利用Libev写一个简单的client和server程序

#ifndef _COMMON_H_
#define _COMMON_H_

#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <strings.h>
#include <cstdlib>
#include <cstdio>
#include <cstddef>
#include <string>

namespace common{

#define D(exp,fmt,...) do {                     \
if(!(exp)){                             \
fprintf(stderr,fmt,##__VA_ARGS__);  \
abort();                            \
}                                       \
}while(0)

static void setnonblock(int fd){
fcntl(fd,F_SETFL,fcntl(fd,F_GETFL) | O_NONBLOCK);
}
static void setreuseaddr(int fd){
int ok=1;
setsockopt(fd,SOL_SOCKET,SO_REUSEADDR,&ok,sizeof(ok));
}

static void setaddress(const char* ip,int port,struct sockaddr_in* addr){
bzero(addr,sizeof(*addr));
addr->sin_family=AF_INET;
inet_pton(AF_INET,ip,&(addr->sin_addr));
addr->sin_port=htons(port);
}

static std::string address_to_string(struct sockaddr_in* addr){
char ip[128];
inet_ntop(AF_INET,&(addr->sin_addr),ip,sizeof(ip));
char port[32];
snprintf(port,sizeof(port),"%d",ntohs(addr->sin_port));
std::string r;
r=r+"("+ip+":"+port+")";
return r;
}

static int new_tcp_server(int port){
int fd=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
D(fd>0,"socket failed(%m)\n");
setnonblock(fd);
setreuseaddr(fd);
sockaddr_in addr;
setaddress("0.0.0.0",port,&addr);
bind(fd,(struct sockaddr*)&addr,sizeof(addr));
listen(fd,64); // backlog = 64
return fd;
}

static int new_tcp_client(const char* ip,int port){
int fd=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
setnonblock(fd);
sockaddr_in addr;
setaddress(ip,port,&addr);
connect(fd,(struct sockaddr*)(&addr),sizeof(addr));
return fd;
}

}; // namespace common

#endif // _COMMON_H_

#include "ev.h"
#include "common.h"

static void do_connected(struct ev_loop* reactor,ev_io* w,int events){
close(w->fd);
ev_break(reactor,EVBREAK_ALL);
}

int main(){
struct ev_loop* reactor=ev_loop_new(EVFLAG_AUTO);
int fd=common::new_tcp_client("127.0.0.1",34567);
ev_io io;
ev_io_init(&io,&do_connected,fd,EV_WRITE);
ev_io_start(reactor,&io);
ev_run(reactor,0);
close(fd);
ev_loop_destroy(reactor);
return 0;
}

#include "ev.h"
#include "common.h"

static void do_accept(struct ev_loop* reactor,ev_io* w,int events){
struct sockaddr_in addr;
socklen_t addr_size=sizeof(addr);
int conn=accept(w->fd,(struct sockaddr*)&addr,&addr_size);
std::string r=common::address_to_string(&addr);
fprintf(stderr,"accept %s\n",r.c_str());
close(conn);
}

int main(){
struct ev_loop* reactor=ev_loop_new(EVFLAG_AUTO);
int fd=common::new_tcp_server(34567);
ev_io w;
ev_io_init(&w,do_accept,fd,EV_READ);
ev_io_start(reactor,&w);
ev_run(reactor,0);
close(fd);
ev_loop_destroy(reactor);
}