/* time.h -- An implementation of the standard Unix <sys/time.h> file.
   Written by Geoffrey Noer <noer@cygnus.com>
   Public domain; no rights reserved. */

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * 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	8.5 (Berkeley) 5/4/95
 * $FreeBSD: head/sys/sys/time.h 340664 2018-11-20 07:11:23Z imp $
 */

#ifndef _SYS_TIME_H_
#define	_SYS_TIME_H_

#include <_ansi.h>
#include <sys/cdefs.h>
#include <sys/_timeval.h>
#include <sys/types.h>
#include <sys/timespec.h>

#if __BSD_VISIBLE || __POSIX_VISIBLE >= 200112 || __XSI_VISIBLE
#include <sys/select.h>
#endif

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 */

#if __BSD_VISIBLE
struct bintime {
	time_t	sec;
	uint64_t frac;
};

static __inline void
bintime_addx(struct bintime *_bt, uint64_t _x)
{
	uint64_t _u;

	_u = _bt->frac;
	_bt->frac += _x;
	if (_u > _bt->frac)
		_bt->sec++;
}

static __inline void
bintime_add(struct bintime *_bt, const struct bintime *_bt2)
{
	uint64_t _u;

	_u = _bt->frac;
	_bt->frac += _bt2->frac;
	if (_u > _bt->frac)
		_bt->sec++;
	_bt->sec += _bt2->sec;
}

static __inline void
bintime_sub(struct bintime *_bt, const struct bintime *_bt2)
{
	uint64_t _u;

	_u = _bt->frac;
	_bt->frac -= _bt2->frac;
	if (_u < _bt->frac)
		_bt->sec--;
	_bt->sec -= _bt2->sec;
}

static __inline void
bintime_mul(struct bintime *_bt, u_int _x)
{
	uint64_t _p1, _p2;

	_p1 = (_bt->frac & 0xffffffffull) * _x;
	_p2 = (_bt->frac >> 32) * _x + (_p1 >> 32);
	_bt->sec *= _x;
	_bt->sec += (_p2 >> 32);
	_bt->frac = (_p2 << 32) | (_p1 & 0xffffffffull);
}

static __inline void
bintime_shift(struct bintime *_bt, int _exp)
{

	if (_exp > 0) {
		_bt->sec <<= _exp;
		_bt->sec |= _bt->frac >> (64 - _exp);
		_bt->frac <<= _exp;
	} else if (_exp < 0) {
		_bt->frac >>= -_exp;
		_bt->frac |= (uint64_t)_bt->sec << (64 + _exp);
		_bt->sec >>= -_exp;
	}
}

#define	bintime_clear(a)	((a)->sec = (a)->frac = 0)
#define	bintime_isset(a)	((a)->sec || (a)->frac)
#define	bintime_cmp(a, b, cmp)						\
	(((a)->sec == (b)->sec) ?					\
	    ((a)->frac cmp (b)->frac) :					\
	    ((a)->sec cmp (b)->sec))

#define	SBT_1S	((sbintime_t)1 << 32)
#define	SBT_1M	(SBT_1S * 60)
#define	SBT_1MS	(SBT_1S / 1000)
#define	SBT_1US	(SBT_1S / 1000000)
#define	SBT_1NS	(SBT_1S / 1000000000) /* beware rounding, see nstosbt() */
#define	SBT_MAX	0x7fffffffffffffffLL

static __inline int
sbintime_getsec(sbintime_t _sbt)
{

	return (_sbt >> 32);
}

static __inline sbintime_t
bttosbt(const struct bintime _bt)
{

	return (((sbintime_t)_bt.sec << 32) + (_bt.frac >> 32));
}

static __inline struct bintime
sbttobt(sbintime_t _sbt)
{
	struct bintime _bt;

	_bt.sec = _sbt >> 32;
	_bt.frac = _sbt << 32;
	return (_bt);
}

/*
 * Decimal<->sbt conversions.  Multiplying or dividing by SBT_1NS results in
 * large roundoff errors which sbttons() and nstosbt() avoid.  Millisecond and
 * microsecond functions are also provided for completeness.
 *
 * These functions return the smallest sbt larger or equal to the
 * number of seconds requested so that sbttoX(Xtosbt(y)) == y.  Unlike
 * top of second computations below, which require that we tick at the
 * top of second, these need to be rounded up so we do whatever for at
 * least as long as requested.
 *
 * The naive computation we'd do is this
 *	((unit * 2^64 / SIFACTOR) + 2^32-1) >> 32
 * However, that overflows. Instead, we compute
 *	((unit * 2^63 / SIFACTOR) + 2^31-1) >> 32
 * and use pre-computed constants that are the ceil of the 2^63 / SIFACTOR
 * term to ensure we are using exactly the right constant. We use the lesser
 * evil of ull rather than a uint64_t cast to ensure we have well defined
 * right shift semantics. With these changes, we get all the ns, us and ms
 * conversions back and forth right.
 */
static __inline int64_t
sbttons(sbintime_t _sbt)
{

	return ((1000000000 * _sbt) >> 32);
}

static __inline sbintime_t
nstosbt(int64_t _ns)
{
	sbintime_t sb = 0;

	if (_ns >= SBT_1S) {
		sb = (_ns / 1000000000) * SBT_1S;
		_ns = _ns % 1000000000;
	}
	/* 9223372037 = ceil(2^63 / 1000000000) */
	sb += ((_ns * 9223372037ull) + 0x7fffffff) >> 31;
	return (sb);
}

static __inline int64_t
sbttous(sbintime_t _sbt)
{

	return ((1000000 * _sbt) >> 32);
}

static __inline sbintime_t
ustosbt(int64_t _us)
{
	sbintime_t sb = 0;

	if (_us >= SBT_1S) {
		sb = (_us / 1000000) * SBT_1S;
		_us = _us % 1000000;
	}
	/* 9223372036855 = ceil(2^63 / 1000000) */
	sb += ((_us * 9223372036855ull) + 0x7fffffff) >> 31;
	return (sb);
}

static __inline int64_t
sbttoms(sbintime_t _sbt)
{

	return ((1000 * _sbt) >> 32);
}

static __inline sbintime_t
mstosbt(int64_t _ms)
{
	sbintime_t sb = 0;

	if (_ms >= SBT_1S) {
		sb = (_ms / 1000) * SBT_1S;
		_ms = _ms % 1000;
	}
	/* 9223372036854776 = ceil(2^63 / 1000) */
	sb += ((_ms * 9223372036854776ull) + 0x7fffffff) >> 31;
	return (sb);
}

/*-
 * 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
bintime2timespec(const struct bintime *_bt, struct timespec *_ts)
{

	_ts->tv_sec = _bt->sec;
	_ts->tv_nsec = ((uint64_t)1000000000 *
	    (uint32_t)(_bt->frac >> 32)) >> 32;
}

static __inline void
timespec2bintime(const struct timespec *_ts, struct bintime *_bt)
{

	_bt->sec = _ts->tv_sec;
	/* 18446744073 = int(2^64 / 1000000000) */
	_bt->frac = _ts->tv_nsec * (uint64_t)18446744073LL;
}

static __inline void
bintime2timeval(const struct bintime *_bt, struct timeval *_tv)
{

	_tv->tv_sec = _bt->sec;
	_tv->tv_usec = ((uint64_t)1000000 * (uint32_t)(_bt->frac >> 32)) >> 32;
}

static __inline void
timeval2bintime(const struct timeval *_tv, struct bintime *_bt)
{

	_bt->sec = _tv->tv_sec;
	/* 18446744073709 = int(2^64 / 1000000) */
	_bt->frac = _tv->tv_usec * (uint64_t)18446744073709LL;
}

static __inline struct timespec
sbttots(sbintime_t _sbt)
{
	struct timespec _ts;

	_ts.tv_sec = _sbt >> 32;
	_ts.tv_nsec = sbttons((uint32_t)_sbt);
	return (_ts);
}

static __inline sbintime_t
tstosbt(struct timespec _ts)
{

	return (((sbintime_t)_ts.tv_sec << 32) + nstosbt(_ts.tv_nsec));
}

static __inline struct timeval
sbttotv(sbintime_t _sbt)
{
	struct timeval _tv;

	_tv.tv_sec = _sbt >> 32;
	_tv.tv_usec = sbttous((uint32_t)_sbt);
	return (_tv);
}

static __inline sbintime_t
tvtosbt(struct timeval _tv)
{

	return (((sbintime_t)_tv.tv_sec << 32) + ustosbt(_tv.tv_usec));
}
#endif /* __BSD_VISIBLE */

/*
 * 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 */
};

#ifndef _KERNEL
#include <time.h>

__BEGIN_DECLS
int utimes (const char *__path, const struct timeval *__tvp);

#if __BSD_VISIBLE
int adjtime (const struct timeval *, struct timeval *);
int futimes (int, const struct timeval *);
int lutimes (const char *, const struct timeval *);
int settimeofday (const struct timeval *, const struct timezone *);
#endif

#if __MISC_VISIBLE || __XSI_VISIBLE
int getitimer (int __which, struct itimerval *__value);
int setitimer (int __which, const struct itimerval *__restrict __value,
					struct itimerval *__restrict __ovalue);
#endif

int gettimeofday (struct timeval *__restrict __p,
			  void *__restrict __tz);

#if __GNU_VISIBLE
int futimesat (int, const char *, const struct timeval [2]);
#endif

#ifdef _COMPILING_NEWLIB
int _gettimeofday (struct timeval *__p, void *__tz);
#endif

__END_DECLS

#endif /* !_KERNEL */
#include <machine/_time.h>

#endif /* !_SYS_TIME_H_ */
