[Mpi-22] [MPI Forum] #55: MPI-2.1 Cross-language attribute example is wrong

[William Gropp]

Eek!  Not for 2.2 !  Maybe a historical advice to users ....

Bill

On Jan 27, 2009, at 4:49 PM, Jeff Squyres wrote:

> On Jan 27, 2009, at 5:35 PM, William Gropp wrote:
>
>> On the last point, the real answer is that since the attributes
>> behave as if they were set by the now deprecated functions, they
>> should themselves be deprecated, since we must not change their
>> behavior.  This is also the source of the int/MPI_Fint issue - there
>> was no MPI_Fint in MPI-1.
>
> Wow, the scope of this ticket keeps expanding.  :-)
>
> I see the following attributes in OMPI's mpi.h:
>
>     /* MPI-1 */
>     MPI_TAG_UB,
>     MPI_HOST,
>     MPI_IO,
>     MPI_WTIME_IS_GLOBAL,
>
>     /* MPI-2 */
>     MPI_APPNUM,
>     MPI_LASTUSEDCODE,
>     MPI_UNIVERSE_SIZE,
>     MPI_WIN_BASE,
>     MPI_WIN_SIZE,
>     MPI_WIN_DISP_UNIT,
>
> Excluding MPI_WIN_BASE (which, IIRC, is the only address-sized
> attribute in this list), if we deprecate these names, I assume we'll
> simply replace them with new names that behave as if they were set
> from Fortran MPI_COMM_SET_ATTR.  Specifically, the sizes of the values
> will be such that you have to access them with
> INTEGER(KIND=MPI_ADDRESS_KIND) and (MPI_Aint*).
>
> Is that what you're thinking?  If so, how about s/MPI_/MPI_ATTR_/ in
> all the names (perhaps also creating an alias for MPI_WIN_BASE ->
> MPI_ATTR_WIN_BASE just for symmetry)?  I'm open to suggestions for new
> names.
>
> I'd almost prefer to make that a separate (but related) ticket -- the
> issues in #55 are already quite tangled... (i.e., leave out any
> mention of the predefined attributes from #55 and have a new ticket
> for those issues)  Sound reasonable?
>
> -- 
> Jeff Squyres
> Cisco Systems
>
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William Gropp
Deputy Director for Research
Institute for Advanced Computing Applications and Technologies
Paul and Cynthia Saylor Professor of Computer Science
University of Illinois Urbana-Champaign