diff options
Diffstat (limited to 'lib/libc/sys/clock_gettime.2')
-rw-r--r-- | lib/libc/sys/clock_gettime.2 | 45 |
1 files changed, 27 insertions, 18 deletions
diff --git a/lib/libc/sys/clock_gettime.2 b/lib/libc/sys/clock_gettime.2 index 7b325a2bb394..c8bef4c5424f 100644 --- a/lib/libc/sys/clock_gettime.2 +++ b/lib/libc/sys/clock_gettime.2 @@ -94,20 +94,29 @@ Returns the execution time of the calling thread. .El .Pp The clock IDs -.Fa CLOCK_REALTIME_FAST , -.Fa CLOCK_MONOTONIC_FAST , -.Fa CLOCK_UPTIME_FAST -are analogs of corresponding IDs without _FAST suffix but do not perform +.Dv CLOCK_REALTIME , +.Dv CLOCK_MONOTONIC , +and +.Dv CLOCK_UPTIME +perform a full time counter query. +The clock IDs with the _FAST suffix, i.e., +.Dv CLOCK_REALTIME_FAST , +.Dv CLOCK_MONOTONIC_FAST , +and +.Dv CLOCK_UPTIME_FAST , +do not perform a full time counter query, so their accuracy is one timer tick. Similarly, -.Fa CLOCK_REALTIME_PRECISE , -.Fa CLOCK_MONOTONIC_PRECISE , -.Fa CLOCK_UPTIME_PRECISE +.Dv CLOCK_REALTIME_PRECISE , +.Dv CLOCK_MONOTONIC_PRECISE , +and +.Dv CLOCK_UPTIME_PRECISE are used to get the most exact value as possible, at the expense of execution time. The clock IDs -.Fa CLOCK_REALTIME_COARSE , -.Fa CLOCK_MONOTONIC_COARSE +.Dv CLOCK_REALTIME_COARSE +and +.Dv CLOCK_MONOTONIC_COARSE are aliases of corresponding IDs with _FAST suffix for compatibility with other systems. Finally, @@ -129,7 +138,7 @@ struct timespec { .Ed .Pp Only the super-user may set the time of day, using only -.Fa CLOCK_REALTIME . +.Dv CLOCK_REALTIME . If the system .Xr securelevel 7 is greater than 1 (see @@ -177,14 +186,14 @@ and system calls conform to .St -p1003.1b-93 . The clock IDs -.Fa CLOCK_REALTIME_FAST , -.Fa CLOCK_REALTIME_PRECISE , -.Fa CLOCK_MONOTONIC_FAST , -.Fa CLOCK_MONOTONIC_PRECISE , -.Fa CLOCK_UPTIME , -.Fa CLOCK_UPTIME_FAST , -.Fa CLOCK_UPTIME_PRECISE , -.Fa CLOCK_SECOND +.Dv CLOCK_REALTIME_FAST , +.Dv CLOCK_REALTIME_PRECISE , +.Dv CLOCK_MONOTONIC_FAST , +.Dv CLOCK_MONOTONIC_PRECISE , +.Dv CLOCK_UPTIME , +.Dv CLOCK_UPTIME_FAST , +.Dv CLOCK_UPTIME_PRECISE , +.Dv CLOCK_SECOND are .Fx extensions to the POSIX interface. |