MPI_Recv_init.openmpi(3)

Builds a handle for a receive.

Section 3 openmpi-doc bookworm source

Description

MPI_Recv_init

NAME

MPI_Recv_init - Builds a handle for a receive.

SYNTAX

C Syntax

#include <mpi.h>
int MPI_Recv_init(void *buf, int count, MPI_Datatype datatype,

int source, int tag, MPI_Comm comm, MPI_Request *request)

Fortran Syntax

USE MPI
! or the older form: INCLUDE ’mpif.h’
MPI_RECV_INIT(BUF, COUNT, DATATYPE, SOURCE, TAG, COMM, REQUEST,

	IERROR)
<type>		BUF(*)
INTEGER		COUNT, DATATYPE, SOURCE, TAG, COMM, REQUEST, IERROR

Fortran 2008 Syntax

USE mpi_f08
MPI_Recv_init(buf, count, datatype, source, tag, comm, request, ierror)

	TYPE(), DIMENSION(..), ASYNCHRONOUS :: buf*
	INTEGER, INTENT(IN) :: count, source, tag
	TYPE(MPI_Datatype), INTENT(IN) :: datatype
	TYPE(MPI_Comm), INTENT(IN) :: comm
	TYPE(MPI_Request), INTENT(OUT) :: request
	INTEGER, OPTIONAL, INTENT(OUT) :: ierror

C++ Syntax

#include <mpi.h>
Prequest Comm::Recv_init(void* buf, int count, const

Datatype& datatype, int source, int tag) const

INPUT PARAMETERS

	count		Maximum number of elements to receive (integer).
	datatype		Type of each entry (handle).
	source		Rank of source (integer).
	tag		Message tag (integer).
	comm		Communicator (handle).

INPUT/OUTPUT PARAMETER

buf

Initial address of receive buffer (choice).

OUTPUT PARAMETERS

	request		Communication request (handle).
	IERROR		Fortran only: Error status (integer).

DESCRIPTION

Creates a persistent communication request for a receive operation. The argument buf is marked as OUT because the user gives permission to write on the receive buffer by passing the argument to MPI_Recv_init.

A persistent communication request is inactive after it is created -- no active communication is attached to the request.

A communication (send or receive) that uses a persistent request is initiated by the function MPI_Start or MPI_Startall.

ERRORS

Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument. C++ functions do not return errors. If the default error handler is set to MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception mechanism will be used to throw an MPI::Exception object.

Before the error value is returned, the current MPI error handler is called. By default, this error handler aborts the MPI job, except for I/O function errors. The error handler may be changed with MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned. Note that MPI does not guarantee that an MPI program can continue past an error.