libevent函数库核心思想
/*** epoll_loop.c ***/ #include<stdio.h> #include<sys/epoll.h> #include<sys/socket.h> #include<arpa/inet.h> #include<fcntl.h> #include<unistd.h> #include<errno.h> #include<string.h> #include<stdlib.h> #include<time.h>#define MAX_EVENTS 2014 #define BUFLEN 4096 #define SERV_PORT 8080void recvdata(int fd,int events,void *arg); void senddata(int fd,int events,void *arg);struct myevent_s {int fd;int events;void *arg;void (*call_back)(int fd,int events,void *arg);int status;char buf[BUFLEN];int len;long last_active; };int g_efd; struct myevent_s g_events[MAX_EVENTS + 1];void eventset(struct myevent_s *ev,int fd,void (*call_back)(int,int,void*),void *arg) {ev->fd = fd;ev->call_back = call_back;ev->events = 0;ev->arg = arg;ev->status = 0;ev->last_active = time(NULL);return; }void eventadd(int efd,int events,struct myevent_s *ev) {struct epoll_event epv = {0,{0}};int op;epv.data.ptr = ev;epv.events = ev->events = events;if(ev->status == 1){op = EPOLL_CTL_MOD; }else{op = EPOLL_CTL_ADD;ev->status = 1; }if(epoll_ctl(efd,op,ev->fd,&epv) < 0){printf("event add failed [fd=%d],evens[%d]\n",ev->fd,events) ;}else{printf("event add OK[fd=%d],op = %d,evens[%0X]\n",ev->fd,op,events) ;}return; }void eventdel(int efd,struct myevent_s *ev) {struct epoll_event epv = {0,{0}};if(ev->status != 1){return; }epv.data.ptr = ev;ev->status = 0;epoll_ctl(efd,EPOLL_CTL_DEL,ev->fd,&epv);return; }void acceptconn(int lfd,int events,void *arg) {struct sockaddr_in cin;socklen_t len = sizeof(cin);int cfd,i;if((cfd = accept(lfd,(struct sockaddr *)&cin,&len)) == -1){if(errno != EAGAIN && errno != EINTR) {}printf("%s : accept,%s \n",__func__,strerror(errno));return ;}do{for(i = 0; i < MAX_EVENTS; i++) {if(g_events[i].status == 0) {break; }}if(i == MAX_EVENTS){printf("%s: max connect limit[%d]\n]",__func__,MAX_EVENTS) ;return;}int flag = 0;if((flag = fcntl(cfd,F_SETFL,O_NONBLOCK)) < 0){printf("%s : accept,%s \n",__func__,strerror(errno));break;}eventset(&g_events[i],cfd,recvdata,&g_events[i]);eventadd(g_efd,EPOLLIN,&g_events[i]);}while(0);printf("new connect [%s:%d][time:%ld],pos[%d]\n",inet_ntoa(cin.sin_addr),ntohs(cin.sin_port),g_events[i].last_active,i);return; }void recvdata(int fd,int events,void *arg) {struct myevent_s *ev = (struct myevent_s *)arg;int len;len = recv(fd,ev->buf,sizeof(ev->buf),0);eventdel(g_efd,ev);if(len > 0){ev->len = len;ev->buf[len] = 0;printf("C[%d]:%s\n",fd,ev->buf);eventset(ev,fd,senddata,ev);eventadd(g_efd,EPOLLOUT,ev);}else if(len == 0){close(ev->fd) ;printf("[fd = %d] pos[%ld],close\n",fd,ev-g_events);}else{close(ev->fd) ;printf("recv[fd=%d] error[%d]:%s\n",fd,errno,strerror(errno));}return; }void senddata(int fd,int events,void *arg) {struct myevent_s *ev = (struct myevent_s *)arg;int len;len = send(fd,ev->buf,ev->len,0);if(len > 0){printf("send[fd=%d],[%d]%s\n",fd,len,ev->buf) ;eventdel(g_efd,ev);eventset(ev,fd,recvdata,ev);eventadd(g_efd,EPOLLIN,ev);}else{close(ev->fd) ;eventdel(g_efd,ev);printf("send[fd=%d] error %s\n",fd,strerror(errno));}return; }void initlistensocket(int efd,short port) {int lfd = socket(AF_INET,SOCK_STREAM,0);fcntl(lfd,F_SETFL,O_NONBLOCK);eventset(&g_events[MAX_EVENTS],lfd,acceptconn,&g_events[MAX_EVENTS]);eventadd(efd,EPOLLIN,&g_events[MAX_EVENTS]);struct sockaddr_in sin;memset(&sin,0,sizeof(sin));sin.sin_addr.s_addr = INADDR_ANY;sin.sin_family = AF_INET;sin.sin_port = htons(port);bind(lfd,(struct sockaddr*)&sin,sizeof(sin));listen(lfd,20);return ; }int main(int argc, char *argv[]) {unsigned short port = SERV_PORT;if(argc == 2){port = atoi(argv[1]) ;}g_efd = epoll_create(MAX_EVENTS+1);if(g_efd <= 0){printf("Create efd in %s error %s\n",__func__,strerror(errno)) ;}initlistensocket(g_efd,port);struct epoll_event events[MAX_EVENTS+1];printf("server running:port[%d]\n",port);int checkpos = 0,i;while(1){long now = time(NULL) ;for(i = 0 ; i < 100; i++,checkpos++){if(checkpos == MAX_EVENTS) checkpos = 0;if(g_events[checkpos].status != 1){continue; }long duration = now - g_events[checkpos].last_active;if(duration >= 60){close(g_events[checkpos].fd) ;printf("[fd=%d] timeout\n",g_events[checkpos].fd);eventdel(g_efd,&g_events[checkpos]);}}int nfd = epoll_wait(g_efd,events,MAX_EVENTS+1,1000);if(nfd < 0){printf("epoll_wait error, exit\n") ;break;}for(i = 0; i < nfd; i++){struct myevent_s *ev = (struct myevent_s *)events[i].data.ptr;if((events[i].events & EPOLLIN) && (ev->events & EPOLLIN)){ev->call_back(ev->fd,events[i].events,ev->arg) ;}if((events[i].events & EPOLLOUT) && (ev->events & EPOLLOUT)){ev->call_back(ev->fd,events[i].events,ev->arg);}}}return 0; }
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