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 root (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 processes.

Parameters

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

Returns

the value from r for this process

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 root (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 root 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 each process to every other.

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 this process from each source 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 every process to every other.

Template Parameters

T	serializable data type

Parameters

t	object to send
comm	An MPI communicator.

Returns

all t values