[lwip-users] using Lwip without callback in non-OS environment

[Mrutyunjay]

hi,
I need to port a application from different processor and proprietary Tcp stack which is also OS-less,
to lwip OS-less environment.


existing code uses round robin framework. each function worst case in-out time is 300 miliSeconds

while(1){
function0   tcp stack process
function1   h/w process
function2   tcp server process (tcp listener)
function3   tcp client process (tcp opener )
function4   udp server/client process
}

function  1 to 4 have access to external blocking device like say (SPI/I2C/UART). ( only one process access the external device at a given time ).  

I need to use lwip without callback , if i use call back i cannot control the sequence of external device access.

All tcp connection are persistent between function calls (sort of reentrant /state based ).
example:in function2
---------------------------------
switch (tcpstate){
listening :
connected :
data_available_to_read :
data_is_being_written :
closing :
closed :
default :
}
----------------------------------

Any sample code of simple echo server would greatly help. based on states

Regards,
Mrutyunjay B Patel