Detailed Description

template<nda::Array A>
struct mpi::lazy< mpi::tag::reduce, A >

Specialization of the mpi::lazy class for nda::Array types and the mpi::tag::reduce tag.

An object of this class is returned when reducing nda::Array objects across multiple MPI processes.

It models an nda::ArrayInitializer, that means it can be used to initialize and assign to nda::basic_array and nda::basic_array_view objects. The target array will have the same shape as the input arrays.

See nda::mpi_reduce for an example.

Template Parameters

A	nda::Array type to be reduced.

Definition at line 50 of file reduce.hpp.

Public Types
using	const_view_type = decltype(std::declval<const A>()())
	Const view type of the array/view stored in the lazy object.

using	value_type = typename std::decay_t<A>::value_type
	Value type of the array/view.

Public Member Functions
template<nda::Array T>
void	invoke (T &&target) const
	Execute the lazy MPI operation and write the result to a target array/view.

auto	shape () const
	Compute the shape of the target array.

Public Attributes
const bool	all {false}
	Should all processes receive the result.

mpi::communicator	comm
	MPI communicator.

const MPI_Op	op {MPI_SUM}
	MPI reduction operation.

const_view_type	rhs
	View of the array/view to be reduced.

const int	root {0}
	MPI root process.

Member Function Documentation

template<nda::Array A>

template<nda::Array T>

void mpi::lazy< mpi::tag::reduce, A >::invoke ( T && target ) const

inline

Execute the lazy MPI operation and write the result to a target array/view.

If the target array/view is the same as the input array/view, i.e. if their data pointers are the same, the reduction is performed in-place.

Template Parameters

T	nda::Array type of the target array/view.

Parameters

target Target array/view.

Definition at line 89 of file reduce.hpp.

template<nda::Array A>

auto mpi::lazy< mpi::tag::reduce, A >::shape ( ) const

inlinenodiscard

Compute the shape of the target array.

Note: It is assumed that the shape of the input array is the same for all MPI processes.

Definition at line 77 of file reduce.hpp.

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