Re: 2nd proposal for "perm" in MPI_Open

William C. Saphir (wcs@nas.nasa.gov)
Fri, 27 Sep 1996 11:16:35 -0700

Seems to me that the right model for MPI_Open is not
POSIX open() but ANSI C fopen(). fopen() does not have
a permissions argument, for good reason: C is not designed
only for a POSIX environment. MPI should also not be
tailored for a POSIX environment if at all possible.

Someone mentioned security concerns as a motivation for
the permissions argument. If this is a real issue, the model
should probably be something like DFS, where POSIX permissions
are incomplete and can even be misleading.

I don't understand the suggestion that there be
a POSIX-like permission as an argument to MPI_Open,
with the possibility of putting fancier things in
the info argument. What advantage does this have
over putting permissions in the info argument?
I assert there is none. There is no portability
advantage; There is no functional advantage;
there is no semantic advantage. Having an argument other
than info which is implementation-dependent and is
routinely ignored or overriden seems like a bad idea.

Bill