Re: [lwip-users] Assertion failure in tcp_receive

[Kieran Mansley]

On Fri, 2006-03-17 at 08:59 +0800, Jeffery Du wrote:
> Hi,
> 
>        I am a software engineer from China. I am working on a set top box 
> project, in which we use TCP/IP protocol to transmit control command and user 
> data. I've ported the LWIP (1.1.0) to our platform (OS20 of ST 
> Microelectronics) and it can work basically. 
>     But I encountered a problem currently. When a large amount of data are 
> transmitting, the program is very easy to crash at an assertion in 
> tcp_receive:
>        if (pcb->snd_queuelen != 0) { 
> LWIP_ASSERT("tcp_receive: valid queue length",
>           pcb->unacked != NULL || pcb->unsent != NULL);
>             }
>       I've checked the bug list on website: 
> http://savannah.nongnu.org/projects/lwip, 
> But I didn't find any report about this problem. I wrote application to use 
> raw API directly.

Most likely would be concurrent access to the stack from two different
threads.  If you're using the raw API you need to protect the stack
using locks where necessary.

Kieran