#include <deal.II/base/mpi_consensus_algorithms.h>

Inheritance diagram for Utilities::MPI::ConsensusAlgorithms::NBX< RequestType, AnswerType >:

Public Member Functions
	NBX ()=default

	NBX (Process< RequestType, AnswerType > &process, const MPI_Comm comm)

virtual	~NBX ()=default

virtual std::vector< unsigned int >	run (const std::vector< unsigned int > &targets, const std::function< RequestType(const unsigned int)> &create_request, const std::function< AnswerType(const unsigned int, const RequestType &)> &answer_request, const std::function< void(const unsigned int, const AnswerType &)> &process_answer, const MPI_Comm comm) override

std::vector< unsigned int >	run ()

std::vector< unsigned int >	run (Process< RequestType, AnswerType > &process, const MPI_Comm comm)

Private Member Functions
bool	all_locally_originated_receives_are_completed (const std::function< void(const unsigned int, const AnswerType &)> &process_answer, const MPI_Comm comm)

void	signal_finish (const MPI_Comm comm)

bool	all_remotely_originated_receives_are_completed ()

void	maybe_answer_one_request (const std::function< AnswerType(const unsigned int, const RequestType &)> &answer_request, const MPI_Comm comm)

void	start_communication (const std::vector< unsigned int > &targets, const std::function< RequestType(const unsigned int)> &create_request, const MPI_Comm comm)

void	clean_up_and_end_communication (const MPI_Comm comm)

Private Attributes
std::vector< std::vector< char > >	send_buffers

std::vector< MPI_Request >	send_requests

std::vector< std::unique_ptr< std::vector< char > > >	request_buffers

std::vector< std::unique_ptr< MPI_Request > >	request_requests

unsigned int	n_outstanding_answers

MPI_Request	barrier_request

std::set< unsigned int >	requesting_processes

Process< RequestType, AnswerType > *	process

MPI_Comm	comm

Detailed Description

template<typename RequestType, typename AnswerType>
class Utilities::MPI::ConsensusAlgorithms::NBX< RequestType, AnswerType >

This class implements a concrete algorithm for the ConsensusAlgorithms::Interface base class, using only point-to-point communications and a single IBarrier. This algorithm is suitable for very large process counts because it does not require the allocation of arrays with size proportional to the number of processes.

Note: This class closely follows [98], but our implementation also deals with payloads.

Template Parameters

RequestType	The type of the elements of the vector to be sent.
AnswerType	The type of the elements of the vector to be received.

Definition at line 357 of file mpi_consensus_algorithms.h.

Constructor & Destructor Documentation

◆ NBX() [1/2]

template<typename RequestType , typename AnswerType >

Utilities::MPI::ConsensusAlgorithms::NBX< RequestType, AnswerType >::NBX ( )

default

Default constructor.

◆ NBX() [2/2]

template<typename RequestType , typename AnswerType >

Utilities::MPI::ConsensusAlgorithms::NBX< RequestType, AnswerType >::NBX	(	Process< RequestType, AnswerType > &	process,
		const MPI_Comm	comm
	)

Constructor.

Parameters

process	Process to be run during consensus algorithm.
comm	MPI Communicator

Deprecated:: This constructor stores the Process object and the communicator so that one can later call the run() function without arguments. This approach is deprecated. Instead, use the default constructor of this class along with the run() function that takes an argument.

◆ ~NBX()

template<typename RequestType , typename AnswerType >

virtual Utilities::MPI::ConsensusAlgorithms::NBX< RequestType, AnswerType >::~NBX ( )

virtualdefault

Destructor.

Member Function Documentation

◆ run() [1/3]

template<typename RequestType , typename AnswerType >

virtual std::vector< unsigned int > Utilities::MPI::ConsensusAlgorithms::NBX< RequestType, AnswerType >::run	(	const std::vector< unsigned int > &	targets,
		const std::function< RequestType(const unsigned int)> &	create_request,
		const std::function< AnswerType(const unsigned int, const RequestType &)> &	answer_request,
		const std::function< void(const unsigned int, const AnswerType &)> &	process_answer,
		const MPI_Comm	comm
	)

overridevirtual

Run the consensus algorithm and return a vector of process ranks that have requested answers from the current process.

Deprecated:: This function is deprecated. It can be called if the Process object and communicator to be used have previously been provided to the non-default constructor. Use the run() functions taking arguments instead.

Implements Utilities::MPI::ConsensusAlgorithms::Interface< RequestType, AnswerType >.

◆ all_locally_originated_receives_are_completed()

template<typename RequestType , typename AnswerType >

bool Utilities::MPI::ConsensusAlgorithms::NBX< RequestType, AnswerType >::all_locally_originated_receives_are_completed	(	const std::function< void(const unsigned int, const AnswerType &)> &	process_answer,
		const MPI_Comm	comm
	)

private

Check whether all of the requests for answers that were created by the communication posted from the current process to other ranks have been satisfied.

◆ signal_finish()

template<typename RequestType , typename AnswerType >

void Utilities::MPI::ConsensusAlgorithms::NBX< RequestType, AnswerType >::signal_finish ( const MPI_Comm comm )

private

Signal to all other ranks that this rank has received all request answers via entering IBarrier.

◆ all_remotely_originated_receives_are_completed()

template<typename RequestType , typename AnswerType >

bool Utilities::MPI::ConsensusAlgorithms::NBX< RequestType, AnswerType >::all_remotely_originated_receives_are_completed ( )

private

Check whether all of the requests for answers that were created by communication posted from other processes to the current rank have been satisfied.

◆ maybe_answer_one_request()

template<typename RequestType , typename AnswerType >

void Utilities::MPI::ConsensusAlgorithms::NBX< RequestType, AnswerType >::maybe_answer_one_request	(	const std::function< AnswerType(const unsigned int, const RequestType &)> &	answer_request,
		const MPI_Comm	comm
	)

private

Check whether a request message from another rank has been received, and if so, process the request by storing the data and sending an answer.

◆ start_communication()

template<typename RequestType , typename AnswerType >

void Utilities::MPI::ConsensusAlgorithms::NBX< RequestType, AnswerType >::start_communication	(	const std::vector< unsigned int > &	targets,
		const std::function< RequestType(const unsigned int)> &	create_request,
		const MPI_Comm	comm
	)

private

Start to send all requests via ISend and post IRecvs for the incoming answer messages.

◆ clean_up_and_end_communication()

template<typename RequestType , typename AnswerType >

void Utilities::MPI::ConsensusAlgorithms::NBX< RequestType, AnswerType >::clean_up_and_end_communication ( const MPI_Comm comm )

private

After all rank has received all answers, the MPI data structures can be freed and the received answers can be processed.

◆ run() [2/3]

template<typename RequestType , typename AnswerType >

std::vector< unsigned int > Utilities::MPI::ConsensusAlgorithms::Interface< RequestType, AnswerType >::run ( )

inherited

Run the consensus algorithm and return a vector of process ranks that have requested answers from the current process.

Deprecated:: This function is deprecated. It can be called if the Process object and communicator to be used have previously been provided to the non-default constructor. Use the run() functions taking arguments instead.

◆ run() [3/3]

template<typename RequestType , typename AnswerType >

std::vector< unsigned int > Utilities::MPI::ConsensusAlgorithms::Interface< RequestType, AnswerType >::run	(	Process< RequestType, AnswerType > &	process,
		const MPI_Comm	comm
	)

inherited

Run the consensus algorithm and return a vector of process ranks that have requested answers from the current process.

This version of the run() function simply unpacks the functions packaged in process and calls the version of the run() function that takes a number of std::function arguments.

Member Data Documentation

◆ send_buffers

template<typename RequestType , typename AnswerType >

std::vector<std::vector<char> > Utilities::MPI::ConsensusAlgorithms::NBX< RequestType, AnswerType >::send_buffers

private

Buffers for sending requests.

Definition at line 406 of file mpi_consensus_algorithms.h.

◆ send_requests

template<typename RequestType , typename AnswerType >

std::vector<MPI_Request> Utilities::MPI::ConsensusAlgorithms::NBX< RequestType, AnswerType >::send_requests

private

Requests for sending requests.

Definition at line 411 of file mpi_consensus_algorithms.h.

◆ request_buffers

template<typename RequestType , typename AnswerType >

std::vector<std::unique_ptr<std::vector<char> > > Utilities::MPI::ConsensusAlgorithms::NBX< RequestType, AnswerType >::request_buffers

private

Buffers for sending answers to requests. We use a vector of pointers because that guarantees that the buffers themselves are newer moved around in memory, even if the vector is resized and consequently its elements (the pointers) are moved around.

Definition at line 420 of file mpi_consensus_algorithms.h.

◆ request_requests

template<typename RequestType , typename AnswerType >

std::vector<std::unique_ptr<MPI_Request> > Utilities::MPI::ConsensusAlgorithms::NBX< RequestType, AnswerType >::request_requests

private

Requests for sending answers to requests.

Definition at line 425 of file mpi_consensus_algorithms.h.

◆ n_outstanding_answers

template<typename RequestType , typename AnswerType >

unsigned int Utilities::MPI::ConsensusAlgorithms::NBX< RequestType, AnswerType >::n_outstanding_answers

private

The number of processes from which we are still expecting answers.

Definition at line 430 of file mpi_consensus_algorithms.h.

◆ barrier_request

template<typename RequestType , typename AnswerType >

MPI_Request Utilities::MPI::ConsensusAlgorithms::NBX< RequestType, AnswerType >::barrier_request

private

Definition at line 433 of file mpi_consensus_algorithms.h.

◆ requesting_processes

template<typename RequestType , typename AnswerType >

std::set<unsigned int> Utilities::MPI::ConsensusAlgorithms::NBX< RequestType, AnswerType >::requesting_processes

private

List of processes who have made a request to this process.

Definition at line 439 of file mpi_consensus_algorithms.h.

◆ process

template<typename RequestType , typename AnswerType >

Process<RequestType, AnswerType>* Utilities::MPI::ConsensusAlgorithms::Interface< RequestType, AnswerType >::process

privateinherited

Reference to the process provided by the user.

This member variable is only used in the deprecated constructor and the run() function without argument. It is a nullptr otherwise

Definition at line 330 of file mpi_consensus_algorithms.h.

◆ comm

template<typename RequestType , typename AnswerType >

MPI_Comm Utilities::MPI::ConsensusAlgorithms::Interface< RequestType, AnswerType >::comm

privateinherited

MPI communicator.

This member variable is only used in the deprecated constructor and the run() function without argument.

Definition at line 339 of file mpi_consensus_algorithms.h.

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

include/deal.II/base/mpi_consensus_algorithms.h

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ NBX() [1/2]

◆ NBX() [2/2]

◆ ~NBX()

Member Function Documentation

◆ run() [1/3]

◆ all_locally_originated_receives_are_completed()

◆ signal_finish()

◆ all_remotely_originated_receives_are_completed()

◆ maybe_answer_one_request()

◆ start_communication()

◆ clean_up_and_end_communication()

◆ run() [2/3]

◆ run() [3/3]

Member Data Documentation

◆ send_buffers

◆ send_requests

◆ request_buffers

◆ request_requests

◆ n_outstanding_answers

◆ barrier_request

◆ requesting_processes

◆ process

◆ comm