RE: [lwip-users] Dropping existing TCP connections to service new ones

[Kieran Mansley]

On Thu, 2008-02-21 at 09:35 -0500, Bill Auerbach wrote:
> > -----Original Message-----
> > From: address@hidden
> > [mailto:address@hidden On Behalf
> > Of Kieran Mansley
> > Sent: Thursday, February 21, 2008 6:49 AM
> > To: Mailing list for lwIP users
> > Subject: Re: [lwip-users] Dropping existing TCP connections to service new
> > ones
> > 
> > On Wed, 2008-02-20 at 11:03 -0800, Art R. wrote:
> > > Is this a bug? Should the code read "if (pcb->prio < prio && ..."  (less
> > > than instead of less or equal)?
> > 
> > Sounds to me like that would be more sensible, but I've not looked into
> > it in any detail.  Feel free to file a bug if you'd like this changed.
> 
> This would break existing programs that use TCP_MAX_PRIO, since these would
> be killed in current lwIP versions but won't be in future versions with this
> < instead of <=  change.

Are there programs that rely on this?  

> Maybe we want:
> 
> #define TCP_NO_KILL_PRIO (TCP_MAX_PRIO+1)
> 
> And recommend using TCP_NO_KILL_PRIO for pcbs that cannot be killed due to
> inactivity.

It would certainly make sense to have a way to say "don't kill this
connection", but that leaves the question open of what to do if all the
connections have TCP_MAX_PRIO and it wants to create another one.

Kieran