/*
 * call-seq:
 *    conn.send_describe_portal( portal_name ) -> nil
 *
 * Asynchronously send _command_ to the server. Does not block. 
 * Use in combination with +conn.get_result+.
 */
static VALUE
pgconn_send_describe_portal(VALUE self, VALUE portal)
{
    VALUE error;
    PGconn *conn = get_pgconn(self);
    /* returns 0 on failure */
    if(PQsendDescribePortal(conn,StringValuePtr(portal)) == 0) {
        error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn));
        rb_iv_set(error, "@connection", self);
        rb_exc_raise(error);
    }
    return Qnil;
}