xref: /freebsd/sys/sys/time.h (revision 7255a2969ff9ed2763391c854d7c2bed71a1a1c8)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1982, 1986, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef _SYS_TIME_H_
33 #define	_SYS_TIME_H_
34 
35 #include <sys/_timeval.h>
36 #include <sys/types.h>
37 #include <sys/timespec.h>
38 #include <sys/_clock_id.h>
39 
40 struct timezone {
41 	int	tz_minuteswest;	/* minutes west of Greenwich */
42 	int	tz_dsttime;	/* type of dst correction */
43 };
44 #define	DST_NONE	0	/* not on dst */
45 #define	DST_USA		1	/* USA style dst */
46 #define	DST_AUST	2	/* Australian style dst */
47 #define	DST_WET		3	/* Western European dst */
48 #define	DST_MET		4	/* Middle European dst */
49 #define	DST_EET		5	/* Eastern European dst */
50 #define	DST_CAN		6	/* Canada */
51 
52 #if __BSD_VISIBLE
53 struct bintime {
54 	time_t	sec;
55 	uint64_t frac;
56 };
57 
58 static __inline void
bintime_addx(struct bintime * _bt,uint64_t _x)59 bintime_addx(struct bintime *_bt, uint64_t _x)
60 {
61 	uint64_t _u;
62 
63 	_u = _bt->frac;
64 	_bt->frac += _x;
65 	if (_u > _bt->frac)
66 		_bt->sec++;
67 }
68 
69 static __inline void
bintime_add(struct bintime * _bt,const struct bintime * _bt2)70 bintime_add(struct bintime *_bt, const struct bintime *_bt2)
71 {
72 	uint64_t _u;
73 
74 	_u = _bt->frac;
75 	_bt->frac += _bt2->frac;
76 	if (_u > _bt->frac)
77 		_bt->sec++;
78 	_bt->sec += _bt2->sec;
79 }
80 
81 static __inline void
bintime_sub(struct bintime * _bt,const struct bintime * _bt2)82 bintime_sub(struct bintime *_bt, const struct bintime *_bt2)
83 {
84 	uint64_t _u;
85 
86 	_u = _bt->frac;
87 	_bt->frac -= _bt2->frac;
88 	if (_u < _bt->frac)
89 		_bt->sec--;
90 	_bt->sec -= _bt2->sec;
91 }
92 
93 static __inline void
bintime_mul(struct bintime * _bt,u_int _x)94 bintime_mul(struct bintime *_bt, u_int _x)
95 {
96 	uint64_t _p1, _p2;
97 
98 	_p1 = (_bt->frac & 0xffffffffull) * _x;
99 	_p2 = (_bt->frac >> 32) * _x + (_p1 >> 32);
100 	_bt->sec *= _x;
101 	_bt->sec += (_p2 >> 32);
102 	_bt->frac = (_p2 << 32) | (_p1 & 0xffffffffull);
103 }
104 
105 static __inline void
bintime_shift(struct bintime * _bt,int _exp)106 bintime_shift(struct bintime *_bt, int _exp)
107 {
108 
109 	if (_exp > 0) {
110 		_bt->sec <<= _exp;
111 		_bt->sec |= _bt->frac >> (64 - _exp);
112 		_bt->frac <<= _exp;
113 	} else if (_exp < 0) {
114 		_bt->frac >>= -_exp;
115 		_bt->frac |= (uint64_t)_bt->sec << (64 + _exp);
116 		_bt->sec >>= -_exp;
117 	}
118 }
119 
120 #define	bintime_clear(a)	((a)->sec = (a)->frac = 0)
121 #define	bintime_isset(a)	((a)->sec || (a)->frac)
122 #define	bintime_cmp(a, b, cmp)						\
123 	(((a)->sec == (b)->sec) ?					\
124 	    ((a)->frac cmp (b)->frac) :					\
125 	    ((a)->sec cmp (b)->sec))
126 
127 #define	SBT_1S	((sbintime_t)1 << 32)
128 #define	SBT_1M	(SBT_1S * 60)
129 #define	SBT_1MS	(SBT_1S / 1000)
130 #define	SBT_1US	(SBT_1S / 1000000)
131 #define	SBT_1NS	(SBT_1S / 1000000000) /* beware rounding, see nstosbt() */
132 #define	SBT_MAX	0x7fffffffffffffffLL
133 
134 static __inline int
sbintime_getsec(sbintime_t _sbt)135 sbintime_getsec(sbintime_t _sbt)
136 {
137 
138 	return (_sbt >> 32);
139 }
140 
141 static __inline sbintime_t
bttosbt(const struct bintime _bt)142 bttosbt(const struct bintime _bt)
143 {
144 
145 	return (((sbintime_t)_bt.sec << 32) + (_bt.frac >> 32));
146 }
147 
148 static __inline struct bintime
sbttobt(sbintime_t _sbt)149 sbttobt(sbintime_t _sbt)
150 {
151 	struct bintime _bt;
152 
153 	_bt.sec = _sbt >> 32;
154 	_bt.frac = _sbt << 32;
155 	return (_bt);
156 }
157 
158 /*
159  * Scaling functions for signed and unsigned 64-bit time using any
160  * 32-bit fraction:
161  */
162 
163 static __inline int64_t
__stime64_scale32_ceil(int64_t x,int32_t factor,int32_t divisor)164 __stime64_scale32_ceil(int64_t x, int32_t factor, int32_t divisor)
165 {
166 	const int64_t rem = x % divisor;
167 
168 	return (x / divisor * factor + (rem * factor + divisor - 1) / divisor);
169 }
170 
171 static __inline int64_t
__stime64_scale32_floor(int64_t x,int32_t factor,int32_t divisor)172 __stime64_scale32_floor(int64_t x, int32_t factor, int32_t divisor)
173 {
174 	const int64_t rem = x % divisor;
175 
176 	return (x / divisor * factor + (rem * factor) / divisor);
177 }
178 
179 static __inline uint64_t
__utime64_scale32_ceil(uint64_t x,uint32_t factor,uint32_t divisor)180 __utime64_scale32_ceil(uint64_t x, uint32_t factor, uint32_t divisor)
181 {
182 	const uint64_t rem = x % divisor;
183 
184 	return (x / divisor * factor + (rem * factor + divisor - 1) / divisor);
185 }
186 
187 static __inline uint64_t
__utime64_scale32_floor(uint64_t x,uint32_t factor,uint32_t divisor)188 __utime64_scale32_floor(uint64_t x, uint32_t factor, uint32_t divisor)
189 {
190 	const uint64_t rem = x % divisor;
191 
192 	return (x / divisor * factor + (rem * factor) / divisor);
193 }
194 
195 /*
196  * This function finds the common divisor between the two arguments,
197  * in powers of two. Use a macro, so the compiler will output a
198  * warning if the value overflows!
199  *
200  * Detailed description:
201  *
202  * Create a variable with 1's at the positions of the leading 0's
203  * starting at the least significant bit, producing 0 if none (e.g.,
204  * 01011000 -> 0000 0111). Then these two variables are bitwise AND'ed
205  * together, to produce the greatest common power of two minus one. In
206  * the end add one to flip the value to the actual power of two (e.g.,
207  * 0000 0111 + 1 -> 0000 1000).
208  */
209 #define	__common_powers_of_two(a, b) \
210 	((~(a) & ((a) - 1) & ~(b) & ((b) - 1)) + 1)
211 
212 /*
213  * Scaling functions for signed and unsigned 64-bit time assuming
214  * reducable 64-bit fractions to 32-bit fractions:
215  */
216 
217 static __inline int64_t
__stime64_scale64_ceil(int64_t x,int64_t factor,int64_t divisor)218 __stime64_scale64_ceil(int64_t x, int64_t factor, int64_t divisor)
219 {
220 	const int64_t gcd = __common_powers_of_two(factor, divisor);
221 
222 	return (__stime64_scale32_ceil(x, factor / gcd, divisor / gcd));
223 }
224 
225 static __inline int64_t
__stime64_scale64_floor(int64_t x,int64_t factor,int64_t divisor)226 __stime64_scale64_floor(int64_t x, int64_t factor, int64_t divisor)
227 {
228 	const int64_t gcd = __common_powers_of_two(factor, divisor);
229 
230 	return (__stime64_scale32_floor(x, factor / gcd, divisor / gcd));
231 }
232 
233 static __inline uint64_t
__utime64_scale64_ceil(uint64_t x,uint64_t factor,uint64_t divisor)234 __utime64_scale64_ceil(uint64_t x, uint64_t factor, uint64_t divisor)
235 {
236 	const uint64_t gcd = __common_powers_of_two(factor, divisor);
237 
238 	return (__utime64_scale32_ceil(x, factor / gcd, divisor / gcd));
239 }
240 
241 static __inline uint64_t
__utime64_scale64_floor(uint64_t x,uint64_t factor,uint64_t divisor)242 __utime64_scale64_floor(uint64_t x, uint64_t factor, uint64_t divisor)
243 {
244 	const uint64_t gcd = __common_powers_of_two(factor, divisor);
245 
246 	return (__utime64_scale32_floor(x, factor / gcd, divisor / gcd));
247 }
248 
249 /*
250  * Decimal<->sbt conversions. Multiplying or dividing by SBT_1NS
251  * results in large roundoff errors which sbttons() and nstosbt()
252  * avoid. Millisecond and microsecond functions are also provided for
253  * completeness.
254  *
255  * When converting from sbt to another unit, the result is always
256  * rounded down. When converting back to sbt the result is always
257  * rounded up. This gives the property that sbttoX(Xtosbt(y)) == y .
258  *
259  * The conversion functions can also handle negative values.
260  */
261 #define	SBT_DECLARE_CONVERSION_PAIR(name, units_per_second)	\
262 static __inline int64_t \
263 sbtto##name(sbintime_t sbt) \
264 { \
265 	return (__stime64_scale64_floor(sbt, units_per_second, SBT_1S)); \
266 } \
267 static __inline sbintime_t \
268 name##tosbt(int64_t name) \
269 { \
270 	return (__stime64_scale64_ceil(name, SBT_1S, units_per_second)); \
271 }
272 
273 SBT_DECLARE_CONVERSION_PAIR(ns, 1000000000)
274 SBT_DECLARE_CONVERSION_PAIR(us, 1000000)
275 SBT_DECLARE_CONVERSION_PAIR(ms, 1000)
276 
277 /*-
278  * Background information:
279  *
280  * When converting between timestamps on parallel timescales of differing
281  * resolutions it is historical and scientific practice to round down rather
282  * than doing 4/5 rounding.
283  *
284  *   The date changes at midnight, not at noon.
285  *
286  *   Even at 15:59:59.999999999 it's not four'o'clock.
287  *
288  *   time_second ticks after N.999999999 not after N.4999999999
289  */
290 
291 static __inline void
bintime2timespec(const struct bintime * _bt,struct timespec * _ts)292 bintime2timespec(const struct bintime *_bt, struct timespec *_ts)
293 {
294 
295 	_ts->tv_sec = _bt->sec;
296 	_ts->tv_nsec = __utime64_scale64_floor(
297 	    _bt->frac, 1000000000, 1ULL << 32) >> 32;
298 }
299 
300 static __inline uint64_t
bintime2ns(const struct bintime * _bt)301 bintime2ns(const struct bintime *_bt)
302 {
303 	uint64_t ret;
304 
305 	ret = (uint64_t)(_bt->sec) * (uint64_t)1000000000;
306 	ret += __utime64_scale64_floor(
307 	    _bt->frac, 1000000000, 1ULL << 32) >> 32;
308 	return (ret);
309 }
310 
311 static __inline void
timespec2bintime(const struct timespec * _ts,struct bintime * _bt)312 timespec2bintime(const struct timespec *_ts, struct bintime *_bt)
313 {
314 
315 	_bt->sec = _ts->tv_sec;
316 	_bt->frac = __utime64_scale64_floor(
317 	    (uint64_t)_ts->tv_nsec << 32, 1ULL << 32, 1000000000);
318 }
319 
320 static __inline void
bintime2timeval(const struct bintime * _bt,struct timeval * _tv)321 bintime2timeval(const struct bintime *_bt, struct timeval *_tv)
322 {
323 
324 	_tv->tv_sec = _bt->sec;
325 	_tv->tv_usec = __utime64_scale64_floor(
326 	    _bt->frac, 1000000, 1ULL << 32) >> 32;
327 }
328 
329 static __inline void
timeval2bintime(const struct timeval * _tv,struct bintime * _bt)330 timeval2bintime(const struct timeval *_tv, struct bintime *_bt)
331 {
332 
333 	_bt->sec = _tv->tv_sec;
334 	_bt->frac = __utime64_scale64_floor(
335 	    (uint64_t)_tv->tv_usec << 32, 1ULL << 32, 1000000);
336 }
337 
338 static __inline struct timespec
sbttots(sbintime_t _sbt)339 sbttots(sbintime_t _sbt)
340 {
341 	struct timespec _ts;
342 
343 	_ts.tv_sec = _sbt >> 32;
344 	_ts.tv_nsec = sbttons((uint32_t)_sbt);
345 	return (_ts);
346 }
347 
348 static __inline sbintime_t
tstosbt(struct timespec _ts)349 tstosbt(struct timespec _ts)
350 {
351 
352 	return (((sbintime_t)_ts.tv_sec << 32) + nstosbt(_ts.tv_nsec));
353 }
354 
355 static __inline struct timeval
sbttotv(sbintime_t _sbt)356 sbttotv(sbintime_t _sbt)
357 {
358 	struct timeval _tv;
359 
360 	_tv.tv_sec = _sbt >> 32;
361 	_tv.tv_usec = sbttous((uint32_t)_sbt);
362 	return (_tv);
363 }
364 
365 static __inline sbintime_t
tvtosbt(struct timeval _tv)366 tvtosbt(struct timeval _tv)
367 {
368 
369 	return (((sbintime_t)_tv.tv_sec << 32) + ustosbt(_tv.tv_usec));
370 }
371 #endif /* __BSD_VISIBLE */
372 
373 #ifdef _KERNEL
374 /*
375  * Simple macros to convert ticks to milliseconds
376  * or microseconds and vice-versa. The answer
377  * will always be at least 1. Note the return
378  * value is a uint32_t however we step up the
379  * operations to 64 bit to avoid any overflow/underflow
380  * problems.
381  */
382 #define TICKS_2_MSEC(t) max(1, (uint32_t)(hz == 1000) ? \
383 	  (t) : (((uint64_t)(t) * (uint64_t)1000)/(uint64_t)hz))
384 #define TICKS_2_USEC(t) max(1, (uint32_t)(hz == 1000) ? \
385 	  ((t) * 1000) : (((uint64_t)(t) * (uint64_t)1000000)/(uint64_t)hz))
386 #define MSEC_2_TICKS(m) max(1, (uint32_t)((hz == 1000) ? \
387 	  (m) : ((uint64_t)(m) * (uint64_t)hz)/(uint64_t)1000))
388 #define USEC_2_TICKS(u) max(1, (uint32_t)((hz == 1000) ? \
389 	 ((u) / 1000) : ((uint64_t)(u) * (uint64_t)hz)/(uint64_t)1000000))
390 
391 #endif
392 /* Operations on timespecs */
393 #define	timespecclear(tvp)	((tvp)->tv_sec = (tvp)->tv_nsec = 0)
394 #define	timespecisset(tvp)	((tvp)->tv_sec || (tvp)->tv_nsec)
395 #define	timespeccmp(tvp, uvp, cmp)					\
396 	(((tvp)->tv_sec == (uvp)->tv_sec) ?				\
397 	    ((tvp)->tv_nsec cmp (uvp)->tv_nsec) :			\
398 	    ((tvp)->tv_sec cmp (uvp)->tv_sec))
399 
400 #define	timespecadd(tsp, usp, vsp)					\
401 	do {								\
402 		(vsp)->tv_sec = (tsp)->tv_sec + (usp)->tv_sec;		\
403 		(vsp)->tv_nsec = (tsp)->tv_nsec + (usp)->tv_nsec;	\
404 		if ((vsp)->tv_nsec >= 1000000000L) {			\
405 			(vsp)->tv_sec++;				\
406 			(vsp)->tv_nsec -= 1000000000L;			\
407 		}							\
408 	} while (0)
409 #define	timespecsub(tsp, usp, vsp)					\
410 	do {								\
411 		(vsp)->tv_sec = (tsp)->tv_sec - (usp)->tv_sec;		\
412 		(vsp)->tv_nsec = (tsp)->tv_nsec - (usp)->tv_nsec;	\
413 		if ((vsp)->tv_nsec < 0) {				\
414 			(vsp)->tv_sec--;				\
415 			(vsp)->tv_nsec += 1000000000L;			\
416 		}							\
417 	} while (0)
418 #define	timespecvalid_interval(tsp)	((tsp)->tv_sec >= 0 &&		\
419 	    (tsp)->tv_nsec >= 0 && (tsp)->tv_nsec < 1000000000L)
420 
421 #ifdef _KERNEL
422 
423 /* Operations on timevals. */
424 
425 #define	timevalclear(tvp)		((tvp)->tv_sec = (tvp)->tv_usec = 0)
426 #define	timevalisset(tvp)		((tvp)->tv_sec || (tvp)->tv_usec)
427 #define	timevalcmp(tvp, uvp, cmp)					\
428 	(((tvp)->tv_sec == (uvp)->tv_sec) ?				\
429 	    ((tvp)->tv_usec cmp (uvp)->tv_usec) :			\
430 	    ((tvp)->tv_sec cmp (uvp)->tv_sec))
431 
432 /* timevaladd and timevalsub are not inlined */
433 
434 #endif /* _KERNEL */
435 
436 #ifndef _KERNEL			/* NetBSD/OpenBSD compatible interfaces */
437 
438 #define	timerclear(tvp)		((tvp)->tv_sec = (tvp)->tv_usec = 0)
439 #define	timerisset(tvp)		((tvp)->tv_sec || (tvp)->tv_usec)
440 #define	timercmp(tvp, uvp, cmp)					\
441 	(((tvp)->tv_sec == (uvp)->tv_sec) ?				\
442 	    ((tvp)->tv_usec cmp (uvp)->tv_usec) :			\
443 	    ((tvp)->tv_sec cmp (uvp)->tv_sec))
444 #define	timeradd(tvp, uvp, vvp)						\
445 	do {								\
446 		(vvp)->tv_sec = (tvp)->tv_sec + (uvp)->tv_sec;		\
447 		(vvp)->tv_usec = (tvp)->tv_usec + (uvp)->tv_usec;	\
448 		if ((vvp)->tv_usec >= 1000000) {			\
449 			(vvp)->tv_sec++;				\
450 			(vvp)->tv_usec -= 1000000;			\
451 		}							\
452 	} while (0)
453 #define	timersub(tvp, uvp, vvp)						\
454 	do {								\
455 		(vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec;		\
456 		(vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec;	\
457 		if ((vvp)->tv_usec < 0) {				\
458 			(vvp)->tv_sec--;				\
459 			(vvp)->tv_usec += 1000000;			\
460 		}							\
461 	} while (0)
462 #endif
463 
464 /*
465  * Names of the interval timers, and structure
466  * defining a timer setting.
467  */
468 #define	ITIMER_REAL	0
469 #define	ITIMER_VIRTUAL	1
470 #define	ITIMER_PROF	2
471 
472 struct itimerval {
473 	struct	timeval it_interval;	/* timer interval */
474 	struct	timeval it_value;	/* current value */
475 };
476 
477 /*
478  * Getkerninfo clock information structure
479  */
480 struct clockinfo {
481 	int	hz;		/* clock frequency */
482 	int	tick;		/* micro-seconds per hz tick */
483 	int	spare;
484 	int	stathz;		/* statistics clock frequency */
485 	int	profhz;		/* profiling clock frequency */
486 };
487 
488 #if __BSD_VISIBLE
489 #define	CPUCLOCK_WHICH_PID	0
490 #define	CPUCLOCK_WHICH_TID	1
491 #endif
492 
493 #if defined(_KERNEL) || defined(_STANDALONE)
494 
495 /*
496  * Kernel to clock driver interface.
497  */
498 void	inittodr(time_t base);
499 void	resettodr(void);
500 
501 extern volatile time_t	time_second;
502 extern volatile time_t	time_uptime;
503 extern struct bintime tc_tick_bt;
504 extern sbintime_t tc_tick_sbt;
505 extern time_t tick_seconds_max;
506 extern struct bintime tick_bt;
507 extern sbintime_t tick_sbt;
508 extern int tc_precexp;
509 extern int tc_timepercentage;
510 extern struct bintime bt_timethreshold;
511 extern struct bintime bt_tickthreshold;
512 extern sbintime_t sbt_timethreshold;
513 extern sbintime_t sbt_tickthreshold;
514 
515 extern volatile int rtc_generation;
516 
517 /*
518  * Functions for looking at our clock: [get]{bin,nano,micro}[up]time()
519  *
520  * Functions without the "get" prefix returns the best timestamp
521  * we can produce in the given format.
522  *
523  * "bin"   == struct bintime  == seconds + 64 bit fraction of seconds.
524  * "nano"  == struct timespec == seconds + nanoseconds.
525  * "micro" == struct timeval  == seconds + microseconds.
526  *
527  * Functions containing "up" returns time relative to boot and
528  * should be used for calculating time intervals.
529  *
530  * Functions without "up" returns UTC time.
531  *
532  * Functions with the "get" prefix returns a less precise result
533  * much faster than the functions without "get" prefix and should
534  * be used where a precision of 1/hz seconds is acceptable or where
535  * performance is priority. (NB: "precision", _not_ "resolution" !)
536  */
537 
538 void	binuptime(struct bintime *bt);
539 void	nanouptime(struct timespec *tsp);
540 void	microuptime(struct timeval *tvp);
541 
542 static __inline sbintime_t
sbinuptime(void)543 sbinuptime(void)
544 {
545 	struct bintime _bt;
546 
547 	binuptime(&_bt);
548 	return (bttosbt(_bt));
549 }
550 
551 void	bintime(struct bintime *bt);
552 void	nanotime(struct timespec *tsp);
553 void	microtime(struct timeval *tvp);
554 
555 void	getbinuptime(struct bintime *bt);
556 void	getnanouptime(struct timespec *tsp);
557 void	getmicrouptime(struct timeval *tvp);
558 
559 static __inline sbintime_t
getsbinuptime(void)560 getsbinuptime(void)
561 {
562 	struct bintime _bt;
563 
564 	getbinuptime(&_bt);
565 	return (bttosbt(_bt));
566 }
567 
568 void	getbintime(struct bintime *bt);
569 void	getnanotime(struct timespec *tsp);
570 void	getmicrotime(struct timeval *tvp);
571 
572 void	getboottime(struct timeval *boottime);
573 void	getboottimebin(struct bintime *boottimebin);
574 
575 /* Other functions */
576 int	itimerdecr(struct itimerval *itp, int usec);
577 int	itimerfix(struct timeval *tv);
578 int	eventratecheck(struct timeval *, int *, int);
579 #define	ppsratecheck(t, c, m) eventratecheck(t, c, m)
580 int	ratecheck(struct timeval *, const struct timeval *);
581 void	timevaladd(struct timeval *t1, const struct timeval *t2);
582 void	timevalsub(struct timeval *t1, const struct timeval *t2);
583 int	tvtohz(struct timeval *tv);
584 
585 /*
586  * The following HZ limits allow the tvtohz() function
587  * to only use integer computations.
588  */
589 #define	HZ_MAXIMUM (INT_MAX / (1000000 >> 6)) /* 137kHz */
590 #define	HZ_MINIMUM 8 /* hz */
591 
592 #define	TC_DEFAULTPERC		5
593 
594 #define	BT2FREQ(bt)                                                     \
595 	(((uint64_t)0x8000000000000000 + ((bt)->frac >> 2)) /           \
596 	    ((bt)->frac >> 1))
597 
598 #define	SBT2FREQ(sbt)	((SBT_1S + ((sbt) >> 1)) / (sbt))
599 
600 #define	FREQ2BT(freq, bt)                                               \
601 {									\
602 	(bt)->sec = 0;                                                  \
603 	(bt)->frac = ((uint64_t)0x8000000000000000  / (freq)) << 1;     \
604 }
605 
606 #define	TIMESEL(sbt, sbt2)						\
607 	(((sbt2) >= sbt_timethreshold) ?				\
608 	    ((*(sbt) = getsbinuptime()), 1) : ((*(sbt) = sbinuptime()), 0))
609 
610 #else /* !_KERNEL && !_STANDALONE */
611 #include <time.h>
612 
613 #include <sys/cdefs.h>
614 #ifndef _STANDALONE
615 #include <sys/select.h>
616 #endif
617 
618 __BEGIN_DECLS
619 int	setitimer(int, const struct itimerval *, struct itimerval *);
620 int	utimes(const char *, const struct timeval *);
621 
622 #if __BSD_VISIBLE
623 int	adjtime(const struct timeval *, struct timeval *);
624 int	clock_getcpuclockid2(id_t, int, clockid_t *);
625 int	futimes(int, const struct timeval *);
626 int	futimesat(int, const char *, const struct timeval [2]);
627 int	lutimes(const char *, const struct timeval *);
628 int	settimeofday(const struct timeval *, const struct timezone *);
629 #endif
630 
631 #if __XSI_VISIBLE
632 int	getitimer(int, struct itimerval *);
633 int	gettimeofday(struct timeval *, struct timezone *);
634 #endif
635 
636 __END_DECLS
637 
638 #endif /* !_KERNEL */
639 
640 #endif /* !_SYS_TIME_H_ */
641