Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!usc!samsung!think!mintaka!mit-eddie!apollo!apollo.hp.com!mishkin
From: mishkin@apollo.HP.COM (Nathaniel Mishkin)
Newsgroups: comp.sys.apollo
Subject: Re: The White Paper
Keywords: RPC, networking
Message-ID: <47492647.20b6d@apollo.HP.COM>
Date: 7 Dec 89 16:21:00 GMT
References: <15101@joshua.athertn.Atherton.COM> <14983@joshua.athertn.Atherton.COM> <31904@cci632.UUCP> <46f42a6a.20b6d@apollo.HP.COM> <471b93ba.20b6d@apollo.HP.COM>
Sender: root@apollo.HP.COM
Reply-To: mishkin@apollo.HP.COM (Nathaniel Mishkin)
Organization: Hewlett-Packard Apollo Division - Chelmsford, MA
Lines: 91

In article <15101@joshua.athertn.Atherton.COM>,
joshua@athertn.Atherton.COM (Flame Bait) writes:
> % = Achille Petrilli
> # = Nat Mishkin
> > = Joshua Levy (me)
> 
> # I don't think
> # it's easier to use when I can only pass one parameter as input thereby
> # requiring me to manually write code to assign my "logical" input parameters
> # into fields of a struct before making a remote call.  
> 
> This is a non-issue, at least in my mind.  Both Sun and Apollo allow you to 
> pass as many arguments as you want, they use slightly different syntax, but 
> it is no big deal.  We can argue about syntax forever, but why bother.

OK, I'll grant you the right to like what you like, but I just want to
make it clear to all our readers what we're talking about.  Suppose I
want to define and call some procedure (say "proc1") that takes 3 input
params and returns 2 output params.  With Sun RPC you have to do (something
like):

    struct proc1s_ins {
        int in1;
        char in2;
        float in3;
    };         

    struct proc1s_outs {
        short out1;
        double out2;
    }

    proc1s_outs proc1(proc1s_ins);

You have to make up a struct for each unique combination of input and output
parameters used in your interface.

In NCS you just do:

    void proc1(
        int [in] in1,
        char [in] in2,
        float [in] in3,
        short [out] *out1,
        double [out] *out2
    );

Sure it's "just syntax", but I think it matters.

> Using your compiler analogy: C is simple.  I understand how to write
> a compiler for it.  Even though I never will, the fact that I could is 
> very important.  It shows that the language is understandable.  The fact
> that I could write an XDR compiler shows how easy and straight forward
> the language is.  The fact that I can not for NDR shows the problem; that
> NDR is compilcated.

First, you write a compiler for NIDL, not NDR.  Second, I guess I don't
understand what you're trying to say.  Simplicity is not the only metric
of the utility of a language.  The "language" (instruction set) of most
RISC systems is simple, that doesn't mean I want to program in it.

> Besides source code availability, there is also "plain old" availablity.
> Take a company which makes a product for IBM RT, DEC ULTIRX, Suns, Apollos,
> and HPs, and wants to expand to VMS and IBM PCs.  Sun RPC is available on
> all these platforms; Apollo's RPC is not.  (The ringer is the IBM RT, which
> does not yet have Apollo RPC, as far as I can tell.)  The bottom line is
> that every new UNIX machine coming out now has Sun RPC as part of its 
> standard software bundle.  Most of them have Apollo RPC also, but the 
> difference between all and most is important.  

You can get NCS in binary form from Apollo for Ultrix, Sun, Apollos,
VMS, and MS/DOS.  IBM has licensed NCS from Apollo.  We'll have to see
what they ship.  DEC and Apollo (HP) have announced that the two companies
are doing joint work on NCS.  I won't argue that Sun RPC is probably
being shipped in binary form by more vendors today than NCS.  But let's
recall that this discussion started as one of technical merits.  I can
only hope that the technical merits will eventually change the availability
situation.

> Since everyone must use NFS (like it or not) everyone has Sun's RPC.
> If you want to pay $25,000 you can get Apollo's RPC also.

The $25K number is completely out of context.  That's the price of the
NIDL compiler source.  The NCS runtime library source sells for something
like $1000.  (The source to both is available for essentially nothing
to universities.) I think the binary forms of both the compiler and the
runtime are around $500-1000 each.

                    -- Nat Mishkin
                       Hewlett Packard Company / Apollo Systems Division
                       mishkin@apollo.com