/*---------------------------------------------------------------  * Copyright (c) 1999,2000,2001,2002,2003                               * The Board of Trustees of the University of Illinois             * All Rights Reserved.                                            *---------------------------------------------------------------  * Permission is hereby granted, free of charge, to any person     * obtaining a copy of this software (Iperf) and associated        * documentation files (the "Software"), to deal in the Software   * without restriction, including without limitation the           * rights to use, copy, modify, merge, publish, distribute,         * sublicense, and/or sell copies of the Software, and to permit      * persons to whom the Software is furnished to do * so, subject to the following conditions:  * *      * Redistributions of source code must retain the above  * copyright notice, this list of conditions and  * the following disclaimers.  * *      * Redistributions in binary form must reproduce the above  * copyright notice, this list of conditions and the following  * disclaimers in the documentation and/or other materials  * provided with the distribution.  *  *      * Neither the names of the University of Illinois, NCSA,  * nor the names of its contributors may be used to endorse  * or promote products derived from this Software without * specific prior written permission.  *  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES  * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND  * NONINFRINGEMENT. IN NO EVENT SHALL THE CONTIBUTORS OR COPYRIGHT  * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,  * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  * ________________________________________________________________ * National Laboratory for Applied Network Research  * National Center for Supercomputing Applications  * University of Illinois at Urbana-Champaign  * http://www.ncsa.uiuc.edu * ________________________________________________________________  * * delay.c * by Mark Gates <mgates@nlanr.net> * ------------------------------------------------------------------- * accurate microsecond delay * ------------------------------------------------------------------- */#include "Timestamp.hpp"#include "delay.hpp"/* ------------------------------------------------------------------- * A micro-second delay function. This uses gettimeofday (underneith * the Timestamp) which has a resolution of upto microseconds. I've * found it's good to within about 10 usecs. * I used to do calibration, but iperf automatically adjusts itself * so that isn't necesary, and it causes some problems if the * calibration adjustment is larger than your sleep time. * ------------------------------------------------------------------- */void delay_loop( unsigned long usec ) {    Timestamp end;    end.add( usec * 1e-6 );    Timestamp now;    while ( now.before( end ) ) {        now.setnow();    }}