Re: [lwip-devel] core/timers.c with NO_SYS?

[Kieran Mansley]

On 12 Jun 2011, at 14:19, Leon Woestenberg wrote:

> Agreed. We have sys_arch code in core. However, these functions and
> macro's may all be no-ops on a NO_SYS implementation, thus there is no
> hard dependency.

[snip]

> The timers.c is the first module that requires the sys_now() to be
> implemented. Sorry, I was indeed confused by the "sys_" prefix being a
> sys_arch function.

I think this is worth sorting out so that there is no ambiguity.  We currently 
have:

1) sys_now() used in the timers.c, but we're agreed that despite the name this 
is not part of the sys_arch code.

2) some other sys_arch() code (such as those examples given by Simon) used in 
other parts of the core that can be safely no-op-defined out in the way Leon 
describes if you're doing a NO_SYS implementation.

That sounds to me like we've got what Leon wanted, albeit with some code such 
as sys_now that is poorly named (for a good reason of backwards compatibility). 
 If this distinction can be clarified, either with code changes or 
documentation, then I'd be very happy to see that.

On the general point of avoiding sys_arch code in the core, I'm agreed that 
this is a good principle.  We would need to have a strong justification to 
start introducing sys_arch code there.

Finally, thank you Leon for the code review and the questions; it is useful and 
very welcome to get a critical pair of eyes on the changes have been made.

Kieran