diff options
| author | Mateusz Piotrowski <0mp@FreeBSD.org> | 2022-07-08 19:54:10 +0000 |
|---|---|---|
| committer | Ed Maste <emaste@FreeBSD.org> | 2024-05-13 14:26:10 +0000 |
| commit | c595a834ebbd4b6fa49b40c8f9cb4e3dda082c4b (patch) | |
| tree | 02b85b417c6edb1003b847e2ef39b32d87d43fc6 | |
| parent | 3c05a91910d7ee809f884ca6ed46944bfda260e4 (diff) | |
| download | src-c595a834ebbd4b6fa49b40c8f9cb4e3dda082c4b.tar.gz src-c595a834ebbd4b6fa49b40c8f9cb4e3dda082c4b.zip | |
clock_gettime.2: Clarify CLOCK_*
Clarify that CLOCK_* (e.g., CLOCK_REALTIME) do not necessarily default
to CLOCK_*_FAST.
PR: 259642
(cherry picked from commit 16e4487e5f82e1ff501fe5af6afbfbd0435a1cbf)
| -rw-r--r-- | lib/libc/sys/clock_gettime.2 | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/lib/libc/sys/clock_gettime.2 b/lib/libc/sys/clock_gettime.2 index 7b325a2bb394..ed469153a40e 100644 --- a/lib/libc/sys/clock_gettime.2 +++ b/lib/libc/sys/clock_gettime.2 @@ -94,19 +94,28 @@ Returns the execution time of the calling thread. .El .Pp The clock IDs +.Fa CLOCK_REALTIME , +.Fa CLOCK_MONOTONIC , +and +.Fa CLOCK_UPTIME +perform a full time counter query. +The clock IDs with the _FAST suffix, i.e., .Fa CLOCK_REALTIME_FAST , .Fa CLOCK_MONOTONIC_FAST , -.Fa CLOCK_UPTIME_FAST -are analogs of corresponding IDs without _FAST suffix but do not perform +and +.Fa 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 , +and .Fa 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_REALTIME_COARSE +and .Fa CLOCK_MONOTONIC_COARSE are aliases of corresponding IDs with _FAST suffix for compatibility with other systems. |