MPI

These require MPI tasks, not the MPI backend. More...

Functions
template<typename T >
std::vector< T >	all_gatherv (const T &t, MPI_Comm comm=MPI_COMM_WORLD)
	All gather communication pattern implemented using MPI_Allgather.
template<typename R >
auto	all_to_allv (R &&r, MPI_Comm comm=MPI_COMM_WORLD)
	All-to-All (variable) communication pattern.
template<class R >
auto	one_to_alli (R &&r, std::size_t mem=1<< 20, MPI_Comm comm=MPI_COMM_WORLD)
	Send data from rank 0 to all others, controlling memory usage.
template<typename R >
auto	one_to_allv (R &&r, MPI_Comm comm=MPI_COMM_WORLD)
	One-to-All (variable) communication pattern.
int	size (MPI_Comm comm=MPI_COMM_WORLD)
	Convenience function to get basic MPI communicator information.

Detailed Description

These require MPI tasks, not the MPI backend.

Contents are in flecsi::util::mpi unless otherwise specified.

Function Documentation

size()

int size

(

MPI_Comm

comm = MPI_COMM_WORLD

)

Convenience function to get basic MPI communicator information.

one_to_allv()

template<typename R >

auto one_to_allv	(	R &&	r,
		MPI_Comm	comm = MPI_COMM_WORLD )

One-to-All (variable) communication pattern.

This function uses the FleCSI serialization interface to communicate data from the root rank (0) to all other ranks.

Parameters

r	range or functor with signature (rank) or (deprecated) (rank, size), read/invoked only on rank 0 and in recipient order
comm	An MPI communicator.

Returns

the value from r for the current rank

one_to_alli()

template<class R >

auto one_to_alli	(	R &&	r,
		std::size_t	mem = 1 << 20,
		MPI_Comm	comm = MPI_COMM_WORLD )

Send data from rank 0 to all others, controlling memory usage.

No messages are constructed while data in transit exceeds mem (transmission occurs, at least serially, even if it is 0).

Parameters

r	range or functor with signature (rank) or (deprecated) (rank, size), read/invoked only on rank 0 and in recipient order
mem	bytes of memory to use before waiting

all_to_allv()

template<typename R >

auto all_to_allv	(	R &&	r,
		MPI_Comm	comm = MPI_COMM_WORLD )

All-to-All (variable) communication pattern.

This function uses the FleCSI serialization interface with a packing callable object to communicate data from all ranks to all other ranks.

Parameters

r	range or functor with signature (rank) or (deprecated) (rank, size), read/invoked in recipient order
comm	An MPI communicator.

Returns

a std::vector of the values for the current rank from each rank's r

all_gatherv()

template<typename T >

std::vector< T > all_gatherv	(	const T &	t,
		MPI_Comm	comm = MPI_COMM_WORLD )

All gather communication pattern implemented using MPI_Allgather.

This function is convenient for passing more complicated types. Otherwise, it may make more sense to use MPI_Allgather directly.

This function uses the FleCSI serialization interface to copy data from all ranks to all other ranks.

Template Parameters

T	serializable data type

Parameters

t	object to send
comm	An MPI communicator.

Returns

the values from each rank