Re: [PATCH 2/6] libxl: portiblity fixes

[Keir Fraser <keir.fraser@eu.citrix.com>]

On 28/07/2010 10:06, "Christoph Egger" <Christoph.Egger@amd.com> wrote:

>> This patch is wrong because it introduces a couple of function
>> declarations but it does not introduce the definitions; your later
>> patch which introduces the definitions is wrong because it introduces
>> some functions which are intended to replace existing code, but the
>> patch does not replace the existing code and the new functions are not
>> called anywhere in that patch.
> 
> The function declarations are the API and the function defintions
> are the OS dependent implementations of the API.
> Implementations and use of the API is used in different patches.
> This is my understanding of defining and implementing an API
> in C.

I find that kind of way of splitting up a patch series annoying as well. As
Ian said, we want each patch to be a logical and separate whole. That means
providing an interface *and* its implementation. Possibly its users as well,
depending on how complicated that bit is -- it's certainly arguable they
belong in a separate patch, at least.

> blktap support for linux and netbsd are very different in their
> implementation.
> In netbsd, blktap will be implemented using puffs
> (http://netbsd.gw.com/cgi-bin/man-cgi?puffs+3+NetBSD-current)

A bit of a sidestep I know, but: shouldn't the blktap library be hiding this
osdep stuff?

 -- Keir