From: Jeff Squyres <jsquyres@XXXXXXXXX>
Date: January 21, 2008 8:42:02 AM CST
To: mpi-21@XXXXXXXXXXXXX,mpi-21@XXXXXXXXXXX
Subject: [mpi-21] Ballot 4 proposal: INOUT arguments
Reply-To: mpi-21@XXXXXXXXXXXXX

This is not already on Bill's errata page.

Proposal: change the INOUT designation of the MPI handle parameters in several MPI-2 functions to be IN, because the values of the handles are not changing.  Only the underlying MPI objects are changing.  The C bindings for each of these functions do *not* pass the MPI handle by reference, therefore disallowing the possibility of these parameters actually being INOUT.  By the same argument, the C++ methods for these functions should be const since the C++ object invoking the method will not be changed.

The functions in question are:

MPI_*_SET_NAME for communicators, datatypes, windows
MPI_*_SET_ATTR for communicators, datatypes, windows
MPI_*_SET_ERRHANDLER for communicators, files, windows

Locations of specific text to be changed (INOUT -> IN, add "const" to C++ methods):

MPI_COMM_SET_NAME: MPI-2:8.4, p177:35,44
                   MPI-2:A.8.5, p336:28
MPI_TYPE_SET_NAME: MPI-2:8.4, p179:41, p180:2
                   MPI-2:A.8.5, p337:2
MPI_WIN_SET_NAME: MPI-2:8.4, p181:25,35
                   MPI-2:A.8.5, p337:36

MPI_COMM_SET_ATTR: MPI-2:8.8.1, p201:6,17
                   MPI-2:A.8.5, p336:27
MPI_WIN_SET_ATTR: MPI-2:8.8.2, p204:2,12
                   MPI-2:A.8.5, p337:35
MPI_TYPE_SET_ATTR: MPI-2:8.8.3, p206:26,37
                   MPI-2:A.8.5, p337:1

MPI_COMM_SET_ERRHANDLER: MPI-2:4.13.1, p62:35,43
                         MPI-2:A.8.1, p331:38
MPI_WIN_SET_ERRHANDLER: MPI-2:4.13.2, p64:2,10
                        MPI-2:A.8.1, p333:13
MPI_FILE_SET_ERRHANDLER: MPI-2:4.13.3, p65:14,22
                         MPI-2:A.8.1, p332:34

NOTE: The "const" issues of this proposal will be dependent upon a 2nd proposal about re-instituting the "const" on MPI predefined handles that was removed in ballot 2.

-- 
Jeff Squyres
Cisco Systems