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
   9 struct timespec {
  10         time_t  tv_sec;         /* seconds */
  11         long    tv_nsec;        /* nanoseconds */
  12 };
  13 #endif /* _STRUCT_TIMESPEC */
  14
  15 /*
  16  * Change timeval to jiffies, trying to avoid the
  17  * most obvious overflows..
  18  *
  19  * And some not so obvious.
  20  *
  21  * Note that we don't want to return MAX_LONG, because
  22  * for various timeout reasons we often end up having
  23  * to wait "jiffies+1" in order to guarantee that we wait
  24  * at _least_ "jiffies" - so "jiffies+1" had better still
  25  * be positive.
  26  */
  27 #define MAX_JIFFY_OFFSET ((~0UL >> 1)-1)
  28
  29 static __inline__ unsigned long
  30 timespec_to_jiffies(struct timespec *value)
  31 {
  32         unsigned long sec = value->tv_sec;
  33         long nsec = value->tv_nsec;
  34
  35         if (sec >= (MAX_JIFFY_OFFSET / HZ))
  36                 return MAX_JIFFY_OFFSET;
  37         nsec += 1000000000L / HZ - 1;
  38         nsec /= 1000000000L / HZ;
  39         return HZ * sec + nsec;
  40 }
  41
  42 static __inline__ void
  43 jiffies_to_timespec(unsigned long jiffies, struct timespec *value)
  44 {
  45         value->tv_nsec = (jiffies % HZ) * (1000000000L / HZ);
  46         value->tv_sec = jiffies / HZ;
  47 }
  48
  49 struct timeval {
  50         time_t          tv_sec;         /* seconds */
  51         suseconds_t     tv_usec;        /* microseconds */
  52 };
  53
  54 struct timezone {
  55         int     tz_minuteswest; /* minutes west of Greenwich */
  56         int     tz_dsttime;     /* type of dst correction */
  57 };
  58
  59 #define NFDBITS                 __NFDBITS
  60
  61 #ifdef __KERNEL__
  62 extern void do_gettimeofday(struct timeval *tv);
  63 extern void do_settimeofday(struct timeval *tv);
  64 extern void get_fast_time(struct timeval *tv);
  65 extern void (*do_get_fast_time)(struct timeval *);
  66 #endif
  67
  68 #define FD_SETSIZE              __FD_SETSIZE
  69 #define FD_SET(fd,fdsetp)       __FD_SET(fd,fdsetp)
  70 #define FD_CLR(fd,fdsetp)       __FD_CLR(fd,fdsetp)
  71 #define FD_ISSET(fd,fdsetp)     __FD_ISSET(fd,fdsetp)
  72 #define FD_ZERO(fdsetp)         __FD_ZERO(fdsetp)
  73
  74 /*
  75  * Names of the interval timers, and structure
  76  * defining a timer setting.
  77  */
  78 #define ITIMER_REAL     0
  79 #define ITIMER_VIRTUAL  1
  80 #define ITIMER_PROF     2
  81
  82 struct  itimerspec {
  83         struct  timespec it_interval;    /* timer period */
  84         struct  timespec it_value;       /* timer expiration */
  85 };
  86
  87 struct  itimerval {
  88         struct  timeval it_interval;    /* timer interval */
  89         struct  timeval it_value;       /* current value */
  90 };
  91
  92 #endif