(j3.2006) synchronizing I/O

Aleksandar Donev donev1
Tue Feb 10 14:54:13 EST 2009

On Tuesday 10 February 2009 04:01, John Reid wrote:
> You begin to convince me that we should require the user to ensure
> that there is an ordering of the i/o statements to one of these
> files.
What would the requirement mean:
1) The user can write to stdout from unordered segments, but there is no 
guarantees that what comes out is not garbled (this is pretty much MPIs 
no-guarantee approach).
2) Two WRITEs to stdout by two different images must be in ordered 
I can go along with the first. If you put in the second, then it makes 
it harder for vendors to do extensions and allow nice and quick sorted 
I/O. After all, it isn't that hard to implement---just buffer until the 
record is complete, no?

Aleksandar Donev, Ph.D.
Lawrence Postdoctoral Fellow @ Lawrence Livermore National Laboratory
High Performance Computational Materials Science and Chemistry
E-mail: donev1 at llnl.gov
Phone: (925) 424-6816  Fax: (925) 423-0785
Address: P.O.Box 808, L-367, Livermore, CA 94551-9900
Web: http://cherrypit.princeton.edu/donev

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