Re: [lwip-users] LWIP HTTP Issue sending multiple packets

[Sergio R. Caprile]

If you are using an Atmel http server, you should check at the Atmel forums.

In case that server is coincident with the one in the contrib tree, and
also with the RAW API, and you are not using an OS (which you don't say,
btw), I can try to help.
I don't understand what you are trying to do, you say you open the
connection but you don't in an http server, the client does. Can you
please explain how you handle the whole process, if possible in proper
http terms, and where does your code differ from the tested and working
http server in the contrib tree ?

Example:
The browser calls for this html page wich does blablabla and then a CGI
function gets called which does blablabla and so blablabla.

In a system with RAW API and no OS (NO_SYS=1), the user usually reads
the eth controller from the main loop, and for every frame the stack
gets called, which in turn leads to your application function getting
called. Many functions are not reentrant, so you can't call them from
within an interrupt handler, you will call tcp_send functions when your
app function is called. You will also get called to your tcp_acked
function, which will release  buffers in order for more data to be sent.
If you don't release buffers, then you won't be able to send more data,
unless you provide more buffering space, which you do in lwipopts.h
I suggest you study and understand the examples in the contrib tree
before you dive into writing a full asynchronous application.