diff options
Diffstat (limited to 'man-pages-posix-2013/man3p/getitimer.3p')
| -rw-r--r-- | man-pages-posix-2013/man3p/getitimer.3p | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/man-pages-posix-2013/man3p/getitimer.3p b/man-pages-posix-2013/man3p/getitimer.3p new file mode 100644 index 0000000..cd48ace --- /dev/null +++ b/man-pages-posix-2013/man3p/getitimer.3p @@ -0,0 +1,167 @@ +'\" et +.TH GETITIMER "3P" 2013 "IEEE/The Open Group" "POSIX Programmer's Manual" +.SH PROLOG +This manual page is part of the POSIX Programmer's Manual. +The Linux implementation of this interface may differ (consult +the corresponding Linux manual page for details of Linux behavior), +or the interface may not be implemented on Linux. + +.SH NAME +getitimer, +setitimer +\(em get and set value of interval timer +.SH SYNOPSIS +.LP +.nf +#include <sys/time.h> +.P +int getitimer(int \fIwhich\fP, struct itimerval *\fIvalue\fP); +int setitimer(int \fIwhich\fP, const struct itimerval *restrict \fIvalue\fP, + struct itimerval *restrict \fIovalue\fP); +.fi +.SH DESCRIPTION +The +\fIgetitimer\fR() +function shall store the current value of the timer specified by +.IR which +into the structure pointed to by +.IR value . +The +\fIsetitimer\fR() +function shall set the timer specified by +.IR which +to the value specified in the structure pointed to by +.IR value , +and if +.IR ovalue +is not a null pointer, store the previous value of the timer in the +structure pointed to by +.IR ovalue . +.P +A timer value is defined by the +.BR itimerval +structure, specified in +.IR <sys/time.h> . +If +.IR it_value +is non-zero, it shall indicate the time to the next timer expiration. +If +.IR it_interval +is non-zero, it shall specify a value to be used in reloading +.IR it_value +when the timer expires. Setting +.IR it_value +to 0 shall disable a timer, regardless of the value of +.IR it_interval . +Setting +.IR it_interval +to 0 shall disable a timer after its next expiration (assuming +.IR it_value +is non-zero). +.P +Implementations may place limitations on the granularity of timer +values. For each interval timer, if the requested timer value requires +a finer granularity than the implementation supports, the actual timer +value shall be rounded up to the next supported value. +.P +An XSI-conforming implementation provides each process with at least +three interval timers, which are indicated by the +.IR which +argument: +.IP ITIMER_PROF 14 +Decrements both in process virtual time and when the system is running +on behalf of the process. It is designed to be used by interpreters in +statistically profiling the execution of interpreted programs. Each +time the ITIMER_PROF timer expires, the SIGPROF signal is delivered. +.IP ITIMER_REAL 14 +Decrements in real time. A SIGALRM signal is delivered when this timer +expires. +.IP ITIMER_VIRTUAL 14 +Decrements in process virtual time. It runs only when the process is +executing. A SIGVTALRM signal is delivered when it expires. +.P +The interaction between +\fIsetitimer\fR() +and +\fIalarm\fR() +or +\fIsleep\fR() +is unspecified. +.SH "RETURN VALUE" +Upon successful completion, +\fIgetitimer\fR() +or +\fIsetitimer\fR() +shall return 0; otherwise, \(mi1 shall be returned and +.IR errno +set to indicate the error. +.SH ERRORS +The +\fIsetitimer\fR() +function shall fail if: +.TP +.BR EINVAL +The +.IR value +argument is not in canonical form. (In canonical form, the number of +microseconds is a non-negative integer less than 1\|000\|000 and the +number of seconds is a non-negative integer.) +.P +The +\fIgetitimer\fR() +and +\fIsetitimer\fR() +functions may fail if: +.TP +.BR EINVAL +The +.IR which +argument is not recognized. +.LP +.IR "The following sections are informative." +.SH EXAMPLES +None. +.SH "APPLICATION USAGE" +Applications should use the +\fItimer_gettime\fR() +and +\fItimer_settime\fR() +functions instead of the obsolescent +\fIgetitimer\fR() +and +\fIsetitimer\fR() +functions, respectively. +.SH RATIONALE +None. +.SH "FUTURE DIRECTIONS" +The +\fIgetitimer\fR() +and +\fIsetitimer\fR() +functions may be removed in a future version. +.SH "SEE ALSO" +.IR "\fIalarm\fR\^(\|)", +.IR "\fIexec\fR\^", +.IR "\fIsleep\fR\^(\|)", +.IR "\fItimer_getoverrun\fR\^(\|)" +.P +The Base Definitions volume of POSIX.1\(hy2008, +.IR "\fB<signal.h>\fP", +.IR "\fB<sys_time.h>\fP" +.SH COPYRIGHT +Portions of this text are reprinted and reproduced in electronic form +from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology +-- Portable Operating System Interface (POSIX), The Open Group Base +Specifications Issue 7, Copyright (C) 2013 by the Institute of +Electrical and Electronics Engineers, Inc and The Open Group. +(This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the +event of any discrepancy between this version and the original IEEE and +The Open Group Standard, the original IEEE and The Open Group Standard +is the referee document. The original Standard can be obtained online at +http://www.unix.org/online.html . + +Any typographical or formatting errors that appear +in this page are most likely +to have been introduced during the conversion of the source files to +man page format. To report such errors, see +https://www.kernel.org/doc/man-pages/reporting_bugs.html . |