1/* Return the time used by the program so far (user time + system time).
2 Copyright (C) 1991-2017 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 <http://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 timespec ts;
27
28 _Static_assert (CLOCKS_PER_SEC == 1000000,
29 "CLOCKS_PER_SEC should be 1000000");
30
31 /* clock_gettime shouldn't fail here since CLOCK_PROCESS_CPUTIME_ID is
32 supported since 2.6.12. Check the return value anyway in case the kernel
33 barfs on us for some reason. */
34 if (__glibc_unlikely (__clock_gettime (CLOCK_PROCESS_CPUTIME_ID, &ts) != 0))
35 return (clock_t) -1;
36
37 return (ts.tv_sec * CLOCKS_PER_SEC
38 + ts.tv_nsec / (1000000000 / CLOCKS_PER_SEC));
39}
40