Re: Highres delay help

From: A. Melinte (nospam_at_nospam.com)
Date: 05/27/05 

Date: Fri, 27 May 2005 14:01:18 -0400

"Carl W" <calle79@inorbit.com> wrote in message
news:c6416781.0505270421.5ff3ef02@posting.google.com...
> Dear all.
>
> I need a way to implement a high resolution delay with at least a
> resolution of 1 ms.

You can use select() to have a microsec resolution in a portable way:

/* restart select if call interrupted */
static int
rselect( int n, fd_set *rds, fd_set *wds, fd_set *eds, struct timeval
*tout )
{
    int rc;

    do {
        rc = select( n, rds, wds, eds, tout );
    } while ( rc == -1 && errno == EINTR );

    return rc;
}

int
microsleep( int sock, int microsec )
{
    struct timeval tv;
    fd_set rfs, wfs, efs;
    int ret;

    tv.tv_sec = 0;
    tv.tv_usec = microsec;

    if ( sock == CFGST_INVALID_SOCKET ) {
        ret = rselect( 0, NULL, NULL, NULL, &tv );
    } else {
        FD_ZERO( &rfs ); FD_SET( sock, &rfs );
        FD_ZERO( &wfs ); //FD_SET( sock, &wfs );
        FD_ZERO( &efs ); //FD_SET( sock, &efs );
        ret = rselect( sock+1, &rfs, &wfs, &efs, &tv );
    }

    return ret;
}

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