clock_getcpuclockid (3) - Linux Man Pages
clock_getcpuclockid: obtain ID of a process CPU-time clock
clock_getcpuclockid - obtain ID of a process CPU-time clock
int clock_getcpuclockid(pid_t pid, clockid_t *clock_id);
Link with -lrt (only for glibc versions before 2.17).
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
- _POSIX_C_SOURCE >= 200112L
DESCRIPTIONThe clock_getcpuclockid() function obtains the ID of the CPU-time clock of the process whose ID is pid, and returns it in the location pointed to by clock_id. If pid is zero, then the clock ID of the CPU-time clock of the calling process is returned.
RETURN VALUEOn success, clock_getcpuclockid() returns 0; on error, it returns one of the positive error numbers listed in ERRORS.
- The kernel does not support obtaining the per-process CPU-time clock of another process, and pid does not specify the calling process.
- The caller does not have permission to access the CPU-time clock of the process specified by pid. (Specified 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.)
- There is no process with the ID pid.
VERSIONSThe clock_getcpuclockid() function is available in glibc since version 2.2.
ATTRIBUTESFor an explanation of the terms used in this section, see attributes(7).
CONFORMING TOPOSIX.1-2001, POSIX.1-2008.
NOTESCalling clock_gettime(2) with the clock ID obtained by a call to clock_getcpuclockid() with a pid of 0, is the same as using the clock ID CLOCK_PROCESS_CPUTIME_ID.
EXAMPLEThe example program below obtains the CPU-time clock ID of the process whose ID is given on the command line, and then uses clock_gettime(2) to obtain the time on that clock. An example run is the following:
Program source#define _XOPEN_SOURCE 600 #include <stdio.h> #include <unistd.h> #include <stdlib.h> #include <time.h>
main(int argc, char *argv)
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