ntpd: better selection of initial sync; fewer gettimeofday calls
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko
parent
185e691ec1
commit
0b002812a8
@ -47,9 +47,10 @@
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#define RETRY_INTERVAL 5 /* on error, retry in N secs */
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#define QUERYTIME_MAX 15 /* wait for reply up to N secs */
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#define RESPONSE_INTERVAL 15 /* wait for reply up to N secs */
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#define FREQ_TOLERANCE 0.000015 /* % frequency tolerance (15 PPM) */
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#define BURSTPOLL 0
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#define MINPOLL 4 /* % minimum poll interval (6: 64 s) */
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#define MAXPOLL 12 /* % maximum poll interval (12: 1.1h, 17: 36.4h) (was 17) */
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#define MINDISP 0.01 /* % minimum dispersion (s) */
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@ -162,13 +163,13 @@ typedef struct {
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char *p_dotted;
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/* when to send new query (if p_fd == -1)
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* or when receive times out (if p_fd >= 0): */
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time_t next_action_time;
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int p_fd;
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int datapoint_idx;
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uint32_t lastpkt_refid;
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uint8_t lastpkt_status;
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uint8_t lastpkt_stratum;
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uint8_t p_reachable_bits;
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uint8_t reachable_bits;
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double next_action_time;
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double p_xmttime;
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double lastpkt_recv_time;
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double lastpkt_delay;
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@ -196,6 +197,7 @@ enum {
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};
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struct globals {
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double cur_time;
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/* total round trip delay to currently selected reference clock */
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double rootdelay;
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/* reference timestamp: time when the system clock was last set or corrected */
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@ -245,7 +247,8 @@ struct globals {
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#define G_precision_sec (1.0 / (1 << (- G_precision_exp)))
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uint8_t stratum;
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/* Bool. After set to 1, never goes back to 0: */
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uint8_t adjtimex_was_done;
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smallint adjtimex_was_done;
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smallint initial_poll_complete;
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uint8_t discipline_state; // doc calls it c.state
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uint8_t poll_exp; // s.poll
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@ -303,7 +306,8 @@ gettime1900d(void)
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{
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struct timeval tv;
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gettimeofday(&tv, NULL); /* never fails */
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return (tv.tv_sec + 1.0e-6 * tv.tv_usec + OFFSET_1900_1970);
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G.cur_time = tv.tv_sec + (1.0e-6 * tv.tv_usec) + OFFSET_1900_1970;
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return G.cur_time;
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}
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static void
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@ -355,13 +359,13 @@ d_to_sfp(double d)
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#endif
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static double
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dispersion(const datapoint_t *dp, double t)
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dispersion(const datapoint_t *dp)
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{
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return dp->d_dispersion + FREQ_TOLERANCE * (t - dp->d_recv_time);
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return dp->d_dispersion + FREQ_TOLERANCE * (G.cur_time - dp->d_recv_time);
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}
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static double
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root_distance(peer_t *p, double t)
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root_distance(peer_t *p)
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{
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/* The root synchronization distance is the maximum error due to
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* all causes of the local clock relative to the primary server.
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@ -371,21 +375,21 @@ root_distance(peer_t *p, double t)
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return MAXD(MINDISP, p->lastpkt_rootdelay + p->lastpkt_delay) / 2
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+ p->lastpkt_rootdisp
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+ p->filter_dispersion
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+ FREQ_TOLERANCE * (t - p->lastpkt_recv_time)
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+ FREQ_TOLERANCE * (G.cur_time - p->lastpkt_recv_time)
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+ p->filter_jitter;
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}
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static void
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set_next(peer_t *p, unsigned t)
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{
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p->next_action_time = time(NULL) + t;
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p->next_action_time = G.cur_time + t;
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}
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/*
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* Peer clock filter and its helpers
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*/
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static void
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filter_datapoints(peer_t *p, double t)
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filter_datapoints(peer_t *p)
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{
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int i, idx;
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int got_newest;
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@ -427,14 +431,14 @@ filter_datapoints(peer_t *p, double t)
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bb_error_msg("datapoint[%d]: off:%f disp:%f(%f) age:%f%s",
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i,
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p->filter_datapoint[idx].d_offset,
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p->filter_datapoint[idx].d_dispersion, dispersion(&p->filter_datapoint[idx], t),
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t - p->filter_datapoint[idx].d_recv_time,
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p->filter_datapoint[idx].d_dispersion, dispersion(&p->filter_datapoint[idx]),
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G.cur_time - p->filter_datapoint[idx].d_recv_time,
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(minoff == p->filter_datapoint[idx].d_offset || maxoff == p->filter_datapoint[idx].d_offset)
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? " (outlier by offset)" : ""
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);
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}
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sum += dispersion(&p->filter_datapoint[idx], t) / (2 << i);
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sum += dispersion(&p->filter_datapoint[idx]) / (2 << i);
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if (minoff == p->filter_datapoint[idx].d_offset) {
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minoff -= 1; /* so that we don't match it ever again */
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@ -443,7 +447,7 @@ filter_datapoints(peer_t *p, double t)
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maxoff += 1;
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} else {
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oldest_off = p->filter_datapoint[idx].d_offset;
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oldest_age = t - p->filter_datapoint[idx].d_recv_time;
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oldest_age = G.cur_time - p->filter_datapoint[idx].d_recv_time;
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if (!got_newest) {
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got_newest = 1;
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newest_off = oldest_off;
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@ -466,10 +470,13 @@ filter_datapoints(peer_t *p, double t)
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* and then we have this estimation, ~25% off from 0.7:
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* 0.1/32 + 0.2/32 + 0.3/16 + 0.4/8 + 0.5/4 + 0.6/2 = 0.503125
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*/
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x = newest_age / (oldest_age - newest_age); /* in above example, 100 / (600 - 100) */
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if (x < 1) {
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x = (newest_off - oldest_off) * x; /* 0.5 * 100/500 = 0.1 */
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wavg += x;
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x = oldest_age - newest_age;
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if (x != 0) {
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x = newest_age / x; /* in above example, 100 / (600 - 100) */
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if (x < 1) { /* paranoia check */
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x = (newest_off - oldest_off) * x; /* 0.5 * 100/500 = 0.1 */
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wavg += x;
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}
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}
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p->filter_offset = wavg;
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@ -499,7 +506,7 @@ filter_datapoints(peer_t *p, double t)
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}
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static void
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reset_peer_stats(peer_t *p, double t, double offset)
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reset_peer_stats(peer_t *p, double offset)
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{
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int i;
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for (i = 0; i < NUM_DATAPOINTS; i++) {
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@ -509,7 +516,7 @@ reset_peer_stats(peer_t *p, double t, double offset)
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p->filter_datapoint[i].d_offset -= offset;
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}
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} else {
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p->filter_datapoint[i].d_recv_time = t;
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p->filter_datapoint[i].d_recv_time = G.cur_time;
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p->filter_datapoint[i].d_offset = 0;
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p->filter_datapoint[i].d_dispersion = MAXDISP;
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}
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@ -517,11 +524,11 @@ reset_peer_stats(peer_t *p, double t, double offset)
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if (offset < 16 * STEP_THRESHOLD) {
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p->lastpkt_recv_time -= offset;
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} else {
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p->p_reachable_bits = 0;
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p->lastpkt_recv_time = t;
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p->reachable_bits = 0;
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p->lastpkt_recv_time = G.cur_time;
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}
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filter_datapoints(p, t); /* recalc p->filter_xxx */
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p->next_action_time -= (time_t)offset;
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filter_datapoints(p); /* recalc p->filter_xxx */
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p->next_action_time -= offset;
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VERB5 bb_error_msg("%s->lastpkt_recv_time=%f", p->p_dotted, p->lastpkt_recv_time);
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}
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@ -535,8 +542,8 @@ add_peers(char *s)
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p->p_dotted = xmalloc_sockaddr2dotted_noport(&p->p_lsa->u.sa);
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p->p_fd = -1;
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p->p_xmt_msg.m_status = MODE_CLIENT | (NTP_VERSION << 3);
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p->next_action_time = time(NULL); /* = set_next(p, 0); */
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reset_peer_stats(p, gettime1900d(), 16 * STEP_THRESHOLD);
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p->next_action_time = G.cur_time; /* = set_next(p, 0); */
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reset_peer_stats(p, 16 * STEP_THRESHOLD);
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/* Speed up initial sync: with small offsets from peers,
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* 3 samples will sync
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*/
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@ -567,7 +574,7 @@ do_sendto(int fd,
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return 0;
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}
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static int
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static void
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send_query_to_peer(peer_t *p)
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{
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/* Why do we need to bind()?
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@ -632,20 +639,19 @@ send_query_to_peer(peer_t *p)
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close(p->p_fd);
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p->p_fd = -1;
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set_next(p, RETRY_INTERVAL);
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return -1;
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return;
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}
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p->p_reachable_bits <<= 1;
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p->reachable_bits <<= 1;
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VERB1 bb_error_msg("sent query to %s", p->p_dotted);
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set_next(p, QUERYTIME_MAX);
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return 0;
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set_next(p, RESPONSE_INTERVAL);
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}
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static void
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static NOINLINE void
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step_time(double offset)
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{
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llist_t *item;
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double dtime;
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struct timeval tv;
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char buf[80];
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@ -663,6 +669,17 @@ step_time(double offset)
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strftime(buf, sizeof(buf), "%a %b %e %H:%M:%S %Z %Y", localtime(&tval));
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bb_error_msg("setting clock to %s (offset %fs)", buf, offset);
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/* Correct various fields which contain time-relative values: */
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/* p->lastpkt_recv_time, p->next_action_time and such: */
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for (item = G.ntp_peers; item != NULL; item = item->link) {
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peer_t *pp = (peer_t *) item->data;
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reset_peer_stats(pp, offset);
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}
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/* Globals: */
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G.cur_time -= offset;
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G.last_update_recv_time -= offset;
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}
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@ -700,7 +717,8 @@ compare_survivor_metric(const void *aa, const void *bb)
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static int
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fit(peer_t *p, double rd)
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{
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if (p->p_reachable_bits == 0) {
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if ((p->reachable_bits & (p->reachable_bits-1)) == 0) {
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/* One or zero bits in reachable_bits */
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VERB3 bb_error_msg("peer %s unfit for selection: unreachable", p->p_dotted);
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return 0;
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}
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@ -712,7 +730,7 @@ fit(peer_t *p, double rd)
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return 0;
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}
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#endif
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/* rd is root_distance(p, t) */
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/* rd is root_distance(p) */
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if (rd > MAXDIST + FREQ_TOLERANCE * (1 << G.poll_exp)) {
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VERB3 bb_error_msg("peer %s unfit for selection: root distance too high", p->p_dotted);
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return 0;
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@ -724,7 +742,7 @@ fit(peer_t *p, double rd)
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return 1;
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}
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static peer_t*
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select_and_cluster(double t)
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select_and_cluster(void)
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{
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llist_t *item;
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int i, j;
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@ -742,9 +760,9 @@ select_and_cluster(double t)
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num_points = 0;
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item = G.ntp_peers;
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while (item != NULL) {
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if (G.initial_poll_complete) while (item != NULL) {
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peer_t *p = (peer_t *) item->data;
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double rd = root_distance(p, t);
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double rd = root_distance(p);
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double offset = p->filter_offset;
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if (!fit(p, rd)) {
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@ -775,7 +793,7 @@ select_and_cluster(double t)
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num_candidates = num_points / 3;
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if (num_candidates == 0) {
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VERB3 bb_error_msg("no valid datapoints, no peer selected");
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return NULL; /* never happers? */
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return NULL;
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}
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//TODO: sorting does not seem to be done in reference code
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qsort(point, num_points, sizeof(point[0]), compare_point_edge);
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@ -856,7 +874,7 @@ select_and_cluster(double t)
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p = point[i].p;
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survivor[num_survivors].p = p;
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//TODO: save root_distance in point_t and reuse here?
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survivor[num_survivors].metric = MAXDIST * p->lastpkt_stratum + root_distance(p, t);
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survivor[num_survivors].metric = MAXDIST * p->lastpkt_stratum + root_distance(p);
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VERB4 bb_error_msg("survivor[%d] metric:%f peer:%s",
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num_survivors, survivor[num_survivors].metric, p->p_dotted);
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num_survivors++;
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@ -952,7 +970,7 @@ select_and_cluster(double t)
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VERB3 bb_error_msg("selected peer %s filter_offset:%f age:%f",
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survivor[0].p->p_dotted,
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survivor[0].p->filter_offset,
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t - survivor[0].p->lastpkt_recv_time
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G.cur_time - survivor[0].p->lastpkt_recv_time
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);
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return survivor[0].p;
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}
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@ -981,8 +999,8 @@ set_new_values(int disc_state, double offset, double recv_time)
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#define STATE_FREQ 3 /* initial frequency */
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#define STATE_SYNC 4 /* clock synchronized (normal operation) */
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/* Return: -1: decrease poll interval, 0: leave as is, 1: increase */
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static int
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update_local_clock(peer_t *p, double t)
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static NOINLINE int
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update_local_clock(peer_t *p)
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{
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int rc;
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long old_tmx_offset;
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@ -1037,8 +1055,6 @@ update_local_clock(peer_t *p, double t)
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* offset exceeds the step threshold and when it does not.
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*/
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if (abs_offset > STEP_THRESHOLD) {
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llist_t *item;
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switch (G.discipline_state) {
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case STATE_SYNC:
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/* The first outlyer: ignore it, switch to SPIK state */
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@ -1089,10 +1105,6 @@ update_local_clock(peer_t *p, double t)
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G.polladj_count = 0;
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G.poll_exp = MINPOLL;
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G.stratum = MAXSTRAT;
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for (item = G.ntp_peers; item != NULL; item = item->link) {
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peer_t *pp = (peer_t *) item->data;
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reset_peer_stats(pp, t, offset);
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}
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if (G.discipline_state == STATE_NSET) {
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set_new_values(STATE_FREQ, /*offset:*/ 0, recv_time);
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return 1; /* "ok to increase poll interval" */
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@ -1101,8 +1113,9 @@ update_local_clock(peer_t *p, double t)
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} else { /* abs_offset <= STEP_THRESHOLD */
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if (G.poll_exp < MINPOLL) {
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VERB3 bb_error_msg("saw small offset %f, disabling burst mode", offset);
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if (G.poll_exp < MINPOLL && G.initial_poll_complete) {
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VERB3 bb_error_msg("small offset:%f, disabling burst mode", offset);
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G.polladj_count = 0;
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G.poll_exp = MINPOLL;
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}
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@ -1128,7 +1141,7 @@ update_local_clock(peer_t *p, double t)
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*/
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set_new_values(STATE_FREQ, offset, recv_time);
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VERB3 bb_error_msg("transitioning to FREQ, datapoint ignored");
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return -1; /* "decrease poll interval" */
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return 0; /* "leave poll interval as is" */
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#if 0 /* this is dead code for now */
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case STATE_FSET:
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@ -1180,12 +1193,12 @@ update_local_clock(peer_t *p, double t)
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G.stratum = p->lastpkt_stratum + 1;
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}
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G.reftime = t;
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G.reftime = G.cur_time;
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G.ntp_status = p->lastpkt_status;
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G.refid = p->lastpkt_refid;
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G.rootdelay = p->lastpkt_rootdelay + p->lastpkt_delay;
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dtemp = p->filter_jitter; // SQRT(SQUARE(p->filter_jitter) + SQUARE(s.jitter));
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dtemp += MAXD(p->filter_dispersion + FREQ_TOLERANCE * (t - p->lastpkt_recv_time) + abs_offset, MINDISP);
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dtemp += MAXD(p->filter_dispersion + FREQ_TOLERANCE * (G.cur_time - p->lastpkt_recv_time) + abs_offset, MINDISP);
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G.rootdisp = p->lastpkt_rootdisp + dtemp;
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VERB3 bb_error_msg("updating leap/refid/reftime/rootdisp from peer %s", p->p_dotted);
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@ -1318,19 +1331,20 @@ retry_interval(void)
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return interval;
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}
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static unsigned
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poll_interval(int exponent) /* exp is always -1 or 0 */
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poll_interval(int exponent)
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{
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/* Want to send next packet at (1 << G.poll_exp) + small random value */
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unsigned interval, r;
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exponent += G.poll_exp; /* G.poll_exp is always > 0 */
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/* never true: if (exp < 0) exp = 0; */
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exponent = G.poll_exp + exponent;
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if (exponent < 0)
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exponent = 0;
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interval = 1 << exponent;
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r = random();
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interval += ((r & (interval-1)) >> 4) + ((r >> 8) & 1); /* + 1/16 of interval, max */
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VERB3 bb_error_msg("chose poll interval:%u (poll_exp:%d exp:%d)", interval, G.poll_exp, exponent);
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return interval;
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}
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static void
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static NOINLINE void
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recv_and_process_peer_pkt(peer_t *p)
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{
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int rc;
|
||||
@ -1410,12 +1424,12 @@ recv_and_process_peer_pkt(peer_t *p)
|
||||
T1 = p->p_xmttime;
|
||||
T2 = lfp_to_d(msg.m_rectime);
|
||||
T3 = lfp_to_d(msg.m_xmttime);
|
||||
T4 = gettime1900d();
|
||||
T4 = G.cur_time;
|
||||
|
||||
p->lastpkt_recv_time = T4;
|
||||
|
||||
VERB5 bb_error_msg("%s->lastpkt_recv_time=%f", p->p_dotted, p->lastpkt_recv_time);
|
||||
p->datapoint_idx = p->p_reachable_bits ? (p->datapoint_idx + 1) % NUM_DATAPOINTS : 0;
|
||||
p->datapoint_idx = p->reachable_bits ? (p->datapoint_idx + 1) % NUM_DATAPOINTS : 0;
|
||||
datapoint = &p->filter_datapoint[p->datapoint_idx];
|
||||
datapoint->d_recv_time = T4;
|
||||
datapoint->d_offset = ((T2 - T1) + (T3 - T4)) / 2;
|
||||
@ -1429,7 +1443,7 @@ recv_and_process_peer_pkt(peer_t *p)
|
||||
if (p->lastpkt_delay < G_precision_sec)
|
||||
p->lastpkt_delay = G_precision_sec;
|
||||
datapoint->d_dispersion = LOG2D(msg.m_precision_exp) + G_precision_sec;
|
||||
if (!p->p_reachable_bits) {
|
||||
if (!p->reachable_bits) {
|
||||
/* 1st datapoint ever - replicate offset in every element */
|
||||
int i;
|
||||
for (i = 1; i < NUM_DATAPOINTS; i++) {
|
||||
@ -1437,20 +1451,20 @@ recv_and_process_peer_pkt(peer_t *p)
|
||||
}
|
||||
}
|
||||
|
||||
p->p_reachable_bits |= 1;
|
||||
p->reachable_bits |= 1;
|
||||
VERB1 {
|
||||
bb_error_msg("reply from %s: reach 0x%02x offset %f delay %f",
|
||||
p->p_dotted,
|
||||
p->p_reachable_bits,
|
||||
p->reachable_bits,
|
||||
datapoint->d_offset, p->lastpkt_delay);
|
||||
}
|
||||
|
||||
/* Muck with statictics and update the clock */
|
||||
filter_datapoints(p, T4);
|
||||
q = select_and_cluster(T4);
|
||||
filter_datapoints(p);
|
||||
q = select_and_cluster();
|
||||
rc = -1;
|
||||
if (q)
|
||||
rc = update_local_clock(q, T4);
|
||||
rc = update_local_clock(q);
|
||||
|
||||
if (rc != 0) {
|
||||
/* Adjust the poll interval by comparing the current offset
|
||||
@ -1524,12 +1538,11 @@ recv_and_process_peer_pkt(peer_t *p)
|
||||
}
|
||||
|
||||
#if ENABLE_FEATURE_NTPD_SERVER
|
||||
static void
|
||||
static NOINLINE void
|
||||
recv_and_process_client_pkt(void /*int fd*/)
|
||||
{
|
||||
ssize_t size;
|
||||
uint8_t version;
|
||||
double rectime;
|
||||
len_and_sockaddr *to;
|
||||
struct sockaddr *from;
|
||||
msg_t msg;
|
||||
@ -1565,8 +1578,9 @@ recv_and_process_client_pkt(void /*int fd*/)
|
||||
msg.m_stratum = G.stratum;
|
||||
msg.m_ppoll = G.poll_exp;
|
||||
msg.m_precision_exp = G_precision_exp;
|
||||
rectime = gettime1900d();
|
||||
msg.m_xmttime = msg.m_rectime = d_to_lfp(rectime);
|
||||
/* this time was obtained between poll() and recv() */
|
||||
msg.m_rectime = d_to_lfp(G.cur_time);
|
||||
msg.m_xmttime = d_to_lfp(gettime1900d()); /* this instant */
|
||||
msg.m_reftime = d_to_lfp(G.reftime);
|
||||
msg.m_orgtime = query_xmttime;
|
||||
msg.m_rootdelay = d_to_sfp(G.rootdelay);
|
||||
@ -1686,33 +1700,10 @@ static NOINLINE void ntp_init(char **argv)
|
||||
bb_error_msg_and_die(bb_msg_you_must_be_root);
|
||||
|
||||
/* Set some globals */
|
||||
#if 0
|
||||
/* With constant b = 100, G.precision_exp is also constant -6.
|
||||
* Uncomment this to verify.
|
||||
*/
|
||||
{
|
||||
int prec = 0;
|
||||
int b;
|
||||
# if 0
|
||||
struct timespec tp;
|
||||
/* We can use sys_clock_getres but assuming 10ms tick should be fine */
|
||||
clock_getres(CLOCK_REALTIME, &tp);
|
||||
tp.tv_sec = 0;
|
||||
tp.tv_nsec = 10000000;
|
||||
b = 1000000000 / tp.tv_nsec; /* convert to Hz */
|
||||
# else
|
||||
b = 100; /* b = 1000000000/10000000 = 100 */
|
||||
# endif
|
||||
while (b > 1)
|
||||
prec--, b >>= 1;
|
||||
/*G.precision_exp = prec;*/
|
||||
/*G.precision_sec = (1.0 / (1 << (- prec)));*/
|
||||
bb_error_msg("G.precision_exp:%d sec:%f", prec, G_precision_sec); /* -6 */
|
||||
}
|
||||
#endif
|
||||
G.stratum = MAXSTRAT;
|
||||
G.poll_exp = 1; /* should use MINPOLL, but 1 speeds up initial sync */
|
||||
G.reftime = G.last_update_recv_time = gettime1900d();
|
||||
if (BURSTPOLL != 0)
|
||||
G.poll_exp = BURSTPOLL; /* speeds up initial sync */
|
||||
G.reftime = G.last_update_recv_time = gettime1900d(); /* sets G.cur_time too */
|
||||
|
||||
/* Parse options */
|
||||
peers = NULL;
|
||||
@ -1752,61 +1743,66 @@ static NOINLINE void ntp_init(char **argv)
|
||||
int ntpd_main(int argc UNUSED_PARAM, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
||||
int ntpd_main(int argc UNUSED_PARAM, char **argv)
|
||||
{
|
||||
struct globals g;
|
||||
#undef G
|
||||
struct globals G;
|
||||
struct pollfd *pfd;
|
||||
peer_t **idx2peer;
|
||||
unsigned cnt;
|
||||
|
||||
memset(&g, 0, sizeof(g));
|
||||
SET_PTR_TO_GLOBALS(&g);
|
||||
memset(&G, 0, sizeof(G));
|
||||
SET_PTR_TO_GLOBALS(&G);
|
||||
|
||||
ntp_init(argv);
|
||||
|
||||
{
|
||||
/* if ENABLE_FEATURE_NTPD_SERVER, + 1 for listen_fd: */
|
||||
unsigned cnt = g.peer_cnt + ENABLE_FEATURE_NTPD_SERVER;
|
||||
idx2peer = xzalloc(sizeof(idx2peer[0]) * cnt);
|
||||
pfd = xzalloc(sizeof(pfd[0]) * cnt);
|
||||
}
|
||||
/* If ENABLE_FEATURE_NTPD_SERVER, + 1 for listen_fd: */
|
||||
cnt = G.peer_cnt + ENABLE_FEATURE_NTPD_SERVER;
|
||||
idx2peer = xzalloc(sizeof(idx2peer[0]) * cnt);
|
||||
pfd = xzalloc(sizeof(pfd[0]) * cnt);
|
||||
|
||||
/* Countdown: we never sync before we sent 5 packets to each peer
|
||||
* NB: if some peer is not responding, we may end up sending
|
||||
* fewer packets to it and more to other peers.
|
||||
* NB2: sync usually happens using 5-1=4 packets, since last reply
|
||||
* does not come back instantaneously.
|
||||
*/
|
||||
cnt = G.peer_cnt * 5;
|
||||
|
||||
while (!bb_got_signal) {
|
||||
llist_t *item;
|
||||
unsigned i, j;
|
||||
unsigned sent_cnt, trial_cnt;
|
||||
int nfds, timeout;
|
||||
time_t cur_time, nextaction;
|
||||
double nextaction;
|
||||
|
||||
/* Nothing between here and poll() blocks for any significant time */
|
||||
|
||||
cur_time = time(NULL);
|
||||
nextaction = cur_time + 3600;
|
||||
nextaction = G.cur_time + 3600;
|
||||
|
||||
i = 0;
|
||||
#if ENABLE_FEATURE_NTPD_SERVER
|
||||
if (g.listen_fd != -1) {
|
||||
pfd[0].fd = g.listen_fd;
|
||||
if (G.listen_fd != -1) {
|
||||
pfd[0].fd = G.listen_fd;
|
||||
pfd[0].events = POLLIN;
|
||||
i++;
|
||||
}
|
||||
#endif
|
||||
/* Pass over peer list, send requests, time out on receives */
|
||||
sent_cnt = trial_cnt = 0;
|
||||
for (item = g.ntp_peers; item != NULL; item = item->link) {
|
||||
for (item = G.ntp_peers; item != NULL; item = item->link) {
|
||||
peer_t *p = (peer_t *) item->data;
|
||||
|
||||
/* Overflow-safe "if (p->next_action_time <= cur_time) ..." */
|
||||
if ((int)(cur_time - p->next_action_time) >= 0) {
|
||||
if (p->next_action_time <= G.cur_time) {
|
||||
if (p->p_fd == -1) {
|
||||
/* Time to send new req */
|
||||
trial_cnt++;
|
||||
if (send_query_to_peer(p) == 0)
|
||||
sent_cnt++;
|
||||
if (--cnt == 0) {
|
||||
G.initial_poll_complete = 1;
|
||||
}
|
||||
send_query_to_peer(p);
|
||||
} else {
|
||||
/* Timed out waiting for reply */
|
||||
close(p->p_fd);
|
||||
p->p_fd = -1;
|
||||
timeout = poll_interval(-1); /* try a bit faster */
|
||||
timeout = poll_interval(-2); /* -2: try a bit sooner */
|
||||
bb_error_msg("timed out waiting for %s, reach 0x%02x, next query in %us",
|
||||
p->p_dotted, p->p_reachable_bits, timeout);
|
||||
p->p_dotted, p->reachable_bits, timeout);
|
||||
set_next(p, timeout);
|
||||
}
|
||||
}
|
||||
@ -1823,23 +1819,26 @@ int ntpd_main(int argc UNUSED_PARAM, char **argv)
|
||||
}
|
||||
}
|
||||
|
||||
timeout = nextaction - cur_time;
|
||||
if (timeout < 1)
|
||||
timeout = 1;
|
||||
timeout = nextaction - G.cur_time;
|
||||
if (timeout < 0)
|
||||
timeout = 0;
|
||||
timeout++; /* (nextaction - G.cur_time) rounds down, compensating */
|
||||
|
||||
/* Here we may block */
|
||||
VERB2 bb_error_msg("poll %us, sockets:%u", timeout, i);
|
||||
nfds = poll(pfd, i, timeout * 1000);
|
||||
gettime1900d(); /* sets G.cur_time */
|
||||
if (nfds <= 0)
|
||||
continue;
|
||||
|
||||
/* Process any received packets */
|
||||
j = 0;
|
||||
#if ENABLE_FEATURE_NTPD_SERVER
|
||||
if (g.listen_fd != -1) {
|
||||
if (G.listen_fd != -1) {
|
||||
if (pfd[0].revents /* & (POLLIN|POLLERR)*/) {
|
||||
nfds--;
|
||||
recv_and_process_client_pkt(/*g.listen_fd*/);
|
||||
recv_and_process_client_pkt(/*G.listen_fd*/);
|
||||
gettime1900d(); /* sets G.cur_time */
|
||||
}
|
||||
j = 1;
|
||||
}
|
||||
@ -1848,6 +1847,7 @@ int ntpd_main(int argc UNUSED_PARAM, char **argv)
|
||||
if (pfd[j].revents /* & (POLLIN|POLLERR)*/) {
|
||||
nfds--;
|
||||
recv_and_process_peer_pkt(idx2peer[j]);
|
||||
gettime1900d(); /* sets G.cur_time */
|
||||
}
|
||||
}
|
||||
} /* while (!bb_got_signal) */
|
||||
|
||||
Loading…
Reference in New Issue
Block a user