Re: [lwip-users] SOCK_RAW

[Ed Sutter]

Thanks for the information.
I'm considering converting the stack in MicroMonitor over to LWIP
using the state machine model.  I haven't done anything thus far
with that API, so I suppose I need to start!

I'm sure the answer to this is no (since the sockets API uses the 
sequential API), but I'll ask anyway...
Is there any reason why a mix of both sockets and sequential API
cannot be run within the same application?

Ed

address@hidden wrote:
> 
> On Fri, 27 Feb 2004, Ed Sutter wrote:
> > Assuming the sluggishness is in fact due to the sockets layer, has
> > anyone considered improving it or does the underlying design of the
> > sequential API just make it difficult to implement an efficient
> > sockets layer on top of it?
> 
> I havn't looked at or used the socket emulation layer, but I am familiar
> with BSD sockets generally, and here are some of the problems I can think
> of generally...
> 
> 1) The socket API requires copy of received packets
> 2) The socket API requires additional synchronisation and threads
> 3) The socket API lends itself to implementations which use a large number
>    of threads (Though this can be avoided with poll).
> 4) Polling sucks.
> 5) Using extra threads means you incur context switch overheads
> 6) Although not strictly necessary, it is would be difficult to implement
>    the socket layer without adding an extra layer of buffering between the
>    application and the IP stack.
> 
> The native interface is vastly more elegant than BSD sockets from a design
> perspective, though I wouldn't make any claims about it being perfect. You
> just need to learn to think in terms of state machines rather than threads
> to make it work well.
> 
> What we really need is more applications which support the native interface!
> 
> --
> Luke