include/linux/time.h

18330 #ifndef _LINUX_TIME_H
18331 #define _LINUX_TIME_H
18332 
18333 #include <asm/param.h>
18334 #include <linux/types.h>
18335 
18336 #ifndef _STRUCT_TIMESPEC
18337 #define _STRUCT_TIMESPEC
18338 struct timespec {
18339   time_t  tv_sec;         /* seconds */
18340   long    tv_nsec;        /* nanoseconds */
18341 };
18342 #endif /* _STRUCT_TIMESPEC */
18343 
18344 /* Change timeval to jiffies, trying to avoid the most
18345  * obvious overflows..
18346  *
18347  * And some not so obvious.
18348  *
18349  * Note that we don't want to return MAX_LONG, because
18350  * for various timeout reasons we often end up having to
18351  * wait "jiffies+1" in order to guarantee that we wait at
18352  * _least_ "jiffies" - so "jiffies+1" had better still be
18353  * positive.  */
18354 #define MAX_JIFFY_OFFSET ((~0UL >> 1)-1)
18355 
18356 static __inline__ unsigned long
18357 timespec_to_jiffies(struct timespec *value)
18358 {
18359   unsigned long sec = value->tv_sec;
18360   long nsec = value->tv_nsec;
18361 
18362   if (sec >= (MAX_JIFFY_OFFSET / HZ))
18363     return MAX_JIFFY_OFFSET;
18364   nsec += 1000000000L / HZ - 1;
18365   nsec /= 1000000000L / HZ;
18366   return HZ * sec + nsec;
18367 }
18368 
18369 static __inline__ void
18370 jiffies_to_timespec(unsigned long jiffies,
18371                     struct timespec *value)
18372 {
18373   value->tv_nsec = (jiffies % HZ) * (1000000000L / HZ);
18374   value->tv_sec = jiffies / HZ;
18375 }
18376 
18377 struct timeval {
18378   time_t          tv_sec;         /* seconds */
18379   suseconds_t     tv_usec;        /* microseconds */
18380 };
18381 
18382 struct timezone {
18383   int     tz_minuteswest; /* minutes west of Greenwich */
18384   int     tz_dsttime;     /* type of dst correction */
18385 };
18386 
18387 #define NFDBITS                 __NFDBITS
18388 
18389 #ifdef __KERNEL__
18390 extern void do_gettimeofday(struct timeval *tv);
18391 extern void do_settimeofday(struct timeval *tv);
18392 extern void get_fast_time(struct timeval *tv);
18393 extern void (*do_get_fast_time)(struct timeval *);
18394 #endif
18395 
18396 #define FD_SETSIZE              __FD_SETSIZE
18397 #define FD_SET(fd,fdsetp)       __FD_SET(fd,fdsetp)
18398 #define FD_CLR(fd,fdsetp)       __FD_CLR(fd,fdsetp)
18399 #define FD_ISSET(fd,fdsetp)     __FD_ISSET(fd,fdsetp)
18400 #define FD_ZERO(fdsetp)         __FD_ZERO(fdsetp)
18401 
18402 /* Names of the interval timers, and structure defining a
18403  * timer setting.  */
18404 #define ITIMER_REAL     0
18405 #define ITIMER_VIRTUAL  1
18406 #define ITIMER_PROF     2
18407 
18408 struct  itimerspec {
18409   struct  timespec it_interval;    /* timer period */
18410   struct  timespec it_value;       /* timer expiration */
18411 };
18412 
18413 struct  itimerval {
18414   struct  timeval it_interval;    /* timer interval */
18415   struct  timeval it_value;       /* current value */
18416 };
18417 
18418 #endif