Re: [lwip-users] Debugging doesn´t work with HTTP example

[Sergio R. Caprile]

I missed your other post,

You shouldn't have threading issues with netconn, however, these can be 
at a lower level, check how frames are dispatched, all calls to 
low-level functions must be on the same thread (unless you clearly know 
what you are doing)

> > Furthermore, now you say you are using an RTOS... You must check your
> > port is not violating the single-threading rules, exactly which HTTP
> > server code are you using ? With which API ? [netconn] Is it lwIP original code 
> > ?
> > Is it vendor modified ? Which lwIP version ? [1.4.1]

Regarding printf(), you know you don't have a full-fledged preemptive 
multitasking OS there, do you ? The debug output function needs to send 
chars out of a UART or something, and that 1) takes a finite time, 
introducing unexpected delays, which can wreak havoc on your RTOS task 
dispatching if those guys didn't take that into account or assigned 
priorities in a loose fashion (neither add big buffers to the printing 
function, by the way). 2) may not be a reentrant function, and be called 
by two different threads trying to report their stuff at the same time.