.\" -*- nroff -*-
.\" Copyright 2010 Cisco Systems, Inc.  All rights reserved.
.\" Copyright 2007-2008 Sun Microsystems, Inc.
.\" Copyright (c) 1996 Thinking Machines Corporation
.\" $COPYRIGHT$
.TH MPI_Win_post 3 "May 26, 2022" "4.1.4" "Open MPI"
.SH NAME
\fBMPI_Win_post\fP \- Starts an RMA exposure epoch for the local window associated with \fIwin\fP

.SH SYNTAX
.ft R
.SH C Syntax
.nf
#include <mpi.h>
int MPI_Win_post(MPI_Group \fIgroup\fP, int assert, MPI_Win \fIwin\fP)

.fi
.SH Fortran Syntax
.nf
USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_WIN_POST(\fIGROUP, ASSERT, WIN, IERROR\fP)
	INTEGER GROUP, ASSERT, WIN, IERROR

.fi
.SH Fortran 2008 Syntax
.nf
USE mpi_f08
MPI_Win_post(\fIgroup\fP, \fIassert\fP, \fIwin\fP, \fIierror\fP)
	TYPE(MPI_Group), INTENT(IN) :: \fIgroup\fP
	INTEGER, INTENT(IN) :: \fIassert\fP
	TYPE(MPI_Win), INTENT(IN) :: \fIwin\fP
	INTEGER, OPTIONAL, INTENT(OUT) :: \fIierror\fP

.fi
.SH C++ Syntax
.nf
#include <mpi.h>
void MPI::Win::Post(const MPI::Group& group, int assert) const


.fi
.SH INPUT PARAMETERS
.ft R
.TP 1i
group
The group of origin processes (handle)
.TP 1i
assert
Program assertion (integer)
.TP 1i
win
Window object (handle)

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

.SH DESCRIPTION

Starts an RMA exposure epoch for the local window associated with \fIwin\fP. Only the processes belonging to \fIgroup\fP should access the window with RMA calls on \fIwin\fP during this epoch. Each process in \fIgroup\fP must issue a matching call to MPI_Win_start. MPI_Win_post does not block.

.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. 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.
.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_Win_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
MPI_Win_start
MPI_Win_wait
.br