1 /* time.h -- An implementation of the standard Unix <sys/time.h> file.
2    Written by Geoffrey Noer <noer@cygnus.com>
3    Public domain; no rights reserved. */
4 
5 /*-
6  * SPDX-License-Identifier: BSD-3-Clause
7  *
8  * Copyright (c) 1982, 1986, 1993
9  *	The Regents of the University of California.  All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  *	@(#)time.h	8.5 (Berkeley) 5/4/95
36  * $FreeBSD: head/sys/sys/time.h 346176 2019-04-13 04:46:35Z imp $
37  */
38 
39 #ifndef _SYS_TIME_H_
40 #define	_SYS_TIME_H_
41 
42 #include <sys/cdefs.h>
43 #include <sys/_types.h>
44 #include <sys/_timeval.h>
45 #include <sys/_timespec.h>
46 #include <sys/_select.h>
47 
48 _BEGIN_STD_C
49 
50 #ifndef _SUSECONDS_T_DECLARED
51 typedef	__suseconds_t	suseconds_t;
52 #define	_SUSECONDS_T_DECLARED
53 #endif
54 
55 /*
56  * Names of the interval timers, and structure
57  * defining a timer setting.
58  */
59 #define	ITIMER_REAL	0
60 #define	ITIMER_VIRTUAL	1
61 #define	ITIMER_PROF	2
62 
63 struct itimerval {
64 	struct	timeval it_interval;	/* timer interval */
65 	struct	timeval it_value;	/* current value */
66 };
67 
68 int getitimer (int __which, struct itimerval *__value);
69 int gettimeofday (struct timeval *__restrict __p,
70 			  void *__restrict __tz);
71 int setitimer (int __which, const struct itimerval *__restrict __value,
72 					struct itimerval *__restrict __ovalue);
73 int utimes (const char *, const struct timeval [2]);
74 
75 #if __BSD_VISIBLE
76 
77 struct timezone {
78 	int	tz_minuteswest;	/* minutes west of Greenwich */
79 	int	tz_dsttime;	/* type of dst correction */
80 };
81 
82 int adjtime (const struct timeval *, struct timeval *);
83 int futimes (int, const struct timeval [2]);
84 int lutimes (const char *, const struct timeval [2]);
85 int settimeofday (const struct timeval *, const struct timezone *);
86 
87 #define	DST_NONE	0	/* not on dst */
88 #define	DST_USA		1	/* USA style dst */
89 #define	DST_AUST	2	/* Australian style dst */
90 #define	DST_WET		3	/* Western European dst */
91 #define	DST_MET		4	/* Middle European dst */
92 #define	DST_EET		5	/* Eastern European dst */
93 #define	DST_CAN		6	/* Canada */
94 
95 #ifndef _SBINTIME_T_DECLARED
96 typedef	__int64_t	sbintime_t;
97 #define _SBINTIME_T_DECLARED
98 #endif
99 
100 struct bintime {
101 	time_t	sec;
102 	__uint64_t frac;
103 };
104 
105 static __inline void
bintime_addx(struct bintime * _bt,__uint64_t _x)106 bintime_addx(struct bintime *_bt, __uint64_t _x)
107 {
108 	__uint64_t _u;
109 
110 	_u = _bt->frac;
111 	_bt->frac += _x;
112 	if (_u > _bt->frac)
113 		_bt->sec++;
114 }
115 
116 static __inline void
bintime_add(struct bintime * _bt,const struct bintime * _bt2)117 bintime_add(struct bintime *_bt, const struct bintime *_bt2)
118 {
119 	__uint64_t _u;
120 
121 	_u = _bt->frac;
122 	_bt->frac += _bt2->frac;
123 	if (_u > _bt->frac)
124 		_bt->sec++;
125 	_bt->sec += _bt2->sec;
126 }
127 
128 static __inline void
bintime_sub(struct bintime * _bt,const struct bintime * _bt2)129 bintime_sub(struct bintime *_bt, const struct bintime *_bt2)
130 {
131 	__uint64_t _u;
132 
133 	_u = _bt->frac;
134 	_bt->frac -= _bt2->frac;
135 	if (_u < _bt->frac)
136 		_bt->sec--;
137 	_bt->sec -= _bt2->sec;
138 }
139 
140 static __inline void
bintime_mul(struct bintime * _bt,unsigned int _x)141 bintime_mul(struct bintime *_bt, unsigned int _x)
142 {
143 	__uint64_t _p1, _p2;
144 
145 	_p1 = (_bt->frac & 0xffffffffull) * _x;
146 	_p2 = (_bt->frac >> 32) * _x + (_p1 >> 32);
147 	_bt->sec *= _x;
148 	_bt->sec += (_p2 >> 32);
149 	_bt->frac = (_p2 << 32) | (_p1 & 0xffffffffull);
150 }
151 
152 static __inline void
bintime_shift(struct bintime * _bt,int _exp)153 bintime_shift(struct bintime *_bt, int _exp)
154 {
155 
156 	if (_exp > 0) {
157 		_bt->sec <<= _exp;
158 		_bt->sec |= _bt->frac >> (64 - _exp);
159 		_bt->frac <<= _exp;
160 	} else if (_exp < 0) {
161 		_bt->frac >>= -_exp;
162 		_bt->frac |= (__uint64_t)_bt->sec << (64 + _exp);
163 		_bt->sec >>= -_exp;
164 	}
165 }
166 
167 #define	bintime_clear(a)	((a)->sec = (a)->frac = 0)
168 #define	bintime_isset(a)	((a)->sec || (a)->frac)
169 #define	bintime_cmp(a, b, cmp)						\
170 	(((a)->sec == (b)->sec) ?					\
171 	    ((a)->frac cmp (b)->frac) :					\
172 	    ((a)->sec cmp (b)->sec))
173 
174 #define	SBT_1S	((sbintime_t)1 << 32)
175 #define	SBT_1M	(SBT_1S * 60)
176 #define	SBT_1MS	(SBT_1S / 1000)
177 #define	SBT_1US	(SBT_1S / 1000000)
178 #define	SBT_1NS	(SBT_1S / 1000000000) /* beware rounding, see nstosbt() */
179 #define	SBT_MAX	0x7fffffffffffffffLL
180 
181 static __inline int
sbintime_getsec(sbintime_t _sbt)182 sbintime_getsec(sbintime_t _sbt)
183 {
184 
185 	return (_sbt >> 32);
186 }
187 
188 static __inline sbintime_t
bttosbt(const struct bintime _bt)189 bttosbt(const struct bintime _bt)
190 {
191 
192 	return (((sbintime_t)_bt.sec << 32) + (_bt.frac >> 32));
193 }
194 
195 static __inline struct bintime
sbttobt(sbintime_t _sbt)196 sbttobt(sbintime_t _sbt)
197 {
198 	struct bintime _bt;
199 
200 	_bt.sec = _sbt >> 32;
201 	_bt.frac = _sbt << 32;
202 	return (_bt);
203 }
204 
205 /*
206  * Decimal<->sbt conversions.  Multiplying or dividing by SBT_1NS results in
207  * large roundoff errors which sbttons() and nstosbt() avoid.  Millisecond and
208  * microsecond functions are also provided for completeness.
209  *
210  * These functions return the smallest sbt larger or equal to the
211  * number of seconds requested so that sbttoX(Xtosbt(y)) == y.  Unlike
212  * top of second computations below, which require that we tick at the
213  * top of second, these need to be rounded up so we do whatever for at
214  * least as long as requested.
215  *
216  * The naive computation we'd do is this
217  *	((unit * 2^64 / SIFACTOR) + 2^32-1) >> 32
218  * However, that overflows. Instead, we compute
219  *	((unit * 2^63 / SIFACTOR) + 2^31-1) >> 32
220  * and use pre-computed constants that are the ceil of the 2^63 / SIFACTOR
221  * term to ensure we are using exactly the right constant. We use the lesser
222  * evil of ull rather than a __uint64_t cast to ensure we have well defined
223  * right shift semantics. With these changes, we get all the ns, us and ms
224  * conversions back and forth right.
225  */
226 static __inline __int64_t
sbttons(sbintime_t _sbt)227 sbttons(sbintime_t _sbt)
228 {
229 	__uint64_t ns;
230 
231 	ns = _sbt;
232 	if (ns >= SBT_1S)
233 		ns = (ns >> 32) * 1000000000;
234 	else
235 		ns = 0;
236 
237 	return (ns + (1000000000 * (_sbt & 0xffffffffu) >> 32));
238 }
239 
240 static __inline sbintime_t
nstosbt(__int64_t _ns)241 nstosbt(__int64_t _ns)
242 {
243 	sbintime_t sb = 0;
244 
245 	if (_ns >= SBT_1S) {
246 		sb = (_ns / 1000000000) * SBT_1S;
247 		_ns = _ns % 1000000000;
248 	}
249 	/* 9223372037 = ceil(2^63 / 1000000000) */
250 	sb += ((_ns * 9223372037ull) + 0x7fffffff) >> 31;
251 	return (sb);
252 }
253 
254 static __inline __int64_t
sbttous(sbintime_t _sbt)255 sbttous(sbintime_t _sbt)
256 {
257 
258 	return ((1000000 * _sbt) >> 32);
259 }
260 
261 static __inline sbintime_t
ustosbt(__int64_t _us)262 ustosbt(__int64_t _us)
263 {
264 	sbintime_t sb = 0;
265 
266 	if (_us >= SBT_1S) {
267 		sb = (_us / 1000000) * SBT_1S;
268 		_us = _us % 1000000;
269 	}
270 	/* 9223372036855 = ceil(2^63 / 1000000) */
271 	sb += ((_us * 9223372036855ull) + 0x7fffffff) >> 31;
272 	return (sb);
273 }
274 
275 static __inline __int64_t
sbttoms(sbintime_t _sbt)276 sbttoms(sbintime_t _sbt)
277 {
278 
279 	return ((1000 * _sbt) >> 32);
280 }
281 
282 static __inline sbintime_t
mstosbt(__int64_t _ms)283 mstosbt(__int64_t _ms)
284 {
285 	sbintime_t sb = 0;
286 
287 	if (_ms >= SBT_1S) {
288 		sb = (_ms / 1000) * SBT_1S;
289 		_ms = _ms % 1000;
290 	}
291 	/* 9223372036854776 = ceil(2^63 / 1000) */
292 	sb += ((_ms * 9223372036854776ull) + 0x7fffffff) >> 31;
293 	return (sb);
294 }
295 
296 /*-
297  * Background information:
298  *
299  * When converting between timestamps on parallel timescales of differing
300  * resolutions it is historical and scientific practice to round down rather
301  * than doing 4/5 rounding.
302  *
303  *   The date changes at midnight, not at noon.
304  *
305  *   Even at 15:59:59.999999999 it's not four'o'clock.
306  *
307  *   time_second ticks after N.999999999 not after N.4999999999
308  */
309 
310 static __inline void
bintime2timespec(const struct bintime * _bt,struct timespec * _ts)311 bintime2timespec(const struct bintime *_bt, struct timespec *_ts)
312 {
313 
314 	_ts->tv_sec = _bt->sec;
315 	_ts->tv_nsec = ((__uint64_t)1000000000 *
316 	    (__uint32_t)(_bt->frac >> 32)) >> 32;
317 }
318 
319 static __inline void
timespec2bintime(const struct timespec * _ts,struct bintime * _bt)320 timespec2bintime(const struct timespec *_ts, struct bintime *_bt)
321 {
322 
323 	_bt->sec = _ts->tv_sec;
324 	/* 18446744073 = int(2^64 / 1000000000) */
325 	_bt->frac = _ts->tv_nsec * (__uint64_t)18446744073LL;
326 }
327 
328 static __inline void
bintime2timeval(const struct bintime * _bt,struct timeval * _tv)329 bintime2timeval(const struct bintime *_bt, struct timeval *_tv)
330 {
331 
332 	_tv->tv_sec = _bt->sec;
333 	_tv->tv_usec = ((__uint64_t)1000000 * (__uint32_t)(_bt->frac >> 32)) >> 32;
334 }
335 
336 static __inline void
timeval2bintime(const struct timeval * _tv,struct bintime * _bt)337 timeval2bintime(const struct timeval *_tv, struct bintime *_bt)
338 {
339 
340 	_bt->sec = _tv->tv_sec;
341 	/* 18446744073709 = int(2^64 / 1000000) */
342 	_bt->frac = _tv->tv_usec * (__uint64_t)18446744073709LL;
343 }
344 
345 static __inline struct timespec
sbttots(sbintime_t _sbt)346 sbttots(sbintime_t _sbt)
347 {
348 	struct timespec _ts;
349 
350 	_ts.tv_sec = _sbt >> 32;
351 	_ts.tv_nsec = sbttons((__uint32_t)_sbt);
352 	return (_ts);
353 }
354 
355 static __inline sbintime_t
tstosbt(struct timespec _ts)356 tstosbt(struct timespec _ts)
357 {
358 
359 	return (((sbintime_t)_ts.tv_sec << 32) + nstosbt(_ts.tv_nsec));
360 }
361 
362 static __inline struct timeval
sbttotv(sbintime_t _sbt)363 sbttotv(sbintime_t _sbt)
364 {
365 	struct timeval _tv;
366 
367 	_tv.tv_sec = _sbt >> 32;
368 	_tv.tv_usec = sbttous((__uint32_t)_sbt);
369 	return (_tv);
370 }
371 
372 static __inline sbintime_t
tvtosbt(struct timeval _tv)373 tvtosbt(struct timeval _tv)
374 {
375 
376 	return (((sbintime_t)_tv.tv_sec << 32) + ustosbt(_tv.tv_usec));
377 }
378 
379 /* Operations on timespecs */
380 #define	timespecclear(tvp)	((tvp)->tv_sec = (tvp)->tv_nsec = 0)
381 #define	timespecisset(tvp)	((tvp)->tv_sec || (tvp)->tv_nsec)
382 #define	timespeccmp(tvp, uvp, cmp)					\
383 	(((tvp)->tv_sec == (uvp)->tv_sec) ?				\
384 	    ((tvp)->tv_nsec cmp (uvp)->tv_nsec) :			\
385 	    ((tvp)->tv_sec cmp (uvp)->tv_sec))
386 
387 #define	timespecadd(tsp, usp, vsp)					\
388 	do {								\
389 		(vsp)->tv_sec = (tsp)->tv_sec + (usp)->tv_sec;		\
390 		(vsp)->tv_nsec = (tsp)->tv_nsec + (usp)->tv_nsec;	\
391 		if ((vsp)->tv_nsec >= 1000000000L) {			\
392 			(vsp)->tv_sec++;				\
393 			(vsp)->tv_nsec -= 1000000000L;			\
394 		}							\
395 	} while (0)
396 #define	timespecsub(tsp, usp, vsp)					\
397 	do {								\
398 		(vsp)->tv_sec = (tsp)->tv_sec - (usp)->tv_sec;		\
399 		(vsp)->tv_nsec = (tsp)->tv_nsec - (usp)->tv_nsec;	\
400 		if ((vsp)->tv_nsec < 0) {				\
401 			(vsp)->tv_sec--;				\
402 			(vsp)->tv_nsec += 1000000000L;			\
403 		}							\
404 	} while (0)
405 
406 #define	timerclear(tvp)		((tvp)->tv_sec = (tvp)->tv_usec = 0)
407 #define	timerisset(tvp)		((tvp)->tv_sec || (tvp)->tv_usec)
408 #define	timercmp(tvp, uvp, cmp)					\
409 	(((tvp)->tv_sec == (uvp)->tv_sec) ?				\
410 	    ((tvp)->tv_usec cmp (uvp)->tv_usec) :			\
411 	    ((tvp)->tv_sec cmp (uvp)->tv_sec))
412 #define	timeradd(tvp, uvp, vvp)						\
413 	do {								\
414 		(vvp)->tv_sec = (tvp)->tv_sec + (uvp)->tv_sec;		\
415 		(vvp)->tv_usec = (tvp)->tv_usec + (uvp)->tv_usec;	\
416 		if ((vvp)->tv_usec >= 1000000) {			\
417 			(vvp)->tv_sec++;				\
418 			(vvp)->tv_usec -= 1000000;			\
419 		}							\
420 	} while (0)
421 #define	timersub(tvp, uvp, vvp)						\
422 	do {								\
423 		(vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec;		\
424 		(vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec;	\
425 		if ((vvp)->tv_usec < 0) {				\
426 			(vvp)->tv_sec--;				\
427 			(vvp)->tv_usec += 1000000;			\
428 		}							\
429 	} while (0)
430 
431 #endif /* __BSD_VISIBLE */
432 
433 #if __GNU_VISIBLE
434 int futimesat (int, const char *, const struct timeval [2]);
435 #endif
436 
437 #include <machine/_time.h>
438 
439 _END_STD_C
440 
441 #endif /* !_SYS_TIME_H_ */
442