async_server.c

linux的socket的非阻塞函数fcntl的用法

/*server.c*/

#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <netinet/in.h>
#include <fcntl.h>
#include <signal.h>

#define PORT			4321
#define BUFFER_SIZE		1024
#define MAX_QUE_CONN_NM	5

struct sockaddr_in server_sockaddr, client_sockaddr;
int sockfd, client_fd;
char buf[BUFFER_SIZE];
int sin_size, recvbytes;

int do_work()
{
	while(1)
	{
		sleep(1);
		printf("I'm working...\n");
	}
}

void accept_async(int sig_num)
{
	sin_size = sizeof(client_sockaddr);
	if ((client_fd = accept(sockfd, (struct sockaddr *)&client_sockaddr, &sin_size)) == -1)
	{
		perror("accept");
		exit(1);
	}
	
	/*调用recv函数接收客户端的请求*/
	memset(buf , 0, sizeof(buf));
	if ((recvbytes = recv(client_fd, buf, BUFFER_SIZE, 0)) == -1)
	{
		perror("recv");
		exit(1);
	}
	printf("Asyncronous method: received a message: %s\n", buf);
	
}

int main()
{
	int flags;

	signal(SIGIO, accept_async);
	/*建立socket连接*/
	if ((sockfd = socket(AF_INET, SOCK_STREAM, 0))== -1)
	{
		perror("socket");
		exit(1);
	}
	printf("Socket id = %d\n",sockfd);
		
	/*设置sockaddr_in 结构体中相关参数*/
	server_sockaddr.sin_family = AF_INET;
	server_sockaddr.sin_port = htons(PORT);
	server_sockaddr.sin_addr.s_addr = INADDR_ANY;
	bzero(&(server_sockaddr.sin_zero), 8);
	
	int i = 1;/* 使得重复使用本地地址与套接字进行绑定 */
	setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i));	
	
	/*绑定函数bind*/
	if (bind(sockfd, (struct sockaddr *)&server_sockaddr, sizeof(struct sockaddr))== -1)
	{
		perror("bind");
		exit(1);
	}
	printf("Bind success!\n");
	
	/*调用listen函数*/
	if (listen(sockfd, MAX_QUE_CONN_NM) == -1)
	{
		perror("listen");
		exit(1);
	}
	printf("Listening....\n");

	fcntl(sockfd, F_SETOWN, getpid());	
	flags = fcntl(sockfd, F_GETFL);
	if (flags < 0 || fcntl(sockfd, F_SETFL, flags | O_ASYNC) < 0)
	{
		perror("fcntl");
	}

	printf("Do work...\n");
	do_work();
	close(sockfd);
	exit(0);
}