Re: [lwip-users] Handling ERR_MEM from tcp_close()

[Sergio R. Caprile]

Too much code, I won't look at it.

From the wiki:
http://lwip.wikia.com/wiki/Raw/TCP

"The function may return ERR_MEM if no memory was available for closing 
the connection. If so, the application should wait and try again either 
by using the acknowledgment callback or the polling functionality. If 
the close succeeds, the function returns ERR_OK."

I use an extra CLOSING state, so the poll callback can kick in.
When closing, if close succeeds, state is CLOSED and everybody is happy. 
Otherwise, state is CLOSING and the poll callback will retry.