usr/src/usr.sbin/timed/timed/networkdelta.c

/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
static char sccsid[] = "@(#)networkdelta.c      2.4 (Berkeley) 6/1/90";
#endif /* not lint */

#include "globals.h"
#include <protocols/timed.h>

extern int machup;

/*
 * `networkdelta' selects the largest set of deltas that fall within the
 * interval RANGE, and uses them to compute the network average delta
 */

long networkdelta()
{
        int i, j, maxind, minind;
        int ext;
        int tempind;
        long tempdata;
        long x[NHOSTS];
        long average;

        for (i=0; i<slvcount; i++)
                x[i] = hp[i].delta;
        for (i=0; i<slvcount-1; i++) {
                tempdata = x[i];
                tempind = i;
                for (j=i+1; j<slvcount; j++) {
                        if (x[j] < tempdata) {
                                tempdata = x[j];
                                tempind = j;
                        }
                }
                x[tempind] = x[i];
                x[i] = tempdata;
        }

        /* this piece of code is critical: DO NOT TOUCH IT! */
/****/
        i=0; j=1; minind=0; maxind=1;
        if (machup == 2)
                goto compute;
        do {
                if (x[j]-x[i] <= RANGE)
                        j++;
                else {
                        if (j > i+1)
                                j--;
                        if ((x[j]-x[i] <= RANGE) && (j-i >= maxind-minind)) {
                                minind=i;
                                maxind=j;
                        }
                        i++;
                        if(i = j)
                                j++;
                }
        } while (j < machup);
        if ((x[machup-1] - x[i] <= RANGE) && (machup-i-1 >= maxind-minind)) {
                minind=i; maxind=machup-1;
        }
/****/
compute:
        ext = maxind - minind + 1;
        average = 0;
        for (i=minind; i<=maxind; i++)
                average += x[i];
        average /= ext;
        return(average);
}