diff options
Diffstat (limited to 'man2/nanosleep.2')
| -rw-r--r-- | man2/nanosleep.2 | 48 |
1 files changed, 25 insertions, 23 deletions
diff --git a/man2/nanosleep.2 b/man2/nanosleep.2 index 0bd03d0de..4693dc80a 100644 --- a/man2/nanosleep.2 +++ b/man2/nanosleep.2 @@ -12,7 +12,7 @@ .\" NOTES: describe case where clock_nanosleep() can be preferable. .\" NOTES: describe CLOCK_REALTIME versus CLOCK_NANOSLEEP .\" Replace crufty discussion of HZ with a pointer to time(7). -.TH nanosleep 2 2023-02-12 "Linux man-pages 6.03" +.TH nanosleep 2 2023-03-30 "Linux man-pages 6.05.01" .SH NAME nanosleep \- high-resolution sleep .SH LIBRARY @@ -109,27 +109,7 @@ The value in the field was not in the range [0, 999999999] or .I tv_sec was negative. -.SH STANDARDS -POSIX.1-2001, POSIX.1-2008. -.SH NOTES -If the interval specified in -.I req -is not an exact multiple of the granularity underlying clock (see -.BR time (7)), -then the interval will be rounded up to the next multiple. -Furthermore, after the sleep completes, there may still be a delay before -the CPU becomes free to once again execute the calling thread. -.PP -The fact that -.BR nanosleep () -sleeps for a relative interval can be problematic if the call -is repeatedly restarted after being interrupted by signals, -since the time between the interruptions and restarts of the call -will lead to drift in the time when the sleep finally completes. -This problem can be avoided by using -.BR clock_nanosleep (2) -with an absolute time value. -.PP +.SH VERSIONS POSIX.1 specifies that .BR nanosleep () should measure time against the @@ -161,7 +141,11 @@ function; ... Consequently, these time services shall expire when the requested relative interval elapses, independently of the new or old value of the clock. .RE -.SS Old behavior +.SH STANDARDS +POSIX.1-2008. +.SH HISTORY +POSIX.1-2001. +.PP In order to support applications requiring much more precise pauses (e.g., in order to control some time-critical hardware), .BR nanosleep () @@ -173,6 +157,24 @@ or .BR SCHED_RR . This special extension was removed in Linux 2.5.39, and is thus not available in Linux 2.6.0 and later kernels. +.SH NOTES +If the interval specified in +.I req +is not an exact multiple of the granularity underlying clock (see +.BR time (7)), +then the interval will be rounded up to the next multiple. +Furthermore, after the sleep completes, there may still be a delay before +the CPU becomes free to once again execute the calling thread. +.PP +The fact that +.BR nanosleep () +sleeps for a relative interval can be problematic if the call +is repeatedly restarted after being interrupted by signals, +since the time between the interruptions and restarts of the call +will lead to drift in the time when the sleep finally completes. +This problem can be avoided by using +.BR clock_nanosleep (2) +with an absolute time value. .SH BUGS If a program that catches signals and uses .BR nanosleep () |