[mpi-21] Ballot 4 - MPI_File_set_info update or replacement

[Rolf Rabenseifner]

This is a proposal for MPI 2.1, Ballot 4.

I'm asking especially the implementors to check, whether
this interpretation is implemented in their MPI implementations,
or does not contradict to the existing implementation.

This is a follow up to:
  MPI_File_set_info
  in http://www.cs.uiuc.edu/homes/wgropp/projects/parallel/MPI/mpi-errata/index.html
with mail discussion not yet existing
___________________________________

Proposal:
Add in MPI-2.0 Sect. 9.2.8, File Info, page 218, after line 18 the 
following sentences:

  With MPI_FILE_SET_VIEW and MPI_FILE_SET_INFO the current setting
  of all hints used by the system to this open file is updated by 
  the (key,value) pairs in the info argument.
___________________________________
Rationale for this clarification:
  This text was missing. It was not clear, whether a info handles
  in MPI_FILE_SET_VIEW and MPI_FILE_SET_INFO are updating or replacing
  the current set of used hints. 
  The developers from ROMIO decided to update the current set of used hints.
  Therefore, this behavior should be the expected behavior of a majority
  of users.
___________________________________

Best regards
Rolf

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)