static
void
internal_adjust_major_fuzz(float *major_fuzz) {
int i;
float f;
/* here we want a randomness of .40 - .80 */
i = RANDOM()%40;
f = (float) i / 100; /* 0 - 100% */
f += .40f;
*major_fuzz = internal_trim(f, 0.40f, 0.80f);
}
static
void
internal_adjust_minor_fuzz(float *minor_fuzz) {
int i;
float f;
/* here we want a randomness of .03 - .07 */
i = RANDOM()%4;
f = (float) i / 100;
f += .03f;
*minor_fuzz = internal_trim (f, 0.03f, 0.07f);
}
static
void
internal_adjust_next_event(struct NetKeepAlive *nka, int got_reply, int ct) {
/* if we are in the comfort zone,
apply minor_fuzz.
Otherwise, apply major_fuzz
If we are in the comfort zone and got no
reply, force us out of it.
*/
int i;
struct timeval tv;
float minor_minimum, major_minimum;
i = RANDOM()&0x01; /* positive or negative shift? */
minor_minimum = KA_INITIAL_KEEPALIVE;
major_minimum = (float) nka->maximal_keepalive * 0.75f;
/* next_event = current_event * +/- factor */
if (nka->current_keepalive >= major_minimum) {
// we are in the comfort zone
// did we get any reply?
// if not, bump down outside the zone
// also ensure that if we
// are stuck at either ends of the
// spectrum, we get out fast
#ifdef FAST_HANDOVER
if (got_reply == 0 && ct > 1)
nka->current_keepalive = major_minimum - 1;
else
#endif
{
float fuzz_factor;
if (nka->current_keepalive == nka->maximal_keepalive)
fuzz_factor = 1 - nka->minor_fuzz;
else if (nka->current_keepalive == major_minimum)
fuzz_factor = 1 + nka->minor_fuzz;
else fuzz_factor = i ? (1 - nka->minor_fuzz) : (1 + nka->minor_fuzz);
nka->current_keepalive = internal_trim((float)nka->current_keepalive * fuzz_factor,
major_minimum, (float) nka->maximal_keepalive);
}
}
/* else we are NOT in the comfort zone */
if (nka->current_keepalive < major_minimum) {
/* if we got_reply we go up, otherwise
we go down */
#ifdef FAST_HANDOVER
float fuzz_factor;
fuzz_factor = (ct < 2) ? (1 + nka->major_fuzz) : ( 1 - nka->major_fuzz);
#else
float fuzz_factor = 1;
if (ct < 2)
fuzz_factor = 1 + nka->major_fuzz;
#endif
nka->current_keepalive = internal_trim((float)nka->current_keepalive * fuzz_factor,
minor_minimum, (float) nka->maximal_keepalive);
}
/* then put the next event in the timeval */
GETTIMEOFDAY(&tv, NULL);
nka->next_event.tv_sec = tv.tv_sec + (int) nka->current_keepalive;
nka->next_event.tv_usec = (long)( nka->current_keepalive - (int) nka->current_keepalive ) * 1000000;
Display(LOG_LEVEL_3, ELInfo, "internal_adjust_next_event", HEX_STR_NEXT_KA_IN, nka->current_keepalive);
return;
}
/* Removes leaves from the trie with frequency under a certain amount */
void trim(int level) {
internal_trim(level);
}
