gko::experimental::mpi::CollectiveCommunicator Class Reference

Interface for a collective communicator. More...

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

Inheritance diagram for gko::experimental::mpi::CollectiveCommunicator:

Public Types
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 *)

Public Member Functions
	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
virtual std::unique_ptr< CollectiveCommunicator >	create_with_same_type (communicator base, index_map_ptr imap) const =0
	Creates a new CollectiveCommunicator with the same dynamic type. More...
virtual std::unique_ptr< CollectiveCommunicator >	create_inverse () const =0
	Creates a CollectiveCommunicator with the inverse communication pattern than this object. More...
virtual 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 =0
	Create new communicator that sends and receives a different number of elements to/from each rank in its current pattern. More...
virtual comm_index_type	get_recv_size () const =0
	Get the number of elements received by this process within this communication pattern. More...
virtual comm_index_type	get_send_size () const =0
	Get the number of elements sent by this process within this communication pattern. More...

Detailed Description

Interface for a collective communicator.

A collective communicator only provides routines for collective communications. At the moment this is restricted to the variable all-to-all.

Member Function Documentation

create_inverse()

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

pure virtual

Creates a CollectiveCommunicator with the inverse communication pattern than this object.

Returns

a CollectiveCommunicator with the inverse communication pattern.

Implemented in gko::experimental::mpi::DenseCommunicator, and gko::experimental::mpi::NeighborhoodCommunicator.

create_with_same_type()

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

pure virtual

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

Implemented in gko::experimental::mpi::NeighborhoodCommunicator, and gko::experimental::mpi::DenseCommunicator.

get_recv_size()

virtual comm_index_type gko::experimental::mpi::CollectiveCommunicator::get_recv_size ( ) const

pure virtual

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

Returns

number of received elements.

Implemented in gko::experimental::mpi::NeighborhoodCommunicator, and gko::experimental::mpi::DenseCommunicator.

get_send_size()

virtual comm_index_type gko::experimental::mpi::CollectiveCommunicator::get_send_size ( ) const

pure virtual

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

Returns

number of sent elements.

Implemented in gko::experimental::mpi::NeighborhoodCommunicator, and gko::experimental::mpi::DenseCommunicator.

i_all_to_all_v() [1/2]

template<typename SendType , typename RecvType >

request gko::experimental::mpi::CollectiveCommunicator::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.

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

resize()

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

pure virtual

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

Implemented in gko::experimental::mpi::NeighborhoodCommunicator, and gko::experimental::mpi::DenseCommunicator.

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

• ginkgo/core/distributed/collective_communicator.hpp