1/* Return the time used by the program so far (user time + system time).
2 Copyright (C) 1991-2022 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 <sys/times.h>
20#include <time.h>
21#include <unistd.h>
22
23clock_t
24clock (void)
25{
26 struct __timespec64 ts;
27
28 _Static_assert (CLOCKS_PER_SEC == 1000000,
29 "CLOCKS_PER_SEC should be 1000000");
30
31 if (__glibc_unlikely (__clock_gettime64 (CLOCK_PROCESS_CPUTIME_ID, &ts) != 0))
32 return (clock_t) -1;
33
34 return (ts.tv_sec * CLOCKS_PER_SEC
35 + ts.tv_nsec / (1000000000 / CLOCKS_PER_SEC));
36}
37

source code of glibc/sysdeps/unix/sysv/linux/clock.c