用libev的c语言版本实现简单的网络通信服务器

由于最近现网的epoll版本服务器，出现了点诡异的问题，不得已改用libev快速上线，在这里先记录下简单的使用实例。代码中可能存在部分bug，此代码并非线上跑的代码，不过已经五脏俱全，如果有任何疑问，欢迎一起讨论。

转载注明出处：http://blog.csdn.net/lengzijian/article/details/8315133

#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 10240struct 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);        //创建一个io watcher和一个timer watcher    struct ev_io socket_accept;    struct ev_timer timeout_w;    //创建socket连接    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;    }    //设置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，用于监听fd    ev_io_init(&socket_accept, accept_cb, sd, EV_READ);    ev_io_start(loop, &socket_accept);        //可以向远端发送心跳包    //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){    /*        如果有链接，则继续监听fd；    */    struct sockaddr_in client_addr;    socklen_t client_len = sizeof(client_addr);    int client_sd;    //创建客户端的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 ;    }        //获取与客户端相连的fd    client_sd = accept(watcher->fd, (struct sockaddr*)&client_addr, &client_len);    if(client_sd < 0)    {        printf("accept error\n");        return;    }    //如果连接数超出指定范围，则关闭连接    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");    //监听新的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);        //如果客户端断开连接，释放响应的资源，并且关闭监听        freelibev(loop, watcher->fd);        return;    }    else    {        //buffer[read] = '\0';        printf("receive message:%s\n", buffer);    }    //返回给客户端    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;    //这里可以发送心跳包，也可以什么都不做    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;    }*/    //清理相关资源        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：

CC=gccFLAGS=-I. -I/home/lengzijian/c/libev/libev-4.11 LDFLAGS=-L/usr/lib -L/home/lengzijian/c/libev/libev-4.11/.libs -lev -WallOBJECTS=server.oALL_BIN=serverall:$(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中的头文件路径，和动态链接库的路径

测试时，只需要telnet ip 57789 即可