Information exchange between processors. More...

#include <arcane/core/IParallelExchanger.h>

Public Types
enum	eExchangeMode { EM_Independant = ParallelExchangerOptions::EM_Independant , EM_Collective = ParallelExchangerOptions::EM_Collective , EM_Auto = ParallelExchangerOptions::EM_Auto }

Public Member Functions
virtual bool	initializeCommunicationsMessages ()=0
	Calculates communications.
virtual void	initializeCommunicationsMessages (Int32ConstArrayView recv_ranks)=0
	Calculates communications.
virtual void	processExchange ()=0
	Performs the exchange using the default options of ParallelExchangerOptions.
virtual void	processExchange (const ParallelExchangerOptions &options)=0
	Performs the exchange using the options options.
virtual IParallelMng *	parallelMng () const =0
virtual Integer	nbSender () const =0
	Number of processors to which we send.
virtual Int32ConstArrayView	senderRanks () const =0
	List of ranks of processors to which we send.
virtual void	addSender (Int32 rank)=0
	Adds a processor to send to.
virtual ISerializeMessage *	messageToSend (Integer i)=0
	Message intended for the i-th processor.
virtual Integer	nbReceiver () const =0
	Number of processors from which we will receive messages.
virtual Int32ConstArrayView	receiverRanks ()=0
	List of ranks of processors from which we will receive messages.
virtual ISerializeMessage *	messageToReceive (Integer i)=0
	Message received from the i-th processor.
virtual void	setExchangeMode (eExchangeMode mode)=0
	Sets the exchange mode.
virtual eExchangeMode	exchangeMode () const =0
	Specified exchange mode.
virtual void	setVerbosityLevel (Int32 v)=0
	Sets the verbosity level.
virtual Int32	verbosityLevel () const =0
	Verbosity level.
virtual void	setName (const String &name)=0
	Sets the instance name. This name is used during prints.
virtual String	name () const =0
	Instance name.

Detailed Description

Information exchange between processors.

This class allows sending and receiving arbitrary messages from any number of other processors.

The operation is as follows.

indicate the other PEs you wish to communicate with by calling addSender(), possibly multiple times.
call initializeCommunicationsMessages() to determine the list of PEs from which we must receive information. There are two overloads for this method depending on whether we know the number of ranks for which we must receive information.
for each outgoing message, serialize the information you wish to send.
perform the sends and receives by calling processExchange()
retrieve the received messages (via messageToReceive()) and deserialize their information.

It is possible to specify, before calling processExchange(), how the messages will be sent via setExchangeMode(). By default, the mechanism used is that of point-to-point communications (EM_Independant) but it is possible to use a collective mode (EM_Collective) which uses 'all to all' type messages.

Definition at line 56 of file IParallelExchanger.h.

Member Enumeration Documentation

◆ eExchangeMode

enum Arcane::IParallelExchanger::eExchangeMode

Enumerator
EM_Independant	Uses point-to-point exchanges (send/recv).
EM_Collective	Uses collective operations (allToAll).
EM_Auto	Automatically chooses between point-to-point or collective.

Definition at line 60 of file IParallelExchanger.h.

Member Function Documentation

◆ initializeCommunicationsMessages() [1/2]

virtual bool Arcane::IParallelExchanger::initializeCommunicationsMessages ( )

pure virtual

Calculates communications.

Based on m_send_ranks provided by each processor, determines the list of processors to which a message must be sent.

To know the processors from which information is expected, it is necessary to perform a communication (allGatherVariable()). If we know these processors beforehand, we must use one of the overloaded versions of this method.

Return values

true	if there is nothing to exchange
false	otherwise.

◆ initializeCommunicationsMessages() [2/2]

virtual void Arcane::IParallelExchanger::initializeCommunicationsMessages ( Int32ConstArrayView recv_ranks )

pure virtual

Calculates communications.

Assumes that the list of processors from which information is desired is in recv_ranks.

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

IParallelExchanger.h