[MPICH] Behavour if MPI_File_Open fails on some nodes

[Robert Latham]

On Mon, Aug 20, 2007 at 02:57:55PM +0100, James S Perrin wrote:
> Case 2 would be fine, however MPI_File_Open (rank 0) is not
> returning at all in the situation I've described.

That's odd.  I ran your test program, creating a file on one processor
that did not exist on others, and got the expcected behavior
(MPI_File_open returns an error on all processes. no process hangs).
Wonder what's different about our environments?   
 
> BTW since I don't know if the file is shared or duplicated I'm only
> using MPI_File_Open, MPI_File_view, MPI_File_read and
> MPI_File_close. ie nothing that should depended on the shared file
> pointer.

In this context, "shared file pointer" refers to how the file pointer
offset is incremented when a file is accessed.  It doesn't speak to
the availabilty of the file on all processes.   

==rob

-- 
Rob Latham
Mathematics and Computer Science Division    A215 0178 EA2D B059 8CDF
Argonne National Lab, IL USA                 B29D F333 664A 4280 315B