.\" -*- nroff -*-
.\" Copyright 2013 Los Alamos National Security, LLC. All rights reserved.
.\" Copyright 2006-2008 Sun Microsystems, Inc.
.\" Copyright (c) 1996 Thinking Machines Corporation
.\" Copyright (c) 2010 Cisco Systems, Inc.  All rights reserved.
.\" $COPYRIGHT$
.TH MPI_T_pvar_read 3 "Sep 30, 2023" "4.1.6" "Open MPI"
.
.SH NAME
\fBMPI_T_pvar_read\fP \- Read the value of a performance variable
.
.SH SYNTAX
.ft R
.
.SH C Syntax
.nf
#include <mpi.h>
int MPI_T_pvar_read(MPI_T_pvar_session \fIsession\fP, MPI_T_pvar_handle \fIhandle\fP, const void *\fIbuf\fP)

.fi
.SH INPUT PARAMETERS
.ft R
.TP 1i
session
Performance experiment session.
.TP 1i
handle
Performance variable handle.
.TP 1i
buf
Initial address of storage location for variable value.

.SH DESCRIPTION
.ft R
MPI_T_pvar_read queries the value of a performance variable identified by the handle
specified in \fIhandle\fP in the session specified in \fIsession\fP. The result is
stored in the buffer pointed to by \fIbuf\fP. The caller must ensure that the
buffer pointed to by \fIbuf\fP is large enough to hold the entire value of the
performance variable.

.SH ERRORS
.ft R
MPI_T_pvar_read() will fail if:
.TP 1i
[MPI_T_ERR_NOT_INITIALIZED]
The MPI Tools interface not initialized
.TP 1i
[MPI_T_ERR_INVALID_HANDLE]
The handle is invalid or not associated with the session
.TP 1i
[MPI_T_ERR_INVALID_SESSION]
Session argument is not a valid session

.SH SEE ALSO
.ft R
.nf
MPI_T_pvar_handle_alloc
MPI_T_pvar_get_info
MPI_T_pvar_session_create