개요

• 솔라나라에 설명된 어플리케이션에 대해 맨 페이지를 찾아 출력한다.
• MAN 페이지에 대한 설명은 윈디하나의 솔라나라: MAN 페이지을 참고하자.
• svcadm(8)을 검색하려면 섹션에서 8 을 선택하고, 맨 페이지 이름에 svcadm을 입력하고 검색을 누른다.

gethrtime(3c)

gethrtime(3C)            Standard C Library Functions            gethrtime(3C)

NAME
       gethrtime, gethrvtime - get high resolution time

SYNOPSIS
       #include <sys/time.h>

       hrtime_t gethrtime(void);


       hrtime_t gethrvtime(void);

DESCRIPTION
       The gethrtime() function returns the current high-resolution real time.
       Time is expressed as nanoseconds since some arbitrary time in the past.
       It  does  not  necessarily represent time elapsed since boot, nor it is
       correlated in any way to the time of day, and thus is  not  subject  to
       resetting or drifting by way of adjtime(2) or settimeofday(3C). The hi-
       res  timer  is  ideally  suited to performance measurement tasks, where
       cheap, accurate interval timing is required.


       The gethrvtime() function returns the current high-resolution LWP  vir‐
       tual time, expressed as total nanoseconds of execution time.


       The  gethrtime()  and  gethrvtime()  functions both return an hrtime_t,
       which is a 64-bit (long long) signed integer.

EXAMPLES
       The following code fragment measures the average cost of getpid(2):

         hrtime_t start, end;
         int i, iters = 100;

         start = gethrtime();
         for (i = 0; i < iters; i++)
                 getpid();
         end = gethrtime();

         printf("Avg getpid() time = %lld nsec\n", (end − start) / iters);


ATTRIBUTES
       See attributes(7) for descriptions of the following attributes:

       tab() box; cw(2.75i) |cw(2.75i) lw(2.75i) |lw(2.75i) ATTRIBUTE  TYPEAT‐
       TRIBUTE VALUE _ MT-LevelMT-Safe


SEE ALSO
       proc(1),   adjtime(2),  time(2),  clock_gettime(3C),  gettimeofday(3C),
       settimeofday(3C), attributes(7)

NOTES
       Although the units of hi-res time are always  the  same  (nanoseconds),
       the  actual resolution is hardware dependent. Hi-res time is guaranteed
       to be monotonic (it won't go backward, it won't periodically wrap)  and
       linear  (it  won't  occasionally  speed up or slow down for adjustment,
       like the time of day can), but not necessarily unique: two sufficiently
       proximate calls may return the same value.


       These functions are not specified in any standard.  For  similar  func‐
       tionality in standard interfaces, see clock_gettime(3C).

HISTORY
       The gethrtime() and gethrvtime() functions were added in Solaris 2.2.

Oracle Solaris 11.4               27 Aug 2025                    gethrtime(3C)