time.h revision 175429
1/*-
2 * Copyright (c) 1982, 1986, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 *	@(#)time.h	8.5 (Berkeley) 5/4/95
30 * $FreeBSD: head/sys/sys/time.h 175429 2008-01-18 07:04:42Z davidxu $
31 */
32
33#ifndef _SYS_TIME_H_
34#define _SYS_TIME_H_
35
36#include <sys/_timeval.h>
37#include <sys/types.h>
38#include <sys/timespec.h>
39
40struct 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
53struct bintime {
54	time_t	sec;
55	uint64_t frac;
56};
57
58static __inline void
59bintime_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
69static __inline void
70bintime_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
81static __inline void
82bintime_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/*-
94 * Background information:
95 *
96 * When converting between timestamps on parallel timescales of differing
97 * resolutions it is historical and scientific practice to round down rather
98 * than doing 4/5 rounding.
99 *
100 *   The date changes at midnight, not at noon.
101 *
102 *   Even at 15:59:59.999999999 it's not four'o'clock.
103 *
104 *   time_second ticks after N.999999999 not after N.4999999999
105 */
106
107static __inline void
108bintime2timespec(const struct bintime *bt, struct timespec *ts)
109{
110
111	ts->tv_sec = bt->sec;
112	ts->tv_nsec = ((uint64_t)1000000000 * (uint32_t)(bt->frac >> 32)) >> 32;
113}
114
115static __inline void
116timespec2bintime(const struct timespec *ts, struct bintime *bt)
117{
118
119	bt->sec = ts->tv_sec;
120	/* 18446744073 = int(2^64 / 1000000000) */
121	bt->frac = ts->tv_nsec * (uint64_t)18446744073LL;
122}
123
124static __inline void
125bintime2timeval(const struct bintime *bt, struct timeval *tv)
126{
127
128	tv->tv_sec = bt->sec;
129	tv->tv_usec = ((uint64_t)1000000 * (uint32_t)(bt->frac >> 32)) >> 32;
130}
131
132static __inline void
133timeval2bintime(const struct timeval *tv, struct bintime *bt)
134{
135
136	bt->sec = tv->tv_sec;
137	/* 18446744073709 = int(2^64 / 1000000) */
138	bt->frac = tv->tv_usec * (uint64_t)18446744073709LL;
139}
140#endif /* __BSD_VISIBLE */
141
142#ifdef _KERNEL
143
144/* Operations on timespecs */
145#define	timespecclear(tvp)	((tvp)->tv_sec = (tvp)->tv_nsec = 0)
146#define	timespecisset(tvp)	((tvp)->tv_sec || (tvp)->tv_nsec)
147#define	timespeccmp(tvp, uvp, cmp)					\
148	(((tvp)->tv_sec == (uvp)->tv_sec) ?				\
149	    ((tvp)->tv_nsec cmp (uvp)->tv_nsec) :			\
150	    ((tvp)->tv_sec cmp (uvp)->tv_sec))
151#define timespecadd(vvp, uvp)						\
152	do {								\
153		(vvp)->tv_sec += (uvp)->tv_sec;				\
154		(vvp)->tv_nsec += (uvp)->tv_nsec;			\
155		if ((vvp)->tv_nsec >= 1000000000) {			\
156			(vvp)->tv_sec++;				\
157			(vvp)->tv_nsec -= 1000000000;			\
158		}							\
159	} while (0)
160#define timespecsub(vvp, uvp)						\
161	do {								\
162		(vvp)->tv_sec -= (uvp)->tv_sec;				\
163		(vvp)->tv_nsec -= (uvp)->tv_nsec;			\
164		if ((vvp)->tv_nsec < 0) {				\
165			(vvp)->tv_sec--;				\
166			(vvp)->tv_nsec += 1000000000;			\
167		}							\
168	} while (0)
169
170/* Operations on timevals. */
171
172#define	timevalclear(tvp)		((tvp)->tv_sec = (tvp)->tv_usec = 0)
173#define	timevalisset(tvp)		((tvp)->tv_sec || (tvp)->tv_usec)
174#define	timevalcmp(tvp, uvp, cmp)					\
175	(((tvp)->tv_sec == (uvp)->tv_sec) ?				\
176	    ((tvp)->tv_usec cmp (uvp)->tv_usec) :			\
177	    ((tvp)->tv_sec cmp (uvp)->tv_sec))
178
179/* timevaladd and timevalsub are not inlined */
180
181#endif /* _KERNEL */
182
183#ifndef _KERNEL			/* NetBSD/OpenBSD compatible interfaces */
184
185#define	timerclear(tvp)		((tvp)->tv_sec = (tvp)->tv_usec = 0)
186#define	timerisset(tvp)		((tvp)->tv_sec || (tvp)->tv_usec)
187#define	timercmp(tvp, uvp, cmp)					\
188	(((tvp)->tv_sec == (uvp)->tv_sec) ?				\
189	    ((tvp)->tv_usec cmp (uvp)->tv_usec) :			\
190	    ((tvp)->tv_sec cmp (uvp)->tv_sec))
191#define timeradd(tvp, uvp, vvp)						\
192	do {								\
193		(vvp)->tv_sec = (tvp)->tv_sec + (uvp)->tv_sec;		\
194		(vvp)->tv_usec = (tvp)->tv_usec + (uvp)->tv_usec;	\
195		if ((vvp)->tv_usec >= 1000000) {			\
196			(vvp)->tv_sec++;				\
197			(vvp)->tv_usec -= 1000000;			\
198		}							\
199	} while (0)
200#define timersub(tvp, uvp, vvp)						\
201	do {								\
202		(vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec;		\
203		(vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec;	\
204		if ((vvp)->tv_usec < 0) {				\
205			(vvp)->tv_sec--;				\
206			(vvp)->tv_usec += 1000000;			\
207		}							\
208	} while (0)
209#endif
210
211/*
212 * Names of the interval timers, and structure
213 * defining a timer setting.
214 */
215#define	ITIMER_REAL	0
216#define	ITIMER_VIRTUAL	1
217#define	ITIMER_PROF	2
218
219struct itimerval {
220	struct	timeval it_interval;	/* timer interval */
221	struct	timeval it_value;	/* current value */
222};
223
224/*
225 * Getkerninfo clock information structure
226 */
227struct clockinfo {
228	int	hz;		/* clock frequency */
229	int	tick;		/* micro-seconds per hz tick */
230	int	spare;
231	int	stathz;		/* statistics clock frequency */
232	int	profhz;		/* profiling clock frequency */
233};
234
235/* These macros are also in time.h. */
236#ifndef CLOCK_REALTIME
237#define CLOCK_REALTIME	0
238#define CLOCK_VIRTUAL	1
239#define CLOCK_PROF	2
240#define CLOCK_MONOTONIC	4
241#define CLOCK_UPTIME	5		/* FreeBSD-specific. */
242#define CLOCK_UPTIME_PRECISE	7	/* FreeBSD-specific. */
243#define CLOCK_UPTIME_FAST	8	/* FreeBSD-specific. */
244#define CLOCK_REALTIME_PRECISE	9	/* FreeBSD-specific. */
245#define CLOCK_REALTIME_FAST	10	/* FreeBSD-specific. */
246#define CLOCK_MONOTONIC_PRECISE	11	/* FreeBSD-specific. */
247#define CLOCK_MONOTONIC_FAST	12	/* FreeBSD-specific. */
248#define CLOCK_SECOND	13		/* FreeBSD-specific. */
249#define CLOCK_THREAD_CPUTIME_ID	14
250#endif
251
252#ifndef TIMER_ABSTIME
253#define TIMER_RELTIME	0x0	/* relative timer */
254#define TIMER_ABSTIME	0x1	/* absolute timer */
255#endif
256
257#ifdef _KERNEL
258extern time_t	time_second;
259extern time_t	time_uptime;
260extern struct timeval boottime;
261
262/*
263 * Functions for looking at our clock: [get]{bin,nano,micro}[up]time()
264 *
265 * Functions without the "get" prefix returns the best timestamp
266 * we can produce in the given format.
267 *
268 * "bin"   == struct bintime  == seconds + 64 bit fraction of seconds.
269 * "nano"  == struct timespec == seconds + nanoseconds.
270 * "micro" == struct timeval  == seconds + microseconds.
271 *
272 * Functions containing "up" returns time relative to boot and
273 * should be used for calculating time intervals.
274 *
275 * Functions without "up" returns GMT time.
276 *
277 * Functions with the "get" prefix returns a less precise result
278 * much faster than the functions without "get" prefix and should
279 * be used where a precision of 10 msec is acceptable or where
280 * performance is priority. (NB: "precision", _not_ "resolution" !)
281 *
282 */
283
284void	binuptime(struct bintime *bt);
285void	nanouptime(struct timespec *tsp);
286void	microuptime(struct timeval *tvp);
287
288void	bintime(struct bintime *bt);
289void	nanotime(struct timespec *tsp);
290void	microtime(struct timeval *tvp);
291
292void	getbinuptime(struct bintime *bt);
293void	getnanouptime(struct timespec *tsp);
294void	getmicrouptime(struct timeval *tvp);
295
296void	getbintime(struct bintime *bt);
297void	getnanotime(struct timespec *tsp);
298void	getmicrotime(struct timeval *tvp);
299
300/* Other functions */
301int	itimerdecr(struct itimerval *itp, int usec);
302int	itimerfix(struct timeval *tv);
303int	ppsratecheck(struct timeval *, int *, int);
304int	ratecheck(struct timeval *, const struct timeval *);
305void	timevaladd(struct timeval *t1, const struct timeval *t2);
306void	timevalsub(struct timeval *t1, const struct timeval *t2);
307int	tvtohz(struct timeval *tv);
308uint64_t	dtrace_gethrtime(void);
309uint64_t	dtrace_gethrestime(void);
310#else /* !_KERNEL */
311#include <time.h>
312
313#include <sys/cdefs.h>
314
315__BEGIN_DECLS
316int	adjtime(const struct timeval *, struct timeval *);
317int	futimes(int, const struct timeval *);
318int	getitimer(int, struct itimerval *);
319int	gettimeofday(struct timeval *, struct timezone *);
320int	lutimes(const char *, const struct timeval *);
321int	setitimer(int, const struct itimerval *, struct itimerval *);
322int	settimeofday(const struct timeval *, const struct timezone *);
323int	utimes(const char *, const struct timeval *);
324__END_DECLS
325
326#endif /* !_KERNEL */
327
328#endif /* !_SYS_TIME_H_ */
329