最近学习了一下Libev库，写了一个简单一问一答式回射服务器，目的在于于了解和熟悉libev库，并参照：http://www.ibm.com/developerworks/cn/linux/l-cn-edntwk/描述的基本模型。

 

 

 

/*********************
*auther email:cksea@126.com
*usage: echo back
*compile: gcc  -g -c test.c -I/usr/local/libev/include
               gcc  -g -Wall -o test test.o -L/usr/local/libev/lib -lev
************************/

 

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <pthread.h>
#include <ev.h>
#define MAXLEN 1023
#define PORT 9999
#define ADDR_IP "127.0.0.1"

int socket_init();
void accept_callback(struct ev_loop *loop, ev_io *w, int revents);
void recv_callback(struct ev_loop *loop, ev_io *w, int revents);
void write_callback(struct ev_loop *loop, ev_io *w, int revents);

int main(int argc ,char** argv)
{
 int listen;
 ev_io ev_io_watcher;
 listen=socket_init();
 struct ev_loop *loop = ev_loop_new(EVBACKEND_EPOLL);
 ev_io_init(&ev_io_watcher, accept_callback,listen, EV_READ);
 ev_io_start(loop,&ev_io_watcher); 
 ev_loop(loop,0);
 ev_loop_destroy(loop);
 return 0;
 
}

 

int socket_init()
{
 struct sockaddr_in my_addr;
 int listener;
 if ((listener = socket(AF_INET, SOCK_STREAM, 0)) == -1)
 {
  perror("socket");
  exit(1);
 }
 else
 {
  printf("SOCKET CREATE SUCCESS!/n");
 }
 //setnonblocking(listener);
 int so_reuseaddr=1;
 setsockopt(listener,SOL_SOCKET,SO_REUSEADDR,&so_reuseaddr,sizeof(so_reuseaddr));
 bzero(&my_addr, sizeof(my_addr));
 my_addr.sin_family = PF_INET;
 my_addr.sin_port = htons(PORT);
 my_addr.sin_addr.s_addr = inet_addr(ADDR_IP);

 if (bind(listener, (struct sockaddr *) &my_addr, sizeof(struct sockaddr))== -1)
 {
  perror("bind error!/n");
  exit(1);
 }
 else
 {
  printf("IP BIND SUCCESS,IP:%s/n",ADDR_IP);
 }

 if (listen(listener, 1024) == -1)
 {
  perror("listen error!/n");
  exit(1);
 }
 else
 {
  printf("LISTEN SUCCESS,PORT:%d/n",PORT);
 }
 return listener;
}

 

void accept_callback(struct ev_loop *loop, ev_io *w, int revents)
{
 int newfd;
 struct sockaddr_in sin;
 socklen_t addrlen = sizeof(struct sockaddr);
 ev_io* accept_watcher=malloc(sizeof(ev_io));
 while ((newfd = accept(w->fd, (struct sockaddr *)&sin, &addrlen)) < 0)
 {
  if (errno == EAGAIN || errno == EWOULDBLOCK) 
  {
   //these are transient, so don't log anything.
   continue; 
  }
  else
  {
   printf("accept error.[%s]/n", strerror(errno));
   break;
  }
 }
 ev_io_init(accept_watcher,recv_callback,newfd,EV_READ);
 ev_io_start(loop,accept_watcher);
 printf("accept callback : fd :%d/n",accept_watcher->fd);
 
}

void recv_callback(struct ev_loop *loop, ev_io *w, int revents)
{
 char buffer[1024]={0};
 int ret =0;
 //ev_io write_event;
loop:
 ret=recv(w->fd,buffer,MAXLEN,0);
 if(ret > 0)
 {
  printf("recv message :%s  /n",buffer);
  
 }
 else if(ret ==0)
 {
  printf("remote socket closed!socket fd: %d/n",w->fd);
  close(w->fd);
  ev_io_stop(loop, w);
  free(w);
  return;
 }
 else
 {
  if(errno == EAGAIN ||errno == EWOULDBLOCK)
  {
    goto loop;
  }
  else
  {
   printf("ret :%d ,close socket fd : %d/n",ret,w->fd);
   close(w->fd);
   ev_io_stop(loop, w);
   free(w);
   return;
  }
 }
 int fd=w->fd;
 ev_io_stop(loop,  w);
 ev_io_init(w,write_callback,fd,EV_WRITE);
 ev_io_start(loop,w);
 printf("socket fd : %d, turn read 2 write loop! ",fd);
 
}

void write_callback(struct ev_loop *loop, ev_io *w, int revents)
{
 char buffer[1024]={0};
 //ev_io read_event;
 snprintf(buffer,1023,"this is a test!");
 write(w->fd,buffer,strlen(buffer),0);
 int fd=w->fd;
 ev_io_stop(loop,  w);
 ev_io_init(w,recv_callback,fd,EV_READ);
 ev_io_start(loop,w);
}