Importance: Normal
Subject: Re: Handling errors in handle transfer functions
To: mpi-core@XXXXXXXXXXX,owner-mpi-core@XXXXXXXXXXXXX
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From: "Marc Snir" <snir@XXXXXXXXXX>
Date: Wed, 6 Jun 2001 18:17:54 -0400
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The behavior that the standard specifies for handle conversion, as was
explained by Dick Treumann, is garbage in, same garbage out. A
justification for this specification was that, in the case where handles
are really one and the same in both languages, then there would be no code
in the conversion process. I also think this is the "semantically correct"
behavior: the move from one language to another is transparent. Consider,
for example, a library written in C, that checks carefully its inputs and
generates elaborate error codes and reports. With the current
specification, a Fortran interface to the same library does not need to
have additional exception handling capabilities: no matter what garbage is
passed in, the input will be received and handled correctly inside the C
library.

Marc Snir
IBM T.J. Watson Research Center
P.O. Box 218, Yorktown Heights, NY 10598
Tel: 914-945-3204 (8-862-3204)
Fax: 914-945-4425 (8-862-4425)
URL: http://www.research.ibm.com/people/s/snir