Re: [lwip-users] endless loop in netconn_write

[M. Gotink]

> On Wed, 2006-07-26 at 12:10 +0200, E. Spijksma wrote:
> > We've been studying the debug info the lwipstack provides and noticed that
> this 
> > happens with multiple threads to the stack.
> > 
> > Sometimes a "tcp_receive: received FIN" isn't followed by
> > TCP connection closed 3613 -> 80.
> > 
> > tcp_pcb_purge
> > 
> > This would mean the buffers aren't purged and wouldn't this end up in 
> > a loop in netconn_write() because len = 0 due to unpurged data in the send
> > buffer?
> 
> I'm not sure about the details of your problem, but a received FIN will
> not result in a closed connection until the process at the local end
> also closes it.  The received FIN just means that the other end will not
> send any more data, but the connection is still usable for the local end
> to send.
> 
> Kieran


Our process is a webserver so the server (lwIP) sends a FIN packet when its 
done sending the data (we call netconn_close at the end of the process), the 
client will ack this FIN with a FIN packet from his side. When that packet is 
received the connection should be closed and the pcb should be purged... But 
thats not happening.