FreeBSD/Linux Kernel Cross Reference
sys/sys/time.h

     /*-
      * 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
     * $FreeBSD$
     */
    
    #ifndef _SYS_TIME_H_
    #define _SYS_TIME_H_
    
    #include <sys/_timeval.h>
    #include <sys/types.h>
    #include <sys/timespec.h>
    #include <sys/_clock_id.h>
    
    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);
   }
   
   /*
    * Scaling functions for signed and unsigned 64-bit time using any
    * 32-bit fraction:
    */
   
   static __inline int64_t
   __stime64_scale32_ceil(int64_t x, int32_t factor, int32_t divisor)
   {
           const int64_t rem = x % divisor;
   
           return (x / divisor * factor + (rem * factor + divisor - 1) / divisor);
   }
   
   static __inline int64_t
   __stime64_scale32_floor(int64_t x, int32_t factor, int32_t divisor)
   {
           const int64_t rem = x % divisor;
   
           return (x / divisor * factor + (rem * factor) / divisor);
   }
   
   static __inline uint64_t
   __utime64_scale32_ceil(uint64_t x, uint32_t factor, uint32_t divisor)
   {
           const uint64_t rem = x % divisor;
   
           return (x / divisor * factor + (rem * factor + divisor - 1) / divisor);
   }
   
   static __inline uint64_t
   __utime64_scale32_floor(uint64_t x, uint32_t factor, uint32_t divisor)
   {
           const uint64_t rem = x % divisor;
   
           return (x / divisor * factor + (rem * factor) / divisor);
   }
   
   /*
    * This function finds the common divisor between the two arguments,
    * in powers of two. Use a macro, so the compiler will output a
    * warning if the value overflows!
    *
    * Detailed description:
    *
    * Create a variable with 1's at the positions of the leading 0's
    * starting at the least significant bit, producing 0 if none (e.g.,
    * 01011000 -> 0000 0111). Then these two variables are bitwise AND'ed
    * together, to produce the greatest common power of two minus one. In
    * the end add one to flip the value to the actual power of two (e.g.,
    * 0000 0111 + 1 -> 0000 1000).
    */
   #define __common_powers_of_two(a, b) \
           ((~(a) & ((a) - 1) & ~(b) & ((b) - 1)) + 1)
   
   /*
    * Scaling functions for signed and unsigned 64-bit time assuming
    * reducable 64-bit fractions to 32-bit fractions:
    */
   
   static __inline int64_t
   __stime64_scale64_ceil(int64_t x, int64_t factor, int64_t divisor)
   {
           const int64_t gcd = __common_powers_of_two(factor, divisor);
   
           return (__stime64_scale32_ceil(x, factor / gcd, divisor / gcd));
   }
   
   static __inline int64_t
   __stime64_scale64_floor(int64_t x, int64_t factor, int64_t divisor)
   {
           const int64_t gcd = __common_powers_of_two(factor, divisor);
   
           return (__stime64_scale32_floor(x, factor / gcd, divisor / gcd));
   }
   
   static __inline uint64_t
   __utime64_scale64_ceil(uint64_t x, uint64_t factor, uint64_t divisor)
   {
           const uint64_t gcd = __common_powers_of_two(factor, divisor);
   
           return (__utime64_scale32_ceil(x, factor / gcd, divisor / gcd));
   }
   
   static __inline uint64_t
   __utime64_scale64_floor(uint64_t x, uint64_t factor, uint64_t divisor)
   {
           const uint64_t gcd = __common_powers_of_two(factor, divisor);
   
           return (__utime64_scale32_floor(x, factor / gcd, divisor / gcd));
   }
   
   /*
    * 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.
    *
    * When converting from sbt to another unit, the result is always
    * rounded down. When converting back to sbt the result is always
    * rounded up. This gives the property that sbttoX(Xtosbt(y)) == y .
    *
    * The conversion functions can also handle negative values.
    */
   #define SBT_DECLARE_CONVERSION_PAIR(name, units_per_second)     \
   static __inline int64_t \
   sbtto##name(sbintime_t sbt) \
   { \
           return (__stime64_scale64_floor(sbt, units_per_second, SBT_1S)); \
   } \
   static __inline sbintime_t \
   name##tosbt(int64_t name) \
   { \
           return (__stime64_scale64_ceil(name, SBT_1S, units_per_second)); \
   }
   
   SBT_DECLARE_CONVERSION_PAIR(ns, 1000000000)
   SBT_DECLARE_CONVERSION_PAIR(us, 1000000)
   SBT_DECLARE_CONVERSION_PAIR(ms, 1000)
   
   /*-
    * 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 = __utime64_scale64_floor(
               _bt->frac, 1000000000, 1ULL << 32) >> 32;
   }
   
   static __inline uint64_t
   bintime2ns(const struct bintime *_bt)
   {
           uint64_t ret;
   
           ret = (uint64_t)(_bt->sec) * (uint64_t)1000000000;
           ret += __utime64_scale64_floor(
               _bt->frac, 1000000000, 1ULL << 32) >> 32;
           return (ret);
   }
   
   static __inline void
   timespec2bintime(const struct timespec *_ts, struct bintime *_bt)
   {
   
           _bt->sec = _ts->tv_sec;
           _bt->frac = __utime64_scale64_floor(
               (uint64_t)_ts->tv_nsec << 32, 1ULL << 32, 1000000000);
   }
   
   static __inline void
   bintime2timeval(const struct bintime *_bt, struct timeval *_tv)
   {
   
           _tv->tv_sec = _bt->sec;
           _tv->tv_usec = __utime64_scale64_floor(
               _bt->frac, 1000000, 1ULL << 32) >> 32;
   }
   
   static __inline void
   timeval2bintime(const struct timeval *_tv, struct bintime *_bt)
   {
   
           _bt->sec = _tv->tv_sec;
           _bt->frac = __utime64_scale64_floor(
               (uint64_t)_tv->tv_usec << 32, 1ULL << 32, 1000000);
   }
   
   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 */
   
   #ifdef _KERNEL
   /*
    * Simple macros to convert ticks to milliseconds
    * or microseconds and vice-versa. The answer
    * will always be at least 1. Note the return
    * value is a uint32_t however we step up the
    * operations to 64 bit to avoid any overflow/underflow
    * problems.
    */
   #define TICKS_2_MSEC(t) max(1, (uint32_t)(hz == 1000) ? \
             (t) : (((uint64_t)(t) * (uint64_t)1000)/(uint64_t)hz))
   #define TICKS_2_USEC(t) max(1, (uint32_t)(hz == 1000) ? \
             ((t) * 1000) : (((uint64_t)(t) * (uint64_t)1000000)/(uint64_t)hz))
   #define MSEC_2_TICKS(m) max(1, (uint32_t)((hz == 1000) ? \
             (m) : ((uint64_t)(m) * (uint64_t)hz)/(uint64_t)1000))
   #define USEC_2_TICKS(u) max(1, (uint32_t)((hz == 1000) ? \
            ((u) / 1000) : ((uint64_t)(u) * (uint64_t)hz)/(uint64_t)1000000))
   
   #endif
   /* Operations on timespecs */
   #define timespecclear(tvp)      ((tvp)->tv_sec = (tvp)->tv_nsec = 0)
   #define timespecisset(tvp)      ((tvp)->tv_sec || (tvp)->tv_nsec)
   #define timespeccmp(tvp, uvp, cmp)                                      \
           (((tvp)->tv_sec == (uvp)->tv_sec) ?                             \
               ((tvp)->tv_nsec cmp (uvp)->tv_nsec) :                       \
               ((tvp)->tv_sec cmp (uvp)->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)
   #define timespecvalid_interval(tsp)     ((tsp)->tv_sec >= 0 &&          \
               (tsp)->tv_nsec >= 0 && (tsp)->tv_nsec < 1000000000L)
   
   #ifdef _KERNEL
   
   /* Operations on timevals. */
   
   #define timevalclear(tvp)               ((tvp)->tv_sec = (tvp)->tv_usec = 0)
   #define timevalisset(tvp)               ((tvp)->tv_sec || (tvp)->tv_usec)
   #define timevalcmp(tvp, uvp, cmp)                                       \
           (((tvp)->tv_sec == (uvp)->tv_sec) ?                             \
               ((tvp)->tv_usec cmp (uvp)->tv_usec) :                       \
               ((tvp)->tv_sec cmp (uvp)->tv_sec))
   
   /* timevaladd and timevalsub are not inlined */
   
   #endif /* _KERNEL */
   
   #ifndef _KERNEL                 /* NetBSD/OpenBSD compatible interfaces */
   
   #define timerclear(tvp)         ((tvp)->tv_sec = (tvp)->tv_usec = 0)
   #define timerisset(tvp)         ((tvp)->tv_sec || (tvp)->tv_usec)
   #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)
   #endif
   
   /*
    * 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 */
   };
   
   /*
    * Getkerninfo clock information structure
    */
   struct clockinfo {
           int     hz;             /* clock frequency */
           int     tick;           /* micro-seconds per hz tick */
           int     spare;
           int     stathz;         /* statistics clock frequency */
           int     profhz;         /* profiling clock frequency */
   };
   
   #if __BSD_VISIBLE
   #define CPUCLOCK_WHICH_PID      0
   #define CPUCLOCK_WHICH_TID      1
   #endif
   
   #if defined(_KERNEL) || defined(_STANDALONE)
   
   /*
    * Kernel to clock driver interface.
    */
   void    inittodr(time_t base);
   void    resettodr(void);
   
   extern volatile time_t  time_second;
   extern volatile time_t  time_uptime;
   extern struct bintime tc_tick_bt;
   extern sbintime_t tc_tick_sbt;
   extern time_t tick_seconds_max;
   extern struct bintime tick_bt;
   extern sbintime_t tick_sbt;
   extern int tc_precexp;
   extern int tc_timepercentage;
   extern struct bintime bt_timethreshold;
   extern struct bintime bt_tickthreshold;
   extern sbintime_t sbt_timethreshold;
   extern sbintime_t sbt_tickthreshold;
   
   extern volatile int rtc_generation;
   
   /*
    * Functions for looking at our clock: [get]{bin,nano,micro}[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 without "up" returns UTC 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 1/hz seconds is acceptable or where
    * performance is priority. (NB: "precision", _not_ "resolution" !)
    */
   
   void    binuptime(struct bintime *bt);
   void    nanouptime(struct timespec *tsp);
   void    microuptime(struct timeval *tvp);
   
   static __inline sbintime_t
   sbinuptime(void)
   {
           struct bintime _bt;
   
           binuptime(&_bt);
           return (bttosbt(_bt));
   }
   
   void    bintime(struct bintime *bt);
   void    nanotime(struct timespec *tsp);
   void    microtime(struct timeval *tvp);
   
   void    getbinuptime(struct bintime *bt);
   void    getnanouptime(struct timespec *tsp);
   void    getmicrouptime(struct timeval *tvp);
   
   static __inline sbintime_t
   getsbinuptime(void)
   {
           struct bintime _bt;
   
           getbinuptime(&_bt);
           return (bttosbt(_bt));
   }
   
   void    getbintime(struct bintime *bt);
   void    getnanotime(struct timespec *tsp);
   void    getmicrotime(struct timeval *tvp);
   
   void    getboottime(struct timeval *boottime);
   void    getboottimebin(struct bintime *boottimebin);
   
   /* Other functions */
   int     itimerdecr(struct itimerval *itp, int usec);
   int     itimerfix(struct timeval *tv);
   int     ppsratecheck(struct timeval *, int *, int);
   int     ratecheck(struct timeval *, const struct timeval *);
   void    timevaladd(struct timeval *t1, const struct timeval *t2);
   void    timevalsub(struct timeval *t1, const struct timeval *t2);
   int     tvtohz(struct timeval *tv);
   
   /*
    * The following HZ limits allow the tvtohz() function
    * to only use integer computations.
    */
   #define HZ_MAXIMUM (INT_MAX / (1000000 >> 6)) /* 137kHz */
   #define HZ_MINIMUM 8 /* hz */
   
   #define TC_DEFAULTPERC          5
   
   #define BT2FREQ(bt)                                                     \
           (((uint64_t)0x8000000000000000 + ((bt)->frac >> 2)) /           \
               ((bt)->frac >> 1))
   
   #define SBT2FREQ(sbt)   ((SBT_1S + ((sbt) >> 1)) / (sbt))
   
   #define FREQ2BT(freq, bt)                                               \
   {                                                                       \
           (bt)->sec = 0;                                                  \
           (bt)->frac = ((uint64_t)0x8000000000000000  / (freq)) << 1;     \
   }
   
   #define TIMESEL(sbt, sbt2)                                              \
           (((sbt2) >= sbt_timethreshold) ?                                \
               ((*(sbt) = getsbinuptime()), 1) : ((*(sbt) = sbinuptime()), 0))
   
   #else /* !_KERNEL && !_STANDALONE */
   #include <time.h>
   
   #include <sys/cdefs.h>
   #include <sys/select.h>
   
   __BEGIN_DECLS
   int     setitimer(int, const struct itimerval *, struct itimerval *);
   int     utimes(const char *, const struct timeval *);
   
   #if __BSD_VISIBLE
   int     adjtime(const struct timeval *, struct timeval *);
   int     clock_getcpuclockid2(id_t, int, clockid_t *);
   int     futimes(int, const struct timeval *);
   int     futimesat(int, const char *, const struct timeval [2]);
   int     lutimes(const char *, const struct timeval *);
   int     settimeofday(const struct timeval *, const struct timezone *);
   #endif
   
   #if __XSI_VISIBLE
   int     getitimer(int, struct itimerval *);
   int     gettimeofday(struct timeval *, struct timezone *);
   #endif
   
   __END_DECLS
   
   #endif /* !_KERNEL */
   
   #endif /* !_SYS_TIME_H_ */

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