Subject: Re: SoC ideas - mbuf API
To: Pavel Cahyna <pavel@NetBSD.org>
From: Jason Thorpe <thorpej@shagadelic.org>
List: tech-net
Date: 09/04/2006 19:59:25
On Sep 3, 2006, at 2:23 PM, Pavel Cahyna wrote:

> BTW I have looked at the Mac OS X mbuf KPI and wasn't impressed.  
> There is
> not much innovation (renaming struct mbuf * - > mbuf_t, m_ -> mbuf_  
> does
> not count). I don't see what is gained by replacing the direct  
> access to
> struct mbuf members by accessor functions, especially when the  
> semantics is
> not well defined (how do the function that change mbuf length interact
> with the packet length?), or not well chosen (mbuf_setdata? why does  
> it
> accept a pointer when it must set the data pointer to data inside  
> the mbuf
> storage?)

The main benefits of was OS X did here was:

- clean up the symbol namespace (important for having nice, stable ABIs)

- Make the mbuf type opaque (again, for stable ABIs)

-- thorpej