diff options
Diffstat (limited to 'erts/emulator/beam/erl_time_sup.c')
| -rw-r--r-- | erts/emulator/beam/erl_time_sup.c | 2167 |
1 files changed, 1702 insertions, 465 deletions
diff --git a/erts/emulator/beam/erl_time_sup.c b/erts/emulator/beam/erl_time_sup.c index 3272a5326d..7327e0b48c 100644 --- a/erts/emulator/beam/erl_time_sup.c +++ b/erts/emulator/beam/erl_time_sup.c @@ -1,77 +1,28 @@ /* * %CopyrightBegin% * - * Copyright Ericsson AB 1999-2012. All Rights Reserved. + * Copyright Ericsson AB 1999-2015. All Rights Reserved. * - * The contents of this file are subject to the Erlang Public License, - * Version 1.1, (the "License"); you may not use this file except in - * compliance with the License. You should have received a copy of the - * Erlang Public License along with this software. If not, it can be - * retrieved online at http://www.erlang.org/. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at * - * Software distributed under the License is distributed on an "AS IS" - * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See - * the License for the specific language governing rights and limitations - * under the License. + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. * * %CopyrightEnd% */ /* -** Support routines for the timer wheel -** -** This code contains two strategies for dealing with -** date/time changes in the system. -** If the system has some kind of high resolution timer (HAVE_GETHRTIME), -** the high resolution timer is used to correct the time-of-day and the -** timeouts, the base source is the hrtimer, but at certain intervals the -** OS time-of-day is checked and if it is not within certain bounds, the -** delivered time gets slowly adjusted for each call until -** it corresponds to the system time (built-in adjtime...). -** The call gethrtime() is detected by autoconf on Unix, but other -** platforms may define it in erl_*_sys.h and implement -** their own high resolution timer. The high resolution timer -** strategy is (probably) best on all systems where the timer have -** a resolution higher or equal to gettimeofday (or what's implemented -** is sys_gettimeofday()). The actual resolution is the interesting thing, -** not the unit's thats used (i.e. on VxWorks, nanoseconds can be -** retrieved in terms of units, but the actual resolution is the same as -** for the clock ticks). -** If the systems best timer routine is kernel ticks returned from -** sys_times(), and the actual resolution of sys_gettimeofday() is -** better (like most unixes that does not have any realtime extensions), -** another strategy is used. The tolerant gettimeofday() corrects -** the value with respect to uptime (sys_times() return value) and checks -** for correction both when delivering timeticks and delivering nowtime. -** this strategy is slower, but accurate on systems without better timer -** routines. The kernel tick resolution is not enough to implement -** a gethrtime routine. On Linux and other non solaris unix-boxes the second -** strategy is used, on all other platforms we use the first. -** -** The following is expected (from sys.[ch] and erl_*_sys.h): -** -** 64 bit integers. So it is, and so it will be. -** -** sys_init_time(), will return the clock resolution in MS and -** that's about it. More could be added of course -** If the clock-rate is constant (i.e. 1 ms) one can define -** SYS_CLOCK_RESOLUTION (to 1), -** which makes erts_deliver_time/erts_time_remaining a bit faster. -** -** if HAVE_GETHRTIME is defined: -** sys_gethrtime() will return a SysHrTime (long long) representing -** nanoseconds, sys_init_hrtime() will do any initialization. -** else -** a long (64bit) integer type called Sint64 should be defined. -** -** sys_times() will return clock_ticks since start and -** fill in a SysTimes structure (struct tms). Instead of CLK_TCK, -** SYS_CLK_TCK is used to determine the resolution of kernel ticks. -** -** sys_gettimeofday() will take a SysTimeval (a struct timeval) as parameter -** and fill it in as gettimeofday(X,NULL). -** -*/ + * Support routines for the time + */ + +/* #define ERTS_TIME_CORRECTION_PRINT */ #ifdef HAVE_CONFIG_H # include "config.h" @@ -80,384 +31,1256 @@ #include "sys.h" #include "erl_vm.h" #include "global.h" - +#define ERTS_WANT_TIMER_WHEEL_API +#include "erl_time.h" + static erts_smp_mtx_t erts_timeofday_mtx; - -static SysTimeval inittv; /* Used everywhere, the initial time-of-day */ +static erts_smp_mtx_t erts_get_time_mtx; static SysTimes t_start; /* Used in elapsed_time_both */ -static SysTimeval gtv; /* Used in wall_clock_elapsed_time_both */ -static SysTimeval then; /* Used in get_now */ -static SysTimeval last_emu_time; /* Used in erts_get_emu_time() */ -SysTimeval erts_first_emu_time; /* Used in erts_get_emu_time() */ +static ErtsMonotonicTime prev_wall_clock_elapsed; /* Used in wall_clock_elapsed_time_both */ +static ErtsMonotonicTime previous_now; /* Used in get_now */ + +static ErtsMonitor *time_offset_monitors = NULL; +static Uint no_time_offset_monitors = 0; -union { - erts_smp_atomic_t time; - char align[ERTS_CACHE_LINE_SIZE]; -} approx erts_align_attribute(ERTS_CACHE_LINE_SIZE); +#ifdef DEBUG +static int time_sup_initialized = 0; +#endif + +#define ERTS_MONOTONIC_TIME_KILO \ + ((ErtsMonotonicTime) 1000) +#define ERTS_MONOTONIC_TIME_MEGA \ + (ERTS_MONOTONIC_TIME_KILO*ERTS_MONOTONIC_TIME_KILO) +#define ERTS_MONOTONIC_TIME_GIGA \ + (ERTS_MONOTONIC_TIME_MEGA*ERTS_MONOTONIC_TIME_KILO) +#define ERTS_MONOTONIC_TIME_TERA \ + (ERTS_MONOTONIC_TIME_GIGA*ERTS_MONOTONIC_TIME_KILO) static void -init_approx_time(void) +schedule_send_time_offset_changed_notifications(ErtsMonotonicTime new_offset); + +struct time_sup_read_only__ { + ErtsMonotonicTime (*get_time)(void); + int correction; + 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; + int os_monotonic_time_locked; + Uint64 os_monotonic_time_resolution; + Uint64 os_monotonic_time_extended; +#endif + char *os_system_time_func; + char *os_system_time_clock_id; + int os_system_time_locked; + Uint64 os_system_time_resolution; + Uint64 os_system_time_extended; + struct { + ErtsMonotonicTime large_diff; + ErtsMonotonicTime small_diff; + } adj; + struct { + ErtsMonotonicTime error; + ErtsMonotonicTime resolution; + int intervals; + int use_avg; + } drift_adj; +}; + +typedef struct { + ErtsMonotonicTime drift; /* Correction for os monotonic drift */ + ErtsMonotonicTime error; /* Correction for error between system times */ +} ErtsMonotonicCorrection; + +typedef struct { + ErtsMonotonicTime erl_mtime; + ErtsMonotonicTime os_mtime; + ErtsMonotonicCorrection correction; +} ErtsMonotonicCorrectionInstance; + +#define ERTS_MAX_DRIFT_INTERVALS 50 +typedef struct { + struct { + struct { + ErtsMonotonicTime sys; + ErtsMonotonicTime mon; + } diff; + struct { + ErtsMonotonicTime sys; + ErtsMonotonicTime mon; + } time; + } intervals[ERTS_MAX_DRIFT_INTERVALS]; + struct { + ErtsMonotonicTime sys; + ErtsMonotonicTime mon; + } acc; + int ix; + int dirty_counter; +} ErtsMonotonicDriftData; + +typedef struct { + ErtsMonotonicCorrectionInstance prev; + ErtsMonotonicCorrectionInstance curr; +} ErtsMonotonicCorrectionInstances; + +typedef struct { + ErtsMonotonicCorrectionInstances insts; + ErtsMonotonicDriftData drift; + ErtsMonotonicTime last_check; + int short_check_interval; +} ErtsMonotonicCorrectionData; + +struct time_sup_infrequently_changed__ { +#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT + struct { + erts_smp_rwmtx_t rwmtx; + ErtsTWheelTimer timer; + ErtsMonotonicCorrectionData cdata; + } parmon; + ErtsMonotonicTime minit; +#endif + ErtsSystemTime sinit; + ErtsMonotonicTime not_corrected_moffset; + erts_smp_atomic64_t offset; + ErtsMonotonicTime shadow_offset; + erts_smp_atomic32_t preliminary_offset; +}; + +struct time_sup_frequently_changed__ { + ErtsMonotonicTime last_not_corrected_time; +}; + +static struct { + union { + struct time_sup_read_only__ o; + char align__[ERTS_ALC_CACHE_LINE_ALIGN_SIZE(sizeof(struct time_sup_read_only__))]; + } r; + union { + struct time_sup_infrequently_changed__ c; + char align__[ERTS_ALC_CACHE_LINE_ALIGN_SIZE(sizeof(struct time_sup_infrequently_changed__))]; + } inf; + union { + struct time_sup_frequently_changed__ c; + char align__[ERTS_ALC_CACHE_LINE_ALIGN_SIZE(sizeof(struct time_sup_frequently_changed__))]; + } f; +} time_sup erts_align_attribute(ERTS_CACHE_LINE_SIZE); + +ErtsTimeSupData erts_time_sup__ erts_align_attribute(ERTS_CACHE_LINE_SIZE); + +/* + * erts_get_approx_time() returns an *approximate* time + * in seconds. NOTE that this time may jump backwards!!! + */ +erts_approx_time_t +erts_get_approx_time(void) +{ + ErtsSystemTime stime = erts_os_system_time(); + return (erts_approx_time_t) ERTS_MONOTONIC_TO_SEC(stime); +} + +static ERTS_INLINE void +init_time_offset(ErtsMonotonicTime offset) { - erts_smp_atomic_init_nob(&approx.time, 0); + erts_smp_atomic64_init_nob(&time_sup.inf.c.offset, (erts_aint64_t) offset); } -static ERTS_INLINE erts_approx_time_t -get_approx_time(void) +static ERTS_INLINE void +set_time_offset(ErtsMonotonicTime offset) { - return (erts_approx_time_t) erts_smp_atomic_read_nob(&approx.time); + 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_smp_atomic64_read_acqb(&time_sup.inf.c.offset); } static ERTS_INLINE void -update_approx_time(SysTimeval *tv) +update_last_mtime(ErtsSchedulerData *esdp, ErtsMonotonicTime mtime) { - erts_approx_time_t new_secs = (erts_approx_time_t) tv->tv_sec; - erts_approx_time_t old_secs = get_approx_time(); - if (old_secs != new_secs) - erts_smp_atomic_set_nob(&approx.time, new_secs); + if (!esdp) + esdp = erts_get_scheduler_data(); + if (esdp) { + ASSERT(mtime >= esdp->last_monotonic_time); + esdp->last_monotonic_time = mtime; + esdp->check_time_reds = 0; + } } +#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT + /* - * erts_get_approx_time() returns an *approximate* time - * in seconds. NOTE that this time may jump backwards!!! + * Time correction adjustments made due to + * error between Erlang system time and OS + * system time: + * - Large adjustment ~1% + * - Small adjustment ~0.05% */ -erts_approx_time_t -erts_get_approx_time(void) +#define ERTS_TCORR_ERR_UNIT 2048 +#define ERTS_TCORR_ERR_LARGE_ADJ 20 +#define ERTS_TCORR_ERR_SMALL_ADJ 1 + +#define ERTS_INIT_SHORT_INTERVAL_COUNTER 10 +#define ERTS_LONG_TIME_CORRECTION_CHECK ERTS_SEC_TO_MONOTONIC(60) +#define ERTS_SHORT_TIME_CORRECTION_CHECK ERTS_SEC_TO_MONOTONIC(15) + +#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, + int os_drift_corrected) { - return get_approx_time(); + ErtsMonotonicTime erl_mtime, diff = os_mtime - cip->os_mtime; + ERTS_TIME_ASSERT(diff >= 0); + 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); + if (os_mdiff_p) + *os_mdiff_p = diff; + return erl_mtime; } -#ifdef HAVE_GETHRTIME +static ERTS_INLINE ErtsMonotonicTime +read_corrected_time(int os_drift_corrected) +{ + ErtsMonotonicTime os_mtime; + ErtsMonotonicCorrectionInstance ci; -int erts_disable_tolerant_timeofday; + erts_smp_rwmtx_rlock(&time_sup.inf.c.parmon.rwmtx); -static SysHrTime hr_init_time, hr_last_correction_check, - hr_correction, hr_last_time; + os_mtime = erts_os_monotonic_time(); -static void init_tolerant_timeofday(void) -{ - /* Should be in sys.c */ -#if defined(HAVE_SYSCONF) && defined(_SC_NPROCESSORS_CONF) - if (sysconf(_SC_NPROCESSORS_CONF) > 1) { - char b[1024]; - int maj,min,build; - os_flavor(b,1024); - os_version(&maj,&min,&build); - if (!strcmp(b,"sunos") && maj <= 5 && min <= 7) { - erts_disable_tolerant_timeofday = 1; - } + if (os_mtime >= time_sup.inf.c.parmon.cdata.insts.curr.os_mtime) + ci = time_sup.inf.c.parmon.cdata.insts.curr; + else { + if (os_mtime < time_sup.inf.c.parmon.cdata.insts.prev.os_mtime) + erl_exit(ERTS_ABORT_EXIT, + "OS monotonic time stepped backwards\n"); + ci = time_sup.inf.c.parmon.cdata.insts.prev; } + + erts_smp_rwmtx_runlock(&time_sup.inf.c.parmon.rwmtx); + + return calc_corrected_erl_mtime(os_mtime, &ci, 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 + +static ERTS_INLINE void +print_correction(int change, + ErtsMonotonicTime sdiff, + ErtsMonotonicTime old_ecorr, + ErtsMonotonicTime old_dcorr, + ErtsMonotonicTime new_ecorr, + ErtsMonotonicTime new_dcorr, + Uint tmo) +{ + ErtsMonotonicTime usec_sdiff; + if (sdiff < 0) + usec_sdiff = -1*ERTS_MONOTONIC_TO_USEC(-1*sdiff); + else + usec_sdiff = ERTS_MONOTONIC_TO_USEC(sdiff); + + if (!change) + 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 + 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 - hr_init_time = sys_gethrtime(); - hr_last_correction_check = hr_last_time = hr_init_time; - hr_correction = 0; + +static ERTS_INLINE ErtsMonotonicTime +get_timeout_pos(ErtsMonotonicTime now, ErtsMonotonicTime tmo) +{ + ErtsMonotonicTime tpos; + tpos = ERTS_MONOTONIC_TO_CLKTCKS(now - 1); + tpos += ERTS_MSEC_TO_CLKTCKS(tmo); + tpos += 1; + return tpos; } -static void get_tolerant_timeofday(SysTimeval *tv) +static void +check_time_correction(void *vesdp) { - SysHrTime diff_time, curr; + int init_drift_adj = !vesdp; + ErtsSchedulerData *esdp = (ErtsSchedulerData *) vesdp; + ErtsMonotonicCorrection new_correction; + ErtsMonotonicCorrectionInstance ci; + ErtsMonotonicTime mdiff, sdiff, os_mtime, erl_mtime, os_stime, + erl_stime, time_offset, timeout_pos; + Uint timeout; + 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); + + erts_os_times(&os_mtime, &os_stime); + + ci = time_sup.inf.c.parmon.cdata.insts.curr; + + erts_smp_rwmtx_runlock(&time_sup.inf.c.parmon.rwmtx); - if (erts_disable_tolerant_timeofday) { - sys_gettimeofday(tv); - return; + if (os_mtime < ci.os_mtime) + erl_exit(ERTS_ABORT_EXIT, + "OS monotonic time stepped backwards\n"); + + erl_mtime = calc_corrected_erl_mtime(os_mtime, &ci, &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; } - *tv = inittv; - diff_time = ((curr = sys_gethrtime()) + hr_correction - hr_init_time) / 1000; - if (curr < hr_init_time) { - erl_exit(1,"Unexpected behaviour from operating system high " - "resolution timer"); + new_correction = ci.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)) { + /* System time diff exeeded limits; change time offset... */ + time_offset -= sdiff; + sdiff = 0; + set_time_offset(time_offset); + schedule_send_time_offset_changed_notifications(time_offset); + begin_short_intervals = 1; + if (ci.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 (ci.correction.error != 0) { + set_new_correction = 1; + new_correction.error = 0; + } + } + else if (ci.correction.error == 0) { + if (sdiff < -time_sup.r.o.adj.small_diff) { + set_new_correction = 1; + if (sdiff < -time_sup.r.o.adj.large_diff) + new_correction.error = ERTS_TCORR_ERR_LARGE_ADJ; + else + new_correction.error = ERTS_TCORR_ERR_SMALL_ADJ; + } + else if (sdiff > time_sup.r.o.adj.small_diff) { + set_new_correction = 1; + if (sdiff > time_sup.r.o.adj.large_diff) + new_correction.error = -ERTS_TCORR_ERR_LARGE_ADJ; + else + new_correction.error = -ERTS_TCORR_ERR_SMALL_ADJ; + } + } + else if (ci.correction.error > 0) { + if (sdiff < 0) { + if (ci.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; + } + } + else if (sdiff > time_sup.r.o.adj.small_diff) { + set_new_correction = 1; + if (sdiff > time_sup.r.o.adj.large_diff) + new_correction.error = -ERTS_TCORR_ERR_LARGE_ADJ; + else + new_correction.error = -ERTS_TCORR_ERR_SMALL_ADJ; + } + else { + set_new_correction = 1; + new_correction.error = 0; + } + } + else /* if (ci.correction.error < 0) */ { + if (0 < sdiff) { + if (ci.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; + } + } + else if (sdiff < -time_sup.r.o.adj.small_diff) { + set_new_correction = 1; + if (sdiff < -time_sup.r.o.adj.large_diff) + new_correction.error = ERTS_TCORR_ERR_LARGE_ADJ; + else + new_correction.error = ERTS_TCORR_ERR_SMALL_ADJ; + } + else { + set_new_correction = 1; + new_correction.error = 0; + } } - if ((curr - hr_last_correction_check) / 1000 > 1000000) { - /* Check the correction need */ - SysHrTime tv_diff, diffdiff; - SysTimeval tmp; - int done = 0; - - sys_gettimeofday(&tmp); - tv_diff = ((SysHrTime) tmp.tv_sec) * 1000000 + tmp.tv_usec; - tv_diff -= ((SysHrTime) inittv.tv_sec) * 1000000 + inittv.tv_usec; - diffdiff = diff_time - tv_diff; - if (diffdiff > 10000) { - SysHrTime corr = (curr - hr_last_time) / 100; - if (corr / 1000 >= diffdiff) { - ++done; - hr_correction -= ((SysHrTime)diffdiff) * 1000; - } else { - hr_correction -= corr; + if (!os_drift_corrected) { + ErtsMonotonicDriftData *ddp = &time_sup.inf.c.parmon.cdata.drift; + int ix = ddp->ix; + ErtsMonotonicTime mtime_diff, old_os_mtime; + + old_os_mtime = ddp->intervals[ix].time.mon; + mtime_diff = os_mtime - old_os_mtime; + + if ((mtime_diff >= ERTS_MIN_MONOTONIC_DRIFT_MEASUREMENT) + | init_drift_adj) { + ErtsMonotonicTime drift_adj, drift_adj_diff, old_os_stime, + 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) + / mtime_acc); + + mtime_diff = os_mtime - old_os_mtime; + stime_diff = os_stime - old_os_stime; + smtime_diff = stime_diff - mtime_diff; + ix++; + if (ix >= time_sup.r.o.drift_adj.intervals) + ix = 0; + mtime_acc -= ddp->intervals[ix].diff.mon; + mtime_acc += mtime_diff; + stime_acc -= ddp->intervals[ix].diff.sys; + stime_acc += stime_diff; + + ddp->intervals[ix].diff.mon = mtime_diff; + ddp->intervals[ix].diff.sys = stime_diff; + ddp->intervals[ix].time.mon = os_mtime; + ddp->intervals[ix].time.sys = os_stime; + + ddp->ix = ix; + ddp->acc.mon = mtime_acc; + ddp->acc.sys = stime_acc; + + 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; } - diff_time = (curr + hr_correction - hr_init_time) / 1000; - } else if (diffdiff < -10000) { - SysHrTime corr = (curr - hr_last_time) / 100; - if (corr / 1000 >= -diffdiff) { - ++done; - hr_correction -= ((SysHrTime)diffdiff) * 1000; - } else { - hr_correction += corr; + 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; + } + 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) + drift_adj_diff = ERTS_TIME_DRIFT_MAX_ADJ_DIFF; + 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; + } + } } - diff_time = (curr + hr_correction - hr_init_time) / 1000; - } else { - ++done; } - if (done) { - hr_last_correction_check = curr; + } + + begin_short_intervals |= set_new_correction; + + if (begin_short_intervals) { + time_sup.inf.c.parmon.cdata.short_check_interval + = ERTS_INIT_SHORT_INTERVAL_COUNTER; + } + else if ((os_mtime - time_sup.inf.c.parmon.cdata.last_check + >= ERTS_SHORT_TIME_CORRECTION_CHECK - ERTS_MONOTONIC_TIME_UNIT) + && time_sup.inf.c.parmon.cdata.short_check_interval > 0) { + time_sup.inf.c.parmon.cdata.short_check_interval--; + } + time_sup.inf.c.parmon.cdata.last_check = os_mtime; + + if (new_correction.error == 0) + timeout = ERTS_MONOTONIC_TO_MSEC(ERTS_LONG_TIME_CORRECTION_CHECK); + else { + ErtsMonotonicTime ecorr = new_correction.error; + ErtsMonotonicTime abs_sdiff; + abs_sdiff = (sdiff < 0) ? -1*sdiff : sdiff; + if (ecorr < 0) + ecorr = -1*ecorr; + 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*abs_sdiff)/ecorr); + if (timeout < 10) + timeout = 10; } } - tv->tv_sec += (int) (diff_time / ((SysHrTime) 1000000)); - tv->tv_usec += (int) (diff_time % ((SysHrTime) 1000000)); - if (tv->tv_usec >= 1000000) { - tv->tv_usec -= 1000000; - tv->tv_sec += 1; + + 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.drift.dirty_counter >= 0)) { + timeout = ERTS_MONOTONIC_TO_MSEC(ERTS_SHORT_TIME_CORRECTION_CHECK); } - hr_last_time = curr; -} -#define correction (hr_correction/1000000) + timeout_pos = get_timeout_pos(erl_mtime, timeout); -#else /* !HAVE_GETHRTIME */ -#if !defined(CORRECT_USING_TIMES) -#define init_tolerant_timeofday() -#define get_tolerant_timeofday(tvp) sys_gettimeofday(tvp) -#else +#ifdef ERTS_TIME_CORRECTION_PRINT + print_correction(set_new_correction, + sdiff, + ci.correction.error, + ci.correction.drift, + new_correction.error, + new_correction.drift, + timeout); +#endif -typedef Sint64 Milli; - -static clock_t init_ct; -static Sint64 ct_wrap; -static Milli init_tv_m; -static Milli correction_supress; -static Milli last_ct_diff; -static Milli last_cc; -static clock_t last_ct; - -/* sys_times() might need to be wrapped and the values shifted (right) - a bit to cope with newer linux (2.5.*) kernels, this has to be taken care - of dynamically to start with, a special version that uses - the times() return value as a high resolution timer can be made - to fully utilize the faster ticks, like on windows, but for now, we'll - settle with this silly workaround */ -#ifdef ERTS_WRAP_SYS_TIMES -#define KERNEL_TICKS() (sys_times_wrap() & \ - ((1UL << ((sizeof(clock_t) * 8) - 1)) - 1)) -#else -SysTimes dummy_tms; + if (set_new_correction) { + erts_smp_rwmtx_rwlock(&time_sup.inf.c.parmon.rwmtx); -#define KERNEL_TICKS() (sys_times(&dummy_tms) & \ - ((1UL << ((sizeof(clock_t) * 8) - 1)) - 1)) + os_mtime = erts_os_monotonic_time(); -#endif + /* Save previous correction instance */ + time_sup.inf.c.parmon.cdata.insts.prev = ci; -static void init_tolerant_timeofday(void) -{ - last_ct = init_ct = KERNEL_TICKS(); - last_cc = 0; - init_tv_m = (((Milli) inittv.tv_sec) * 1000) + - (inittv.tv_usec / 1000); - ct_wrap = 0; - correction_supress = 0; + /* + * Current correction instance begin when + * OS monotonic time has increased two units. + */ + os_mtime += 2; + + /* + * Erlang monotonic time corresponding to + * next OS monotonic time using previous + * correction. + */ + erl_mtime = calc_corrected_erl_mtime(os_mtime, &ci, NULL, + os_drift_corrected); + + /* + * Save new current correction instance. + */ + time_sup.inf.c.parmon.cdata.insts.curr.erl_mtime = erl_mtime; + time_sup.inf.c.parmon.cdata.insts.curr.os_mtime = os_mtime; + time_sup.inf.c.parmon.cdata.insts.curr.correction = new_correction; + + erts_smp_rwmtx_rwunlock(&time_sup.inf.c.parmon.rwmtx); + } + + if (!esdp) + esdp = erts_get_scheduler_data(); + + erts_twheel_set_timer(esdp->timer_wheel, + &time_sup.inf.c.parmon.timer, + check_time_correction, + NULL, + (void *) esdp, + timeout_pos); } +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; +} -static void get_tolerant_timeofday(SysTimeval *tvp) +static void +check_time_offset(void *vesdp) { - clock_t current_ct; - SysTimeval current_tv; - Milli ct_diff; - Milli tv_diff; - Milli current_correction; - Milli act_correction; /* long shown to be too small */ - Milli max_adjust; - - if (erts_disable_tolerant_timeofday) { - sys_gettimeofday(tvp); - return; - } + ErtsSchedulerData *esdp = (ErtsSchedulerData *) vesdp; + ErtsMonotonicTime sdiff, os_mtime, erl_mtime, os_stime, + erl_stime, time_offset, timeout, timeout_pos; -#ifdef ERTS_WRAP_SYS_TIMES -#define TICK_MS (1000 / SYS_CLK_TCK_WRAP) -#else -#define TICK_MS (1000 / SYS_CLK_TCK) + 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 - current_ct = KERNEL_TICKS(); - sys_gettimeofday(¤t_tv); - - /* I dont know if uptime can move some units backwards - on some systems, but I allow for small backward - jumps to avoid such problems if they exist...*/ - if (last_ct > 100 && current_ct < (last_ct - 100)) { - ct_wrap += ((Sint64) 1) << ((sizeof(clock_t) * 8) - 1); + time_offset -= sdiff; + sdiff = 0; + set_time_offset(time_offset); + schedule_send_time_offset_changed_notifications(time_offset); } - last_ct = current_ct; - ct_diff = ((ct_wrap + current_ct) - init_ct) * TICK_MS; +#ifdef ERTS_TIME_CORRECTION_PRINT + else erts_fprintf(stderr, "sdiff = %b64d nsec\n", + ERTS_MONOTONIC_TO_NSEC(sdiff)); +#endif - /* - * We will adjust the time in milliseconds and we allow for 1% - * adjustments, but if this function is called more often then every 100 - * millisecond (which is obviously possible), we will never adjust, so - * we accumulate small times by setting last_ct_diff iff max_adjust > 0 - */ - if ((max_adjust = (ct_diff - last_ct_diff)/100) > 0) - last_ct_diff = ct_diff; + timeout = ERTS_MONOTONIC_TO_MSEC(ERTS_LONG_TIME_CORRECTION_CHECK); + timeout_pos = get_timeout_pos(erl_mtime, timeout); + + erts_twheel_set_timer(esdp->timer_wheel, + &time_sup.inf.c.parmon.timer, + check_time_offset, + NULL, + vesdp, + timeout_pos); +} + +static void +init_check_time_correction(void *vesdp) +{ + ErtsMonotonicDriftData *ddp; + ErtsMonotonicTime old_mtime, old_stime, mtime, stime, mtime_diff, + stime_diff, smtime_diff, max_drift; + int ix; - tv_diff = ((((Milli) current_tv.tv_sec) * 1000) + - (current_tv.tv_usec / 1000)) - init_tv_m; + ddp = &time_sup.inf.c.parmon.cdata.drift; + ix = ddp->ix; + old_mtime = ddp->intervals[0].time.mon; + old_stime = ddp->intervals[0].time.sys; - current_correction = ((ct_diff - tv_diff) / TICK_MS) * TICK_MS; /* trunc */ + erts_os_times(&mtime, &stime); - /* - * We allow the current_correction value to wobble a little, as it - * suffers from the low resolution of the kernel ticks. - * if it hasn't changed more than one tick in either direction, - * we will keep the old value. - */ - if ((last_cc > current_correction + TICK_MS) || - (last_cc < current_correction - TICK_MS)) { - last_cc = current_correction; - } else { - current_correction = last_cc; + mtime_diff = mtime - old_mtime; + stime_diff = stime - old_stime; + 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; } /* - * As time goes, we try to get the actual correction to 0, - * that is, make erlangs time correspond to the systems dito. - * The act correction is what we seem to need (current_correction) - * minus the correction suppression. The correction supression - * will change slowly (max 1% of elapsed time) but in millisecond steps. + * We use old time values in order to trigger + * a drift adjustment, and repeat this interval + * in all slots... */ - act_correction = current_correction - correction_supress; - if (max_adjust > 0) { - /* - * Here we slowly adjust erlangs time to correspond with the - * system time by changing the correction_supress variable. - * It can change max_adjust milliseconds which is 1% of elapsed time - */ - if (act_correction > 0) { - if (current_correction - correction_supress > max_adjust) { - correction_supress += max_adjust; - } else { - correction_supress = current_correction; - } - act_correction = current_correction - correction_supress; - } else if (act_correction < 0) { - if (correction_supress - current_correction > max_adjust) { - correction_supress -= max_adjust; - } else { - correction_supress = current_correction; + 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*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 = time_sup.r.o.drift_adj.intervals; + + check_time_correction(vesdp); +} + +static ErtsMonotonicTime +finalize_corrected_time_offset(ErtsSystemTime *stimep) +{ + ErtsMonotonicTime os_mtime; + ErtsMonotonicCorrectionInstance ci; + int os_drift_corrected = time_sup.r.o.os_corrected_monotonic_time; + + erts_smp_rwmtx_rlock(&time_sup.inf.c.parmon.rwmtx); + + erts_os_times(&os_mtime, stimep); + + ci = time_sup.inf.c.parmon.cdata.insts.curr; + + erts_smp_rwmtx_runlock(&time_sup.inf.c.parmon.rwmtx); + + if (os_mtime < ci.os_mtime) + erl_exit(ERTS_ABORT_EXIT, + "OS monotonic time stepped backwards\n"); + + return calc_corrected_erl_mtime(os_mtime, &ci, NULL, + os_drift_corrected); +} + +static void +late_init_time_correction(ErtsSchedulerData *esdp) +{ + int quick_init_drift_adj; + void (*check_func)(void *); + ErtsMonotonicTime timeout, timeout_pos; + + quick_init_drift_adj = + 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) { + quick_init_drift_adj = 0; + check_func = check_time_offset; + } + else + check_func = check_time_correction; + + timeout_pos = get_timeout_pos(erts_get_monotonic_time(esdp), + timeout); + + erts_twheel_init_timer(&time_sup.inf.c.parmon.timer); + erts_twheel_set_timer(esdp->timer_wheel, + &time_sup.inf.c.parmon.timer, + check_func, + NULL, + (quick_init_drift_adj + ? NULL + : esdp), + timeout_pos); +} + +#endif /* ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT */ + +static ErtsMonotonicTime get_not_corrected_time(void) +{ + ErtsMonotonicTime stime, mtime; + + erts_smp_mtx_lock(&erts_get_time_mtx); + + stime = erts_os_system_time(); + + mtime = stime - time_sup.inf.c.not_corrected_moffset; + + if (mtime >= time_sup.f.c.last_not_corrected_time) + time_sup.f.c.last_not_corrected_time = mtime; + else { + mtime = time_sup.f.c.last_not_corrected_time; + + if (time_sup.r.o.warp_mode == ERTS_MULTI_TIME_WARP_MODE) { + ErtsMonotonicTime new_offset = stime - mtime; + new_offset = ERTS_MONOTONIC_TO_USEC(new_offset); + new_offset = ERTS_USEC_TO_MONOTONIC(new_offset); + if (time_sup.inf.c.not_corrected_moffset != new_offset) { + time_sup.inf.c.not_corrected_moffset = new_offset; + set_time_offset(new_offset); + schedule_send_time_offset_changed_notifications(new_offset); } - act_correction = current_correction - correction_supress; } + } - /* - * The actual correction will correct the timeval so that system - * time warps gets smothed down. - */ - current_tv.tv_sec += act_correction / 1000; - current_tv.tv_usec += (act_correction % 1000) * 1000; - - if (current_tv.tv_usec >= 1000000) { - ++current_tv.tv_sec ; - current_tv.tv_usec -= 1000000; - } else if (current_tv.tv_usec < 0) { - --current_tv.tv_sec; - current_tv.tv_usec += 1000000; - } - *tvp = current_tv; -#undef TICK_MS + + ASSERT(stime == mtime + time_sup.inf.c.not_corrected_moffset); + + erts_smp_mtx_unlock(&erts_get_time_mtx); + + return mtime; } -#endif /* CORRECT_USING_TIMES */ -#endif /* !HAVE_GETHRTIME */ +int erts_check_time_adj_support(int time_correction, + ErtsTimeWarpMode time_warp_mode) +{ + if (!time_correction) + return 1; -/* -** Why this? Well, most platforms have a constant clock resolution of 1, -** we dont want the deliver_time/time_remaining routines to waste -** time dividing and multiplying by/with a variable that's always one. -** so the return value of sys_init_time is ignored on those platforms. -*/ - -#ifndef SYS_CLOCK_RESOLUTION -static int clock_resolution; -#define CLOCK_RESOLUTION clock_resolution + /* User wants time correction */ + +#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT + return !time_sup.r.o.os_monotonic_time_disable; #else -#define CLOCK_RESOLUTION SYS_CLOCK_RESOLUTION + return 0; #endif +} -/* -** The clock resolution should really be the resolution of the -** time function in use, which on most platforms -** is 1. On VxWorks the resolution should be -** the number of ticks per second (or 1, which would work nicely to). -** -** Setting lower resolutions is mostly interesting when timers are used -** instead of something like select. -*/ - -static SysTimeval last_delivered; - -static void init_erts_deliver_time(const SysTimeval *inittv) +int +erts_has_time_correction(void) { - /* We set the initial values for deliver_time here */ - last_delivered = *inittv; - last_delivered.tv_usec = 1000 * (last_delivered.tv_usec / 1000); - /* ms resolution */ + return time_sup.r.o.correction; } -static void do_erts_deliver_time(const SysTimeval *current) +void erts_init_sys_time_sup(void) { - SysTimeval cur_time; - erts_time_t elapsed; - - /* calculate and deliver appropriate number of ticks */ - cur_time = *current; - cur_time.tv_usec = 1000 * (cur_time.tv_usec / 1000); /* ms resolution */ - elapsed = (1000 * (cur_time.tv_sec - last_delivered.tv_sec) + - (cur_time.tv_usec - last_delivered.tv_usec) / 1000) / - CLOCK_RESOLUTION; + ErtsSysInitTimeResult sys_init_time_res + = ERTS_SYS_INIT_TIME_RESULT_INITER; - /* Sometimes the time jump backwards, - resulting in a negative elapsed time. We compensate for - this by simply pretend as if the time stood still. :) */ + sys_init_time(&sys_init_time_res); - if (elapsed > 0) { + erts_time_sup__.r.o.monotonic_time_unit + = sys_init_time_res.os_monotonic_time_unit; - ASSERT(elapsed < ((erts_time_t) ERTS_SHORT_TIME_T_MAX)); +#ifndef SYS_CLOCK_RESOLUTION + erts_time_sup__.r.o.clktck_resolution + = sys_init_time_res.sys_clock_resolution; + erts_time_sup__.r.o.clktck_resolution *= 1000; +#endif - erts_do_time_add((erts_short_time_t) elapsed); - last_delivered = cur_time; - } +#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 + = sys_init_time_res.os_monotonic_time_info.clock_id; + time_sup.r.o.os_monotonic_time_locked + = sys_init_time_res.os_monotonic_time_info.locked_use; + time_sup.r.o.os_monotonic_time_resolution + = sys_init_time_res.os_monotonic_time_info.resolution; + time_sup.r.o.os_monotonic_time_extended + = sys_init_time_res.os_monotonic_time_info.extended; +#endif + time_sup.r.o.os_system_time_func + = sys_init_time_res.os_system_time_info.func; + time_sup.r.o.os_system_time_clock_id + = sys_init_time_res.os_system_time_info.clock_id; + time_sup.r.o.os_system_time_locked + = sys_init_time_res.os_system_time_info.locked_use; + time_sup.r.o.os_system_time_resolution + = sys_init_time_res.os_system_time_info.resolution; } int -erts_init_time_sup(void) +erts_init_time_sup(int time_correction, ErtsTimeWarpMode time_warp_mode) { + ErtsMonotonicTime resolution, ilength, intervals, short_isecs; +#if !ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT + ErtsMonotonicTime abs_native_offset, native_offset; +#endif + + erts_hl_timer_init(); + + ASSERT(ERTS_MONOTONIC_TIME_MIN < ERTS_MONOTONIC_TIME_MAX); + erts_smp_mtx_init(&erts_timeofday_mtx, "timeofday"); + erts_smp_mtx_init(&erts_get_time_mtx, "get_time"); - init_approx_time(); + time_sup.r.o.correction = time_correction; + time_sup.r.o.warp_mode = time_warp_mode; + + if (time_warp_mode == ERTS_SINGLE_TIME_WARP_MODE) + erts_smp_atomic32_init_nob(&time_sup.inf.c.preliminary_offset, 1); + else + erts_smp_atomic32_init_nob(&time_sup.inf.c.preliminary_offset, 0); + time_sup.inf.c.shadow_offset = 0; - last_emu_time.tv_sec = 0; - last_emu_time.tv_usec = 0; +#if !ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT + + /* + * NOTE! erts_time_sup__.r.o.start *need* to be a multiple + * of ERTS_MONOTONIC_TIME_UNIT. + */ + +#ifdef ARCH_32 + erts_time_sup__.r.o.start = ((((ErtsMonotonicTime) 1) << 32)-1); + erts_time_sup__.r.o.start /= ERTS_MONOTONIC_TIME_UNIT; + erts_time_sup__.r.o.start *= ERTS_MONOTONIC_TIME_UNIT; + erts_time_sup__.r.o.start += ERTS_MONOTONIC_TIME_UNIT; + native_offset = erts_time_sup__.r.o.start - ERTS_MONOTONIC_BEGIN; + abs_native_offset = native_offset; +#else /* ARCH_64 */ + if (ERTS_MONOTONIC_TIME_UNIT <= 10*1000*1000) { + erts_time_sup__.r.o.start = 0; + native_offset = -ERTS_MONOTONIC_BEGIN; + abs_native_offset = ERTS_MONOTONIC_BEGIN; + } + else { + erts_time_sup__.r.o.start = ((ErtsMonotonicTime) MIN_SMALL); + erts_time_sup__.r.o.start /= ERTS_MONOTONIC_TIME_UNIT; + erts_time_sup__.r.o.start *= ERTS_MONOTONIC_TIME_UNIT; + native_offset = erts_time_sup__.r.o.start - ERTS_MONOTONIC_BEGIN; + abs_native_offset = -1*native_offset; + } +#endif + + erts_time_sup__.r.o.start_offset.native = native_offset; + erts_time_sup__.r.o.start_offset.nsec = (ErtsMonotonicTime) + erts_time_unit_conversion((Uint64) abs_native_offset, + (Uint32) ERTS_MONOTONIC_TIME_UNIT, + (Uint32) 1000*1000*1000); + erts_time_sup__.r.o.start_offset.usec = (ErtsMonotonicTime) + erts_time_unit_conversion((Uint64) abs_native_offset, + (Uint32) ERTS_MONOTONIC_TIME_UNIT, + (Uint32) 1000*1000); + erts_time_sup__.r.o.start_offset.msec = (ErtsMonotonicTime) + erts_time_unit_conversion((Uint64) abs_native_offset, + (Uint32) ERTS_MONOTONIC_TIME_UNIT, + (Uint32) 1000); + erts_time_sup__.r.o.start_offset.sec = (ErtsMonotonicTime) + erts_time_unit_conversion((Uint64) abs_native_offset, + (Uint32) ERTS_MONOTONIC_TIME_UNIT, + (Uint32) 1); + if (native_offset < 0) { + erts_time_sup__.r.o.start_offset.nsec *= -1; + erts_time_sup__.r.o.start_offset.usec *= -1; + erts_time_sup__.r.o.start_offset.msec *= -1; + erts_time_sup__.r.o.start_offset.sec *= -1; + } -#ifndef SYS_CLOCK_RESOLUTION - clock_resolution = sys_init_time(); -#else - (void) sys_init_time(); #endif - sys_gettimeofday(&inittv); + + resolution = time_sup.r.o.os_system_time_resolution; +#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT + if (resolution > time_sup.r.o.os_monotonic_time_resolution) + resolution = time_sup.r.o.os_monotonic_time_resolution; +#endif + + time_sup.r.o.adj.large_diff = erts_time_sup__.r.o.monotonic_time_unit; + time_sup.r.o.adj.large_diff *= 50; + time_sup.r.o.adj.large_diff /= resolution; + if (time_sup.r.o.adj.large_diff < ERTS_USEC_TO_MONOTONIC(500)) + 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 + 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) + ERTS_INTERNAL_ERROR("Too small monotonic time time unit"); + +#ifndef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT + time_sup.r.o.correction = 0; +#else + if (time_sup.r.o.os_monotonic_time_disable) + time_sup.r.o.correction = 0; + + if (time_sup.r.o.correction) { + ErtsMonotonicCorrectionData *cdatap; + erts_smp_rwmtx_opt_t rwmtx_opts = ERTS_SMP_RWMTX_OPT_DEFAULT_INITER; + ErtsMonotonicTime offset; + 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_BEGIN; + offset = time_sup.inf.c.sinit; + offset -= ERTS_MONOTONIC_BEGIN; + init_time_offset(offset); + + rwmtx_opts.type = ERTS_SMP_RWMTX_TYPE_EXTREMELY_FREQUENT_READ; + rwmtx_opts.lived = ERTS_SMP_RWMTX_LONG_LIVED; + + erts_smp_rwmtx_init_opt(&time_sup.inf.c.parmon.rwmtx, + &rwmtx_opts, "get_corrected_time"); + + cdatap = &time_sup.inf.c.parmon.cdata; -#ifdef HAVE_GETHRTIME - sys_init_hrtime(); + cdatap->drift.intervals[0].time.sys = time_sup.inf.c.sinit; + cdatap->drift.intervals[0].time.mon = time_sup.inf.c.minit; + cdatap->insts.curr.correction.drift = 0; + cdatap->insts.curr.correction.error = 0; + cdatap->insts.curr.erl_mtime = ERTS_MONOTONIC_BEGIN; + cdatap->insts.curr.os_mtime = time_sup.inf.c.minit; + cdatap->last_check = time_sup.inf.c.minit; + cdatap->short_check_interval = ERTS_INIT_SHORT_INTERVAL_COUNTER; + cdatap->insts.prev = cdatap->insts.curr; + + 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 - init_tolerant_timeofday(); + { + ErtsMonotonicTime stime, offset; + time_sup.r.o.get_time = get_not_corrected_time; + stime = time_sup.inf.c.sinit = erts_os_system_time(); + offset = stime - ERTS_MONOTONIC_BEGIN; + time_sup.inf.c.not_corrected_moffset = offset; + init_time_offset(offset); + time_sup.f.c.last_not_corrected_time = 0; + } - init_erts_deliver_time(&inittv); - gtv = inittv; - then.tv_sec = then.tv_usec = 0; + prev_wall_clock_elapsed = 0; - erts_deliver_time(); + previous_now = ERTS_MONOTONIC_TO_USEC(get_time_offset()); - return CLOCK_RESOLUTION; +#ifdef DEBUG + time_sup_initialized = 1; +#endif + + return ERTS_CLKTCK_RESOLUTION/1000; } + +void +erts_late_init_time_sup(void) +{ + erts_late_sys_init_time(); +} + +void +erts_sched_init_time_sup(ErtsSchedulerData *esdp) +{ + esdp->timer_wheel = erts_create_timer_wheel(esdp); + esdp->next_tmo_ref = erts_get_next_timeout_reference(esdp->timer_wheel); + esdp->timer_service = erts_create_timer_service(); +#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT + if (esdp->no == 1) { + /* A timer wheel to use must have beeen initialized */ + if (time_sup.r.o.get_time != get_not_corrected_time) + late_init_time_correction(esdp); + } +#endif +} + +ErtsTimeWarpMode erts_time_warp_mode(void) +{ + return time_sup.r.o.warp_mode; +} + +ErtsTimeOffsetState erts_time_offset_state(void) +{ + switch (time_sup.r.o.warp_mode) { + case ERTS_NO_TIME_WARP_MODE: + return ERTS_TIME_OFFSET_FINAL; + case ERTS_SINGLE_TIME_WARP_MODE: + 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: + ERTS_INTERNAL_ERROR("Invalid time warp mode"); + return ERTS_TIME_OFFSET_VOLATILE; + } +} + +/* + * erts_finalize_time_offset() will only change time offset + * the first time it is called when the emulator has been + * started in "single time warp" mode. Returns previous + * state: + * * ERTS_TIME_OFFSET_PRELIMINARY - Finalization performed + * * ERTS_TIME_OFFSET_FINAL - Already finialized; nothing changed + * * ERTS_TIME_OFFSET_VOLATILE - Not supported, either in + * * no correction mode (or multi time warp mode; not yet implemented). + */ + +ErtsTimeOffsetState +erts_finalize_time_offset(void) +{ + switch (time_sup.r.o.warp_mode) { + case ERTS_NO_TIME_WARP_MODE: + return ERTS_TIME_OFFSET_FINAL; + case ERTS_MULTI_TIME_WARP_MODE: + return ERTS_TIME_OFFSET_VOLATILE; + case ERTS_SINGLE_TIME_WARP_MODE: { + ErtsTimeOffsetState res = ERTS_TIME_OFFSET_FINAL; + + erts_smp_mtx_lock(&erts_get_time_mtx); + + if (erts_smp_atomic32_read_nob(&time_sup.inf.c.preliminary_offset)) { + ErtsMonotonicTime mtime, new_offset; + +#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT + if (!time_sup.r.o.correction) +#endif + { + ErtsMonotonicTime stime = erts_os_system_time(); + + mtime = stime - time_sup.inf.c.not_corrected_moffset; + + if (mtime >= time_sup.f.c.last_not_corrected_time) { + time_sup.f.c.last_not_corrected_time = mtime; + new_offset = time_sup.inf.c.not_corrected_moffset; + } + else { + mtime = time_sup.f.c.last_not_corrected_time; + + ASSERT(time_sup.inf.c.not_corrected_moffset != stime - mtime); + new_offset = stime - mtime; + time_sup.inf.c.not_corrected_moffset = new_offset; + } + + } +#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT + else { + ErtsSystemTime stime; + mtime = finalize_corrected_time_offset(&stime); + new_offset = stime - mtime; + } +#endif + new_offset = ERTS_MONOTONIC_TO_USEC(new_offset); + new_offset = ERTS_USEC_TO_MONOTONIC(new_offset); + + set_time_offset(new_offset); + schedule_send_time_offset_changed_notifications(new_offset); + + 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); + + return res; + } + default: + ERTS_INTERNAL_ERROR("Invalid time warp mode"); + return ERTS_TIME_OFFSET_VOLATILE; + } +} + /* info functions */ void @@ -498,23 +1321,17 @@ elapsed_time_both(UWord *ms_user, UWord *ms_sys, void wall_clock_elapsed_time_both(UWord *ms_total, UWord *ms_diff) { - UWord prev_total; - SysTimeval tv; + ErtsMonotonicTime now, elapsed; erts_smp_mtx_lock(&erts_timeofday_mtx); - get_tolerant_timeofday(&tv); - - *ms_total = 1000 * (tv.tv_sec - inittv.tv_sec) + - (tv.tv_usec - inittv.tv_usec) / 1000; - - prev_total = 1000 * (gtv.tv_sec - inittv.tv_sec) + - (gtv.tv_usec - inittv.tv_usec) / 1000; - *ms_diff = *ms_total - prev_total; - gtv = tv; + now = time_sup.r.o.get_time(); + update_last_mtime(NULL, now); - /* must sync the machine's idea of time here */ - do_erts_deliver_time(&tv); + elapsed = ERTS_MONOTONIC_TO_MSEC(now); + *ms_total = (UWord) elapsed; + *ms_diff = (UWord) (elapsed - prev_wall_clock_elapsed); + prev_wall_clock_elapsed = elapsed; erts_smp_mtx_unlock(&erts_timeofday_mtx); } @@ -890,146 +1707,566 @@ univ_to_local(Sint *year, Sint *month, Sint *day, return 0; } - /* get a timestamp */ void get_now(Uint* megasec, Uint* sec, Uint* microsec) { - SysTimeval now; + ErtsMonotonicTime now_megasec, now_sec, now, mtime, time_offset; + mtime = time_sup.r.o.get_time(); + time_offset = get_time_offset(); + update_last_mtime(NULL, mtime); + now = ERTS_MONOTONIC_TO_USEC(mtime + time_offset); + erts_smp_mtx_lock(&erts_timeofday_mtx); - - get_tolerant_timeofday(&now); - do_erts_deliver_time(&now); - - /* Make sure time is later than last */ - if (then.tv_sec > now.tv_sec || - (then.tv_sec == now.tv_sec && then.tv_usec >= now.tv_usec)) { - now = then; - now.tv_usec++; - } - /* Check for carry from above + general reasonability */ - if (now.tv_usec >= 1000000) { - now.tv_usec = 0; - now.tv_sec++; - } - then = now; + + /* Make sure now time is later than last time */ + if (now <= previous_now) + now = previous_now + 1; + + previous_now = now; erts_smp_mtx_unlock(&erts_timeofday_mtx); - - *megasec = (Uint) (now.tv_sec / 1000000); - *sec = (Uint) (now.tv_sec % 1000000); - *microsec = (Uint) (now.tv_usec); - update_approx_time(&now); + now_megasec = now / ERTS_MONOTONIC_TIME_TERA; + now_sec = now / ERTS_MONOTONIC_TIME_MEGA; + *megasec = (Uint) now_megasec; + *sec = (Uint) (now_sec - now_megasec*ERTS_MONOTONIC_TIME_MEGA); + *microsec = (Uint) (now - now_sec*ERTS_MONOTONIC_TIME_MEGA); + + ASSERT(((ErtsMonotonicTime) *megasec)*ERTS_MONOTONIC_TIME_TERA + + ((ErtsMonotonicTime) *sec)*ERTS_MONOTONIC_TIME_MEGA + + ((ErtsMonotonicTime) *microsec) == now); +} + +ErtsMonotonicTime +erts_get_monotonic_time(ErtsSchedulerData *esdp) +{ + ErtsMonotonicTime mtime = time_sup.r.o.get_time(); + update_last_mtime(esdp, mtime); + return mtime; } void get_sys_now(Uint* megasec, Uint* sec, Uint* microsec) { - SysTimeval now; - - sys_gettimeofday(&now); - - *megasec = (Uint) (now.tv_sec / 1000000); - *sec = (Uint) (now.tv_sec % 1000000); - *microsec = (Uint) (now.tv_usec); + ErtsSystemTime stime = erts_os_system_time(); + ErtsSystemTime ms, s, us; + + us = ERTS_MONOTONIC_TO_USEC(stime); + s = us / (1000*1000); + ms = s / (1000*1000); - update_approx_time(&now); + *megasec = (Uint) ms; + *sec = (Uint) (s - ms*(1000*1000)); + *microsec = (Uint) (us - s*(1000*1000)); } +#ifdef HAVE_ERTS_NOW_CPU +void erts_get_now_cpu(Uint* megasec, Uint* sec, Uint* microsec) { + SysCpuTime t; + SysTimespec tp; -/* deliver elapsed *ticks* to the machine - takes a pointer - to a struct timeval representing current time (to save - a gettimeofday() where possible) or NULL */ + sys_get_proc_cputime(t, tp); + *microsec = (Uint)(tp.tv_nsec / 1000); + t = (tp.tv_sec / 1000000); + *megasec = (Uint)(t % 1000000); + *sec = (Uint)(tp.tv_sec % 1000000); +} +#endif -void erts_deliver_time(void) { - SysTimeval now; - - erts_smp_mtx_lock(&erts_timeofday_mtx); - - get_tolerant_timeofday(&now); - do_erts_deliver_time(&now); - - erts_smp_mtx_unlock(&erts_timeofday_mtx); +#include "big.h" + +void +erts_monitor_time_offset(Eterm id, Eterm ref) +{ + erts_smp_mtx_lock(&erts_get_time_mtx); + erts_add_monitor(&time_offset_monitors, MON_TIME_OFFSET, ref, id, NIL); + no_time_offset_monitors++; + erts_smp_mtx_unlock(&erts_get_time_mtx); +} - update_approx_time(&now); +int +erts_demonitor_time_offset(Eterm ref) +{ + int res; + ErtsMonitor *mon; + ASSERT(is_internal_ref(ref)); + erts_smp_mtx_lock(&erts_get_time_mtx); + mon = erts_remove_monitor(&time_offset_monitors, ref); + if (!mon) + res = 0; + else { + ASSERT(no_time_offset_monitors > 0); + no_time_offset_monitors--; + res = 1; + } + erts_smp_mtx_unlock(&erts_get_time_mtx); + if (res) + erts_destroy_monitor(mon); + return res; } -/* get *real* time (not ticks) remaining until next timeout - if there - isn't one, give a "long" time, that is guaranteed - to not cause overflow when we report elapsed time later on */ +typedef struct { + Eterm pid; + Eterm ref; + Eterm heap[REF_THING_SIZE]; +} ErtsTimeOffsetMonitorInfo; -void erts_time_remaining(SysTimeval *rem_time) +typedef struct { + Uint ix; + ErtsTimeOffsetMonitorInfo *to_mon_info; +} ErtsTimeOffsetMonitorContext; + +static void +save_time_offset_monitor(ErtsMonitor *mon, void *vcntxt) { - erts_time_t ticks; - SysTimeval cur_time; - erts_time_t elapsed; - - /* erts_next_time() returns no of ticks to next timeout or -1 if none */ - - ticks = (erts_time_t) erts_next_time(); - if (ticks == (erts_time_t) -1) { - /* timer queue empty */ - /* this will cause at most 100000000 ticks */ - rem_time->tv_sec = 100000; - rem_time->tv_usec = 0; - } else { - /* next timeout after ticks ticks */ - ticks *= CLOCK_RESOLUTION; - - erts_smp_mtx_lock(&erts_timeofday_mtx); - - get_tolerant_timeofday(&cur_time); - cur_time.tv_usec = 1000 * - (cur_time.tv_usec / 1000);/* ms resolution*/ - elapsed = 1000 * (cur_time.tv_sec - last_delivered.tv_sec) + - (cur_time.tv_usec - last_delivered.tv_usec) / 1000; - - erts_smp_mtx_unlock(&erts_timeofday_mtx); + ErtsTimeOffsetMonitorContext *cntxt; + Eterm *from_hp, *to_hp; + Uint mix; + int hix; + + cntxt = (ErtsTimeOffsetMonitorContext *) vcntxt; + mix = (cntxt->ix)++; + cntxt->to_mon_info[mix].pid = mon->pid; + to_hp = &cntxt->to_mon_info[mix].heap[0]; + + ASSERT(is_internal_ref(mon->ref)); + from_hp = internal_ref_val(mon->ref); + ASSERT(thing_arityval(*from_hp) + 1 == REF_THING_SIZE); + + for (hix = 0; hix < REF_THING_SIZE; hix++) + to_hp[hix] = from_hp[hix]; + + cntxt->to_mon_info[mix].ref + = make_internal_ref(&cntxt->to_mon_info[mix].heap[0]); + +} + +static void +send_time_offset_changed_notifications(void *new_offsetp) +{ + ErtsMonotonicTime new_offset; + ErtsTimeOffsetMonitorInfo *to_mon_info = NULL; /* Shut up faulty warning */ + Uint no_monitors; + char *tmp = NULL; + +#ifdef ARCH_64 + new_offset = (ErtsMonotonicTime) new_offsetp; +#else + new_offset = *((ErtsMonotonicTime *) new_offsetp); + erts_free(ERTS_ALC_T_NEW_TIME_OFFSET, new_offsetp); +#endif + new_offset -= ERTS_MONOTONIC_OFFSET_NATIVE; + + erts_smp_mtx_lock(&erts_get_time_mtx); + + no_monitors = no_time_offset_monitors; + if (no_monitors) { + ErtsTimeOffsetMonitorContext cntxt; + Uint alloc_sz; - if (ticks <= elapsed) { /* Ooops, better hurry */ - rem_time->tv_sec = rem_time->tv_usec = 0; - return; + /* Monitor info array size */ + alloc_sz = no_monitors*sizeof(ErtsTimeOffsetMonitorInfo); + /* + template max size */ + alloc_sz += 6*sizeof(Eterm); /* 5-tuple */ + alloc_sz += ERTS_MAX_SINT64_HEAP_SIZE*sizeof(Eterm); /* max offset size */ + tmp = erts_alloc(ERTS_ALC_T_TMP, alloc_sz); + + to_mon_info = (ErtsTimeOffsetMonitorInfo *) tmp; + cntxt.ix = 0; + cntxt.to_mon_info = to_mon_info; + + erts_doforall_monitors(time_offset_monitors, + save_time_offset_monitor, + &cntxt); + + ASSERT(cntxt.ix == no_monitors); + } + + erts_smp_mtx_unlock(&erts_get_time_mtx); + + if (no_monitors) { + Eterm *hp, *patch_refp, new_offset_term, message_template; + Uint mix, hsz; + + /* Make message template */ + + hp = (Eterm *) (tmp + no_monitors*sizeof(ErtsTimeOffsetMonitorInfo)); + + hsz = 6; /* 5-tuple */ + hsz += REF_THING_SIZE; + hsz += ERTS_SINT64_HEAP_SIZE(new_offset); + + if (IS_SSMALL(new_offset)) + new_offset_term = make_small(new_offset); + else + new_offset_term = erts_sint64_to_big(new_offset, &hp); + message_template = TUPLE5(hp, + am_CHANGE, + THE_NON_VALUE, /* Patch point for ref */ + am_time_offset, + am_clock_service, + new_offset_term); + patch_refp = &hp[2]; + + ASSERT(*patch_refp == THE_NON_VALUE); + + for (mix = 0; mix < no_monitors; mix++) { + Process *rp = erts_proc_lookup(to_mon_info[mix].pid); + if (rp) { + Eterm ref = to_mon_info[mix].ref; + ErtsProcLocks rp_locks = ERTS_PROC_LOCK_LINK; + erts_smp_proc_lock(rp, ERTS_PROC_LOCK_LINK); + if (erts_lookup_monitor(ERTS_P_MONITORS(rp), ref)) { + ErlHeapFragment *bp; + ErlOffHeap *ohp; + Eterm message; + + hp = erts_alloc_message_heap(hsz, &bp, &ohp, rp, &rp_locks); + *patch_refp = ref; + ASSERT(hsz == size_object(message_template)); + message = copy_struct(message_template, hsz, &hp, ohp); + erts_queue_message(rp, &rp_locks, bp, message, NIL); + } + erts_smp_proc_unlock(rp, rp_locks); + } } - rem_time->tv_sec = (ticks - elapsed) / 1000; - rem_time->tv_usec = 1000 * ((ticks - elapsed) % 1000); + + erts_free(ERTS_ALC_T_TMP, tmp); } } -void erts_get_timeval(SysTimeval *tv) +static void +schedule_send_time_offset_changed_notifications(ErtsMonotonicTime new_offset) { - erts_smp_mtx_lock(&erts_timeofday_mtx); - get_tolerant_timeofday(tv); - erts_smp_mtx_unlock(&erts_timeofday_mtx); - update_approx_time(tv); +#ifdef ARCH_64 + void *new_offsetp = (void *) new_offset; + ASSERT(sizeof(void *) == sizeof(ErtsMonotonicTime)); +#else + void *new_offsetp = erts_alloc(ERTS_ALC_T_NEW_TIME_OFFSET, + sizeof(ErtsMonotonicTime)); + *((ErtsMonotonicTime *) new_offsetp) = new_offset; +#endif + erts_schedule_misc_aux_work(1, + send_time_offset_changed_notifications, + new_offsetp); } -erts_time_t -erts_get_time(void) +static ERTS_INLINE Eterm +make_time_val(Process *c_p, ErtsMonotonicTime time_val) { - SysTimeval sys_tv; - - erts_smp_mtx_lock(&erts_timeofday_mtx); - - get_tolerant_timeofday(&sys_tv); - - erts_smp_mtx_unlock(&erts_timeofday_mtx); + Sint64 val = (Sint64) time_val; + Eterm *hp; + Uint sz; - update_approx_time(&sys_tv); + if (IS_SSMALL(val)) + return make_small(val); - return sys_tv.tv_sec; + sz = ERTS_SINT64_HEAP_SIZE(val); + hp = HAlloc(c_p, sz); + return erts_sint64_to_big(val, &hp); } -#ifdef HAVE_ERTS_NOW_CPU -void erts_get_now_cpu(Uint* megasec, Uint* sec, Uint* microsec) { - SysCpuTime t; - SysTimespec tp; +Eterm +erts_get_monotonic_start_time(struct process *c_p) +{ + return make_time_val(c_p, ERTS_MONOTONIC_TIME_START_EXTERNAL); +} - sys_get_proc_cputime(t, tp); - *microsec = (Uint)(tp.tv_nsec / 1000); - t = (tp.tv_sec / 1000000); - *megasec = (Uint)(t % 1000000); - *sec = (Uint)(tp.tv_sec % 1000000); +Eterm +erts_get_monotonic_end_time(struct process *c_p) +{ + return make_time_val(c_p, ERTS_MONOTONIC_TIME_END_EXTERNAL); } + +static Eterm +bld_monotonic_time_source(Uint **hpp, Uint *szp, Sint64 os_mtime) +{ +#ifndef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT + return NIL; +#else + int i = 0; + Eterm k[6]; + Eterm v[6]; + + if (time_sup.r.o.os_monotonic_time_disable) + return NIL; + + k[i] = erts_bld_atom(hpp, szp, "function"); + v[i++] = erts_bld_atom(hpp, szp, + time_sup.r.o.os_monotonic_time_func); + + if (time_sup.r.o.os_monotonic_time_clock_id) { + k[i] = erts_bld_atom(hpp, szp, "clock_id"); + v[i++] = erts_bld_atom(hpp, szp, + time_sup.r.o.os_monotonic_time_clock_id); + } + + k[i] = erts_bld_atom(hpp, szp, "resolution"); + v[i++] = erts_bld_uint64(hpp, szp, + time_sup.r.o.os_monotonic_time_resolution); + + k[i] = erts_bld_atom(hpp, szp, "extended"); + v[i++] = time_sup.r.o.os_monotonic_time_extended ? am_yes : am_no; + + k[i] = erts_bld_atom(hpp, szp, "parallel"); + v[i++] = time_sup.r.o.os_monotonic_time_locked ? am_no : am_yes; + + k[i] = erts_bld_atom(hpp, szp, "time"); + v[i++] = erts_bld_sint64(hpp, szp, os_mtime); + + return erts_bld_2tup_list(hpp, szp, (Sint) i, k, v); +#endif +} + +Eterm +erts_monotonic_time_source(struct process *c_p) +{ + Uint hsz = 0; + Eterm *hp = NULL; + Sint64 os_mtime = 0; +#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT + if (!time_sup.r.o.os_monotonic_time_disable) + os_mtime = (Sint64) erts_os_monotonic_time(); #endif + + bld_monotonic_time_source(NULL, &hsz, os_mtime); + if (hsz) + hp = HAlloc(c_p, hsz); + return bld_monotonic_time_source(&hp, NULL, os_mtime); +} + +static Eterm +bld_system_time_source(Uint **hpp, Uint *szp, Sint64 os_stime) +{ + int i = 0; + Eterm k[5]; + Eterm v[5]; + + k[i] = erts_bld_atom(hpp, szp, "function"); + v[i++] = erts_bld_atom(hpp, szp, + time_sup.r.o.os_system_time_func); + + if (time_sup.r.o.os_system_time_clock_id) { + k[i] = erts_bld_atom(hpp, szp, "clock_id"); + v[i++] = erts_bld_atom(hpp, szp, + time_sup.r.o.os_system_time_clock_id); + } + + k[i] = erts_bld_atom(hpp, szp, "resolution"); + v[i++] = erts_bld_uint64(hpp, szp, + time_sup.r.o.os_system_time_resolution); + + k[i] = erts_bld_atom(hpp, szp, "parallel"); + v[i++] = am_yes; + + k[i] = erts_bld_atom(hpp, szp, "time"); + v[i++] = erts_bld_sint64(hpp, szp, os_stime); + + return erts_bld_2tup_list(hpp, szp, (Sint) i, k, v); +} + +Eterm +erts_system_time_source(struct process *c_p) +{ + Uint hsz = 0; + Eterm *hp = NULL; + Sint64 os_stime = (Sint64) erts_os_system_time(); + + bld_system_time_source(NULL, &hsz, os_stime); + if (hsz) + hp = HAlloc(c_p, hsz); + return bld_system_time_source(&hp, NULL, os_stime); +} + + +#include "bif.h" + +static ERTS_INLINE Eterm +time_unit_conversion(Process *c_p, Eterm term, ErtsMonotonicTime val, ErtsMonotonicTime muloff) +{ + ErtsMonotonicTime result; + BIF_RETTYPE ret; + + if (val < 0) + goto trap_to_erlang_code; + + /* Convert to common user specified time units */ + switch (term) { + case am_seconds: + case make_small(1): + result = ERTS_MONOTONIC_TO_SEC(val) + muloff*ERTS_MONOTONIC_OFFSET_SEC; + ERTS_BIF_PREP_RET(ret, make_time_val(c_p, result)); + break; + case am_milli_seconds: + case make_small(1000): + result = ERTS_MONOTONIC_TO_MSEC(val) + muloff*ERTS_MONOTONIC_OFFSET_MSEC; + ERTS_BIF_PREP_RET(ret, make_time_val(c_p, result)); + break; + case am_micro_seconds: + case make_small(1000*1000): + result = ERTS_MONOTONIC_TO_USEC(val) + muloff*ERTS_MONOTONIC_OFFSET_USEC; + ERTS_BIF_PREP_RET(ret, make_time_val(c_p, result)); + break; +#ifdef ARCH_64 + case am_nano_seconds: + case make_small(1000*1000*1000): + result = ERTS_MONOTONIC_TO_NSEC(val) + muloff*ERTS_MONOTONIC_OFFSET_NSEC; + ERTS_BIF_PREP_RET(ret, make_time_val(c_p, result)); + break; +#endif + default: { + Eterm value, native_res; +#ifndef ARCH_64 + Sint user_res; + if (term == am_nano_seconds) + goto to_nano_seconds; + if (term_to_Sint(term, &user_res)) { + if (user_res == 1000*1000*1000) { + to_nano_seconds: + result = (ERTS_MONOTONIC_TO_NSEC(val) + + muloff*ERTS_MONOTONIC_OFFSET_NSEC); + ERTS_BIF_PREP_RET(ret, make_time_val(c_p, result)); + break; + } + if (user_res <= 0) + goto badarg; + } +#else + if (is_small(term)) { + if (signed_val(term) <= 0) + goto badarg; + } +#endif + else if (is_big(term)) { + if (big_sign(term)) + goto badarg; + } + else { + badarg: + ERTS_BIF_PREP_ERROR(ret, c_p, BADARG); + break; + } + + trap_to_erlang_code: + /* Do it in erlang code instead; pass along values to use... */ + value = make_time_val(c_p, val + muloff*ERTS_MONOTONIC_OFFSET_NATIVE); + native_res = make_time_val(c_p, ERTS_MONOTONIC_TIME_UNIT); + + ERTS_BIF_PREP_TRAP3(ret, erts_convert_time_unit_trap, c_p, + value, native_res, term); + + break; + } + } + + return ret; +} + +/* Built in functions */ + +BIF_RETTYPE monotonic_time_0(BIF_ALIST_0) +{ + ErtsMonotonicTime mtime = time_sup.r.o.get_time(); + update_last_mtime(ERTS_PROC_GET_SCHDATA(BIF_P), mtime); + mtime += ERTS_MONOTONIC_OFFSET_NATIVE; + BIF_RET(make_time_val(BIF_P, mtime)); +} + +BIF_RETTYPE monotonic_time_1(BIF_ALIST_1) +{ + ErtsMonotonicTime mtime = time_sup.r.o.get_time(); + update_last_mtime(ERTS_PROC_GET_SCHDATA(BIF_P), mtime); + BIF_RET(time_unit_conversion(BIF_P, BIF_ARG_1, mtime, 1)); +} + +BIF_RETTYPE system_time_0(BIF_ALIST_0) +{ + ErtsMonotonicTime mtime, offset; + mtime = time_sup.r.o.get_time(); + offset = get_time_offset(); + update_last_mtime(ERTS_PROC_GET_SCHDATA(BIF_P), mtime); + BIF_RET(make_time_val(BIF_P, mtime + offset)); +} + +BIF_RETTYPE system_time_1(BIF_ALIST_0) +{ + ErtsMonotonicTime mtime, offset; + mtime = time_sup.r.o.get_time(); + offset = get_time_offset(); + update_last_mtime(ERTS_PROC_GET_SCHDATA(BIF_P), mtime); + BIF_RET(time_unit_conversion(BIF_P, BIF_ARG_1, mtime + offset, 0)); +} + +BIF_RETTYPE erts_internal_time_unit_0(BIF_ALIST_0) +{ + BIF_RET(make_time_val(BIF_P, ERTS_MONOTONIC_TIME_UNIT)); +} + +BIF_RETTYPE time_offset_0(BIF_ALIST_0) +{ + ErtsMonotonicTime time_offset = get_time_offset(); + time_offset -= ERTS_MONOTONIC_OFFSET_NATIVE; + BIF_RET(make_time_val(BIF_P, time_offset)); +} + +BIF_RETTYPE time_offset_1(BIF_ALIST_1) +{ + BIF_RET(time_unit_conversion(BIF_P, BIF_ARG_1, get_time_offset(), -1)); +} + + +BIF_RETTYPE timestamp_0(BIF_ALIST_0) +{ + Eterm *hp, res; + ErtsMonotonicTime stime, mtime, all_sec, offset; + Uint mega_sec, sec, micro_sec; + + mtime = time_sup.r.o.get_time(); + offset = get_time_offset(); + update_last_mtime(ERTS_PROC_GET_SCHDATA(BIF_P), mtime); + stime = ERTS_MONOTONIC_TO_USEC(mtime + offset); + all_sec = stime / ERTS_MONOTONIC_TIME_MEGA; + mega_sec = (Uint) (stime / ERTS_MONOTONIC_TIME_TERA); + sec = (Uint) (all_sec - (((ErtsMonotonicTime) mega_sec) + * ERTS_MONOTONIC_TIME_MEGA)); + micro_sec = (Uint) (stime - all_sec*ERTS_MONOTONIC_TIME_MEGA); + + ASSERT(((ErtsMonotonicTime) mega_sec)*ERTS_MONOTONIC_TIME_TERA + + ((ErtsMonotonicTime) sec)*ERTS_MONOTONIC_TIME_MEGA + + micro_sec == stime); + + /* + * Mega seconds is the only value that potentially + * ever could be a bignum. However, that wont happen + * during at least the next 4 million years... + * + * (System time will also have wrapped in the + * 64-bit integer before we get there...) + */ + + ASSERT(IS_USMALL(0, mega_sec)); + ASSERT(IS_USMALL(0, sec)); + ASSERT(IS_USMALL(0, micro_sec)); + + hp = HAlloc(BIF_P, 4); + res = TUPLE3(hp, + make_small(mega_sec), + make_small(sec), + make_small(micro_sec)); + BIF_RET(res); +} + +BIF_RETTYPE os_system_time_0(BIF_ALIST_0) +{ + ErtsSystemTime stime = erts_os_system_time(); + BIF_RET(make_time_val(BIF_P, stime)); +} + +BIF_RETTYPE os_system_time_1(BIF_ALIST_0) +{ + ErtsSystemTime stime = erts_os_system_time(); + BIF_RET(time_unit_conversion(BIF_P, BIF_ARG_1, stime, 0)); +} + |