LXR linux-old/include/linux/time.h

   1#ifndef _LINUX_TIME_H
   2#define _LINUX_TIME_H
   3
   4#include <asm/param.h>
   5#include <linux/types.h>
   6
   7#ifndef _STRUCT_TIMESPEC
   8#define _STRUCT_TIMESPEC
   9struct timespec {
  10        time_t  tv_sec;         /* seconds */
  11        long    tv_nsec;        /* nanoseconds */
  12};
  13#endif /* _STRUCT_TIMESPEC */
  14
  15#ifdef __KERNEL__
  16
  17/*
  18 * Change timeval to jiffies, trying to avoid the
  19 * most obvious overflows..
  20 *
  21 * And some not so obvious.
  22 *
  23 * Note that we don't want to return MAX_LONG, because
  24 * for various timeout reasons we often end up having
  25 * to wait "jiffies+1" in order to guarantee that we wait
  26 * at _least_ "jiffies" - so "jiffies+1" had better still
  27 * be positive.
  28 */
  29#define MAX_JIFFY_OFFSET ((~0UL >> 1)-1)
  30
  31static __inline__ unsigned long
  32timespec_to_jiffies(struct timespec *value)
  33{
  34        unsigned long sec = value->tv_sec;
  35        long nsec = value->tv_nsec;
  36
  37        if (sec >= (MAX_JIFFY_OFFSET / HZ))
  38                return MAX_JIFFY_OFFSET;
  39        nsec += 1000000000L / HZ - 1;
  40        nsec /= 1000000000L / HZ;
  41        return HZ * sec + nsec;
  42}
  43
  44static __inline__ void
  45jiffies_to_timespec(unsigned long jiffies, struct timespec *value)
  46{
  47        value->tv_nsec = (jiffies % HZ) * (1000000000L / HZ);
  48        value->tv_sec = jiffies / HZ;
  49}
  50
  51
  52/* Converts Gregorian date to seconds since 1970-01-01 00:00:00.
  53 * Assumes input in normal date format, i.e. 1980-12-31 23:59:59
  54 * => year=1980, mon=12, day=31, hour=23, min=59, sec=59.
  55 *
  56 * [For the Julian calendar (which was used in Russia before 1917,
  57 * Britain & colonies before 1752, anywhere else before 1582,
  58 * and is still in use by some communities) leave out the
  59 * -year/100+year/400 terms, and add 10.]
  60 *
  61 * This algorithm was first published by Gauss (I think).
  62 *
  63 * WARNING: this function will overflow on 2106-02-07 06:28:16 on
  64 * machines were long is 32-bit! (However, as time_t is signed, we
  65 * will already get problems at other places on 2038-01-19 03:14:08)
  66 */
  67static inline unsigned long
  68mktime (unsigned int year, unsigned int mon,
  69        unsigned int day, unsigned int hour,
  70        unsigned int min, unsigned int sec)
  71{
  72        if (0 >= (int) (mon -= 2)) {    /* 1..12 -> 11,12,1..10 */
  73                mon += 12;              /* Puts Feb last since it has leap day */
  74                year -= 1;
  75        }
  76
  77        return (((
  78                (unsigned long) (year/4 - year/100 + year/400 + 367*mon/12 + day) +
  79                        year*365 - 719499
  80            )*24 + hour /* now have hours */
  81          )*60 + min /* now have minutes */
  82        )*60 + sec; /* finally seconds */
  83}
  84
  85#endif /* __KERNEL__ */
  86
  87
  88struct timeval {
  89        time_t          tv_sec;         /* seconds */
  90        suseconds_t     tv_usec;        /* microseconds */
  91};
  92
  93struct timezone {
  94        int     tz_minuteswest; /* minutes west of Greenwich */
  95        int     tz_dsttime;     /* type of dst correction */
  96};
  97
  98#define NFDBITS                 __NFDBITS
  99
 100#ifdef __KERNEL__
 101extern void do_gettimeofday(struct timeval *tv);
 102extern void do_settimeofday(struct timeval *tv);
 103#endif
 104
 105#define FD_SETSIZE              __FD_SETSIZE
 106#define FD_SET(fd,fdsetp)       __FD_SET(fd,fdsetp)
 107#define FD_CLR(fd,fdsetp)       __FD_CLR(fd,fdsetp)
 108#define FD_ISSET(fd,fdsetp)     __FD_ISSET(fd,fdsetp)
 109#define FD_ZERO(fdsetp)         __FD_ZERO(fdsetp)
 110
 111/*
 112 * Names of the interval timers, and structure
 113 * defining a timer setting.
 114 */
 115#define ITIMER_REAL     0
 116#define ITIMER_VIRTUAL  1
 117#define ITIMER_PROF     2
 118
 119struct  itimerspec {
 120        struct  timespec it_interval;    /* timer period */
 121        struct  timespec it_value;       /* timer expiration */
 122};
 123
 124struct  itimerval {
 125        struct  timeval it_interval;    /* timer interval */
 126        struct  timeval it_value;       /* current value */
 127};
 128
 129#endif
 130