Re: 2nd proposal for "perm" in MPI_Open
Terry R. Jones (trj@nimble.llnl.gov)
Fri, 27 Sep 96 13:35:36 PDT
Bill Saphir writes:
>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.
I would argue that adding a perm parameter for permissions
provides functionality in two important ways:
1) Since the perm parameter is not a hint, the semantics are
that implementations are guaranteed to honor it.
In some environments, this matters.
2) Since the vast majority of implementations will likely be
in environments with a POSIX-like interface (at least in the
near term), it provides a familiar and easy to use interface
for the common case.
Ease of use is also important.
-terry