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Willy Tarreaubaaee002006-06-26 02:48:02 +02001/*
2 * Time calculation functions.
3 *
Willy Tarreau45a12512011-09-10 16:56:42 +02004 * Copyright 2000-2011 Willy Tarreau <w@1wt.eu>
Willy Tarreaubaaee002006-06-26 02:48:02 +02005 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 *
11 */
12
Willy Tarreaua1bd1fa2019-03-29 17:26:33 +010013#include <inttypes.h>
Willy Tarreaued72d822018-10-17 19:01:24 +020014#include <unistd.h>
Willy Tarreaubaaee002006-06-26 02:48:02 +020015#include <sys/time.h>
Willy Tarreaue3ba5f02006-06-29 18:54:54 +020016
17#include <common/config.h>
Willy Tarreau5e8f0662007-02-12 00:59:08 +010018#include <common/standard.h>
Willy Tarreau2dd0d472006-06-29 17:53:05 +020019#include <common/time.h>
Christopher Faulet99aad922017-10-31 09:03:51 +010020#include <common/hathreads.h>
Willy Tarreaubaaee002006-06-26 02:48:02 +020021
Christopher Faulet9a655712017-05-11 11:00:15 +020022THREAD_LOCAL unsigned int ms_left_scaled; /* milliseconds left for current second (0..2^32-1) */
23THREAD_LOCAL unsigned int now_ms; /* internal date in milliseconds (may wrap) */
24THREAD_LOCAL unsigned int samp_time; /* total elapsed time over current sample */
25THREAD_LOCAL unsigned int idle_time; /* total idle time over current sample */
Christopher Faulet9a655712017-05-11 11:00:15 +020026THREAD_LOCAL struct timeval now; /* internal date is a monotonic function of real clock */
27THREAD_LOCAL struct timeval date; /* the real current date */
Willy Tarreaubaaee002006-06-26 02:48:02 +020028struct timeval start_date; /* the process's start date */
Christopher Faulet9a655712017-05-11 11:00:15 +020029THREAD_LOCAL struct timeval before_poll; /* system date before calling poll() */
30THREAD_LOCAL struct timeval after_poll; /* system date after leaving poll() */
Willy Tarreaubaaee002006-06-26 02:48:02 +020031
Willy Tarreau9fefc512017-11-23 14:52:28 +010032static THREAD_LOCAL struct timeval tv_offset; /* per-thread time ofsset relative to global time */
Willy Tarreaue70208e2021-03-17 18:52:18 +010033volatile unsigned long long global_now; /* common date between all threads (32:32) */
Willy Tarreau9fefc512017-11-23 14:52:28 +010034
Willy Tarreaubaaee002006-06-26 02:48:02 +020035/*
36 * adds <ms> ms to <from>, set the result to <tv> and returns a pointer <tv>
37 */
Willy Tarreau42aae5c2007-04-29 17:43:56 +020038REGPRM3 struct timeval *_tv_ms_add(struct timeval *tv, const struct timeval *from, int ms)
Willy Tarreaubaaee002006-06-26 02:48:02 +020039{
Willy Tarreau42aae5c2007-04-29 17:43:56 +020040 tv->tv_usec = from->tv_usec + (ms % 1000) * 1000;
41 tv->tv_sec = from->tv_sec + (ms / 1000);
Willy Tarreaubaaee002006-06-26 02:48:02 +020042 while (tv->tv_usec >= 1000000) {
43 tv->tv_usec -= 1000000;
44 tv->tv_sec++;
45 }
46 return tv;
47}
48
49/*
50 * compares <tv1> and <tv2> modulo 1ms: returns 0 if equal, -1 if tv1 < tv2, 1 if tv1 > tv2
Willy Tarreau42aae5c2007-04-29 17:43:56 +020051 * Must not be used when either argument is eternity. Use tv_ms_cmp2() for that.
Willy Tarreaubaaee002006-06-26 02:48:02 +020052 */
Willy Tarreau42aae5c2007-04-29 17:43:56 +020053REGPRM2 int _tv_ms_cmp(const struct timeval *tv1, const struct timeval *tv2)
Willy Tarreaubaaee002006-06-26 02:48:02 +020054{
Willy Tarreau42aae5c2007-04-29 17:43:56 +020055 return __tv_ms_cmp(tv1, tv2);
Willy Tarreaubaaee002006-06-26 02:48:02 +020056}
57
58/*
Willy Tarreaubaaee002006-06-26 02:48:02 +020059 * compares <tv1> and <tv2> modulo 1 ms: returns 0 if equal, -1 if tv1 < tv2, 1 if tv1 > tv2,
Willy Tarreaua6a6a932007-04-28 22:40:08 +020060 * assuming that TV_ETERNITY is greater than everything.
Willy Tarreaubaaee002006-06-26 02:48:02 +020061 */
Willy Tarreau42aae5c2007-04-29 17:43:56 +020062REGPRM2 int _tv_ms_cmp2(const struct timeval *tv1, const struct timeval *tv2)
Willy Tarreaubaaee002006-06-26 02:48:02 +020063{
Willy Tarreau42aae5c2007-04-29 17:43:56 +020064 return __tv_ms_cmp2(tv1, tv2);
Willy Tarreau8d7d1492007-04-29 10:50:43 +020065}
66
67/*
68 * compares <tv1> and <tv2> modulo 1 ms: returns 1 if tv1 <= tv2, 0 if tv1 > tv2,
69 * assuming that TV_ETERNITY is greater than everything. Returns 0 if tv1 is
70 * TV_ETERNITY, and always assumes that tv2 != TV_ETERNITY. Designed to replace
Willy Tarreau42aae5c2007-04-29 17:43:56 +020071 * occurrences of (tv_ms_cmp2(tv,now) <= 0).
Willy Tarreau8d7d1492007-04-29 10:50:43 +020072 */
Willy Tarreau42aae5c2007-04-29 17:43:56 +020073REGPRM2 int _tv_ms_le2(const struct timeval *tv1, const struct timeval *tv2)
Willy Tarreau8d7d1492007-04-29 10:50:43 +020074{
Willy Tarreau42aae5c2007-04-29 17:43:56 +020075 return __tv_ms_le2(tv1, tv2);
76}
Willy Tarreau8d7d1492007-04-29 10:50:43 +020077
Willy Tarreau42aae5c2007-04-29 17:43:56 +020078/*
79 * returns the remaining time between tv1=now and event=tv2
80 * if tv2 is passed, 0 is returned.
81 * Must not be used when either argument is eternity.
82 */
83REGPRM2 unsigned long _tv_ms_remain(const struct timeval *tv1, const struct timeval *tv2)
84{
85 return __tv_ms_remain(tv1, tv2);
Willy Tarreaubaaee002006-06-26 02:48:02 +020086}
87
88/*
89 * returns the remaining time between tv1=now and event=tv2
90 * if tv2 is passed, 0 is returned.
91 * Returns TIME_ETERNITY if tv2 is eternity.
92 */
Willy Tarreau42aae5c2007-04-29 17:43:56 +020093REGPRM2 unsigned long _tv_ms_remain2(const struct timeval *tv1, const struct timeval *tv2)
Willy Tarreaubaaee002006-06-26 02:48:02 +020094{
Willy Tarreaubaaee002006-06-26 02:48:02 +020095 if (tv_iseternity(tv2))
96 return TIME_ETERNITY;
97
Willy Tarreau42aae5c2007-04-29 17:43:56 +020098 return __tv_ms_remain(tv1, tv2);
Willy Tarreaubaaee002006-06-26 02:48:02 +020099}
100
Willy Tarreaubaaee002006-06-26 02:48:02 +0200101/*
Willy Tarreau42aae5c2007-04-29 17:43:56 +0200102 * Returns the time in ms elapsed between tv1 and tv2, assuming that tv1<=tv2.
Willy Tarreaubaaee002006-06-26 02:48:02 +0200103 * Must not be used when either argument is eternity.
104 */
Willy Tarreau42aae5c2007-04-29 17:43:56 +0200105REGPRM2 unsigned long _tv_ms_elapsed(const struct timeval *tv1, const struct timeval *tv2)
Willy Tarreaubaaee002006-06-26 02:48:02 +0200106{
Willy Tarreau42aae5c2007-04-29 17:43:56 +0200107 return __tv_ms_elapsed(tv1, tv2);
Willy Tarreaubaaee002006-06-26 02:48:02 +0200108}
109
110/*
Willy Tarreaud825eef2007-05-12 22:35:00 +0200111 * adds <inc> to <from>, set the result to <tv> and returns a pointer <tv>
112 */
113REGPRM3 struct timeval *_tv_add(struct timeval *tv, const struct timeval *from, const struct timeval *inc)
114{
115 return __tv_add(tv, from, inc);
116}
117
118/*
Willy Tarreau0481c202007-05-13 16:03:27 +0200119 * If <inc> is set, then add it to <from> and set the result to <tv>, then
120 * return 1, otherwise return 0. It is meant to be used in if conditions.
121 */
122REGPRM3 int _tv_add_ifset(struct timeval *tv, const struct timeval *from, const struct timeval *inc)
123{
124 return __tv_add_ifset(tv, from, inc);
125}
126
127/*
Willy Tarreaud825eef2007-05-12 22:35:00 +0200128 * Computes the remaining time between tv1=now and event=tv2. if tv2 is passed,
129 * 0 is returned. The result is stored into tv.
130 */
131REGPRM3 struct timeval *_tv_remain(const struct timeval *tv1, const struct timeval *tv2, struct timeval *tv)
132{
133 return __tv_remain(tv1, tv2, tv);
134}
135
136/*
137 * Computes the remaining time between tv1=now and event=tv2. if tv2 is passed,
138 * 0 is returned. The result is stored into tv. Returns ETERNITY if tv2 is
139 * eternity.
140 */
141REGPRM3 struct timeval *_tv_remain2(const struct timeval *tv1, const struct timeval *tv2, struct timeval *tv)
142{
143 return __tv_remain2(tv1, tv2, tv);
144}
145
Willy Tarreau0481c202007-05-13 16:03:27 +0200146/* tv_isle: compares <tv1> and <tv2> : returns 1 if tv1 <= tv2, otherwise 0 */
147REGPRM2 int _tv_isle(const struct timeval *tv1, const struct timeval *tv2)
148{
149 return __tv_isle(tv1, tv2);
150}
151
152/* tv_isgt: compares <tv1> and <tv2> : returns 1 if tv1 > tv2, otherwise 0 */
153REGPRM2 int _tv_isgt(const struct timeval *tv1, const struct timeval *tv2)
154{
155 return __tv_isgt(tv1, tv2);
156}
157
Willy Tarreau7649aac2017-11-23 11:52:55 +0100158/* tv_update_date: sets <date> to system time, and sets <now> to something as
Willy Tarreaub0b37bc2008-06-23 14:00:57 +0200159 * close as possible to real time, following a monotonic function. The main
160 * principle consists in detecting backwards and forwards time jumps and adjust
161 * an offset to correct them. This function should be called once after each
162 * poll, and never farther apart than MAX_DELAY_MS*2. The poll's timeout should
163 * be passed in <max_wait>, and the return value in <interrupted> (a non-zero
164 * value means that we have not expired the timeout). Calling it with (-1,*)
165 * sets both <date> and <now> to current date, and calling it with (0,1) simply
166 * updates the values.
Christopher Faulet99aad922017-10-31 09:03:51 +0100167 *
Willy Tarreau7649aac2017-11-23 11:52:55 +0100168 * An offset is used to adjust the current time (date), to have a monotonic time
Christopher Faulet99aad922017-10-31 09:03:51 +0100169 * (now). It must be global and thread-safe. But a timeval cannot be atomically
Willy Tarreau7649aac2017-11-23 11:52:55 +0100170 * updated. So instead, we store it in a 64-bits integer (offset) whose 32 MSB
171 * contain the signed seconds adjustment andthe 32 LSB contain the unsigned
172 * microsecond adjustment. We cannot use a timeval for this since it's never
173 * clearly specified whether a timeval may hold negative values or not.
Willy Tarreaub7f694f2008-06-22 17:18:02 +0200174 */
Willy Tarreaub0b37bc2008-06-23 14:00:57 +0200175REGPRM2 void tv_update_date(int max_wait, int interrupted)
Willy Tarreaub7f694f2008-06-22 17:18:02 +0200176{
Willy Tarreaua3315442018-02-05 20:11:38 +0100177 struct timeval adjusted, deadline, tmp_now, tmp_adj;
Willy Tarreau351b3a12017-03-29 15:24:33 +0200178 unsigned int curr_sec_ms; /* millisecond of current second (0..999) */
Willy Tarreau9fefc512017-11-23 14:52:28 +0100179 unsigned long long old_now;
180 unsigned long long new_now;
Willy Tarreaub7f694f2008-06-22 17:18:02 +0200181
Willy Tarreaub0b37bc2008-06-23 14:00:57 +0200182 gettimeofday(&date, NULL);
183 if (unlikely(max_wait < 0)) {
Willy Tarreau9fefc512017-11-23 14:52:28 +0100184 tv_zero(&tv_offset);
Willy Tarreau75590582009-03-05 14:54:50 +0100185 adjusted = date;
Willy Tarreau45a12512011-09-10 16:56:42 +0200186 after_poll = date;
187 samp_time = idle_time = 0;
Willy Tarreau81036f22019-05-20 19:24:50 +0200188 ti->idle_pct = 100;
Willy Tarreau43091ed2019-06-06 16:50:39 +0200189 old_now = global_now;
190 if (!old_now) { // never set
191 new_now = (((unsigned long long)adjusted.tv_sec) << 32) + (unsigned int)adjusted.tv_usec;
192 _HA_ATOMIC_CAS(&global_now, &old_now, new_now);
193 }
Willy Tarreaue6313a32008-06-29 13:47:25 +0200194 goto to_ms;
Willy Tarreaub0b37bc2008-06-23 14:00:57 +0200195 }
Willy Tarreau7649aac2017-11-23 11:52:55 +0100196
Willy Tarreau9fefc512017-11-23 14:52:28 +0100197 __tv_add(&adjusted, &date, &tv_offset);
Willy Tarreau7649aac2017-11-23 11:52:55 +0100198
Willy Tarreau9fefc512017-11-23 14:52:28 +0100199 /* compute the minimum and maximum local date we may have reached based
200 * on our past date and the associated timeout.
201 */
202 _tv_ms_add(&deadline, &now, max_wait + MAX_DELAY_MS);
Willy Tarreau7649aac2017-11-23 11:52:55 +0100203
Willy Tarreau9fefc512017-11-23 14:52:28 +0100204 if (unlikely(__tv_islt(&adjusted, &now) || __tv_islt(&deadline, &adjusted))) {
205 /* Large jump. If the poll was interrupted, we consider that the
206 * date has not changed (immediate wake-up), otherwise we add
207 * the poll time-out to the previous date. The new offset is
208 * recomputed.
209 */
210 _tv_ms_add(&adjusted, &now, interrupted ? 0 : max_wait);
Willy Tarreaub0b37bc2008-06-23 14:00:57 +0200211 }
212
Willy Tarreau9fefc512017-11-23 14:52:28 +0100213 /* now that we have bounded the local time, let's check if it's
214 * realistic regarding the global date, which only moves forward,
215 * otherwise catch up.
Willy Tarreaub0b37bc2008-06-23 14:00:57 +0200216 */
Willy Tarreau9fefc512017-11-23 14:52:28 +0100217 old_now = global_now;
Willy Tarreau75590582009-03-05 14:54:50 +0100218
Willy Tarreau9fefc512017-11-23 14:52:28 +0100219 do {
220 tmp_now.tv_sec = (unsigned int)(old_now >> 32);
221 tmp_now.tv_usec = old_now & 0xFFFFFFFFU;
Willy Tarreaua3315442018-02-05 20:11:38 +0100222 tmp_adj = adjusted;
Willy Tarreau7649aac2017-11-23 11:52:55 +0100223
Willy Tarreaua3315442018-02-05 20:11:38 +0100224 if (__tv_islt(&tmp_adj, &tmp_now))
225 tmp_adj = tmp_now;
Willy Tarreau9fefc512017-11-23 14:52:28 +0100226
227 /* now <adjusted> is expected to be the most accurate date,
228 * equal to <global_now> or newer.
229 */
Willy Tarreaua3315442018-02-05 20:11:38 +0100230 new_now = (((unsigned long long)tmp_adj.tv_sec) << 32) + (unsigned int)tmp_adj.tv_usec;
Willy Tarreau9fefc512017-11-23 14:52:28 +0100231
232 /* let's try to update the global <now> or loop again */
Olivier Houchardcab0f0b2019-03-08 18:55:31 +0100233 } while (!_HA_ATOMIC_CAS(&global_now, &old_now, new_now));
Willy Tarreau9fefc512017-11-23 14:52:28 +0100234
Willy Tarreaua3315442018-02-05 20:11:38 +0100235 adjusted = tmp_adj;
236
Willy Tarreau9fefc512017-11-23 14:52:28 +0100237 /* the new global date when we looked was old_now, and the new one is
238 * new_now == adjusted. We can recompute our local offset.
239 */
240 tv_offset.tv_sec = adjusted.tv_sec - date.tv_sec;
241 tv_offset.tv_usec = adjusted.tv_usec - date.tv_usec;
242 if (tv_offset.tv_usec < 0) {
243 tv_offset.tv_usec += 1000000;
244 tv_offset.tv_sec--;
245 }
Willy Tarreau7649aac2017-11-23 11:52:55 +0100246
Willy Tarreaue6313a32008-06-29 13:47:25 +0200247 to_ms:
Willy Tarreau75590582009-03-05 14:54:50 +0100248 now = adjusted;
249 curr_sec_ms = now.tv_usec / 1000; /* ms of current second */
Willy Tarreaueab777c2012-12-29 21:50:07 +0100250
251 /* For frequency counters, we'll need to know the ratio of the previous
252 * value to add to current value depending on the current millisecond.
253 * The principle is that during the first millisecond, we use 999/1000
254 * of the past value and that during the last millisecond we use 0/1000
255 * of the past value. In summary, we only use the past value during the
256 * first 999 ms of a second, and the last ms is used to complete the
257 * current measure. The value is scaled to (2^32-1) so that a simple
258 * multiply followed by a shift gives us the final value.
259 */
260 ms_left_scaled = (999U - curr_sec_ms) * 4294967U;
Willy Tarreau75590582009-03-05 14:54:50 +0100261 now_ms = now.tv_sec * 1000 + curr_sec_ms;
Willy Tarreaub0b37bc2008-06-23 14:00:57 +0200262 return;
Willy Tarreaub7f694f2008-06-22 17:18:02 +0200263}
264
Willy Tarreaud825eef2007-05-12 22:35:00 +0200265/*
Willy Tarreaubaaee002006-06-26 02:48:02 +0200266 * Local variables:
267 * c-indent-level: 8
268 * c-basic-offset: 8
269 * End:
270 */