faraphel/chrony
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Cache minimum peer delay in sourcestats

Browse source
This commit is contained in:
Miroslav Lichvar 2010-12-03 17:25:50 +01:00
parent 0de82a70a6
commit feb8811f37
1 changed files with 38 additions and 9 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

47
sourcestats.c
View file

@ -77,6 +77,9 @@ struct SST_Stats_Record {
root distance at the present time */
int best_single_sample;
/* The index of the sample with minimum delay in peer_delays */
int min_delay_sample;
/* This is the estimated offset (+ve => local fast) at a particular time */
double estimated_offset;
double estimated_offset_sd;
@ -144,6 +147,11 @@ struct SST_Stats_Record {
/* ================================================== */
static void find_min_delay_sample(SST_Stats inst);
static int get_buf_index(SST_Stats inst, int i);
/* ================================================== */
void
SST_Initialise(void)
{
@ -173,6 +181,7 @@ SST_CreateInstance(unsigned long refid, IPAddr *addr)
inst->runs_samples = 0;
inst->last_sample = 0;
inst->best_single_sample = 0;
inst->min_delay_sample = 0;
inst->estimated_frequency = 0;
inst->skew = 2000.0e-6;
inst->skew_dirn = SST_Skew_Nochange;
@ -202,6 +211,9 @@ SST_DeleteInstance(SST_Stats inst)
static void
prune_register(SST_Stats inst, int new_oldest)
{
if (!new_oldest)
return;
assert(inst->n_samples >= new_oldest);
inst->n_samples -= new_oldest;
inst->runs_samples += new_oldest;
@ -209,6 +221,8 @@ prune_register(SST_Stats inst, int new_oldest)
inst->runs_samples = inst->n_samples * (REGRESS_RUNS_RATIO - 1);
assert(inst->n_samples + inst->runs_samples <= MAX_SAMPLES * REGRESS_RUNS_RATIO);
find_min_delay_sample(inst);
}
/* ================================================== */
@ -239,6 +253,9 @@ SST_AccumulateSample(SST_Stats inst, struct timeval *sample_time,
inst->root_dispersions[m] = root_dispersion;
inst->strata[m] = stratum;
if (!inst->n_samples || inst->peer_delays[m] < inst->peer_delays[inst->min_delay_sample])
inst->min_delay_sample = m;
++inst->n_samples;
}
@ -325,6 +342,22 @@ find_best_sample_index(SST_Stats inst, double *times_back)
/* ================================================== */
static void
find_min_delay_sample(SST_Stats inst)
{
int i, index;
inst->min_delay_sample = get_buf_index(inst, 0);
for (i = 1; i < inst->n_samples; i++) {
index = get_buf_index(inst, i);
if (inst->peer_delays[index] < inst->peer_delays[inst->min_delay_sample])
inst->min_delay_sample = index;
}
}
/* ================================================== */
/* This defines the assumed ratio between the standard deviation of
the samples and the peer distance as measured from the round trip
time. E.g. a value of 4 means that we think the standard deviation
@ -655,15 +688,9 @@ SST_PredictOffset(SST_Stats inst, struct timeval *when)
double
SST_MinRoundTripDelay(SST_Stats inst)
{
double min_delay, delay;
int i;
for (i = 0, min_delay = DBL_MAX; i < inst->n_samples; i++) {
delay = inst->peer_delays[get_buf_index(inst, i)];
if (delay < min_delay)
min_delay = delay;
}
return min_delay;
if (!inst->n_samples)
return DBL_MAX;
return inst->peer_delays[inst->min_delay_sample];
}
/* ================================================== */
@ -748,6 +775,8 @@ SST_LoadFromFile(SST_Stats inst, FILE *in)
inst->last_sample = inst->n_samples - 1;
inst->runs_samples = 0;
find_min_delay_sample(inst);
return 1;
}