Comment #11 on issue 106 by pi3or...@gmail.com: binary protocol parsing can cause memcached server lockup
http://code.google.com/p/memcached/issues/detail?id=106
I think you are right.In my first patch (Comment 1), the recvfrom() call is critical because in that situation, if a UDP socket is in conn_closing state, it will never be recovered, all incoming packets should be dropped. If we recover its state to conn_read, there's no need for the recvfrom() again.
