Re: [lwip-users] netconn_write blocking

[address@hidden]

> Hi,
>   
Hi!
> I have an application that is sending out TCP data to several client using the sequential API.  When a client disconnects gracefully, netconn_write returns a negative value, and I can close the connection. However, if any of the clients locks up (i'm using embedded clients), or a cable gets unplugged, etc.  netconn_write keeps queue packets until it fills up the buffer, and then blocks.  I've been playing around with debugging, and so far all I get is lots of messages about the queue being full.  
>   
It complains about the queue being full?? That would be a 
misconfiguration and maybe an error in your port! The queues should 
never be full! That's why sys_arch_mbox_post has no return value, and 
the port should assert to check that a queue is never full. 
Misconfiguration could lead to this: too big TCP windows vs. too small 
queues...

But to be sure about this, could you post an excerpt of your debug 
output so that I know which function / file complains?
> My question is what is the proper way to deal with ungraceful disconnections using the sequential API? Am I doing something wrong, should netconn_write return an error for ungraceful disconnections, or is there any other way to check if for connection timeouts?  
>   
Unfortunately, there is only RX timeout currently. TX timeout is 
planned, I think...


Simon