This would be in accordance with the existing MPI-1:2.2 language, and therefore (I think) redundant. However, see my summary e-mail from last night about the C++ bindings -- I am wondering why the special case for [IN]OUT handle arguments exists to begin with (that a parameter is OUT if the underlying MPI object is changed when the handle is not). On Jan 22, 2008, at 11:29 AM, Rolf Rabenseifner wrote:
An alternative-proposal would be to add a clarifying sentence in Terms and Conventions, MPI-2.0 Sect. 2.5.1, page 9, line 7: Handle arguments can be marked at INOUT to indicate that the handle itself may be changed by the routine (e.g., in MPI_TYPE_COMMIT), or to indicate that the object referenced by the handle may be changed but the handle itself is kept unchanged (e.g., MPI_TYPE_SET_NAME).
Rolf Rabenseifner
On Mon, 21 Jan 2008 09:42:02 -0500 Jeff Squyres <jsquyres_at_[hidden]> wrote:
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
Dr. Rolf Rabenseifner . . . . . . . . . .. email rabenseifner_at_[hidden] High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530 University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832 Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner Nobelstr. 19, D-70550 Stuttgart, Germany . (Office: Allmandring 30)
-- Jeff Squyres Cisco Systems