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Re: Mixing reproducible and non-reproducible code



> Date: Sat, 01 Dec 2012 19:25:19 -0500
> To: stds-1788                    <stds-1788@xxxxxxxxxxxxxxxxx>
> From: Michel Hack                                <mhack@xxxxxxx>
> Subject: Mixing reproducible and non-reproducible code

	Perhaps I'm missing something here.

	Just what IS "non-reproducible code"?
	And why are we considering it?
	Much less defining it?
	And, CAN one define it?

	Just curious... :-)


			Dan

> 
> As usual, trying to be specific about reproducibility raises various
> tricky issues.  I'm referring now to clause 1.8 item (8) in John's
> 20121130Clauses1-2forVote.pdf, currently under discussion.
> 
> In my earlier comments I wrote:
> > 1.8 item (8):  This needs to be qualified.  It might be necessary to
> >       invoke a "reproducible transformation unit" though a wrapping
> >       interface ("glue module") to incorporate it in a non-reproducible
> >       environment, as the level 3 representations might differ.
> 
> There may be more at stake than representation issues.  Reproducible mode
> may affect global properties, such as forcing single-threaded execution.
> So what do we expect to happen when modes are mixed?
> 
> (1)  The interface module could force single-threaded execution while the
>      reproducible-mode component is running.  Is that generally feasible?
> 
> (2)  The reproducibility properties of the reproducible-mode component
>      could be voided, as basic assumptions of that mode don't pertain.
> 
> I understand the motivations behind requirement (8):  one would like to
> be able to debug components in reproducible mode, and then incorporate
> the debugged code in a larger program.  But given that reproducible mode
> typically requires a number of programming rules to be obeyed, validation
> in reproducible mode becomes meaningless unless those restrictions are
> maintained.  That may be ok if the effect is relatively small when not
> actually running in reproducible mode, but if it involves re-partitioning
> for single-threaded execution this may not be so.
> 
> Michel.
> ---Sent: 2012-12-02 00:46:30 UTC