From edce22eb43c40359ccbd0924412cf13692744779 Mon Sep 17 00:00:00 2001 From: Rickard Green Date: Thu, 26 Mar 2015 22:46:29 +0100 Subject: Misc time improvements - Possibility to chose different clock sources - Improved mach clock usage - Improved linux clock_gettime() usage - ... --- erts/emulator/beam/erl_time_sup.c | 507 +++++++++++++++++++++++++------------- 1 file changed, 340 insertions(+), 167 deletions(-) (limited to 'erts/emulator/beam/erl_time_sup.c') 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: -- cgit v1.2.3