#include <communication.h>

Inheritance diagram for fpmas::api::communication::MpiCommunicator:

[legend]

Public Member Functions
virtual int	getRank () const =0

virtual int	getSize () const =0

virtual void	send (const void *data, int count, MPI_Datatype datatype, int destination, int tag)=0

virtual void	send (const DataPack &data, MPI_Datatype datatype, int destination, int tag)=0

virtual void	send (int destination, int tag)=0

virtual void	Isend (const void *data, int count, MPI_Datatype datatype, int destination, int tag, Request &request)=0

virtual void	Isend (const DataPack &data, MPI_Datatype datatype, int destination, int tag, Request &request)=0

virtual void	Isend (int destination, int tag, Request &request)=0

virtual void	Issend (const void *data, int count, MPI_Datatype datatype, int destination, int tag, Request &request)=0

virtual void	Issend (const DataPack &data, MPI_Datatype datatype, int destination, int tag, Request &request)=0

virtual void	Issend (int destination, int tag, Request &request)=0

virtual void	probe (MPI_Datatype type, int source, int tag, Status &status)=0

virtual bool	Iprobe (MPI_Datatype type, int source, int tag, Status &status)=0

virtual void	recv (int source, int tag, Status &status=Status::IGNORE)=0

virtual void	recv (void *buffer, int count, MPI_Datatype datatype, int source, int tag, Status &status)=0

virtual void	recv (DataPack &data, MPI_Datatype datatype, int source, int tag, Status &status)=0

virtual bool	test (Request &request)=0

virtual void	wait (Request &request)=0

virtual void	waitAll (std::vector< Request > &requests)=0

virtual std::unordered_map< int, DataPack >	allToAll (std::unordered_map< int, DataPack > export_map, MPI_Datatype datatype)=0

virtual std::vector< DataPack >	gather (DataPack data, MPI_Datatype datatype, int root)=0

virtual std::vector< DataPack >	allGather (DataPack data, MPI_Datatype datatype)=0

virtual DataPack	bcast (DataPack data, MPI_Datatype datatype, int root)=0

virtual void	barrier ()=0

Static Public Attributes
static MPI_Datatype	IGNORE_TYPE = MPI_INT

Detailed Description

MpiCommunicator interface.

Defines a low-level wrapper around MPI functions to make it more C++ compliant.

A limited set of functions, that are actually used in the fpmas library, have been adapted. More functions might be added in the future.

Constructor & Destructor Documentation

◆ ~MpiCommunicator()

virtual fpmas::api::communication::MpiCommunicator::~MpiCommunicator ( )

inlinevirtual

Reimplemented in fpmas::communication::MpiCommunicator.

Member Function Documentation

◆ getRank()

virtual int fpmas::api::communication::MpiCommunicator::getRank ( ) const

pure virtual

Returns the rank of this communicator.

Returns: rank

Implemented in fpmas::communication::MpiCommunicatorBase.

◆ getSize()

virtual int fpmas::api::communication::MpiCommunicator::getSize ( ) const

pure virtual

Returns the size of the group to which this communicator belongs.

Returns: group size

Implemented in fpmas::communication::MpiCommunicatorBase.

◆ send() [1/3]

virtual void fpmas::api::communication::MpiCommunicator::send	(	const void *	data,
		int	count,
		MPI_Datatype	datatype,
		int	destination,
		int	tag
	)

pure virtual

Sends data to destination (blocking, asynchronous).

This corresponds to the MPI standard mode. In this case, it is up to the MPI implementation to decide if the message is buffered or not (for example, depending on the message size):

If the message is buffered, the method returns once data has been copied to the buffer.
Else, the method returns only when the matching recv() has been initiated and data is sent, what might produce some deadlock behavior. See the Isend() method to prevent such situations.

Parameters

data	input buffer
count	items count in the buffer
datatype	MPI type of the data to send
destination	rank of the destination process
tag	message tag

Implemented in fpmas::communication::MpiCommunicatorBase.

◆ send() [2/3]

virtual void fpmas::api::communication::MpiCommunicator::send	(	const DataPack &	data,
		MPI_Datatype	datatype,
		int	destination,
		int	tag
	)

pure virtual

Equivalent to send(data.buffer, data.count, datatype, destination, tag)

Parameters

data	input DataPack
datatype	MPI type of the data to send
destination	rank of the destination process
tag	message tag

Implemented in fpmas::communication::MpiCommunicatorBase.

◆ send() [3/3]

virtual void fpmas::api::communication::MpiCommunicator::send	(	int	destination,
		int	tag
	)

pure virtual

Sends a void message to destination (blocking, asynchronous).

This might be useful to send END message for example, when only a message tag without body might be enough.

Parameters

destination	rank of the destination process
tag	message tag

Implemented in fpmas::communication::MpiCommunicatorBase.

◆ Isend() [1/3]

virtual void fpmas::api::communication::MpiCommunicator::Isend	(	const void *	data,
		int	count,
		MPI_Datatype	datatype,
		int	destination,
		int	tag,
		Request &	request
	)

pure virtual

Sends data to destination (non-blocking, asynchronous).

The FPMAS implementation always copy the input data to the input Request.

The method returns immediately, without waiting for the message to be buffered or received by the destination process.

The operation must be completed with wait() or waitAll() so that the request object is properly freed.

Parameters

data	input buffer
count	items count in the buffer
datatype	MPI type of the data to send
destination	rank of the destination process
tag	message tag
request	output Request

Implemented in fpmas::communication::MpiCommunicatorBase.

◆ Isend() [2/3]

virtual void fpmas::api::communication::MpiCommunicator::Isend	(	const DataPack &	data,
		MPI_Datatype	datatype,
		int	destination,
		int	tag,
		Request &	request
	)

pure virtual

Equivalent to send(data.buffer, data.count, datatype, destination, tag, request)

Parameters

data	input DataPack
datatype	MPI type of the data to send
destination	rank of the destination process
tag	message tag
request	output Request

Implemented in fpmas::communication::MpiCommunicatorBase.

◆ Isend() [3/3]

virtual void fpmas::api::communication::MpiCommunicator::Isend	(	int	destination,
		int	tag,
		Request &	request
	)

pure virtual

Sends a void message to destination (non-blocking, asynchronous).

This might be useful to send END message for example, when only a message tag without body might be enough.

Parameters

destination	rank of the destination process
tag	message tag
request	output Request

Implemented in fpmas::communication::MpiCommunicatorBase.

◆ Issend() [1/3]

virtual void fpmas::api::communication::MpiCommunicator::Issend	(	const void *	data,
		int	count,
		MPI_Datatype	datatype,
		int	destination,
		int	tag,
		Request &	request
	)

pure virtual

Sends data to destination (non-blocking, synchronous).

Contrary to the default MPI specification, the specified data buffer can be reused immediately when the method return. This is allowed because the specified data is copied to the input request.

In consequence, the Request must be completed using either test(Request&) or wait(Request&) to properly free the data buffer with the specified request.

The request completes when it is guaranteed that the message has been received by the destination process.

Parameters

data	input buffer
count	items count in the buffer
datatype	MPI type of the data to send
destination	rank of the destination process
tag	message tag
request	output Request

Implemented in fpmas::communication::MpiCommunicatorBase.

◆ Issend() [2/3]

virtual void fpmas::api::communication::MpiCommunicator::Issend	(	const DataPack &	data,
		MPI_Datatype	datatype,
		int	destination,
		int	tag,
		Request &	request
	)

pure virtual

Equivalent to Issend(data.buffer, data.count, datatype, destination, tag, request).

Parameters

data	input DataPack
datatype	MPI type of the data to send
destination	rank of the destination process
tag	message tag
request	output Request

Implemented in fpmas::communication::MpiCommunicatorBase.

◆ Issend() [3/3]

virtual void fpmas::api::communication::MpiCommunicator::Issend	(	int	destination,
		int	tag,
		Request &	request
	)

pure virtual

Sends a void message to destination (non-blocking, synchronous).

This might be useful to send notification messages when only a message tag without body might be enough.

The test(Request&) or wait(Request&) functions can be used to wait for completion.

The request completes when it is guaranteed that the message has been received by the destination process.

Parameters

destination	rank of the destination process
tag	message tag
request	output Request

Implemented in fpmas::communication::MpiCommunicatorBase.

◆ probe()

virtual void fpmas::api::communication::MpiCommunicator::probe	(	MPI_Datatype	type,
		int	source,
		int	tag,
		Status &	status
	)

pure virtual

Blocking probe.

Blocks until a message with the specified tag is received from source.

Upon return, the output status contains information about the message to receive.

Parameters

type	expected message type
source	source rank
tag	recv tag
status	MPI status

Implemented in fpmas::communication::MpiCommunicatorBase.

◆ Iprobe()

virtual bool fpmas::api::communication::MpiCommunicator::Iprobe	(	MPI_Datatype	type,
		int	source,
		int	tag,
		Status &	status
	)

pure virtual

Non-blocking probe.

Returns true if and only if a message with the specified tag can be received from source.

Upon return, the output status contains information about the message to receive.

Parameters

type	expected message type
source	source rank
tag	recv tag
status	MPI status

Returns: true iff a message is available

Implemented in fpmas::communication::MpiCommunicatorBase.

◆ recv() [1/3]

virtual void fpmas::api::communication::MpiCommunicator::recv	(	int	source,
		int	tag,
		Status &	status = `Status::IGNORE`
	)

pure virtual

Receives a message without data.

Completes an eventually corresponding synchronous send operation.

Parameters

source	rank of the process to receive from
tag	message tag
status	output MPI status

Implemented in fpmas::communication::MpiCommunicatorBase.

◆ recv() [2/3]

virtual void fpmas::api::communication::MpiCommunicator::recv	(	void *	buffer,
		int	count,
		MPI_Datatype	datatype,
		int	source,
		int	tag,
		Status &	status
	)

pure virtual

Receives data from source into buffer.

The length of the output buffer should be large enough to contain the message to receive. probe() and Iprobe() might be use to query the length of a message before receiving it.

Parameters

buffer	output buffer
count	items count to receive
datatype	MPI type of the data to receive
source	rank of the process to receive from
tag	message tag
status	output MPI status

Implemented in fpmas::communication::MpiCommunicatorBase.

◆ recv() [3/3]

virtual void fpmas::api::communication::MpiCommunicator::recv	(	DataPack &	data,
		MPI_Datatype	datatype,
		int	source,
		int	tag,
		Status &	status
	)

pure virtual

Equivalent to recv(data.buffer, data.count, datatype, source, tag, status)

Parameters

data	output DataPack
datatype	MPI type of the data to receive
source	rank of the process to receive from
tag	message tag
status	output MPI status

Implemented in fpmas::communication::MpiCommunicatorBase.

◆ test()

virtual bool fpmas::api::communication::MpiCommunicator::test ( Request & request )

pure virtual

Tests if the input request is complete.

Might be use to check the status of requests performed using non-blocking communication methods.

Moreover, the request internal data buffer is freed if completion is detected.

Parameters

request Request to test

Returns: true iff the request is complete

Implemented in fpmas::communication::MpiCommunicatorBase.

◆ wait()

virtual void fpmas::api::communication::MpiCommunicator::wait ( Request & request )

pure virtual

Waits for the input request to complete.

Can be used to complete non-blocking communications. Upon return, the request internal data buffer is freed.

Parameters

request Request to wait

Implemented in fpmas::communication::MpiCommunicatorBase.

◆ waitAll()

virtual void fpmas::api::communication::MpiCommunicator::waitAll ( std::vector< Request > & requests )

pure virtual

Waits for the completion of all requests.

Can be used to complete non-blocking communications. Upon return, all requests internal data buffers are freed.

Parameters

requests Requests to wait

Implemented in fpmas::communication::MpiCommunicatorBase.

◆ allToAll()

virtual std::unordered_map< int, DataPack > fpmas::api::communication::MpiCommunicator::allToAll	(	std::unordered_map< int, DataPack >	export_map,
		MPI_Datatype	datatype
	)

pure virtual

Performs a complete data exchange among processor.

The export_map is a [rank, data] map : each DataPack is sent to the corresponding rank. The map is not required to contain an entry (i.e. data to send) for all available ranks.

From each process, received data is gathered by origin rank in the returned [rank, data] map.

Parameters

export_map	data to export to each process
datatype	MPI type of the data to send / receive

Returns: data received from each process

Implemented in fpmas::communication::MpiCommunicatorBase.

◆ gather()

virtual std::vector< DataPack > fpmas::api::communication::MpiCommunicator::gather	(	DataPack	data,
		MPI_Datatype	datatype,
		int	root
	)

pure virtual

Gathers data at root.

All processes (including root), specify data to send to root. If the current process rank corresponds to root, sent data, ordered by rank, are returned in the output vector. Else, an empty vector is returned.

Notice that input DataPacks might have different length, and can be empty for some processes.

Parameters

data	data to send to root
datatype	MPI datatype
root	rank of the root process

Returns: if rank == root, a vector containing gathered data, else an empty vector.

Implemented in fpmas::communication::MpiCommunicatorBase.

◆ allGather()

virtual std::vector< DataPack > fpmas::api::communication::MpiCommunicator::allGather	(	DataPack	data,
		MPI_Datatype	datatype
	)

pure virtual

Gathers data on all processes.

Each process sends a data instance, and all sent data are received on all processes, ordered by rank. In consequence, vectors returned on all processes are the same.

Notice that input DataPacks might have different length, and can be empty for some processes.

Parameters

data	to send to all processes
datatype	MPI datatype

Returns: data sent by all processes

Implemented in fpmas::communication::MpiCommunicatorBase.

◆ bcast()

virtual DataPack fpmas::api::communication::MpiCommunicator::bcast	(	DataPack	data,
		MPI_Datatype	datatype,
		int	root
	)

pure virtual

Broadcasts data.

data is sent from root to all other processes, and received data is returned (including at root). On other processes than root, the data parameter is ignored.

Notice that the input DataPack might be empty.

Parameters

data	data to broadcast
datatype	MPI datatype
root	rank of the process from which data is sent

Returns: received data from root

Implemented in fpmas::communication::MpiCommunicatorBase.

◆ barrier()

virtual void fpmas::api::communication::MpiCommunicator::barrier ( )

pure virtual

Defines a synchronization barrier.

Blocks the caller until all processes have called it. The call returns at any process only after all processes have entered the call.

Implemented in fpmas::communication::MpiCommunicatorBase.

Member Data Documentation

◆ IGNORE_TYPE

MPI_Datatype fpmas::api::communication::MpiCommunicator::IGNORE_TYPE = MPI_INT

static

Datatype used for recv / send operation without data.

See also: send(int, int, int); recv(int, int, int)

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

src/fpmas/api/communication/communication.h
src/fpmas/api/communication/communication.cpp

Public Member Functions

Static Public Attributes

Detailed Description

Constructor & Destructor Documentation

◆ ~MpiCommunicator()

Member Function Documentation

◆ getRank()

◆ getSize()

◆ send() [1/3]

◆ send() [2/3]

◆ send() [3/3]

◆ Isend() [1/3]

◆ Isend() [2/3]

◆ Isend() [3/3]

◆ Issend() [1/3]

◆ Issend() [2/3]

◆ Issend() [3/3]

◆ probe()

◆ Iprobe()

◆ recv() [1/3]

◆ recv() [2/3]

◆ recv() [3/3]

◆ test()

◆ wait()

◆ waitAll()

◆ allToAll()

◆ gather()

◆ allGather()

◆ bcast()

◆ barrier()

Member Data Documentation

◆ IGNORE_TYPE