include/linux/time.h

   1 #ifndef _LINUX_TIME_H
   2 #define _LINUX_TIME_H
   3
   4 #include <linux/types.h>
   5
   6 #ifdef __KERNEL__
   7 #include <linux/seqlock.h>
   8 #endif
   9
  10 #ifndef _STRUCT_TIMESPEC
  11 #define _STRUCT_TIMESPEC
  12 struct timespec {
  13         time_t  tv_sec;         /* seconds */
  14         long    tv_nsec;        /* nanoseconds */
  15 };
  16 #endif /* _STRUCT_TIMESPEC */
  17
  18 struct timeval {
  19         time_t          tv_sec;         /* seconds */
  20         suseconds_t     tv_usec;        /* microseconds */
  21 };
  22
  23 struct timezone {
  24         int     tz_minuteswest; /* minutes west of Greenwich */
  25         int     tz_dsttime;     /* type of dst correction */
  26 };
  27
  28 #ifdef __KERNEL__
  29
  30 /* Parameters used to convert the timespec values */
  31 #ifndef USEC_PER_SEC
  32 #define USEC_PER_SEC (1000000L)
  33 #endif
  34
  35 #ifndef NSEC_PER_SEC
  36 #define NSEC_PER_SEC (1000000000L)
  37 #endif
  38
  39 #ifndef NSEC_PER_USEC
  40 #define NSEC_PER_USEC (1000L)
  41 #endif
  42
  43 static __inline__ int timespec_equal(struct timespec *a, struct timespec *b)
  44 {
  45         return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
  46 }
  47
  48 /* Converts Gregorian date to seconds since 1970-01-01 00:00:00.
  49  * Assumes input in normal date format, i.e. 1980-12-31 23:59:59
  50  * => year=1980, mon=12, day=31, hour=23, min=59, sec=59.
  51  *
  52  * [For the Julian calendar (which was used in Russia before 1917,
  53  * Britain & colonies before 1752, anywhere else before 1582,
  54  * and is still in use by some communities) leave out the
  55  * -year/100+year/400 terms, and add 10.]
  56  *
  57  * This algorithm was first published by Gauss (I think).
  58  *
  59  * WARNING: this function will overflow on 2106-02-07 06:28:16 on
  60  * machines were long is 32-bit! (However, as time_t is signed, we
  61  * will already get problems at other places on 2038-01-19 03:14:08)
  62  */
  63 static inline unsigned long
  64 mktime (unsigned int year, unsigned int mon,
  65         unsigned int day, unsigned int hour,
  66         unsigned int min, unsigned int sec)
  67 {
  68         if (0 >= (int) (mon -= 2)) {    /* 1..12 -> 11,12,1..10 */
  69                 mon += 12;              /* Puts Feb last since it has leap day */
  70                 year -= 1;
  71         }
  72
  73         return (((
  74                 (unsigned long) (year/4 - year/100 + year/400 + 367*mon/12 + day) +
  75                         year*365 - 719499
  76             )*24 + hour /* now have hours */
  77           )*60 + min /* now have minutes */
  78         )*60 + sec; /* finally seconds */
  79 }
  80
  81 extern struct timespec xtime;
  82 extern struct timespec wall_to_monotonic;
  83 extern seqlock_t xtime_lock;
  84
  85 static inline unsigned long get_seconds(void)
  86 {
  87         return xtime.tv_sec;
  88 }
  89
  90 struct timespec current_kernel_time(void);
  91
  92 #define CURRENT_TIME (current_kernel_time())
  93 #define CURRENT_TIME_SEC ((struct timespec) { xtime.tv_sec, 0 })
  94
  95 extern void do_gettimeofday(struct timeval *tv);
  96 extern int do_settimeofday(struct timespec *tv);
  97 extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
  98 extern void clock_was_set(void); // call when ever the clock is set
  99 extern int do_posix_clock_monotonic_gettime(struct timespec *tp);
 100 extern long do_utimes(char __user * filename, struct timeval * times);
 101 struct itimerval;
 102 extern int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue);
 103 extern int do_getitimer(int which, struct itimerval *value);
 104 extern void getnstimeofday (struct timespec *tv);
 105
 106 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
 107
 108 static inline void
 109 set_normalized_timespec (struct timespec *ts, time_t sec, long nsec)
 110 {
 111         while (nsec > NSEC_PER_SEC) {
 112                 nsec -= NSEC_PER_SEC;
 113                 ++sec;
 114         }
 115         while (nsec < 0) {
 116                 nsec += NSEC_PER_SEC;
 117                 --sec;
 118         }
 119         ts->tv_sec = sec;
 120         ts->tv_nsec = nsec;
 121 }
 122
 123 #endif /* __KERNEL__ */
 124
 125 #define NFDBITS                 __NFDBITS
 126
 127 #define FD_SETSIZE              __FD_SETSIZE
 128 #define FD_SET(fd,fdsetp)       __FD_SET(fd,fdsetp)
 129 #define FD_CLR(fd,fdsetp)       __FD_CLR(fd,fdsetp)
 130 #define FD_ISSET(fd,fdsetp)     __FD_ISSET(fd,fdsetp)
 131 #define FD_ZERO(fdsetp)         __FD_ZERO(fdsetp)
 132
 133 /*
 134  * Names of the interval timers, and structure
 135  * defining a timer setting.
 136  */
 137 #define ITIMER_REAL     0
 138 #define ITIMER_VIRTUAL  1
 139 #define ITIMER_PROF     2
 140
 141 struct  itimerspec {
 142         struct  timespec it_interval;    /* timer period */
 143         struct  timespec it_value;       /* timer expiration */
 144 };
 145
 146 struct  itimerval {
 147         struct  timeval it_interval;    /* timer interval */
 148         struct  timeval it_value;       /* current value */
 149 };
 150
 151
 152 /*
 153  * The IDs of the various system clocks (for POSIX.1b interval timers).
 154  */
 155 #define CLOCK_REALTIME            0
 156 #define CLOCK_MONOTONIC   1
 157 #define CLOCK_PROCESS_CPUTIME_ID 2
 158 #define CLOCK_THREAD_CPUTIME_ID  3
 159 #define CLOCK_REALTIME_HR        4
 160 #define CLOCK_MONOTONIC_HR        5
 161
 162 /*
 163  * The IDs of various hardware clocks
 164  */
 165
 166
 167 #define CLOCK_SGI_CYCLE 10
 168 #define MAX_CLOCKS 16
 169 #define CLOCKS_MASK  (CLOCK_REALTIME | CLOCK_MONOTONIC | \
 170                      CLOCK_REALTIME_HR | CLOCK_MONOTONIC_HR)
 171 #define CLOCKS_MONO (CLOCK_MONOTONIC & CLOCK_MONOTONIC_HR)
 172
 173 /*
 174  * The various flags for setting POSIX.1b interval timers.
 175  */
 176
 177 #define TIMER_ABSTIME 0x01
 178
 179
 180 #endif