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| author | Michael Kerrisk <mtk.manpages@gmail.com> | 2005-04-06 15:29:32 +0000 |
|---|---|---|
| committer | Michael Kerrisk <mtk.manpages@gmail.com> | 2005-04-06 15:29:32 +0000 |
| commit | fcad9022d38d22289b7b4bef81c9cd94dc8be8f4 (patch) | |
| tree | 34edec32c260c2662c9956cbdf0ab6388d6e256b /man2/getitimer.2 | |
| parent | c93df97462cc959c83e73a2a8f91f9be93c911b8 (diff) | |
| download | man-pages-fcad9022d38d22289b7b4bef81c9cd94dc8be8f4.tar.gz | |
Matthias Lang, mtk
Noted MAX_SEC_IN_JIFFIES ceiling.
Added note about treatment of out-of-range tv_usec values.
Diffstat (limited to 'man2/getitimer.2')
| -rw-r--r-- | man2/getitimer.2 | 26 |
1 files changed, 23 insertions, 3 deletions
diff --git a/man2/getitimer.2 b/man2/getitimer.2 index 530a14605b..38e5d399b1 100644 --- a/man2/getitimer.2 +++ b/man2/getitimer.2 @@ -2,6 +2,8 @@ .\" Based on a similar page Copyright 1992 by Rick Faith .\" May be freely distributed .\" Modified Tue Oct 22 00:22:35 EDT 1996 by Eric S. Raymond <esr@thyrsus.com> +.\" 2005-04-06 mtk, Matthias Lang <matthias@corelatus.se> +.\" Noted MAX_SEC_IN_JIFFIES ceiling .TH GETITIMER 2 1993-08-05 "Linux 0.99.11" "Linux Programmer's Manual" .SH NAME getitimer, setitimer \- get or set value of an interval timer @@ -75,10 +77,10 @@ with the current setting for the timer indicated by or .BR ITIMER_PROF ). The element -.B it_value +.I it_value is set to the amount of time remaining on the timer, or zero if the timer is disabled. Similarly, -.B it_interval +.I it_interval is set to the reset value. The function .B setitimer @@ -133,7 +135,7 @@ is not one of or .BR ITIMER_PROF . .SH "CONFORMING TO" -SVr4, 4.4BSD (This call first appeared in 4.2BSD). +POSIX.1-2001, SVr4, 4.4BSD (this call first appeared in 4.2BSD). .SH "SEE ALSO" .BR gettimeofday (2), .BR sigaction (2), @@ -145,3 +147,21 @@ conceivable that under pathologically heavy loading, .B ITIMER_REAL will expire before the signal from a previous expiration has been delivered. The second signal in such an event will be lost. + +On Linux, timer values are represented in jiffies. +If a request is made set a timer with a value whose jiffies +representation exceeds MAX_SEC_IN_JIFFIES +(defined in +.IR include/linux/jiffies.h ), +then the timer is silently truncated to this ceiling value. +On Linux 2.6 on x86 (where a jiffy is 0.001 seconds), +this means that the ceiling value for a timer is +approximately 24.86 days. + +POSIX.1 says that +.B setitimer +should fail if a +.I tv_usec +value is specified that is outside of the range 0 to 999999. +However, Linux does not give an error, but instead silently +adjusts the corresponding seconds value for the timer. |