DHCP 服务器,客户端代码都采用了统一的事件轮询(event loop),包含了任务处理消息,定时器消息,socke收发消息等等. static struct { isc_appmethods_t methods; /*% * The following are defined just for avoiding unused static functions. */ #ifndef BIND9 void *run, *shutdown, *start, *onrun, *reload, *f…