Re: thunking, the next step

[Robert Collins <rbcollins at cygwin dot com>]

On Fri, 2003-11-21 at 22:02, Corinna Vinschen wrote:
> > 
> > Ok. Well for now, I'm going to leave the thunks in place, until / if
> > they become nothing more than if (unicode) ...W() else A(). That said,
> > all the calls we are thunking require kernel mode transitions, so I
> > really don't believe that the thunking will add any overhead on it's
> > own: the context switch going into kernel will obliterate the much
> > smaller overhead of checking which call we want to make.
> 
> I don't think so.  You can't take the kernel into account, really, since
> it spends its time either case.

Well, thats irrelevant anyway. I've already committed to moving the
duplication of tests out of the call path.

> Anyway, *sic* I don't like the thunking.  It's fairly intrusive to the
> code.  It adds another complexity level to a lot of functions which seems
> pretty unnecessary.  It also adds a lot of decisions which are made on
> runtime over and over again, even though actually it would be sufficient
> from a logical level to make this decision once.  Or at least only once
> per Win32 function call.  

Those decisions can live elsewhere - see above. For now, it provides me
a clean way to tell what has been fixed, and what not - and to insert
tracing and debugging statements at *one* place in the code (per win32
function) rather than at multiple places.

> Btw., what does "thunk" mean literally?  While I know its meaning in the
> software context, I can't find a simple translation.  I looked up three
> dictionaries to no avail.

http://www.jargon.8hz.com/jargon_35.html  - see thunk, and meaning 3 is
what I've been using.

Rob

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