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-rw-r--r--erts/emulator/beam/erl_time_sup.c507
1 files changed, 340 insertions, 167 deletions
diff --git a/erts/emulator/beam/erl_time_sup.c b/erts/emulator/beam/erl_time_sup.c
index bbdedcc128..9d572c0b0a 100644
--- a/erts/emulator/beam/erl_time_sup.c
+++ b/erts/emulator/beam/erl_time_sup.c
@@ -133,6 +133,7 @@ struct time_sup_read_only__ {
ErtsTimeWarpMode warp_mode;
#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
ErtsMonotonicTime moffset;
+ int os_corrected_monotonic_time;
int os_monotonic_time_disable;
char *os_monotonic_time_func;
char *os_monotonic_time_clock_id;
@@ -159,12 +160,16 @@ struct time_sup_read_only__ {
ErtsMonotonicTime large_diff;
ErtsMonotonicTime small_diff;
} adj;
+ struct {
+ ErtsMonotonicTime error;
+ ErtsMonotonicTime resolution;
+ int intervals;
+ int use_avg;
+ } drift_adj;
};
typedef struct {
-#ifndef ERTS_HAVE_CORRECTED_OS_MONOTONIC
ErtsMonotonicTime drift; /* Correction for os monotonic drift */
-#endif
ErtsMonotonicTime error; /* Correction for error between system times */
} ErtsMonotonicCorrection;
@@ -174,7 +179,7 @@ typedef struct {
ErtsMonotonicCorrection correction;
} ErtsMonotonicCorrectionInstance;
-#define ERTS_DRIFT_INTERVALS 5
+#define ERTS_MAX_DRIFT_INTERVALS 50
typedef struct {
struct {
struct {
@@ -185,7 +190,7 @@ typedef struct {
ErtsMonotonicTime sys;
ErtsMonotonicTime mon;
} time;
- } intervals[ERTS_DRIFT_INTERVALS];
+ } intervals[ERTS_MAX_DRIFT_INTERVALS];
struct {
ErtsMonotonicTime sys;
ErtsMonotonicTime mon;
@@ -197,9 +202,7 @@ typedef struct {
typedef struct {
ErtsMonotonicCorrectionInstance prev;
ErtsMonotonicCorrectionInstance curr;
-#ifndef ERTS_HAVE_CORRECTED_OS_MONOTONIC
ErtsMonotonicDriftData drift;
-#endif
ErtsMonotonicTime last_check;
int short_check_interval;
} ErtsMonotonicCorrectionData;
@@ -213,10 +216,11 @@ struct time_sup_infrequently_changed__ {
} parmon;
ErtsMonotonicTime minit;
#endif
- int finalized_offset;
ErtsSystemTime sinit;
ErtsMonotonicTime not_corrected_moffset;
- erts_atomic64_t offset;
+ erts_smp_atomic64_t offset;
+ ErtsMonotonicTime shadow_offset;
+ erts_smp_atomic32_t preliminary_offset;
};
struct time_sup_frequently_changed__ {
@@ -254,19 +258,19 @@ erts_get_approx_time(void)
static ERTS_INLINE void
init_time_offset(ErtsMonotonicTime offset)
{
- erts_atomic64_init_nob(&time_sup.inf.c.offset, (erts_aint64_t) offset);
+ erts_smp_atomic64_init_nob(&time_sup.inf.c.offset, (erts_aint64_t) offset);
}
static ERTS_INLINE void
set_time_offset(ErtsMonotonicTime offset)
{
- erts_atomic64_set_relb(&time_sup.inf.c.offset, (erts_aint64_t) offset);
+ erts_smp_atomic64_set_relb(&time_sup.inf.c.offset, (erts_aint64_t) offset);
}
static ERTS_INLINE ErtsMonotonicTime
get_time_offset(void)
{
- return (ErtsMonotonicTime) erts_atomic64_read_acqb(&time_sup.inf.c.offset);
+ return (ErtsMonotonicTime) erts_smp_atomic64_read_acqb(&time_sup.inf.c.offset);
}
@@ -290,16 +294,38 @@ get_time_offset(void)
#define ERTS_TIME_DRIFT_MAX_ADJ_DIFF ERTS_USEC_TO_MONOTONIC(50)
#define ERTS_TIME_DRIFT_MIN_ADJ_DIFF ERTS_USEC_TO_MONOTONIC(5)
+/*
+ * Maximum drift of the OS monotonic clock expected.
+ *
+ * We use 1 milli second per second. If the monotonic
+ * clock drifts more than this we will fail to adjust for
+ * drift, and error correction will kick in instead.
+ * If it is larger than this, one could argue that the
+ * primitive is to poor to be used...
+ */
+#define ERTS_MAX_MONOTONIC_DRIFT ERTS_MSEC_TO_MONOTONIC(1)
+
+/*
+ * We assume that precision is 32 times worse than the
+ * resolution. This is a wild guess, but there are no
+ * practical way to determine actual precision.
+ */
+#define ERTS_ASSUMED_PRECISION_DROP 32
+
+#define ERTS_MIN_MONOTONIC_DRIFT_MEASUREMENT \
+ (ERTS_SHORT_TIME_CORRECTION_CHECK - 2*ERTS_MAX_MONOTONIC_DRIFT)
+
+
static ERTS_INLINE ErtsMonotonicTime
calc_corrected_erl_mtime(ErtsMonotonicTime os_mtime,
ErtsMonotonicCorrectionInstance *cip,
- ErtsMonotonicTime *os_mdiff_p)
+ ErtsMonotonicTime *os_mdiff_p,
+ int os_drift_corrected)
{
ErtsMonotonicTime erl_mtime, diff = os_mtime - cip->os_mtime;
ERTS_TIME_ASSERT(diff >= 0);
-#ifndef ERTS_HAVE_CORRECTED_OS_MONOTONIC
- diff += (cip->correction.drift*diff)/ERTS_MONOTONIC_TIME_UNIT;
-#endif
+ if (!os_drift_corrected)
+ diff += (cip->correction.drift*diff)/ERTS_MONOTONIC_TIME_UNIT;
erl_mtime = cip->erl_mtime;
erl_mtime += diff;
erl_mtime += cip->correction.error*(diff/ERTS_TCORR_ERR_UNIT);
@@ -308,7 +334,8 @@ calc_corrected_erl_mtime(ErtsMonotonicTime os_mtime,
return erl_mtime;
}
-static ErtsMonotonicTime get_corrected_time(void)
+static ERTS_INLINE ErtsMonotonicTime
+read_corrected_time(int os_drift_corrected)
{
ErtsMonotonicTime os_mtime;
ErtsMonotonicCorrectionData cdata;
@@ -331,7 +358,18 @@ static ErtsMonotonicTime get_corrected_time(void)
cip = &cdata.prev;
}
- return calc_corrected_erl_mtime(os_mtime, cip, NULL);
+ return calc_corrected_erl_mtime(os_mtime, cip, NULL,
+ os_drift_corrected);
+}
+
+static ErtsMonotonicTime get_os_drift_corrected_time(void)
+{
+ return read_corrected_time(!0);
+}
+
+static ErtsMonotonicTime get_corrected_time(void)
+{
+ return read_corrected_time(0);
}
#ifdef ERTS_TIME_CORRECTION_PRINT
@@ -352,66 +390,42 @@ print_correction(int change,
usec_sdiff = ERTS_MONOTONIC_TO_USEC(sdiff);
if (!change)
- fprintf(stderr,
- "sdiff = %lld usec : [ec=%lld ppm, dc=%lld ppb] : "
- "tmo = %lld msec\r\n",
- (long long) usec_sdiff,
- (long long) (1000000*old_ecorr) / ERTS_TCORR_ERR_UNIT,
- (long long) (1000000000*old_dcorr) / ERTS_MONOTONIC_TIME_UNIT,
- (long long) tmo);
+ erts_fprintf(stderr,
+ "sdiff = %b64d usec : [ec=%b64d ppm, dc=%b64d ppb] : "
+ "tmo = %bpu msec\r\n",
+ usec_sdiff,
+ (1000000*old_ecorr) / ERTS_TCORR_ERR_UNIT,
+ (1000000000*old_dcorr) / ERTS_MONOTONIC_TIME_UNIT,
+ tmo);
else
- fprintf(stderr,
- "sdiff = %lld usec : [ec=%lld ppm, dc=%lld ppb] "
- "-> [ec=%lld ppm, dc=%lld ppb] : tmo = %lld msec\r\n",
- (long long) usec_sdiff,
- (long long) (1000000*old_ecorr) / ERTS_TCORR_ERR_UNIT,
- (long long) (1000000000*old_dcorr) / ERTS_MONOTONIC_TIME_UNIT,
- (long long) (1000000*new_ecorr) / ERTS_TCORR_ERR_UNIT,
- (long long) (1000000000*new_dcorr) / ERTS_MONOTONIC_TIME_UNIT,
- (long long) tmo);
-
+ erts_fprintf(stderr,
+ "sdiff = %b64d usec : [ec=%b64d ppm, dc=%b64d ppb] "
+ "-> [ec=%b64d ppm, dc=%b64d ppb] : tmo = %bpu msec\r\n",
+ usec_sdiff,
+ (1000000*old_ecorr) / ERTS_TCORR_ERR_UNIT,
+ (1000000000*old_dcorr) / ERTS_MONOTONIC_TIME_UNIT,
+ (1000000*new_ecorr) / ERTS_TCORR_ERR_UNIT,
+ (1000000000*new_dcorr) / ERTS_MONOTONIC_TIME_UNIT,
+ tmo);
}
#endif
static void
-check_time_correction(void *unused)
+check_time_correction(void *idap)
{
-#ifndef ERTS_TIME_CORRECTION_PRINT
-# define ERTS_PRINT_CORRECTION
-#else
-# ifdef ERTS_HAVE_CORRECTED_OS_MONOTONIC
-# define ERTS_PRINT_CORRECTION \
- print_correction(set_new_correction, \
- sdiff, \
- cip->correction.error, \
- 0, \
- new_correction.error, \
- 0, \
- timeout)
-# else
-# define ERTS_PRINT_CORRECTION \
- print_correction(set_new_correction, \
- sdiff, \
- cip->correction.error, \
- cip->correction.drift, \
- new_correction.error, \
- new_correction.drift, \
- timeout)
-# endif
-#endif
+ UWord init_drift_adj = (UWord) idap;
ErtsMonotonicCorrectionData cdata;
ErtsMonotonicCorrection new_correction;
ErtsMonotonicCorrectionInstance *cip;
ErtsMonotonicTime mdiff, sdiff, os_mtime, erl_mtime, os_stime,
erl_stime, time_offset;
Uint timeout;
- int set_new_correction, begin_short_intervals = 0;
+ int os_drift_corrected = time_sup.r.o.os_corrected_monotonic_time;
+ int set_new_correction = 0, begin_short_intervals = 0;
erts_smp_rwmtx_rlock(&time_sup.inf.c.parmon.rwmtx);
- ASSERT(time_sup.inf.c.finalized_offset);
-
erts_os_times(&os_mtime, &os_stime);
cdata = time_sup.inf.c.parmon.cdata;
@@ -423,14 +437,23 @@ check_time_correction(void *unused)
"OS monotonic time stepped backwards\n");
cip = &cdata.curr;
- erl_mtime = calc_corrected_erl_mtime(os_mtime, cip, &mdiff);
+ erl_mtime = calc_corrected_erl_mtime(os_mtime, cip, &mdiff,
+ os_drift_corrected);
time_offset = get_time_offset();
erl_stime = erl_mtime + time_offset;
sdiff = erl_stime - os_stime;
+ if (time_sup.inf.c.shadow_offset) {
+ ERTS_TIME_ASSERT(time_sup.r.o.warp_mode == ERTS_SINGLE_TIME_WARP_MODE);
+ if (erts_smp_atomic32_read_nob(&time_sup.inf.c.preliminary_offset))
+ sdiff += time_sup.inf.c.shadow_offset;
+ else
+ time_sup.inf.c.shadow_offset = 0;
+ }
+
new_correction = cip->correction;
-
+
if (time_sup.r.o.warp_mode == ERTS_MULTI_TIME_WARP_MODE
&& (sdiff < -2*time_sup.r.o.adj.small_diff
|| 2*time_sup.r.o.adj.small_diff < sdiff)) {
@@ -440,9 +463,24 @@ check_time_correction(void *unused)
set_time_offset(time_offset);
schedule_send_time_offset_changed_notifications(time_offset);
begin_short_intervals = 1;
- if (cdata.curr.correction.error == 0)
- set_new_correction = 0;
- else {
+ if (cdata.curr.correction.error != 0) {
+ set_new_correction = 1;
+ new_correction.error = 0;
+ }
+ }
+ else if ((time_sup.r.o.warp_mode == ERTS_SINGLE_TIME_WARP_MODE
+ && erts_smp_atomic32_read_nob(&time_sup.inf.c.preliminary_offset))
+ && (sdiff < -2*time_sup.r.o.adj.small_diff
+ || 2*time_sup.r.o.adj.small_diff < sdiff)) {
+ /*
+ * System time diff exeeded limits; change shadow offset
+ * and let OS system time leap away from Erlang system
+ * time.
+ */
+ time_sup.inf.c.shadow_offset -= sdiff;
+ sdiff = 0;
+ begin_short_intervals = 1;
+ if (cdata.curr.correction.error != 0) {
set_new_correction = 1;
new_correction.error = 0;
}
@@ -462,16 +500,11 @@ check_time_correction(void *unused)
else
new_correction.error = -ERTS_TCORR_ERR_SMALL_ADJ;
}
- else {
- set_new_correction = 0;
- }
}
else if (cdata.curr.correction.error > 0) {
if (sdiff < 0) {
- if (cdata.curr.correction.error == ERTS_TCORR_ERR_LARGE_ADJ
- || -time_sup.r.o.adj.large_diff <= sdiff)
- set_new_correction = 0;
- else {
+ if (cdata.curr.correction.error != ERTS_TCORR_ERR_LARGE_ADJ
+ && sdiff < -time_sup.r.o.adj.large_diff) {
new_correction.error = ERTS_TCORR_ERR_LARGE_ADJ;
set_new_correction = 1;
}
@@ -490,14 +523,11 @@ check_time_correction(void *unused)
}
else /* if (cdata.curr.correction.error < 0) */ {
if (0 < sdiff) {
- if (cdata.curr.correction.error == -ERTS_TCORR_ERR_LARGE_ADJ
- || sdiff <= time_sup.r.o.adj.large_diff)
- set_new_correction = 0;
- else {
+ if (cdata.curr.correction.error != -ERTS_TCORR_ERR_LARGE_ADJ
+ && time_sup.r.o.adj.large_diff < sdiff) {
new_correction.error = -ERTS_TCORR_ERR_LARGE_ADJ;
set_new_correction = 1;
}
- set_new_correction = 0;
}
else if (sdiff < -time_sup.r.o.adj.small_diff) {
set_new_correction = 1;
@@ -512,8 +542,7 @@ check_time_correction(void *unused)
}
}
-#ifndef ERTS_HAVE_CORRECTED_OS_MONOTONIC
- {
+ if (!os_drift_corrected) {
ErtsMonotonicDriftData *ddp = &time_sup.inf.c.parmon.cdata.drift;
int ix = ddp->ix;
ErtsMonotonicTime mtime_diff, old_os_mtime;
@@ -521,25 +550,26 @@ check_time_correction(void *unused)
old_os_mtime = ddp->intervals[ix].time.mon;
mtime_diff = os_mtime - old_os_mtime;
- if (mtime_diff >= ERTS_SEC_TO_MONOTONIC(10)) {
+ if ((mtime_diff >= ERTS_MIN_MONOTONIC_DRIFT_MEASUREMENT)
+ | init_drift_adj) {
ErtsMonotonicTime drift_adj, drift_adj_diff, old_os_stime,
- stime_diff, mtime_acc, stime_acc, avg_drift_adj;
+ smtime_diff, stime_diff, mtime_acc, stime_acc,
+ avg_drift_adj, max_drift;
old_os_stime = ddp->intervals[ix].time.sys;
mtime_acc = ddp->acc.mon;
stime_acc = ddp->acc.sys;
- avg_drift_adj = (((stime_acc - mtime_acc)*ERTS_MONOTONIC_TIME_UNIT)
+ avg_drift_adj = (((stime_acc - mtime_acc)
+ * ERTS_MONOTONIC_TIME_UNIT)
/ mtime_acc);
mtime_diff = os_mtime - old_os_mtime;
stime_diff = os_stime - old_os_stime;
- drift_adj = (((stime_diff - mtime_diff)*ERTS_MONOTONIC_TIME_UNIT)
- / mtime_diff);
-
+ smtime_diff = stime_diff - mtime_diff;
ix++;
- if (ix >= ERTS_DRIFT_INTERVALS)
+ if (ix >= time_sup.r.o.drift_adj.intervals)
ix = 0;
mtime_acc -= ddp->intervals[ix].diff.mon;
mtime_acc += mtime_diff;
@@ -555,24 +585,50 @@ check_time_correction(void *unused)
ddp->acc.mon = mtime_acc;
ddp->acc.sys = stime_acc;
- drift_adj_diff = avg_drift_adj - drift_adj;
- if (drift_adj_diff < -ERTS_TIME_DRIFT_MAX_ADJ_DIFF
- || ERTS_TIME_DRIFT_MAX_ADJ_DIFF < drift_adj_diff) {
- ddp->dirty_counter = ERTS_DRIFT_INTERVALS;
+ max_drift = ERTS_MAX_MONOTONIC_DRIFT;
+ max_drift *= ERTS_MONOTONIC_TO_SEC(mtime_diff);
+
+ if (smtime_diff > time_sup.r.o.drift_adj.error + max_drift
+ || smtime_diff < -1*time_sup.r.o.drift_adj.error - max_drift) {
+ dirty_intervals:
+ /*
+ * We had a leap in system time. Mark array as
+ * dirty to ensure that dirty values are rotated
+ * out before we use it again...
+ */
+ ddp->dirty_counter = time_sup.r.o.drift_adj.intervals;
begin_short_intervals = 1;
}
- else {
- if (ddp->dirty_counter <= 0) {
- drift_adj = ((stime_acc - mtime_acc)
- *ERTS_MONOTONIC_TIME_UNIT) / mtime_acc;
+ else if (ddp->dirty_counter > 0) {
+ if (init_drift_adj) {
+ new_correction.drift = ((smtime_diff
+ * ERTS_MONOTONIC_TIME_UNIT)
+ / mtime_diff);
+ set_new_correction = 1;
}
- if (ddp->dirty_counter >= 0) {
- if (ddp->dirty_counter == 0) {
- /* Force set new drift correction... */
- set_new_correction = 1;
- }
+ ddp->dirty_counter--;
+ }
+ else {
+ if (ddp->dirty_counter == 0) {
+ /* Force set new drift correction... */
+ set_new_correction = 1;
ddp->dirty_counter--;
}
+
+ if (time_sup.r.o.drift_adj.use_avg)
+ drift_adj = (((stime_acc - mtime_acc)
+ * ERTS_MONOTONIC_TIME_UNIT)
+ / mtime_acc);
+ else
+ drift_adj = ((smtime_diff
+ * ERTS_MONOTONIC_TIME_UNIT)
+ / mtime_diff);
+
+ drift_adj_diff = avg_drift_adj - drift_adj;
+ if (drift_adj_diff < -ERTS_TIME_DRIFT_MAX_ADJ_DIFF
+ || ERTS_TIME_DRIFT_MAX_ADJ_DIFF < drift_adj_diff)
+ goto dirty_intervals;
+
drift_adj_diff = drift_adj - new_correction.drift;
if (drift_adj_diff) {
if (drift_adj_diff > ERTS_TIME_DRIFT_MAX_ADJ_DIFF)
@@ -580,7 +636,6 @@ check_time_correction(void *unused)
else if (drift_adj_diff < -ERTS_TIME_DRIFT_MAX_ADJ_DIFF)
drift_adj_diff = -ERTS_TIME_DRIFT_MAX_ADJ_DIFF;
new_correction.drift += drift_adj_diff;
-
if (drift_adj_diff < -ERTS_TIME_DRIFT_MIN_ADJ_DIFF
|| ERTS_TIME_DRIFT_MIN_ADJ_DIFF < drift_adj_diff) {
set_new_correction = 1;
@@ -589,7 +644,6 @@ check_time_correction(void *unused)
}
}
}
-#endif
begin_short_intervals |= set_new_correction;
@@ -608,25 +662,34 @@ check_time_correction(void *unused)
timeout = ERTS_MONOTONIC_TO_MSEC(ERTS_LONG_TIME_CORRECTION_CHECK);
else {
ErtsMonotonicTime ecorr = new_correction.error;
- if (sdiff < 0)
- sdiff = -1*sdiff;
+ ErtsMonotonicTime abs_sdiff;
+ abs_sdiff = (sdiff < 0) ? -1*sdiff : sdiff;
if (ecorr < 0)
ecorr = -1*ecorr;
- if (sdiff > ecorr*(ERTS_LONG_TIME_CORRECTION_CHECK/ERTS_TCORR_ERR_UNIT))
+ if (abs_sdiff > ecorr*(ERTS_LONG_TIME_CORRECTION_CHECK/ERTS_TCORR_ERR_UNIT))
timeout = ERTS_MONOTONIC_TO_MSEC(ERTS_LONG_TIME_CORRECTION_CHECK);
else {
- timeout = ERTS_MONOTONIC_TO_MSEC((ERTS_TCORR_ERR_UNIT*sdiff)/ecorr);
+ timeout = ERTS_MONOTONIC_TO_MSEC((ERTS_TCORR_ERR_UNIT*abs_sdiff)/ecorr);
if (timeout < 10)
timeout = 10;
}
}
if (timeout > ERTS_MONOTONIC_TO_MSEC(ERTS_SHORT_TIME_CORRECTION_CHECK)
- && time_sup.inf.c.parmon.cdata.short_check_interval) {
+ && (time_sup.inf.c.parmon.cdata.short_check_interval
+ || time_sup.inf.c.parmon.cdata.drift.dirty_counter >= 0)) {
timeout = ERTS_MONOTONIC_TO_MSEC(ERTS_SHORT_TIME_CORRECTION_CHECK);
}
- ERTS_PRINT_CORRECTION;
+#ifdef ERTS_TIME_CORRECTION_PRINT
+ print_correction(set_new_correction,
+ sdiff,
+ cip->correction.error,
+ cip->correction.drift,
+ new_correction.error,
+ new_correction.drift,
+ timeout);
+#endif
if (set_new_correction) {
erts_smp_rwmtx_rwlock(&time_sup.inf.c.parmon.rwmtx);
@@ -638,16 +701,17 @@ check_time_correction(void *unused)
/*
* Current correction instance begin when
- * OS monotonic time has increased one unit.
+ * OS monotonic time has increased two units.
*/
- os_mtime++;
+ os_mtime += 2;
/*
* Erlang monotonic time corresponding to
* next OS monotonic time using previous
* correction.
*/
- erl_mtime = calc_corrected_erl_mtime(os_mtime, cip, NULL);
+ erl_mtime = calc_corrected_erl_mtime(os_mtime, cip, NULL,
+ os_drift_corrected);
/*
* Save new current correction instance.
@@ -664,18 +728,60 @@ check_time_correction(void *unused)
NULL,
NULL,
timeout);
+}
-#undef ERTS_PRINT_CORRECTION
+static ErtsMonotonicTime get_os_corrected_time(void)
+{
+ ASSERT(time_sup.r.o.warp_mode == ERTS_MULTI_TIME_WARP_MODE);
+ return erts_os_monotonic_time() + time_sup.r.o.moffset;
}
-#ifndef ERTS_HAVE_CORRECTED_OS_MONOTONIC
+static void
+check_time_offset(void *unused)
+{
+ ErtsMonotonicTime sdiff, os_mtime, erl_mtime, os_stime,
+ erl_stime, time_offset;
+
+ ASSERT(time_sup.r.o.warp_mode == ERTS_MULTI_TIME_WARP_MODE);
+
+ erts_os_times(&os_mtime, &os_stime);
+
+ erl_mtime = os_mtime + time_sup.r.o.moffset;
+ time_offset = get_time_offset();
+ erl_stime = erl_mtime + time_offset;
+
+ sdiff = erl_stime - os_stime;
+
+ if ((sdiff < -2*time_sup.r.o.adj.small_diff
+ || 2*time_sup.r.o.adj.small_diff < sdiff)) {
+ /* System time diff exeeded limits; change time offset... */
+#ifdef ERTS_TIME_CORRECTION_PRINT
+ erts_fprintf(stderr, "sdiff = %b64d nsec -> 0 nsec\n",
+ ERTS_MONOTONIC_TO_NSEC(sdiff));
+#endif
+ time_offset -= sdiff;
+ sdiff = 0;
+ set_time_offset(time_offset);
+ schedule_send_time_offset_changed_notifications(time_offset);
+ }
+#ifdef ERTS_TIME_CORRECTION_PRINT
+ else erts_fprintf(stderr, "sdiff = %b64d nsec\n",
+ ERTS_MONOTONIC_TO_NSEC(sdiff));
+#endif
+
+ erts_set_timer(&time_sup.inf.c.parmon.timer,
+ check_time_offset,
+ NULL,
+ NULL,
+ ERTS_MONOTONIC_TO_MSEC(ERTS_LONG_TIME_CORRECTION_CHECK));
+}
static void
-init_check_time_correction(void *unused)
+init_check_time_correction(void *quick_init_drift)
{
ErtsMonotonicDriftData *ddp;
ErtsMonotonicTime old_mtime, old_stime, mtime, stime, mtime_diff,
- stime_diff;
+ stime_diff, smtime_diff, max_drift;
int ix;
ddp = &time_sup.inf.c.parmon.cdata.drift;
@@ -687,7 +793,13 @@ init_check_time_correction(void *unused)
mtime_diff = mtime - old_mtime;
stime_diff = stime - old_stime;
- if (100*stime_diff < 80*mtime_diff || 120*mtime_diff < 100*stime_diff ) {
+ smtime_diff = stime_diff - mtime_diff;
+
+ max_drift = ERTS_MAX_MONOTONIC_DRIFT;
+ max_drift *= ERTS_MONOTONIC_TO_SEC(mtime_diff);
+
+ if (smtime_diff > time_sup.r.o.drift_adj.error + max_drift
+ || smtime_diff < -1*time_sup.r.o.drift_adj.error - max_drift) {
/* Had a system time leap... pretend no drift... */
stime_diff = mtime_diff;
}
@@ -697,29 +809,28 @@ init_check_time_correction(void *unused)
* a drift adjustment, and repeat this interval
* in all slots...
*/
- for (ix = 0; ix < ERTS_DRIFT_INTERVALS; ix++) {
+ for (ix = 0; ix < time_sup.r.o.drift_adj.intervals; ix++) {
ddp->intervals[ix].diff.mon = mtime_diff;
ddp->intervals[ix].diff.sys = stime_diff;
ddp->intervals[ix].time.mon = old_mtime;
ddp->intervals[ix].time.sys = old_stime;
}
- ddp->acc.sys = stime_diff*ERTS_DRIFT_INTERVALS;
- ddp->acc.mon = mtime_diff*ERTS_DRIFT_INTERVALS;
+ ddp->acc.sys = stime_diff*time_sup.r.o.drift_adj.intervals;
+ ddp->acc.mon = mtime_diff*time_sup.r.o.drift_adj.intervals;
ddp->ix = 0;
- ddp->dirty_counter = ERTS_DRIFT_INTERVALS;
+ ddp->dirty_counter = time_sup.r.o.drift_adj.intervals;
- check_time_correction(NULL);
+ check_time_correction(quick_init_drift);
}
-#endif
-
static ErtsMonotonicTime
finalize_corrected_time_offset(ErtsSystemTime *stimep)
{
ErtsMonotonicTime os_mtime;
ErtsMonotonicCorrectionData cdata;
ErtsMonotonicCorrectionInstance *cip;
+ int os_drift_corrected = time_sup.r.o.os_corrected_monotonic_time;
erts_smp_rwmtx_rlock(&time_sup.inf.c.parmon.rwmtx);
@@ -734,25 +845,38 @@ finalize_corrected_time_offset(ErtsSystemTime *stimep)
"OS monotonic time stepped backwards\n");
cip = &cdata.curr;
- return calc_corrected_erl_mtime(os_mtime, cip, NULL);
+ return calc_corrected_erl_mtime(os_mtime, cip, NULL,
+ os_drift_corrected);
}
static void
late_init_time_correction(void)
{
- if (time_sup.inf.c.finalized_offset) {
+ Uint timeout;
+ Uint quick_init_drift_adj;
+ void (*check_func)(void *);
- erts_init_timer(&time_sup.inf.c.parmon.timer);
- erts_set_timer(&time_sup.inf.c.parmon.timer,
-#ifndef ERTS_HAVE_CORRECTED_OS_MONOTONIC
- init_check_time_correction,
-#else
- check_time_correction,
-#endif
- NULL,
- NULL,
- ERTS_MONOTONIC_TO_MSEC(ERTS_SHORT_TIME_CORRECTION_CHECK));
- }
+ quick_init_drift_adj =
+ (Uint) ERTS_MONOTONIC_TO_USEC(time_sup.r.o.drift_adj.error) == 0;
+
+ if (quick_init_drift_adj)
+ timeout = ERTS_MONOTONIC_TO_MSEC(ERTS_SHORT_TIME_CORRECTION_CHECK/10);
+ else
+ timeout = ERTS_MONOTONIC_TO_MSEC(ERTS_SHORT_TIME_CORRECTION_CHECK);
+
+ if (!time_sup.r.o.os_corrected_monotonic_time)
+ check_func = init_check_time_correction;
+ else if (time_sup.r.o.get_time == get_os_corrected_time)
+ check_func = check_time_offset;
+ else
+ check_func = check_time_correction;
+
+ erts_init_timer(&time_sup.inf.c.parmon.timer);
+ erts_set_timer(&time_sup.inf.c.parmon.timer,
+ check_func,
+ NULL,
+ (void *) quick_init_drift_adj,
+ timeout);
}
#endif /* ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT */
@@ -832,6 +956,8 @@ void erts_init_sys_time_sup(void)
#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
time_sup.r.o.os_monotonic_time_disable
= !sys_init_time_res.have_os_monotonic_time;
+ time_sup.r.o.os_corrected_monotonic_time =
+ sys_init_time_res.have_corrected_os_monotonic_time;
time_sup.r.o.os_monotonic_time_func
= sys_init_time_res.os_monotonic_time_info.func;
time_sup.r.o.os_monotonic_time_clock_id
@@ -856,7 +982,7 @@ void erts_init_sys_time_sup(void)
int
erts_init_time_sup(int time_correction, ErtsTimeWarpMode time_warp_mode)
{
- ErtsMonotonicTime resolution;
+ ErtsMonotonicTime resolution, ilength, intervals, short_isecs;
#if !ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT
ErtsMonotonicTime abs_native_offset, native_offset;
#endif
@@ -870,9 +996,10 @@ erts_init_time_sup(int time_correction, ErtsTimeWarpMode time_warp_mode)
time_sup.r.o.warp_mode = time_warp_mode;
if (time_warp_mode == ERTS_SINGLE_TIME_WARP_MODE)
- time_sup.inf.c.finalized_offset = 0;
+ erts_smp_atomic32_init_nob(&time_sup.inf.c.preliminary_offset, 1);
else
- time_sup.inf.c.finalized_offset = ~0;
+ erts_smp_atomic32_init_nob(&time_sup.inf.c.preliminary_offset, 0);
+ time_sup.inf.c.shadow_offset = 0;
#if !ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT
@@ -882,7 +1009,7 @@ erts_init_time_sup(int time_correction, ErtsTimeWarpMode time_warp_mode)
time_sup.r.o.start *= ERTS_MONOTONIC_TIME_UNIT;
time_sup.r.o.start += ERTS_MONOTONIC_TIME_UNIT;
native_offset = time_sup.r.o.start - ERTS_MONOTONIC_TIME_UNIT;
- native_offset = native_offset;
+ abs_native_offset = native_offset;
#else /* ARCH_64 */
if (ERTS_MONOTONIC_TIME_UNIT <= 10*1000*1000) {
time_sup.r.o.start = 0;
@@ -938,17 +1065,66 @@ erts_init_time_sup(int time_correction, ErtsTimeWarpMode time_warp_mode)
time_sup.r.o.adj.large_diff = ERTS_USEC_TO_MONOTONIC(500);
time_sup.r.o.adj.small_diff = time_sup.r.o.adj.large_diff/10;
+ time_sup.r.o.drift_adj.resolution = resolution;
+
+ if (time_sup.r.o.os_corrected_monotonic_time) {
+ time_sup.r.o.drift_adj.use_avg = 0;
+ time_sup.r.o.drift_adj.intervals = 0;
+ time_sup.r.o.drift_adj.error = 0;
+ time_sup.inf.c.parmon.cdata.drift.dirty_counter = -1;
+ }
+ else {
+ /*
+ * Calculate length of the interval in seconds needed
+ * in order to get an error that is at most 1 micro second.
+ * If this interval is longer than the short time correction
+ * check interval we use the average of all values instead
+ * of the latest value.
+ */
+ short_isecs = ERTS_MONOTONIC_TO_SEC(ERTS_SHORT_TIME_CORRECTION_CHECK);
+ ilength = ERTS_ASSUMED_PRECISION_DROP * ERTS_MONOTONIC_TIME_UNIT;
+ ilength /= (resolution * ERTS_USEC_TO_MONOTONIC(1));
+ time_sup.r.o.drift_adj.use_avg = ilength > short_isecs;
+
+ if (ilength == 0)
+ intervals = 5;
+ else {
+ intervals = ilength / short_isecs;
+ if (intervals > ERTS_MAX_DRIFT_INTERVALS)
+ intervals = ERTS_MAX_DRIFT_INTERVALS;
+ else if (intervals < 5)
+ intervals = 5;
+ }
+ time_sup.r.o.drift_adj.intervals = (int) intervals;
+
+ /*
+ * drift_adj.error equals maximum assumed error
+ * over a short time interval. We use this value also
+ * when examining a large interval. In this case the
+ * error will be smaller, but we do not want to
+ * recalculate this over and over again.
+ */
+
+ time_sup.r.o.drift_adj.error = ERTS_MONOTONIC_TIME_UNIT;
+ time_sup.r.o.drift_adj.error *= ERTS_ASSUMED_PRECISION_DROP;
+ time_sup.r.o.drift_adj.error /= resolution * short_isecs;
+ }
#ifdef ERTS_TIME_CORRECTION_PRINT
- fprintf(stderr, "start = %lld\n\r", (long long) ERTS_MONOTONIC_TIME_START);
- fprintf(stderr, "native offset = %lld\n\r", (long long) ERTS_MONOTONIC_OFFSET_NATIVE);
- fprintf(stderr, "nsec offset = %lld\n\r", (long long) ERTS_MONOTONIC_OFFSET_NSEC);
- fprintf(stderr, "usec offset = %lld\n\r", (long long) ERTS_MONOTONIC_OFFSET_USEC);
- fprintf(stderr, "msec offset = %lld\n\r", (long long) ERTS_MONOTONIC_OFFSET_MSEC);
- fprintf(stderr, "sec offset = %lld\n\r", (long long) ERTS_MONOTONIC_OFFSET_SEC);
- fprintf(stderr, "large diff = %lld usec\r\n",
- (long long) ERTS_MONOTONIC_TO_USEC(time_sup.r.o.adj.large_diff));
- fprintf(stderr, "small diff = %lld usec\r\n",
- (long long) ERTS_MONOTONIC_TO_USEC(time_sup.r.o.adj.small_diff));
+ erts_fprintf(stderr, "resolution = %b64d\n", resolution);
+ erts_fprintf(stderr, "adj large diff = %b64d usec\n",
+ ERTS_MONOTONIC_TO_USEC(time_sup.r.o.adj.large_diff));
+ erts_fprintf(stderr, "adj small diff = %b64d usec\n",
+ ERTS_MONOTONIC_TO_USEC(time_sup.r.o.adj.small_diff));
+ if (!time_sup.r.o.os_corrected_monotonic_time) {
+ erts_fprintf(stderr, "drift intervals = %d\n",
+ time_sup.r.o.drift_adj.intervals);
+ erts_fprintf(stderr, "drift adj error = %b64d usec\n",
+ ERTS_MONOTONIC_TO_USEC(time_sup.r.o.drift_adj.error));
+ erts_fprintf(stderr, "drift adj max diff = %b64d nsec\n",
+ ERTS_MONOTONIC_TO_NSEC(ERTS_TIME_DRIFT_MAX_ADJ_DIFF));
+ erts_fprintf(stderr, "drift adj min diff = %b64d nsec\n",
+ ERTS_MONOTONIC_TO_NSEC(ERTS_TIME_DRIFT_MIN_ADJ_DIFF));
+ }
#endif
if (ERTS_MONOTONIC_TIME_UNIT < ERTS_CLKTCK_RESOLUTION)
@@ -967,6 +1143,7 @@ erts_init_time_sup(int time_correction, ErtsTimeWarpMode time_warp_mode)
erts_os_times(&time_sup.inf.c.minit,
&time_sup.inf.c.sinit);
time_sup.r.o.moffset = -1*time_sup.inf.c.minit;
+ time_sup.r.o.moffset += ERTS_MONOTONIC_TIME_UNIT;
offset = time_sup.inf.c.sinit;
offset -= ERTS_MONOTONIC_TIME_UNIT;
init_time_offset(offset);
@@ -979,11 +1156,9 @@ erts_init_time_sup(int time_correction, ErtsTimeWarpMode time_warp_mode)
cdatap = &time_sup.inf.c.parmon.cdata;
-#ifndef ERTS_HAVE_CORRECTED_OS_MONOTONIC
cdatap->drift.intervals[0].time.sys = time_sup.inf.c.sinit;
cdatap->drift.intervals[0].time.mon = time_sup.inf.c.minit;
cdatap->curr.correction.drift = 0;
-#endif
cdatap->curr.correction.error = 0;
cdatap->curr.erl_mtime = ERTS_MONOTONIC_TIME_UNIT;
cdatap->curr.os_mtime = time_sup.inf.c.minit;
@@ -991,7 +1166,12 @@ erts_init_time_sup(int time_correction, ErtsTimeWarpMode time_warp_mode)
cdatap->short_check_interval = ERTS_INIT_SHORT_INTERVAL_COUNTER;
cdatap->prev = cdatap->curr;
- time_sup.r.o.get_time = get_corrected_time;
+ if (!time_sup.r.o.os_corrected_monotonic_time)
+ time_sup.r.o.get_time = get_corrected_time;
+ else if (time_sup.r.o.warp_mode == ERTS_MULTI_TIME_WARP_MODE)
+ time_sup.r.o.get_time = get_os_corrected_time;
+ else
+ time_sup.r.o.get_time = get_os_drift_corrected_time;
}
else
#endif
@@ -1020,8 +1200,8 @@ void
erts_late_init_time_sup(void)
{
#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
- /* Timer wheel must be initialized */
- if (time_sup.r.o.get_time == get_corrected_time)
+ /* Timer wheel must have beeen initialized */
+ if (time_sup.r.o.get_time != get_not_corrected_time)
late_init_time_correction();
#endif
erts_late_sys_init_time();
@@ -1038,9 +1218,9 @@ ErtsTimeOffsetState erts_time_offset_state(void)
case ERTS_NO_TIME_WARP_MODE:
return ERTS_TIME_OFFSET_FINAL;
case ERTS_SINGLE_TIME_WARP_MODE:
- if (time_sup.inf.c.finalized_offset)
- return ERTS_TIME_OFFSET_FINAL;
- return ERTS_TIME_OFFSET_PRELIMINARY;
+ if (erts_smp_atomic32_read_nob(&time_sup.inf.c.preliminary_offset))
+ return ERTS_TIME_OFFSET_PRELIMINARY;
+ return ERTS_TIME_OFFSET_FINAL;
case ERTS_MULTI_TIME_WARP_MODE:
return ERTS_TIME_OFFSET_VOLATILE;
default:
@@ -1073,7 +1253,7 @@ erts_finalize_time_offset(void)
erts_smp_mtx_lock(&erts_get_time_mtx);
- if (!time_sup.inf.c.finalized_offset) {
+ if (erts_smp_atomic32_read_nob(&time_sup.inf.c.preliminary_offset)) {
ErtsMonotonicTime mtime, new_offset;
#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
@@ -1110,19 +1290,12 @@ erts_finalize_time_offset(void)
set_time_offset(new_offset);
schedule_send_time_offset_changed_notifications(new_offset);
- time_sup.inf.c.finalized_offset = ~0;
+ erts_smp_atomic32_set_nob(&time_sup.inf.c.preliminary_offset, 0);
res = ERTS_TIME_OFFSET_PRELIMINARY;
}
erts_smp_mtx_unlock(&erts_get_time_mtx);
-#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
- if (res == ERTS_TIME_OFFSET_PRELIMINARY
- && time_sup.r.o.get_time == get_corrected_time) {
- late_init_time_correction();
- }
-#endif
-
return res;
}
default: