Subject: Re: Error handling (really Environmental ?)

From: [email-masked] (Leslie Hart)
Date: Thu, 19 Aug 93 17:47:31 MDT

Jim,

I like your comments regarding error handlers (I voted in favor of
retaining communicators because of the reasons you gave).  I would
like to see that error statuses are returned if MPI_NULL_HANDLER
(or some such name) is given as the handler.  With the inheritance
you suggest, this would allow an easy way for the user to always
get statuses by assigning the null handler to MPI_COMM_ALL.  

I realize that there are some errors that cannot be associated with
a particular call or are so severe that the only thing to do is abort.
This is a fine behaviour for those (implemnentation dependent) cases.

Regards,
Leslie

P.S. I forgot how the vote went on always having a status returned.

P.P.S.  I would like to see indicating the null handler actually turn
        off signalling for that communicator rather than going through
        a benign handler.  IEEE floating point underflows kill us in some
        configurations of our application (so, we turn it off).

---

From: James Cownie <[email-masked]>
Date: Mon, 23 Aug 1993 10:19:24 +0100

Leslie,

> retaining communicators because of the reasons you gave).
Thanks.

> I would
I would perhaps expect this to be the default anyway...

It's somewhat unclear to me whether there are actually any useful
levels of erros in MPI, or does anything unsuccessful cause total
failure ?

I think the way it is at the moment any erroneous condition is fatal.
This is probably reasonable ...

Anyone any other ideas ? We MUST get this done next time !

-- Jim
James Cownie 
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