, float *x, const int rsrc=0, const int csrc=0) const

void	recv (const int m, const int n, double *x, const int rsrc=0, const int csrc=0) const

void	recv (const int m, const int n, const int ldx, int *x, const int rsrc=0, const int csrc=0) const

void	recv (const int m, const int n, const int ldx, float *x, const int rsrc=0, const int csrc=0) const

void	recv (const int m, const int n, const int ldx, double *x, const int rsrc=0, const int csrc=0) const


void	allreduce (const int m, const int n, int *x, const char scope='A', const blacsops op=BLACS_SUM) const
	Sum reduce operation across all processes in the grid. More...

void	allreduce (const int m, const int n, float *x, const char scope='A', const blacsops op=BLACS_SUM) const

void	allreduce (const int m, const int n, double *x, const char scope='A', const blacsops op=BLACS_SUM) const


void	reduce (const int m, const int n, int *x, const char scope='A', const blacsops op=BLACS_SUM, const int rdest=0, const int cdest=0) const
	Sum reduce operation. More...

void	reduce (const int m, const int n, float *x, const char scope='A', const blacsops op=BLACS_SUM, const int rdest=0, const int cdest=0) const

void	reduce (const int m, const int n, double *x, const char scope='A', const blacsops op=BLACS_SUM, const int rdest=0, const int cdest=0) const


void	bcast (const int m, const int n, int *x, const char scope='A', const int rsrc=0, const int csrc=0) const
	Broadcast. More...

void	bcast (const int m, const int n, float *x, const char scope='A', const int rsrc=0, const int csrc=0) const

void	bcast (const int m, const int n, double *x, const char scope='A', const int rsrc=0, const int csrc=0) const


int	ictxt () const

int	nprocs () const
	The total number of processes bound to the BLACS context.

int	nprow () const
	The number of processes rows in the BLACS context.

int	npcol () const
	The number of processes columns in the BLACS context.

int	myrow () const
	The process row (0-based index) of the calling process.

int	mycol () const
	The process column (0-based index) of the calling process.

Protected Attributes
int	_ictxt

int	_nprocs

int	_nprow

int	_npcol

int	_myrow

int	_mycol

Detailed Description

2-dimensional MPI process grid.

Constructor & Destructor Documentation

◆ grid()

fml::grid::grid ( const gridshape gridtype )

inline

Create a new grid object by initializing a new BLACS process grid.

Parameters

[in] gridtype Should be one of PROC_GRID_SQUARE, PROC_GRID_WIDE, or PROC_GRID_TALL.

Exceptions
If 'gridtype' is not one of PROC_GRID_SQUARE, PROC_GRID_WIDE, or PROC_GRID_TALL, the method will throw a 'runtime_error' exception.

Member Function Documentation

◆ allreduce()

void fml::grid::allreduce	(	const int	m,
		const int	n,
		int *	x,
		const char	scope = `'A'`,
		const blacsops	op = `BLACS_SUM`
	)		const

inline

Sum reduce operation across all processes in the grid.

Parameters

[in]	m,n	Dimensions (number of rows/cols) of the data 'x'.
[in,out]	x	The data to reduce.
	scope	The scope of the operation. For just rows use 'R', just columns use 'C', and for all processes use 'A'.

◆ barrier()

void fml::grid::barrier ( const char scope = 'A' ) const

inline

Execute a barrier across the specified scope of the BLACS grid.

Parameters

scope The scope of the operation. For just rows use 'R', just columns use 'C', and for all processes use 'A'.

◆ bcast()

void fml::grid::bcast	(	const int	m,
		const int	n,
		int *	x,
		const char	scope = `'A'`,
		const int	rsrc = `0`,
		const int	csrc = `0`
	)		const

inline

Broadcast.

Parameters

[in]	m,n	Dimensions (number of rows/cols) of the data 'x'.
[in,out]	x	The data to broadcast.
	scope	The scope of the operation. For just rows use 'R', just columns use 'C', and for all processes use 'A'.
[in]	rsrc,csrc	The process row/column of the BLACS grid that is broadcasting.

◆ finalize()

void fml::grid::finalize ( const bool mpi_continue = false )

inline

Shuts down BLACS, and optionally MPI.

Parameters

mpi_continue Should MPI continue, i.e., not be shut down too?

◆ ictxt()

int fml::grid::ictxt ( ) const

inline

The BLACS integer context.

◆ printf()

void fml::grid::printf	(	const int	row,
		const int	col,
		const char *	fmt,
			...
	)		const

inline

Helper wrapper around the C standard I/O 'printf()' function. Conceptually similar to guarding a normal 'printf()' function with a check for 'row==myrow() && col==mycol()'.

Parameters

[in]	row,col	The process row/column that should do the printing.
[in]	fmt	The printf format string.
[in]	...	additional arguments to printf.

◆ recv()

void fml::grid::recv	(	const int	m,
		const int	n,
		int *	x,
		const int	rsrc = `0`,
		const int	csrc = `0`
	)		const

inline

Point-to-point receive. Should be matched by a corresponding 'send' call.

Parameters

[in]	m,n	Dimensions (number of rows/cols) of the data 'x'.
[in]	x	The data to receive.
[in]	rsrc,csrc	The row/col source in the BLACS grid.

◆ reduce()

void fml::grid::reduce	(	const int	m,
		const int	n,
		int *	x,
		const char	scope = `'A'`,
		const blacsops	op = `BLACS_SUM`,
		const int	rdest = `0`,
		const int	cdest = `0`
	)		const

inline

Sum reduce operation.

Parameters

[in]	m,n	Dimensions (number of rows/cols) of the data 'x'.
[in,out]	x	The data to reduce.
	scope	The scope of the operation. For just rows use 'R', just columns use 'C', and for all processes use 'A'.
[in]	rdest,cdest	The row/column of the BLACS grid to receive the final answer.

◆ send()

void fml::grid::send	(	const int	m,
		const int	n,
		const int *	x,
		const int	rdest = `0`,
		const int	cdest = `0`
	)		const

inline

Point-to-point send. Should be matched by a corresponding 'recv' call.

Parameters

[in]	m,n	Dimensions (number of rows/cols) of the data `x`.
[in]	ldx	Leading dimension of matrix `x`.
[in]	x	The data to send.
[in]	rdest,cdest	The row/col destination in the BLACS grid.

◆ set()

void fml::grid::set ( const int blacs_context )

inline

Create a grid object from an existing BLACS process grid.

Parameters

blacs_context The BLACS integer context number.

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

fml/src/fml/mpi/grid.hh

Public Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ grid()

Member Function Documentation

◆ allreduce()

◆ barrier()

◆ bcast()

◆ finalize()

◆ ictxt()

◆ printf()

◆ recv()

◆ reduce()

◆ send()

◆ set()