[PATCH 1/2] [0.4.8] eloop extension for dbus control interface, v2

Jouni Malinen jkmaline at cc.hut.fi
Mon Apr 17 09:22:28 EDT 2006

On Mon, Apr 17, 2006 at 08:42:21AM -0400, Dan Williams wrote:
> On Sun, 2006-04-16 at 19:26 -0700, Jouni Malinen wrote:
> > This looks quite good. However, type casting a function pointer to
> > different type and then calling read_sock handler function with one
> > extra parameter looks somewhat scary.. Is that guaranteed to work with
> > all commonly used ANSI C compilers and CPUs?
> AFAIK it does, but I'd have to check.  The glib/gtk compatibility
> guidelines say something about this but I'll ping some gcc folk and ask.

After some additional thought on this area, I came up with a more
detailed concern on this.. Thinking about calling conventions, there is
a limit between N and N+1 function arguments where the compiler has to
start using stack instead of registers for passing some of the
arguments.. Because of this, I would assume that this kind of additional
parameter cannot work in general case. In other words, there may be a
need for adding a flag for the backwards compatibility case to know to
use a different call (one less argument) for it.

Jouni Malinen                                            PGP id EFC895FA

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