Re: returning errors

[Neal H. Walfield]

At Mon, 09 Jul 2007 15:49:14 -0400,
Jonathan S. Shapiro wrote:
> 
> On Mon, 2007-07-09 at 14:28 +0200, Espen Skoglund wrote:
> > I agree with you.  Returning the error code is more consistent...
> 
> I think that this outcome is interesting. So far, we have Shapiro
> (Coyotos), Skoglund (L4), Landau (CapROS), Adams (Coyotos), Walfield
> (Hurd, L4), and everybody else I have talked to about this agreeing that
> returning the error code is the preferred outcome.
> 
> Given this, it is interesting (and perhaps unfortunate) that the various
> L4 IDL compilers do not agree with us. :-)

Right, with idl4 and dice (I don't know about magpie), if you want to
know if transmission was successful, you need to check the
environment.  mig always returns an error code.  This variable can be
reused by the object methods to return their own errors--they just
have to be careful to not use the values that the IPC subsystem uses.

At least on the systems that I have worked with, it is rare to call an
IPC stub directly; it is almost always wrapped by a library stub that
at least massages the interface a bit and protects the caller from
having to set up the environment.  This code is usally written by
people in the know.  So, my question is: is this really an issue?

Neal