2008-08-11 10:58:20 +00:00
|
|
|
.\" Copyright (c) 2008, Linux Foundation, written by Michael Kerrisk
|
|
|
|
.\" <mtk.manpages@gmail.com>
|
|
|
|
.\"
|
|
|
|
.\" Permission is granted to make and distribute verbatim copies of this
|
|
|
|
.\" manual provided the copyright notice and this permission notice are
|
|
|
|
.\" preserved on all copies.
|
|
|
|
.\"
|
|
|
|
.\" Permission is granted to copy and distribute modified versions of this
|
|
|
|
.\" manual under the conditions for verbatim copying, provided that the
|
|
|
|
.\" entire resulting derived work is distributed under the terms of a
|
|
|
|
.\" permission notice identical to this one.
|
|
|
|
.\"
|
|
|
|
.\" Since the Linux kernel and libraries are constantly changing, this
|
|
|
|
.\" manual page may be incorrect or out-of-date. The author(s) assume no
|
|
|
|
.\" responsibility for errors or omissions, or for damages resulting from
|
|
|
|
.\" the use of the information contained herein. The author(s) may not
|
|
|
|
.\" have taken the same level of care in the production of this manual,
|
|
|
|
.\" which is licensed free of charge, as they might when working
|
|
|
|
.\" professionally.
|
|
|
|
.\"
|
|
|
|
.\" Formatted or processed versions of this manual, if unaccompanied by
|
|
|
|
.\" the source, must acknowledge the copyright and authors of this work.
|
|
|
|
.\"
|
2010-09-10 05:49:10 +00:00
|
|
|
.TH CLOCK_GETCPUCLOCKID 3 2010-09-10 "Linux" "Linux Programmer's Manual"
|
2008-08-11 10:58:20 +00:00
|
|
|
.SH NAME
|
|
|
|
clock_getcpuclockid \- obtain ID of a process CPU-time clock
|
|
|
|
.SH SYNOPSIS
|
|
|
|
.B #include <time.h>
|
|
|
|
.nf
|
|
|
|
.sp
|
2008-09-10 09:05:33 +00:00
|
|
|
.BI "int clock_getcpuclockid(pid_t " pid ", clockid_t *" clock_id );
|
2008-08-11 10:58:20 +00:00
|
|
|
.fi
|
|
|
|
.sp
|
|
|
|
Link with \fI\-lrt\fP.
|
|
|
|
.sp
|
2010-09-19 16:32:23 +00:00
|
|
|
.ad l
|
2008-08-11 10:58:20 +00:00
|
|
|
.in -4n
|
|
|
|
Feature Test Macro Requirements for glibc (see
|
|
|
|
.BR feature_test_macros (7)):
|
|
|
|
.in
|
|
|
|
.sp
|
|
|
|
.BR clock_getcpuclockid ():
|
2010-09-19 16:32:23 +00:00
|
|
|
.RS 4
|
|
|
|
_XOPEN_SOURCE\ >=\ 600 || _POSIX_C_SOURCE\ >=\ 200112L
|
|
|
|
.RE
|
|
|
|
.ad
|
2008-08-11 10:58:20 +00:00
|
|
|
.SH DESCRIPTION
|
|
|
|
The
|
|
|
|
.BR clock_getcpuclockid ()
|
2008-09-29 09:09:52 +00:00
|
|
|
function obtains the ID of the CPU-time clock of the process whose ID is
|
2008-08-11 10:58:20 +00:00
|
|
|
.IR pid ,
|
|
|
|
and returns it in the location pointed to by
|
|
|
|
.IR clock_id .
|
|
|
|
If
|
|
|
|
.I pid
|
|
|
|
is zero, then the clock ID of the CPU-time clock
|
|
|
|
of the calling process is returned.
|
|
|
|
.SH "RETURN VALUE"
|
|
|
|
On success,
|
|
|
|
.BR clock_getcpuclockid ()
|
|
|
|
returns 0;
|
2010-09-10 05:49:10 +00:00
|
|
|
on error, it returns one of the positive error numbers listed in ERRORS.
|
2008-08-11 10:58:20 +00:00
|
|
|
.SH ERRORS
|
|
|
|
.TP
|
|
|
|
.B ENOSYS
|
|
|
|
The kernel does not support obtaining the per-process
|
|
|
|
CPU-time clock of another process, and
|
|
|
|
.I pid
|
|
|
|
does not specify the calling process.
|
|
|
|
.TP
|
|
|
|
.B EPERM
|
|
|
|
The caller does not have permission to access
|
|
|
|
the CPU-time clock of the process specified by
|
|
|
|
.IR pid .
|
|
|
|
(Specified as an optional error in POSIX.1-2001;
|
|
|
|
does not occur on Linux unless the kernel does not support
|
|
|
|
obtaining the per-process CPU-time clock of another process.)
|
|
|
|
.TP
|
|
|
|
.B ESRCH
|
|
|
|
There is no process with the ID
|
|
|
|
.IR pid .
|
|
|
|
.SH VERSIONS
|
|
|
|
The
|
|
|
|
.BR clock_getcpuclockid ()
|
|
|
|
function is available in glibc since version 2.2.
|
|
|
|
.SH CONFORMING TO
|
|
|
|
POSIX.1-2001.
|
|
|
|
.SH NOTES
|
|
|
|
Calling
|
clock_nanosleep.2, getrusage.2, timerfd_create.2, clock.3, clock_getcpuclockid.3, ftime.3, pthread_create.3, pthread_getcpuclockid.3, pthread_tryjoin_np.3, sem_wait.3, time.7: Global fix: Fix xrefs to clock_*.? pages to reflect move to section 2
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
2009-02-07 21:10:39 +00:00
|
|
|
.BR clock_gettime (2)
|
2008-08-11 10:58:20 +00:00
|
|
|
with the clock ID obtained by a call to
|
|
|
|
.BR clock_getcpuclockid ()
|
|
|
|
with a
|
|
|
|
.I pid
|
|
|
|
of 0,
|
|
|
|
is the same as using the clock ID
|
|
|
|
.BR CLOCK_PROCESS_CPUTIME_ID .
|
|
|
|
.SH EXAMPLE
|
|
|
|
The example program below obtains the
|
|
|
|
CPU-time clock ID of the process whose ID is given on the command line,
|
|
|
|
and then uses
|
clock_nanosleep.2, getrusage.2, timerfd_create.2, clock.3, clock_getcpuclockid.3, ftime.3, pthread_create.3, pthread_getcpuclockid.3, pthread_tryjoin_np.3, sem_wait.3, time.7: Global fix: Fix xrefs to clock_*.? pages to reflect move to section 2
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
2009-02-07 21:10:39 +00:00
|
|
|
.BR clock_gettime (2)
|
2008-08-11 10:58:20 +00:00
|
|
|
to obtain the time on that clock.
|
|
|
|
An example run is the following:
|
|
|
|
.in +4n
|
|
|
|
.nf
|
|
|
|
|
eventfd.2, execve.2, getdents.2, ioprio_set.2, mprotect.2, signalfd.2, timerfd_create.2, wait.2, backtrace.3, clock_getcpuclockid.3, end.3, fmemopen.3, fopencookie.3, frexp.3, getdate.3, getgrouplist.3, getprotoent_r.3, getservent_r.3, gnu_get_libc_version.3, inet.3, inet_pton.3, makecontext.3, malloc.3, matherr.3, offsetof.3, pthread_attr_init.3, pthread_create.3, pthread_getattr_np.3, sem_wait.3, strftime.3, strtok.3, strtol.3, core.5, proc.5, cpuset.7, mq_overview.7: Global fix: Format user input in shell sessions in boldface
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
2008-10-28 15:37:22 +00:00
|
|
|
.RB "$" " ./a.out 1" " # Show CPU clock of init process"
|
2008-08-11 10:58:20 +00:00
|
|
|
CPU-time clock for PID 1 is 2.213466748 seconds
|
|
|
|
.fi
|
|
|
|
.in
|
eventfd.2, getdents.2, mprotect.2, signalfd.2, timerfd_create.2, wait.2, backtrace.3, clock_getcpuclockid.3, end.3, fmemopen.3, fopencookie.3, getdate.3, getgrouplist.3, getprotoent_r.3, getservent_r.3, gnu_get_libc_version.3, inet.3, inet_pton.3, makecontext.3, matherr.3, offsetof.3, pthread_attr_init.3, pthread_create.3, pthread_getattr_np.3, sem_wait.3, strtol.3, core.5: global fix: Add ".SS Program source" to EXAMPLE
Add ".SS Program source" to clearly distinguish shell session and
descriptive text from actual program code.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
2008-10-28 15:51:05 +00:00
|
|
|
.SS Program source
|
eventfd.2, getdents.2, mprotect.2, signalfd.2, timerfd_create.2, wait.2, backtrace.3, clock_getcpuclockid.3, end.3, fmemopen.3, fopencookie.3, frexp.3, getaddrinfo.3, getdate.3, getgrouplist.3, getprotoent_r.3, getservent_r.3, gnu_get_libc_version.3, inet.3, inet_pton.3, makecontext.3, matherr.3, offsetof.3, pthread_attr_init.3, pthread_create.3, pthread_getattr_np.3, sem_wait.3, strftime.3, strtok.3, strtol.3, core.5: srcfix
s/\.R " "/\\\&/ as a way of getting a blank line after a .SS heading.
(Suggested by Sam Varshavchik <mrsam@courier-mta.com>)
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
2008-11-05 01:42:45 +00:00
|
|
|
\&
|
2008-08-11 10:58:20 +00:00
|
|
|
.nf
|
|
|
|
#define _XOPEN_SOURCE 600
|
|
|
|
#include <stdio.h>
|
|
|
|
#include <unistd.h>
|
|
|
|
#include <stdlib.h>
|
|
|
|
#include <time.h>
|
|
|
|
|
|
|
|
int
|
|
|
|
main(int argc, char *argv[])
|
|
|
|
{
|
|
|
|
clockid_t clockid;
|
|
|
|
struct timespec ts;
|
|
|
|
|
|
|
|
if (argc != 2) {
|
|
|
|
fprintf(stderr, "%s <process-ID>\\n", argv[0]);
|
|
|
|
exit(EXIT_FAILURE);
|
|
|
|
}
|
|
|
|
|
|
|
|
if (clock_getcpuclockid(atoi(argv[1]), &clockid) != 0) {
|
|
|
|
perror("clock_getcpuclockid");
|
|
|
|
exit(EXIT_FAILURE);
|
|
|
|
}
|
|
|
|
|
|
|
|
if (clock_gettime(clockid, &ts) == -1) {
|
|
|
|
perror("clock_gettime");
|
|
|
|
exit(EXIT_FAILURE);
|
|
|
|
}
|
|
|
|
|
|
|
|
printf("CPU-time clock for PID %s is %ld.%09ld seconds\\n",
|
|
|
|
argv[1], (long) ts.tv_sec, (long) ts.tv_nsec);
|
|
|
|
exit(EXIT_SUCCESS);
|
|
|
|
}
|
|
|
|
.fi
|
|
|
|
.SH SEE ALSO
|
clock_nanosleep.2, getrusage.2, timerfd_create.2, clock.3, clock_getcpuclockid.3, ftime.3, pthread_create.3, pthread_getcpuclockid.3, pthread_tryjoin_np.3, sem_wait.3, time.7: Global fix: Fix xrefs to clock_*.? pages to reflect move to section 2
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
2009-02-07 21:10:39 +00:00
|
|
|
.BR clock_getres (2),
|
2009-02-10 01:42:17 +00:00
|
|
|
.BR timer_create (2),
|
2009-02-07 08:47:42 +00:00
|
|
|
.BR pthread_getcpuclockid (3),
|
2008-08-11 10:58:20 +00:00
|
|
|
.BR time (7)
|