(j3.2006) MPI usage problems in Fortran

[Aleksandar Donev]

On Tuesday 18 March 2008 11:50, Bill Long wrote:

> Why not the ASYNCHRONOUS attribute instead? ?If you think of the MPI
> data transfers as "I/O", then this is quite close to what asynchronous
> was designed for.
Sounds wonderful in theory, however, if you actually read the words you 
realize asynchronous was not "designed" (at least not intelligently :-). In 
fact, I have asked the committee what asynchronous really means especially 
with respect to dummy arguments with no satisfactory response.

The VOLATILE attribute was designed for this, I believe, but it will kill all 
optimizations, even after the call to the Wait routine completes. And 
VOLATILE has similar issues as ASYNCHRONOUS with respect to dummy/actual 
association and what it means for one/both to be VOLATILE.

Neither solves any kind of copy in/out problem. Only TARGET+assumed-shape does 
that. The assumed-shape being critical.

Best,
Aleks