A CollectiveCommunicator that uses a neighborhood topology. More...

#include <ginkgo/core/distributed/neighborhood_communicator.hpp>

Inheritance diagram for gko::experimental::mpi::NeighborhoodCommunicator:

Collaboration diagram for gko::experimental::mpi::NeighborhoodCommunicator:

Public Member Functions
	NeighborhoodCommunicator (const NeighborhoodCommunicator &other)=default

	NeighborhoodCommunicator (NeighborhoodCommunicator &&other)

NeighborhoodCommunicator &	operator= (const NeighborhoodCommunicator &other)=default

NeighborhoodCommunicator &	operator= (NeighborhoodCommunicator &&other)

	NeighborhoodCommunicator (communicator base)
	Default constructor with empty communication pattern. More...

template<typename LocalIndexType , typename GlobalIndexType >
	NeighborhoodCommunicator (communicator base, const distributed::index_map< LocalIndexType, GlobalIndexType > &imap)
	Create a NeighborhoodCommunicator from an index map. More...

std::unique_ptr< CollectiveCommunicator >	create_with_same_type (communicator base, index_map_ptr imap) const override
	Creates a new CollectiveCommunicator with the same dynamic type. More...

std::unique_ptr< CollectiveCommunicator >	create_inverse () const override
	Creates the inverse NeighborhoodCommunicator by switching sources and destinations. More...

std::pair< std::unique_ptr< CollectiveCommunicator >, std::vector< comm_index_type > >	resize (std::shared_ptr< const Executor > exec, const std::vector< comm_index_type > &send_factors) const override
	Create new communicator that sends and receives a different number of elements to/from each rank in its current pattern. More...

comm_index_type	get_recv_size () const override
	Get the number of elements received by this process within this communication pattern. More...

comm_index_type	get_send_size () const override
	Get the number of elements sent by this process within this communication pattern. More...

template<typename SendType , typename RecvType >
request	i_all_to_all_v (std::shared_ptr< const Executor > exec, const SendType send_buffer, RecvType recv_buffer) const
	Non-blocking all-to-all communication. More...

request	i_all_to_all_v (std::shared_ptr< const Executor > exec, const void send_buffer, MPI_Datatype send_type, void recv_buffer, MPI_Datatype recv_type) const

Public Member Functions inherited from gko::experimental::mpi::CollectiveCommunicator
	CollectiveCommunicator (communicator base=MPI_COMM_NULL)

const communicator &	get_base_communicator () const

template<typename SendType , typename RecvType >
request	i_all_to_all_v (std::shared_ptr< const Executor > exec, const SendType send_buffer, RecvType recv_buffer) const
	Non-blocking all-to-all communication. More...

request	i_all_to_all_v (std::shared_ptr< const Executor > exec, const void send_buffer, MPI_Datatype send_type, void recv_buffer, MPI_Datatype recv_type) const

Friends
bool	operator== (const NeighborhoodCommunicator &a, const NeighborhoodCommunicator &b)
	Compares two communicators for equality locally. More...

bool	operator!= (const NeighborhoodCommunicator &a, const NeighborhoodCommunicator &b)
	Compares two communicators for inequality. More...

Additional Inherited Members
Public Types inherited from gko::experimental::mpi::CollectiveCommunicator
using	index_map_ptr = std::variant< const distributed::index_map< int32, int32 > , const distributed::index_map< int32, int64 > , const distributed::index_map< int64, int64 > * >
	All allowed index_map types (as const *)

Detailed Description

A CollectiveCommunicator that uses a neighborhood topology.

The neighborhood communicator is defined by a list of neighbors this rank sends data to and a list of neighbors this rank receives data from. No communication with any ranks that is not in one of those lists will take place.

Constructor & Destructor Documentation

◆ NeighborhoodCommunicator() [1/2]

gko::experimental::mpi::NeighborhoodCommunicator::NeighborhoodCommunicator ( communicator base )

explicit

Default constructor with empty communication pattern.

Parameters

base	the base communicator

◆ NeighborhoodCommunicator() [2/2]

template<typename LocalIndexType , typename GlobalIndexType >

gko::experimental::mpi::NeighborhoodCommunicator::NeighborhoodCommunicator	(	communicator	base,
		const distributed::index_map< LocalIndexType, GlobalIndexType > &	imap
	)

Create a NeighborhoodCommunicator from an index map.

The receiving neighbors are defined by the remote indices and their owning ranks of the index map. The send neighbors are deduced from that through collective communication.

Template Parameters

LocalIndexType	the local index type of the map
GlobalIndexType	the global index type of the map

Parameters

base	the base communicator
imap	the index map that defines the communication pattern

Member Function Documentation

◆ create_inverse()

std::unique_ptr<CollectiveCommunicator> gko::experimental::mpi::NeighborhoodCommunicator::create_inverse ( ) const

overridevirtual

Creates the inverse NeighborhoodCommunicator by switching sources and destinations.

Returns: CollectiveCommunicator with the inverse communication pattern

Implements gko::experimental::mpi::CollectiveCommunicator.

◆ create_with_same_type()

std::unique_ptr<CollectiveCommunicator> gko::experimental::mpi::NeighborhoodCommunicator::create_with_same_type	(	communicator	base,
		index_map_ptr	imap
	)		const

overridevirtual

Creates a new CollectiveCommunicator with the same dynamic type.

Parameters

base	The base communicator
imap	The index_map that defines the communication pattern

Returns: a CollectiveCommunicator with the same dynamic type

Implements gko::experimental::mpi::CollectiveCommunicator.

◆ get_recv_size()

comm_index_type gko::experimental::mpi::NeighborhoodCommunicator::get_recv_size ( ) const

overridevirtual

Get the number of elements received by this process within this communication pattern.

Returns: number of received elements.

Implements gko::experimental::mpi::CollectiveCommunicator.

◆ get_send_size()

comm_index_type gko::experimental::mpi::NeighborhoodCommunicator::get_send_size ( ) const

overridevirtual

Get the number of elements sent by this process within this communication pattern.

Returns: number of sent elements.

Implements gko::experimental::mpi::CollectiveCommunicator.

◆ i_all_to_all_v() [1/2]

template<typename SendType , typename RecvType >

request gko::experimental::mpi::CollectiveCommunicator::i_all_to_all_v	(	typename SendType	,
		typename RecvType
	)

Non-blocking all-to-all communication.

The send_buffer must have allocated at least get_send_size number of elements, and the recv_buffer must have allocated at least get_recv_size number of elements.

Template Parameters

SendType	the type of the elements to send
RecvType	the type of the elements to receive

Parameters

exec	the executor for the communication
send_buffer	the send buffer
recv_buffer	the receive buffer

Returns: a request handle

◆ i_all_to_all_v() [2/2]

request gko::experimental::mpi::CollectiveCommunicator::i_all_to_all_v

◆ resize()

std::pair<std::unique_ptr<CollectiveCommunicator>, std::vector<comm_index_type> > gko::experimental::mpi::NeighborhoodCommunicator::resize	(	std::shared_ptr< const Executor >	exec,
		const std::vector< comm_index_type > &	send_factors
	)		const

overridevirtual

Create new communicator that sends and receives a different number of elements to/from each rank in its current pattern.

The number of elements to send is deduces from the send_factors. If this communicator is used to send 2 elements to rank 0, and 3 elements to rank 1, then send_factors needs to have size 5, which is equal to get_send_size(). An send_factors = { 4, 2, 1, 3, 2} means that instead of the first element to send to rank 0, four elements are sent, instead of the second element to send to rank 0, two elements are sent, and so on. A visual representation of the transformation is:

[ 1 1 | 1 1 1 ] -> [ 4 2 | 1 3 2] -> [ 1 1 1 1 1 1 | 1 1 1 1 1 1 ]

The communication pattern will not change. Even if send_factors is zero for all elements of one rank, the rank will stay in the new pattern.

Note: This is a collective call.

Parameters

exec	the executor to use for the new communicator
send_factors	the new number of elements to send.

Returns: The new communicator and the recv_factors implied by the send_factors

Implements gko::experimental::mpi::CollectiveCommunicator.

Friends And Related Function Documentation

◆ operator!=

bool operator!=	(	const NeighborhoodCommunicator &	a,
		const NeighborhoodCommunicator &	b
	)

friend

Compares two communicators for inequality.

See also: operator==

◆ operator==

bool operator==	(	const NeighborhoodCommunicator &	a,
		const NeighborhoodCommunicator &	b
	)

friend

Compares two communicators for equality locally.

Equality is defined as having identical or congruent communicators and their communication pattern is equal. No communication is done, i.e. there is no reduction over the local equality check results.

Returns: true if both communicators are equal.

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

ginkgo/core/distributed/neighborhood_communicator.hpp

Public Member Functions

Friends

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ NeighborhoodCommunicator() [1/2]

◆ NeighborhoodCommunicator() [2/2]

Member Function Documentation

◆ create_inverse()

◆ create_with_same_type()

◆ get_recv_size()

◆ get_send_size()

◆ i_all_to_all_v() [1/2]

◆ i_all_to_all_v() [2/2]

◆ resize()

Friends And Related Function Documentation

◆ operator!=

◆ operator==