clock_settime(3RT)					    Realtime Library Functions						clock_settime(3RT)

NAME

       clock_settime, clock_gettime, clock_getres - high-resolution clock operations

SYNOPSIS

       cc [ flag... ] file... -lrt [ library... ]
       #include <time.h>

       int clock_settime(clockid_t clock_id, const struct timespec *tp);

       int clock_gettime(clockid_t clock_id, struct timespec *tp);

       int clock_getres(clockid_t clock_id, struct timespec *res);

DESCRIPTION

       The clock_settime() function sets the specified clock, clock_id, to the value specified by tp. Time values that are between two consecutive
       non-negative integer multiples of the resolution of the specified clock are truncated down to the smaller multiple of the resolution.

       The clock_gettime() function returns the current value tp for the specified clock, clock_id.

       The resolution of any clock can be obtained by calling clock_getres(). Clock resolutions are  system-dependent  and  cannot  be	set  by  a
       process.  If  the  argument  res  is not NULL, the resolution of the specified clock is stored in the location pointed to by res. If res is
       NULL, the clock resolution is not returned. If the time argument of clock_settime() is not a multiple of res, then the value  is  truncated
       to a multiple of res.

       A clock may be systemwide (that is, visible to all processes) or per-process (measuring time that is meaningful only within a process).

       A  clock_id  of	CLOCK_REALTIME is defined in <time.h>. This clock represents the realtime clock for the system. For this clock, the values
       returned by clock_gettime() and specified by clock_settime() represent the amount of time (in seconds and  nanoseconds)	since  the  Epoch.
       Additional clocks may also be supported. The interpretation of time values for these clocks is unspecified.

       A  clock_id  of	CLOCK_HIGHRES  represents  the non-adjustable, high-resolution clock for the system. For this clock, the value returned by
       clock_gettime(3RT) represents the amount of time (in seconds and nanoseconds) since some arbitrary time in the past; it is  not	correlated
       in  any way to the time of day, and thus is not subject to resetting or drifting by way of adjtime(2), ntp_adjtime(2), settimeofday(3C), or
       clock_settime().  The time source for this clock is the same as that for gethrtime(3C).

       Additional clocks may also be supported. The interpretation of time values for these clocks is unspecified.

RETURN VALUES

       Upon successful completion, 0  is returned. Otherwise, -1 is returned and errno is set to indicate the error.

ERRORS

       The clock_settime(), clock_gettime() and clock_getres() functions will fail if:

       EINVAL	       The clock_id argument does not specify a known clock.

       ENOSYS	       The functions clock_settime(), clock_gettime(), and clock_getres() are not supported by this implementation.

       The clock_settime() function will fail if:

       EINVAL	       The tp argument to clock_settime() is outside the range for the given clock ID; or the tp argument specified  a	nanosecond
		       value less than zero or greater than or equal to 1000 million.

       The clock_settime() function may fail if:

       EPERM	       The requesting process does not have the appropriate privilege to set the specified clock.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-------------------------------------+
       |      ATTRIBUTE TYPE	     |		ATTRIBUTE VALUE 	   |
       +-----------------------------+-------------------------------------+
       |Interface Stability	     |Standard				   |
       +-----------------------------+-------------------------------------+
       |MT-Level		     |clock_gettime() is Async-Signal-Safe |
       +-----------------------------+-------------------------------------+

SEE ALSO

       time(2), ctime(3C), gethrtime(3C), time.h(3HEAD), timer_gettime(3RT), attributes(5), standards(5)

SunOS 5.10							    28 Jun 2002 						clock_settime(3RT)