1/* Get a clockid_t for the process CPU clock of a given process. Generic.
2 Copyright (C) 2000-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <errno.h>
20#include <time.h>
21#include <unistd.h>
22#include <shlib-compat.h>
23
24int
25__clock_getcpuclockid (pid_t pid, clockid_t *clock_id)
26{
27 /* We don't allow any process ID but our own. */
28 if (pid != 0 && pid != getpid ())
29 return EPERM;
30
31#ifdef CLOCK_PROCESS_CPUTIME_ID
32 /* Store the number. */
33 *clock_id = CLOCK_PROCESS_CPUTIME_ID;
34
35 return 0;
36#else
37 /* We don't have a timer for that. */
38 return ENOENT;
39#endif
40}
41versioned_symbol (libc, __clock_getcpuclockid, clock_getcpuclockid, GLIBC_2_17);
42/* clock_getcpuclockid moved to libc in version 2.17;
43 old binaries may expect the symbol version it had in librt. */
44#if SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_17)
45compat_symbol (libc, __clock_getcpuclockid, clock_getcpuclockid, GLIBC_2_2);
46#endif
47

source code of glibc/time/clock_getcpuclockid.c