Re: [lwip-users] Nonblocking sockets problem

[address@hidden]

Åke Forslund wrote:
> I see my mistake there, however even with code that is at least theoretically 
> sane I can't establish a connection. lwip_accept() always returns EWOULDBLOCK 
> for me.
>
> from socket debug:
> lwip_accept(0)...
> lwip_accept(0): returning EWOULDBLOCK
> [Repeats forever]
>
> putty reports "Connection closed by remote host" followed by "Network error: Software caused 
> connection abort" or "Connection reset by Peer"

I have pasted your code into test.c in the Win32 port from contrib, 
removed your application-specific code, checked the return value of 
lwip_accept() and I could successfully connect using telnet.exe provided 
with windows XP.

If it's not working for you, that suggests  a problem either in your 
port or in the client application, I guess... What are the thread 
priorities in your system? Are you sure there is only one thread active 
in lwIP at a time? Because that's the main difference between the 
blocking and your non-blocking version: the blocking version just sits 
there and waits for a callback that lets lwip_accept return, while the 
non-blocking version calls into tcpip_thread *very* often - if your 
threading is broken, there's a good chance this will be revealed by your 
way of using non-blocking sockets.

Simon