由於最近現網的epoll版本服務器，出現了點詭異的問題，不得已改用libev快速上線，在這裡先記錄下簡單的使用實例。代碼中可能存在部分bug，此代碼並非線上跑的代碼，不過已經五髒俱全，如果有任何疑問，歡迎一起討論。 [cpp] #include <ev.h> #include <stdio.h> #include <netinet/in.h> #include<stdlib.h> #include <string.h> #define PORT 57789 #define BUFFER_SIZE 2048 #define MAX_ALLOWED_CLIENT 10240 struct ev_io *libevlist[MAX_ALLOWED_CLIENT] = {NULL}; void accept_cb(struct ev_loop *loop, struct ev_io *watcher, int revents); void read_cb(struct ev_loop *loop, struct ev_io *watcher, int revents); void timer_beat(struct ev_loop *loop, struct ev_timer *watcher, int revents); int freelibev(struct ev_loop *loop, int fd); int main() { struct ev_loop *loop=ev_default_loop(0); int sd; struct sockaddr_in addr; int addr_len = sizeof(addr); //創建一個io watcher和一個timer watcher struct ev_io socket_accept; struct ev_timer timeout_w; //創建socket連接 sd = socket(PF_INET, SOCK_STREAM, 0); if(sd < 0) { printf("socket error\n"); return -1; } bzero(&addr, sizeof(addr)); addr.sin_family = AF_INET; addr.sin_port = htons(PORT); addr.sin_addr.s_addr = INADDR_ANY; //正常bind if(bind(sd, (struct sockaddr*)&addr, sizeof(addr)) != 0) { printf("bind error\n"); return -1; } //正常listen if(listen(sd, SOMAXCONN) < 0) { printf("listen error\n"); return -1; } //設置fd可重用 int bReuseaddr=1; if(setsockopt(sd,SOL_SOCKET ,SO_REUSEADDR,(const char*)&bReuseaddr,sizeof(bReuseaddr)) != 0) { printf("setsockopt error in reuseaddr[%d]\n", sd); return ; } //初始化io watcher，用於監聽fd ev_io_init(&socket_accept, accept_cb, sd, EV_READ); ev_io_start(loop, &socket_accept); //可以向遠端發送心跳包 //ev_timer_init(&timeout_w, timer_beat, 1., 0.); //ev_timer_start(loop, &timeout_w); ev_run(loop, 0); return 1; } void accept_cb(struct ev_loop *loop, struct ev_io *watcher, int revents) { /* 如果有鏈接，則繼續監聽fd； */ struct sockaddr_in client_addr; socklen_t client_len = sizeof(client_addr); int client_sd; //創建客戶端的io watcher struct ev_io *w_client = (struct ev_io*) malloc(sizeof(struct ev_io)); if(w_client == NULL) { printf("malloc error in accept_cb\n"); return ; } if(EV_ERROR & revents) { printf("error event in accept\n"); return ; } //獲取與客戶端相連的fd client_sd = accept(watcher->fd, (struct sockaddr*)&client_addr, &client_len); if(client_sd < 0) { printf("accept error\n"); return; } //如果連接數超出指定范圍，則關閉連接 if( client_sd > MAX_ALLOWED_CLIENT) { printf("fd too large[%d]\n", client_sd); close(client_sd); return ; } if(libevlist[client_sd] != NULL) { printf("client_sd not NULL fd is [%d]\n", client_sd); return ; } printf("client connected\n"); //監聽新的fd ev_io_init(w_client, read_cb, client_sd, EV_READ); ev_io_start(loop, w_client); libevlist[client_sd] = w_client; } void read_cb(struct ev_loop *loop, struct ev_io *watcher, int revents) { char buffer[BUFFER_SIZE]; ssize_t read; if(EV_ERROR & revents) { printf("error event in read\n"); return ; } //正常的recv read = recv(watcher->fd, buffer, BUFFER_SIZE, 0); if(read < 0) { printf("read error\n"); return; } if(read == 0) { printf("client disconnected.\n"); //ev_io_stop(loop, watcher); //free(watcher); //如果客戶端斷開連接，釋放響應的資源，並且關閉監聽 freelibev(loop, watcher->fd); return; } else { //buffer[read] = '\0'; printf("receive message:%s\n", buffer); } //返回給客戶端 send(watcher->fd, buffer, read, 0); bzero(buffer, read); } void timer_beat(struct ev_loop *loop, struct ev_timer *watcher, int revents) { float timeout = 2.0; //這裡可以發送心跳包，也可以什麼都不做 printf("send beat per[%f]\n",timeout); fflush(stdout); if(EV_ERROR & revents) { printf("error event in timer_beat\n"); return ; } ev_timer_set(watcher, timeout,0.); ev_timer_start(loop, watcher); return; } int freelibev(struct ev_loop *loop, int fd) { /*if(fd > MAX_ALLOWED_CLIENT) { printf("more than MAX_ALLOWED_CLIENT[%d]", fd); return -1; }*/ //清理相關資源 if(libevlist[fd] == NULL) { printf("the fd already freed[%d]\n", fd); return -1; } close(fd); ev_io_stop(loop, libevlist[fd]); free(libevlist[fd]); libevlist[fd] = NULL; return 1; } makefile： [cpp] CC=gcc FLAGS=-I. -I/home/lengzijian/c/libev/libev-4.11 LDFLAGS=-L/usr/lib -L/home/lengzijian/c/libev/libev-4.11/.libs -lev -Wall OBJECTS=server.o ALL_BIN=server all:$(ALL_BIN) $(ALL_BIN):$(OBJECTS) $(CC) $(FLAGS) $(LDFLAGS) -o $@ $^ %.o:%.c $(CC) -c $< $(FLAGS) $(FLAGS) clean: rm -fr $(OBJECTS) rm -fr $(ALL_BIN) 注意makefile中的頭文件路徑，和動態鏈接庫的路徑
