time.h revision 55205 
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 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 *	@(#)time.h	8.5 (Berkeley) 5/4/95
34 * $FreeBSD: head/sys/sys/time.h 55205 1999-12-29 04:46:21Z peter $
35 */
36
37#ifndef _SYS_TIME_H_
38#define _SYS_TIME_H_
39
40#include <sys/types.h>
41
42/*
43 * Structure returned by gettimeofday(2) system call,
44 * and used in other calls.
45 */
46struct timeval {
47	long	tv_sec;		/* seconds */
48	long	tv_usec;	/* and microseconds */
49};
50
51#ifndef _TIMESPEC_DECLARED
52#define _TIMESPEC_DECLARED
53struct timespec {
54	time_t	tv_sec;		/* seconds */
55	long	tv_nsec;	/* and nanoseconds */
56};
57#endif
58
59#define	TIMEVAL_TO_TIMESPEC(tv, ts)					\
60	do {								\
61		(ts)->tv_sec = (tv)->tv_sec;				\
62		(ts)->tv_nsec = (tv)->tv_usec * 1000;			\
63	} while (0)
64#define	TIMESPEC_TO_TIMEVAL(tv, ts)					\
65	do {								\
66		(tv)->tv_sec = (ts)->tv_sec;				\
67		(tv)->tv_usec = (ts)->tv_nsec / 1000;			\
68	} while (0)
69
70struct timezone {
71	int	tz_minuteswest;	/* minutes west of Greenwich */
72	int	tz_dsttime;	/* type of dst correction */
73};
74#define	DST_NONE	0	/* not on dst */
75#define	DST_USA		1	/* USA style dst */
76#define	DST_AUST	2	/* Australian style dst */
77#define	DST_WET		3	/* Western European dst */
78#define	DST_MET		4	/* Middle European dst */
79#define	DST_EET		5	/* Eastern European dst */
80#define	DST_CAN		6	/* Canada */
81
82/*
83 * Structure used to interface to the machine dependent hardware support
84 * for timekeeping.
85 *
86 * A timecounter is a (hard or soft) binary counter which has two properties:
87 *    * it runs at a fixed, known frequency.
88 *    * it must not roll over in less than (1 + delta)/HZ seconds.  "delta"
89 *	is expected to be less than 20 msec, but no hard data has been
90 *      collected on this.  16 bit at 5 MHz (31 msec) is known to work.
91 *
92 * get_timecount() reads the counter.
93 *
94 * counter_mask removes unimplemented bits from the count value.
95 *
96 * frequency is the counter frequency in hz.
97 *
98 * name is a short mnemonic name for this counter.
99 *
100 * cost is a measure of how long time it takes to read the counter.
101 *
102 * adjustment [PPM << 16] which means that the smallest unit of correction
103 *     you can apply amounts to 481.5 usec/year.
104 *
105 * scale_micro [2^32 * usec/tick].
106 * scale_nano_i [ns/tick].
107 * scale_nano_f [(ns/2^32)/tick].
108 *
109 * offset_count is the contents of the counter which corresponds to the
110 *     rest of the offset_* values.
111 *
112 * offset_sec [s].
113 * offset_micro [usec].
114 * offset_nano [ns/2^32] is misnamed, the real unit is .23283064365...
115 *     attoseconds (10E-18) and before you ask: yes, they are in fact
116 *     called attoseconds, it comes from "atten" for 18 in Danish/Swedish.
117 *
118 * Each timecounter must supply an array of three timecounters, this is needed
119 * to guarantee atomicity in the code.  Index zero is used to transport
120 * modifications, for instance done with sysctl, into the timecounter being
121 * used in a safe way.  Such changes may be adopted with a delay of up to 1/HZ,
122 * index one & two are used alternately for the actual timekeeping.
123 *
124 * 'tc_avail' points to the next available (external) timecounter in a
125 *      circular queue.  This is only valid for index 0.
126 *
127 * `tc_other' points to the next "work" timecounter in a circular queue,
128 *      i.e., for index i > 0 it points to index 1 + (i - 1) % NTIMECOUNTER.
129 *      We also use it to point from index 0 to index 1.
130 *
131 * `tc_tweak' points to index 0.
132 */
133
134struct timecounter;
135typedef unsigned timecounter_get_t __P((struct timecounter *));
136typedef void timecounter_pps_t __P((struct timecounter *));
137
138struct timecounter {
139	/* These fields must be initialized by the driver. */
140	timecounter_get_t	*tc_get_timecount;
141	timecounter_pps_t	*tc_poll_pps;
142	unsigned 		tc_counter_mask;
143	u_int32_t		tc_frequency;
144	char			*tc_name;
145	void			*tc_priv;
146	/* These fields will be managed by the generic code. */
147	int64_t			tc_adjustment;
148	u_int32_t		tc_scale_micro;
149	u_int32_t		tc_scale_nano_i;
150	u_int32_t		tc_scale_nano_f;
151	unsigned 		tc_offset_count;
152	u_int32_t		tc_offset_sec;
153	u_int32_t		tc_offset_micro;
154	u_int64_t		tc_offset_nano;
155	struct timeval		tc_microtime;
156	struct timespec		tc_nanotime;
157	struct timecounter	*tc_avail;
158	struct timecounter	*tc_other;
159	struct timecounter	*tc_tweak;
160};
161
162#ifdef _KERNEL
163
164/* Operations on timespecs */
165#define	timespecclear(tvp)	((tvp)->tv_sec = (tvp)->tv_nsec = 0)
166#define	timespecisset(tvp)	((tvp)->tv_sec || (tvp)->tv_nsec)
167#define	timespeccmp(tvp, uvp, cmp)					\
168	(((tvp)->tv_sec == (uvp)->tv_sec) ?				\
169	    ((tvp)->tv_nsec cmp (uvp)->tv_nsec) :			\
170	    ((tvp)->tv_sec cmp (uvp)->tv_sec))
171#define timespecadd(vvp, uvp)						\
172	do {								\
173		(vvp)->tv_sec += (uvp)->tv_sec;				\
174		(vvp)->tv_nsec += (uvp)->tv_nsec;			\
175		if ((vvp)->tv_nsec >= 1000000000) {			\
176			(vvp)->tv_sec++;				\
177			(vvp)->tv_nsec -= 1000000000;			\
178		}							\
179	} while (0)
180#define timespecsub(vvp, uvp)						\
181	do {								\
182		(vvp)->tv_sec -= (uvp)->tv_sec;				\
183		(vvp)->tv_nsec -= (uvp)->tv_nsec;			\
184		if ((vvp)->tv_nsec < 0) {				\
185			(vvp)->tv_sec--;				\
186			(vvp)->tv_nsec += 1000000000;			\
187		}							\
188	} while (0)
189
190/* Operations on timevals. */
191
192#define	timevalclear(tvp)		(tvp)->tv_sec = (tvp)->tv_usec = 0
193#define	timevalisset(tvp)		((tvp)->tv_sec || (tvp)->tv_usec)
194#define	timevalcmp(tvp, uvp, cmp)					\
195	(((tvp)->tv_sec == (uvp)->tv_sec) ?				\
196	    ((tvp)->tv_usec cmp (uvp)->tv_usec) :			\
197	    ((tvp)->tv_sec cmp (uvp)->tv_sec))
198
199/* timevaladd and timevalsub are not inlined */
200
201#endif /* _KERNEL */
202
203#ifndef _KERNEL			/* NetBSD/OpenBSD compatable interfaces */
204
205#define	timerclear(tvp)		(tvp)->tv_sec = (tvp)->tv_usec = 0
206#define	timerisset(tvp)		((tvp)->tv_sec || (tvp)->tv_usec)
207#define	timercmp(tvp, uvp, cmp)					\
208	(((tvp)->tv_sec == (uvp)->tv_sec) ?				\
209	    ((tvp)->tv_usec cmp (uvp)->tv_usec) :			\
210	    ((tvp)->tv_sec cmp (uvp)->tv_sec))
211#define timeradd(tvp, uvp, vvp)						\
212	do {								\
213		(vvp)->tv_sec = (tvp)->tv_sec + (uvp)->tv_sec;		\
214		(vvp)->tv_usec = (tvp)->tv_usec + (uvp)->tv_usec;	\
215		if ((vvp)->tv_usec >= 1000000) {			\
216			(vvp)->tv_sec++;				\
217			(vvp)->tv_usec -= 1000000;			\
218		}							\
219	} while (0)
220#define timersub(tvp, uvp, vvp)						\
221	do {								\
222		(vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec;		\
223		(vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec;	\
224		if ((vvp)->tv_usec < 0) {				\
225			(vvp)->tv_sec--;				\
226			(vvp)->tv_usec += 1000000;			\
227		}							\
228	} while (0)
229#endif
230
231/*
232 * Names of the interval timers, and structure
233 * defining a timer setting.
234 */
235#define	ITIMER_REAL	0
236#define	ITIMER_VIRTUAL	1
237#define	ITIMER_PROF	2
238
239struct	itimerval {
240	struct	timeval it_interval;	/* timer interval */
241	struct	timeval it_value;	/* current value */
242};
243
244/*
245 * Getkerninfo clock information structure
246 */
247struct clockinfo {
248	int	hz;		/* clock frequency */
249	int	tick;		/* micro-seconds per hz tick */
250	int	tickadj;	/* clock skew rate for adjtime() */
251	int	stathz;		/* statistics clock frequency */
252	int	profhz;		/* profiling clock frequency */
253};
254
255/* CLOCK_REALTIME and TIMER_ABSTIME are supposed to be in time.h */
256
257#ifndef CLOCK_REALTIME
258#define CLOCK_REALTIME	0
259#endif
260#define CLOCK_VIRTUAL	1
261#define CLOCK_PROF	2
262
263#define TIMER_RELTIME	0x0	/* relative timer */
264#ifndef TIMER_ABSTIME
265#define TIMER_ABSTIME	0x1	/* absolute timer */
266#endif
267
268#ifdef _KERNEL
269extern struct timecounter *timecounter;
270extern time_t	time_second;
271
272void	getmicrouptime __P((struct timeval *tv));
273void	getmicrotime __P((struct timeval *tv));
274void	getnanouptime __P((struct timespec *tv));
275void	getnanotime __P((struct timespec *tv));
276void	init_timecounter __P((struct timecounter *tc));
277int	itimerdecr __P((struct itimerval *itp, int usec));
278int	itimerfix __P((struct timeval *tv));
279void	microuptime __P((struct timeval *tv));
280void	microtime __P((struct timeval *tv));
281void	nanouptime __P((struct timespec *ts));
282void	nanotime __P((struct timespec *ts));
283void	set_timecounter __P((struct timespec *ts));
284void	timevaladd __P((struct timeval *, struct timeval *));
285void	timevalsub __P((struct timeval *, struct timeval *));
286int	tvtohz __P((struct timeval *));
287void	update_timecounter __P((struct timecounter *tc));
288#else /* !_KERNEL */
289#include <time.h>
290
291#include <sys/cdefs.h>
292
293__BEGIN_DECLS
294int	adjtime __P((const struct timeval *, struct timeval *));
295int	futimes __P((int, const struct timeval *));
296int	getitimer __P((int, struct itimerval *));
297int	gettimeofday __P((struct timeval *, struct timezone *));
298int	lutimes __P((const char *, const struct timeval *));
299int	setitimer __P((int, const struct itimerval *, struct itimerval *));
300int	settimeofday __P((const struct timeval *, const struct timezone *));
301int	utimes __P((const char *, const struct timeval *));
302__END_DECLS
303
304#endif /* !_KERNEL */
305
306#endif /* !_SYS_TIME_H_ */
307