[lwip-users] lwip_select() blocks even if timeout is 0

[Chu, Zhenwei]

Hi,

It seems that lwIP_select() always block even if timeout is set to 0.

The call stack shows it stops at 
sys_sem_wait(sem);  (line 316: sys.c)
sys_sem_wait_timeout();

Any suggestions? 

Thanks

Zhenwei Chu