(j3.2006) MPI usage problems in Fortran

[Aleksandar Donev]

On Wednesday 19 March 2008 11:20, Bill Long wrote:

> That's because an
> async I/O operation initiated in the subprogram might not finish before
> control is transferred back to the caller
What if the programmer knows it does. Why should async taint leak out of the 
routine back to the actual???

> , and the I/O libraries need a 
> stable target in memory for the data transfers throughout the I/O
> operation.
But, I repeat my issue: What about the actual? Should it have the asynchronous 
attribute? Surely it must since it's values are changing behind the 
compiler's back. If the actual is not async, and the dummy is, what does it 
mean? I would say it means the async I/O is localized inside the routine and 
*completes* before the routine returns.

> Since the user can control the code range where the
> variable is tainted,
I question this statement above. First you tell me putting async on the dummy 
taints actuals, even if they don't have async. Or maybe they don't.

I am still 100% convinced this was badly designed, OR, there are missing words 
in the standard expressing what someone thought but never wrote down for 
others (especially implementors) to understand.

Best,
Aleks