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