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13#include <stdio.h>
14#include <stdlib.h>
15#include <unistd.h>
16#include <fcntl.h>
17#include <math.h>
18#include <sys/socket.h>
19#include <netinet/in.h>
20#include <arpa/inet.h>
21#include <string.h>
22
23#include "utils.h"
24#include "tc_core.h"
25#include "tc_cbq.h"
26
27unsigned int tc_cbq_calc_maxidle(unsigned int bndw, unsigned int rate, unsigned int avpkt,
28 int ewma_log, unsigned int maxburst)
29{
30 double maxidle;
31 double g = 1.0 - 1.0/(1<<ewma_log);
32 double xmt = (double)avpkt/bndw;
33
34 maxidle = xmt*(1-g);
35 if (bndw != rate && maxburst) {
36 double vxmt = (double)avpkt/rate - xmt;
37
38 vxmt *= (pow(g, -(double)maxburst) - 1);
39 if (vxmt > maxidle)
40 maxidle = vxmt;
41 }
42 return tc_core_time2tick(maxidle*(1<<ewma_log)*TIME_UNITS_PER_SEC);
43}
44
45unsigned int tc_cbq_calc_offtime(unsigned int bndw, unsigned int rate, unsigned int avpkt,
46 int ewma_log, unsigned int minburst)
47{
48 double g = 1.0 - 1.0/(1<<ewma_log);
49 double offtime = (double)avpkt/rate - (double)avpkt/bndw;
50
51 if (minburst == 0)
52 return 0;
53 if (minburst == 1)
54 offtime *= pow(g, -(double)minburst) - 1;
55 else
56 offtime *= 1 + (pow(g, -(double)(minburst-1)) - 1)/(1-g);
57 return tc_core_time2tick(offtime*TIME_UNITS_PER_SEC);
58}
59