cputime(2) [plan9 man page]

CPUTIME(2)							System Calls Manual							CPUTIME(2)

NAME

       cputime, times - cpu time in this process and children

SYNOPSIS

       #include <u.h>
       #include <libc.h>

       int    times(long t[4])

       double cputime(void)

DESCRIPTION

       If  t  is  non-null,  times fills it in with the number of milliseconds spent in user code, system calls, child processes in user code, and
       child processes in system calls.  Cputime returns the sum of those same times, converted to seconds.  Times returns the real time, in  mil-
       liseconds used by the process so far.

       These functions read /dev/cputime, opening that file when time is first called.

SOURCE

       /sys/src/libc/9sys

SEE ALSO

       cons(3)

																	CPUTIME(2)

times(3)						     Library Functions Manual							  times(3)

NAME

       times - Gets process and child process times

LIBRARY

       Standard C Library (libc.so, libc.a)

SYNOPSIS

       #include <sys/times.h>

       clock_t times(
	       struct tms *buffer);

       Programs  that  are being developed for conformance to the AT&T System V Interface Definition must specify two #include statements, as fol-
       lows:

       #include <sys/types.h> #include <sys/times.h>

STANDARDS

       Interfaces documented on this reference page conform to industry standards as follows:

       times():  XPG4, XPG4-UNIX

       Refer to the standards(5) reference page for more information about industry standards and associated tags.

PARAMETERS

       Points to type tms structure space where system time information is stored.

DESCRIPTION

       The times() function fills the type tms structure space pointed to by the buffer parameter with time-accounting information.  All time val-
       ues reported by this function are in hardware-dependent clock ticks.

       The  times  of a terminated child process are included in the tms_cutime and tms_cstime elements of the parent process when a wait function
       returns the process ID of that terminated child.

       The tms structure, which  is defined in the sys/times.h header file, contains the following members: User time. The CPU time charged  while
       executing  user	instructions  of  the calling process.	System time. The CPU time charged during system execution on behalf of the calling
       process.  User time, children. The sum of the tms_utime and the tms_cutime times of the child processes.  System time, children. The sum of
       the tms_stime and the tms_cstime times of the child processes.

       When a child process does not wait for its children, its child-process times are not included in its times.

       This information comes from the calling process and each of its terminated child processes for which a wait function has been executed.

RETURN VALUES

       Upon  successful completion, the times() function returns the elapsed real time since an arbitrary reference time in the past (for example,
       system start-up time). The reference time does not change from one invocation of times() within the process to another.	The elapsed  times
       are  in	units  of  1/CLK_TCK  seconds,	where CLK_TCK is processor dependent.  For application portability, the value of CLK_TCK should be
       queried using the sysconf() function (see sysconf(3)).

       The return value may overflow the possible range of type clock_t values. When the  times()  function  fails,  a	value  of  (clock_t)-1	is
       returned.

RELATED INFORMATION

       Commands: cc(1)

       Functions: exec(2), fork(2), getrusage(2), profil(2), stime(3), sysconf(3), time(3), wait(2)

       Standards: standards(5) delim off

																	  times(3)