.\" -*- nroff -*-
.\" Copyright (c) 2010-2014 Cisco Systems, Inc.  All rights reserved.
.\" Copyright 2006-2008 Sun Microsystems, Inc.
.\" Copyright (c) 1996 Thinking Machines Corporation
.\" $COPYRIGHT$
.TH MPI_Attr_delete 3 "Sep 30, 2023" "4.1.6" "Open MPI"
.SH NAME
\fBMPI_Attr_delete\fP \- Deletes attribute value associated with a key -- use of this routine is deprecated.

.SH SYNTAX
.ft R
.SH C Syntax
.nf
#include <mpi.h>
int MPI_Attr_delete(MPI_Comm\fI comm\fP, int\fI keyval\fP)

.fi
.SH Fortran Syntax
.nf
INCLUDE 'mpif.h'
MPI_ATTR_DELETE(\fICOMM\fP,\fI KEYVAL\fP, \fIIERROR\fP)
	INTEGER	\fICOMM\fP,\fI KEYVAL\fP,\fI IERROR\fP


.fi
.SH INPUT PARAMETERS
.ft R
.TP 1i
comm
Communicator to which attribute is attached (handle).
.TP 1i
keyval
The key value of the deleted attribute (integer).

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

.SH DESCRIPTION
Note that use of this routine is \fIdeprecated\fP as of MPI-2, and
was \fIdeleted\fP in MPI-3. Please use MPI_Comm_delete_attr.  This
function does not have a C++ or mpi_f08 binding.
.sp
Delete attribute from cache by key. This function invokes the attribute delete function delete_fn specified when the keyval was created. The call will fail if the delete_fn function returns an error code other than MPI_SUCCESS.

Whenever a communicator is replicated using the function MPI_Comm_dup, all callback copy functions for attributes that are currently set are invoked (in arbitrary order). Whenever a communicator is deleted using the function MPI_Comm_free, all callback delete functions for attributes that are currently set are invoked.


.SH NOTES
Note that it is not defined by the MPI standard what happens if the
delete_fn callback invokes other MPI functions.  In Open MPI, it is
not valid for delete_fn callbacks (or any of their children) to add or
delete attributes on the same object on which the delete_fn callback
is being invoked.


.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_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
MPI_Comm_delete_attr
.br