/*	$OpenBSD: time.h,v 1.50 2020/01/15 13:17:35 mpi Exp $	*/
/*	$NetBSD: time.h,v 1.18 1996/04/23 10:29:33 mycroft Exp $	*/

/*
 * Copyright (c) 1982, 1986, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)time.h	8.2 (Berkeley) 7/10/94
 */

#ifndef _SYS_TIME_H_
#define _SYS_TIME_H_

#include <sys/select.h>

#ifndef _TIMEVAL_DECLARED
#define _TIMEVAL_DECLARED
/*
 * Structure returned by gettimeofday(2) system call,
 * and used in other calls.
 */
struct timeval {
	time_t		tv_sec;		/* seconds */
	suseconds_t	tv_usec;	/* and microseconds */
};
#endif

#ifndef _TIMESPEC_DECLARED
#define _TIMESPEC_DECLARED
/*
 * Structure defined by POSIX.1b to be like a timeval.
 */
struct timespec {
	time_t	tv_sec;		/* seconds */
	long	tv_nsec;	/* and nanoseconds */
};
#endif

#define	TIMEVAL_TO_TIMESPEC(tv, ts) do {				\
	(ts)->tv_sec = (tv)->tv_sec;					\
	(ts)->tv_nsec = (tv)->tv_usec * 1000;				\
} while (0)
#define	TIMESPEC_TO_TIMEVAL(tv, ts) do {				\
	(tv)->tv_sec = (ts)->tv_sec;					\
	(tv)->tv_usec = (ts)->tv_nsec / 1000;				\
} while (0)

struct timezone {
	int	tz_minuteswest;	/* minutes west of Greenwich */
	int	tz_dsttime;	/* type of dst correction */
};
#define	DST_NONE	0	/* not on dst */
#define	DST_USA		1	/* USA style dst */
#define	DST_AUST	2	/* Australian style dst */
#define	DST_WET		3	/* Western European dst */
#define	DST_MET		4	/* Middle European dst */
#define	DST_EET		5	/* Eastern European dst */
#define	DST_CAN		6	/* Canada */

/* Operations on timevals. */
#define	timerclear(tvp)		(tvp)->tv_sec = (tvp)->tv_usec = 0
#define	timerisset(tvp)		((tvp)->tv_sec || (tvp)->tv_usec)
#define	timerisvalid(tvp)						\
	((tvp)->tv_usec >= 0 && (tvp)->tv_usec < 1000000)
#define	timercmp(tvp, uvp, cmp)						\
	(((tvp)->tv_sec == (uvp)->tv_sec) ?				\
	    ((tvp)->tv_usec cmp (uvp)->tv_usec) :			\
	    ((tvp)->tv_sec cmp (uvp)->tv_sec))
#define	timeradd(tvp, uvp, vvp)						\
	do {								\
		(vvp)->tv_sec = (tvp)->tv_sec + (uvp)->tv_sec;		\
		(vvp)->tv_usec = (tvp)->tv_usec + (uvp)->tv_usec;	\
		if ((vvp)->tv_usec >= 1000000) {			\
			(vvp)->tv_sec++;				\
			(vvp)->tv_usec -= 1000000;			\
		}							\
	} while (0)
#define	timersub(tvp, uvp, vvp)						\
	do {								\
		(vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec;		\
		(vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec;	\
		if ((vvp)->tv_usec < 0) {				\
			(vvp)->tv_sec--;				\
			(vvp)->tv_usec += 1000000;			\
		}							\
	} while (0)

/* Operations on timespecs. */
#define	timespecclear(tsp)		(tsp)->tv_sec = (tsp)->tv_nsec = 0
#define	timespecisset(tsp)		((tsp)->tv_sec || (tsp)->tv_nsec)
#define	timespecisvalid(tsp)						\
	((tsp)->tv_nsec >= 0 && (tsp)->tv_nsec < 1000000000L)
#define	timespeccmp(tsp, usp, cmp)					\
	(((tsp)->tv_sec == (usp)->tv_sec) ?				\
	    ((tsp)->tv_nsec cmp (usp)->tv_nsec) :			\
	    ((tsp)->tv_sec cmp (usp)->tv_sec))
#define	timespecadd(tsp, usp, vsp)					\
	do {								\
		(vsp)->tv_sec = (tsp)->tv_sec + (usp)->tv_sec;		\
		(vsp)->tv_nsec = (tsp)->tv_nsec + (usp)->tv_nsec;	\
		if ((vsp)->tv_nsec >= 1000000000L) {			\
			(vsp)->tv_sec++;				\
			(vsp)->tv_nsec -= 1000000000L;			\
		}							\
	} while (0)
#define	timespecsub(tsp, usp, vsp)					\
	do {								\
		(vsp)->tv_sec = (tsp)->tv_sec - (usp)->tv_sec;		\
		(vsp)->tv_nsec = (tsp)->tv_nsec - (usp)->tv_nsec;	\
		if ((vsp)->tv_nsec < 0) {				\
			(vsp)->tv_sec--;				\
			(vsp)->tv_nsec += 1000000000L;			\
		}							\
	} while (0)

/*
 * Names of the interval timers, and structure
 * defining a timer setting.
 */
#define	ITIMER_REAL	0
#define	ITIMER_VIRTUAL	1
#define	ITIMER_PROF	2

struct	itimerval {
	struct	timeval it_interval;	/* timer interval */
	struct	timeval it_value;	/* current value */
};

#if __BSD_VISIBLE
/*
 * clock information structure for sysctl({CTL_KERN, KERN_CLOCKRATE})
 */
struct clockinfo {
	int	hz;		/* clock frequency */
	int	tick;		/* micro-seconds per hz tick */
	int	tickadj;	/* clock skew rate for adjtime() */
	int	stathz;		/* statistics clock frequency */
	int	profhz;		/* profiling clock frequency */
};
#endif /* __BSD_VISIBLE */

#if defined(_KERNEL) || defined(_STANDALONE)
#include <sys/_time.h>

/* Time expressed as seconds and fractions of a second + operations on it. */
struct bintime {
	time_t	sec;
	uint64_t frac;
};

#define bintimecmp(btp, ctp, cmp)					\
	((btp)->sec == (ctp)->sec ?					\
	    (btp)->frac cmp (ctp)->frac :				\
	    (btp)->sec cmp (ctp)->sec)

static inline void
bintimeaddfrac(const struct bintime *bt, uint64_t x, struct bintime *ct)
{
	ct->sec = bt->sec;
	if (bt->frac > bt->frac + x)
		ct->sec++;
	ct->frac = bt->frac + x;
}

static inline void
bintimeadd(const struct bintime *bt, const struct bintime *ct,
    struct bintime *dt)
{
	dt->sec = bt->sec + ct->sec;
	if (bt->frac > bt->frac + ct->frac)
		dt->sec++;
	dt->frac = bt->frac + ct->frac;
}

static inline void
bintimesub(const struct bintime *bt, const struct bintime *ct,
    struct bintime *dt)
{
	dt->sec = bt->sec - ct->sec;
	if (bt->frac < bt->frac - ct->frac)
		dt->sec--;
	dt->frac = bt->frac - ct->frac;
}

/*-
 * Background information:
 *
 * When converting between timestamps on parallel timescales of differing
 * resolutions it is historical and scientific practice to round down rather
 * than doing 4/5 rounding.
 *
 *   The date changes at midnight, not at noon.
 *
 *   Even at 15:59:59.999999999 it's not four'o'clock.
 *
 *   time_second ticks after N.999999999 not after N.4999999999
 */

static inline void
BINTIME_TO_TIMESPEC(const struct bintime *bt, struct timespec *ts)
{
	ts->tv_sec = bt->sec;
	ts->tv_nsec = (long)(((uint64_t)1000000000 * (uint32_t)(bt->frac >> 32)) >> 32);
}

static inline void
TIMESPEC_TO_BINTIME(const struct timespec *ts, struct bintime *bt)
{
	bt->sec = ts->tv_sec;
	/* 18446744073 = int(2^64 / 1000000000) */
	bt->frac = (uint64_t)ts->tv_nsec * (uint64_t)18446744073ULL; 
}

static inline void
BINTIME_TO_TIMEVAL(const struct bintime *bt, struct timeval *tv)
{
	tv->tv_sec = bt->sec;
	tv->tv_usec = (long)(((uint64_t)1000000 * (uint32_t)(bt->frac >> 32)) >> 32);
}

static inline void
TIMEVAL_TO_BINTIME(const struct timeval *tv, struct bintime *bt)
{
	bt->sec = (time_t)tv->tv_sec;
	/* 18446744073709 = int(2^64 / 1000000) */
	bt->frac = (uint64_t)tv->tv_usec * (uint64_t)18446744073709ULL;
}

extern volatile time_t time_second;	/* Seconds since epoch, wall time. */
extern volatile time_t time_uptime;	/* Seconds since reboot. */

/*
 * Functions for looking at our clocks: [get]{bin,nano,micro}[boot|up]time()
 *
 * Functions without the "get" prefix returns the best timestamp
 * we can produce in the given format.
 *
 * "bin"   == struct bintime  == seconds + 64 bit fraction of seconds.
 * "nano"  == struct timespec == seconds + nanoseconds.
 * "micro" == struct timeval  == seconds + microseconds.
 *              
 * Functions containing "up" returns time relative to boot and
 * should be used for calculating time intervals.
 *
 * Functions containing "boot" return the GMT time at which the
 * system booted.
 *
 * Functions with just "time" return the current GMT time.
 *
 * Functions with the "get" prefix returns a less precise result
 * much faster than the functions without "get" prefix and should
 * be used where a precision of 10 msec is acceptable or where
 * performance is priority. (NB: "precision", _not_ "resolution" !) 
 */

void	bintime(struct bintime *);
void	nanotime(struct timespec *);
void	microtime(struct timeval *);

void	getnanotime(struct timespec *);
void	getmicrotime(struct timeval *);

void	binuptime(struct bintime *);
void	nanouptime(struct timespec *);
void	microuptime(struct timeval *);

void	getnanouptime(struct timespec *);
void	getmicrouptime(struct timeval *);

void	binboottime(struct bintime *);
void	microboottime(struct timeval *);
void	nanoboottime(struct timespec *);

struct proc;
int	clock_gettime(struct proc *, clockid_t, struct timespec *);

int	itimerfix(struct timeval *);
int	itimerdecr(struct itimerspec *, long);
int	settime(const struct timespec *);
int	ratecheck(struct timeval *, const struct timeval *);
int	ppsratecheck(struct timeval *, int *, int);

/*
 * "POSIX time" to/from "YY/MM/DD/hh/mm/ss"
 */
struct clock_ymdhms {
        u_short dt_year;
        u_char dt_mon;
        u_char dt_day;
        u_char dt_wday; /* Day of week */
        u_char dt_hour;
        u_char dt_min;
        u_char dt_sec;
};

time_t clock_ymdhms_to_secs(struct clock_ymdhms *);
void clock_secs_to_ymdhms(time_t, struct clock_ymdhms *);
/*
 * BCD to decimal and decimal to BCD.
 */
#define FROMBCD(x)      (((x) >> 4) * 10 + ((x) & 0xf))
#define TOBCD(x)        (((x) / 10 * 16) + ((x) % 10))

/* Some handy constants. */
#define SECDAY          86400L
#define SECYR           (SECDAY * 365)

/* Traditional POSIX base year */
#define POSIX_BASE_YEAR 1970

#include <sys/stdint.h>

static inline void
NSEC_TO_TIMEVAL(uint64_t ns, struct timeval *tv)
{
	tv->tv_sec = ns / 1000000000L;
	tv->tv_usec = (ns % 1000000000L) / 1000;
}

static inline uint64_t
TIMEVAL_TO_NSEC(const struct timeval *tv)
{
	uint64_t nsecs;

	if (tv->tv_sec > UINT64_MAX / 1000000000ULL)
		return UINT64_MAX;
	nsecs = tv->tv_sec * 1000000000ULL;
	if (tv->tv_usec * 1000ULL > UINT64_MAX - nsecs)
		return UINT64_MAX;
	return nsecs + tv->tv_usec * 1000ULL;
}

static inline void
NSEC_TO_TIMESPEC(uint64_t ns, struct timespec *ts)
{
	ts->tv_sec = ns / 1000000000L;
	ts->tv_nsec = ns % 1000000000L;
}

static inline uint64_t
SEC_TO_NSEC(uint64_t seconds)
{
	if (seconds > UINT64_MAX / 1000000000ULL)
		return UINT64_MAX;
	return seconds * 1000000000ULL;
}

static inline uint64_t
MSEC_TO_NSEC(uint64_t milliseconds)
{
	if (milliseconds > UINT64_MAX / 1000000ULL)
		return UINT64_MAX;
	return milliseconds * 1000000ULL;
}

static inline uint64_t
USEC_TO_NSEC(uint64_t microseconds)
{
	if (microseconds > UINT64_MAX / 1000ULL)
		return UINT64_MAX;
	return microseconds * 1000ULL;
}

static inline uint64_t
TIMESPEC_TO_NSEC(const struct timespec *ts)
{
	if (ts->tv_sec > (UINT64_MAX - ts->tv_nsec) / 1000000000ULL)
		return UINT64_MAX;
	return ts->tv_sec * 1000000000ULL + ts->tv_nsec;
}

#else /* !_KERNEL */
#include <time.h>

#if __BSD_VISIBLE || __XPG_VISIBLE
__BEGIN_DECLS
#if __BSD_VISIBLE
int	adjtime(const struct timeval *, struct timeval *);
int	adjfreq(const int64_t *, int64_t *);
#endif
#if __XPG_VISIBLE
int	futimes(int, const struct timeval *);
int	getitimer(int, struct itimerval *);
int	gettimeofday(struct timeval *, struct timezone *);
int	setitimer(int, const struct itimerval *, struct itimerval *);
int	settimeofday(const struct timeval *, const struct timezone *);
int	utimes(const char *, const struct timeval *);
#endif /* __XPG_VISIBLE */
__END_DECLS
#endif /* __BSD_VISIBLE || __XPG_VISIBLE */

#endif /* !_KERNEL */

#endif /* !_SYS_TIME_H_ */
