simple poll echo server example

//    echo_server.cc

#include 			//	fcntl
#include 			//	exit
#include 		//	socket
#include 		//	sockaddr_in
#include 		//	bzero
#include 		//	inet_addr
#include 			//	read
#include 			//	perror
#include 			
#include 

int main()
{
	std::cout << "start poll echo server..." << std::endl;
	
	static const int max_back_log = 10;
	static const int max_poll_fd = 2;
	struct pollfd fds[max_poll_fd];

	for(int i = 0; i < max_poll_fd; ++i)
	{	
		fds[i].fd = -1;
	}
	int listenfd = socket(AF_INET,SOCK_STREAM,0);
	if(-1 == listenfd)
	{
		perror("socket");
		exit(1);
	}

	int option_name = 1;
	if(setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &option_name, sizeof(int)) == -1)
	{
        perror("setsockopt");
        exit(1);
    }

	struct sockaddr_in serveraddr;
	bzero(&serveraddr,sizeof(sockaddr_in));
	serveraddr.sin_family = AF_INET;
	serveraddr.sin_port = htons(9876);
	inet_aton("127.0.0.1",&(serveraddr.sin_addr));
	if( -1 == bind(listenfd,(sockaddr*)&serveraddr,sizeof(sockaddr_in)))
	{
        perror("bind");
        exit(1);
    }

	if( -1 == listen(listenfd,max_back_log))
	{
        perror("bind");
        exit(1);
    }
	
	int cur_poll_fd_num = 0;
	fds[0].fd = 0;
	fds[0].events = POLLIN;
	++cur_poll_fd_num;

	fds[1].fd = listenfd;
	fds[1].events = POLLIN;
	++cur_poll_fd_num;
	
	int timeout_msecs = 50000;
	int connectfd = 0;
	struct sockaddr_in clientaddr;
	socklen_t	client_addr_len;
	int read_data = 0;
	int send_size = 0;
	int read_size = 0;
	while(1)
	{
		int ret = poll(fds,cur_poll_fd_num,timeout_msecs);
		if(-1 == ret)
		{
			perror("poll");
			exit(1);
		}
		else if(0 == ret)
		{
			perror("time out");
			continue;
		}
		for(int i = 0; i 

//    echo_client.cc

#include 			//	exit
#include 		//	sockaddr_in
#include 		//	bzero
#include 		//	inet_addr
#include 
#include 

int main()
{
	int sock = socket(AF_INET,SOCK_STREAM,0);
	if(-1 == sock)
	{
		std::cout << "error at socket"<