高效的半异步半同步模型(学习memchaced的网络模型)主进程负责用libevent监听套接字，并且按照哈希函数的分配法则将accept得到的fd分配给各个子进程，类似于一个小的负载均衡，hash=（一个count计数++ % 总进程数）(The efficient semi asynchronous semi synchronous model (learning memchaced network model) the main process is responsible for listening to the socket with libevent, and assigns the FD obtained by accept to the sub processes according to the allocation rule of the Hashi function, similar to a small load balance, hash= (a count count + +% total process number).)