openmpi/ompi/mpi/man/man3/MPI_Recv_init.3in

.\" -*- nroff -*-
.\" Copyright 2010 Cisco Systems, Inc.  All rights reserved.
.\" Copyright 2006-2008 Sun Microsystems, Inc.
.\" Copyright (c) 1996 Thinking Machines Corporation
.\" Copyright (c) 2020      Google, LLC. All rights reserved.
.\" $COPYRIGHT$
.TH MPI_Recv_init 3 "#OMPI_DATE#" "#PACKAGE_VERSION#" "#PACKAGE_NAME#"
.SH NAME
\fBMPI_Recv_init\fP \- Builds a handle for a receive.

.SH SYNTAX
.ft R
.SH C Syntax
.nf
#include <mpi.h>
int MPI_Recv_init(void *\fIbuf\fP, int\fI count\fP, MPI_Datatype\fI datatype\fP,
	int\fI source\fP, int\fI tag\fP, MPI_Comm\fI comm\fP, MPI_Request\fI *request\fP)

.fi
.SH Fortran Syntax
.nf
USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_RECV_INIT(\fIBUF, COUNT, DATATYPE, SOURCE, TAG, COMM, REQUEST,
		IERROR\fP)
	<type>	\fIBUF\fP(*)
	INTEGER	\fICOUNT, DATATYPE, SOURCE, TAG, COMM, REQUEST, IERROR\fP

.fi
.SH Fortran 2008 Syntax
.nf
USE mpi_f08
MPI_Recv_init(\fIbuf\fP, \fIcount\fP, \fIdatatype\fP, \fIsource\fP, \fItag\fP, \fIcomm\fP, \fIrequest\fP, \fIierror\fP)
	TYPE(*), DIMENSION(..), ASYNCHRONOUS :: \fIbuf\fP
	INTEGER, INTENT(IN) :: \fIcount\fP, \fIsource\fP, \fItag\fP
	TYPE(MPI_Datatype), INTENT(IN) :: \fIdatatype\fP
	TYPE(MPI_Comm), INTENT(IN) :: \fIcomm\fP
	TYPE(MPI_Request), INTENT(OUT) :: \fIrequest\fP
	INTEGER, OPTIONAL, INTENT(OUT) :: \fIierror\fP

.fi
.SH INPUT PARAMETERS
.ft R
.TP 1i
count
Maximum number of elements to receive (integer).
.TP 1i
datatype
Type of each entry (handle).
.TP 1i
source
Rank of source (integer).
.TP 1i
tag
Message tag (integer).
.TP 1i
comm
Communicator (handle).

.SH INPUT/OUTPUT PARAMETER
.TP 1i
buf
Initial address of receive buffer (choice).

.SH OUTPUT PARAMETERS
.ft R
.TP 1i
request
Communication request (handle).
.ft R
.TP 1i
IERROR
Fortran only: Error status (integer).

.SH DESCRIPTION
.ft R
Creates a persistent communication request for a receive operation. The argument \fIbuf\fP is marked as OUT because the user gives permission to write on the receive buffer by passing the argument to MPI_Recv_init.
.sp
A persistent communication request is inactive after it is created -- no active communication is attached to the request.
.sp
A communication (send or receive) that uses a persistent request is initiated by the function MPI_Start or MPI_Startall.

.SH ERRORS
Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument.
.sp
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.

.SH SEE ALSO
.ft R
.sp
MPI_Bsend_init
.br
MPI_Rsend_init
.br
MPI_Send_init
.br
MPI_Sssend_init
.br
MPI_Start
.br
MPI_Startall
.br
MPI_Request_free