socket connect timeout

connection 할때 timeout 처리에 관해 찾아 보는 중.
nonblocking socket을 이용한 Rechard stevens의 소스가 있더군요.

#include	"unp.h"

int
connect_nonb(int sockfd, const SA *saptr, socklen_t salen, int nsec)
{
	int				flags, n, error;
	socklen_t		len;
	fd_set			rset, wset;
	struct timeval	tval;

	flags = Fcntl(sockfd, F_GETFL, 0);
	Fcntl(sockfd, F_SETFL, flags | O_NONBLOCK);

	error = 0;
	if ( (n = connect(sockfd, (struct sockaddr *) saptr, salen)) < 0)
		if (errno != EINPROGRESS)
			return(-1);

	/* Do whatever we want while the connect is taking place. */

	if (n == 0)
		goto done;	/* connect completed immediately */

	FD_ZERO(&rset);
	FD_SET(sockfd, &rset);
	wset = rset;
	tval.tv_sec = nsec;
	tval.tv_usec = 0;

	if ( (n = Select(sockfd+1, &rset, &wset, NULL,
					 nsec ? &tval : NULL)) == 0) {
		close(sockfd);		/* timeout */
		errno = ETIMEDOUT;
		return(-1);
	}

	if (FD_ISSET(sockfd, &rset) || FD_ISSET(sockfd, &wset)) {
		len = sizeof(error);
		if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &error, &len) < 0)
			return(-1);			/* Solaris pending error */
	} else
		err_quit("select error: sockfd not set");

done:
	Fcntl(sockfd, F_SETFL, flags);	/* restore file status flags */

	if (error) {
		close(sockfd);		/* just in case */
		errno = error;
		return(-1);
	}
	return(0);
}

예전에 포스팅 한 http socket client 에 적용하면서 windows 버전으로도 만들어 봤습니다.

int CHttpSocket::connect_nonb(int sockfd, const struct sockaddr *saptr, socklen_t salen, struct timeval tval)
{
    int                flags, n, error;
    socklen_t        len;
    fd_set            rset, wset;

#ifdef WIN32
    int nonblocking =1;
    ioctlsocket(sockfd, FIONBIO, (unsigned long*) &nonblocking);
#else
    flags = fcntl(sockfd, F_GETFL, 0);
    fcntl(sockfd, F_SETFL, flags | O_NONBLOCK);
#endif

    error = 0;
    if ( (n = connect(sockfd, (struct sockaddr *) saptr, salen)) < 0)
    {
#ifdef WIN32
        errno = WSAGetLastError();
#endif
        if (errno != EINPROGRESS && errno!= EWOULDBLOCK)
        {
            return(-1);
        }
    }

    /* Do whatever we want while the connect is taking place. */

    if (n == 0)
        goto done;    /* connect completed immediately */

    FD_ZERO(&rset);
    FD_SET(sockfd, &rset);
    wset = rset;

    if ( (n = select(sockfd+1, &rset, &wset, NULL,
                     ((tval.tv_sec>0) || (tval.tv_usec>0))? &tval : NULL)) == 0)
    {
        close(sockfd);        /* timeout */
        errno = ETIMEDOUT;
        return(-1);
    }

    if (FD_ISSET(sockfd, &rset) || FD_ISSET(sockfd, &wset))
    {
#ifndef WIN32
        len = sizeof(error);
        if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &error, &len) < 0)
            return(-1);            /* Solaris pending error */
#endif
    } else
        return(-1); //err_quit("select error: sockfd not set");

done:
#ifdef WIN32
    nonblocking =0;
    ioctlsocket(sockfd, FIONBIO, (unsigned long*) &nonblocking);
#else
    fcntl(sockfd, F_SETFL, flags);    /* restore file status flags */
#endif

    if (error) {
        close(sockfd);        /* just in case */
        errno = error;
        return(-1);
    }
    return(0);
}