1 | /* clock_getcpuclockid -- Get a clockid_t for process CPU time. Linux version. |
2 | Copyright (C) 2004-2018 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 <errno.h> |
20 | #include <time.h> |
21 | #include <unistd.h> |
22 | #include "kernel-posix-cpu-timers.h" |
23 | |
24 | int |
25 | __clock_getcpuclockid (pid_t pid, clockid_t *clock_id) |
26 | { |
27 | /* The clockid_t value is a simple computation from the PID. |
28 | But we do a clock_getres call to validate it. */ |
29 | |
30 | const clockid_t pidclock = MAKE_PROCESS_CPUCLOCK (pid, CPUCLOCK_SCHED); |
31 | |
32 | INTERNAL_SYSCALL_DECL (err); |
33 | int r = INTERNAL_SYSCALL (clock_getres, err, 2, pidclock, NULL); |
34 | if (!INTERNAL_SYSCALL_ERROR_P (r, err)) |
35 | { |
36 | *clock_id = pidclock; |
37 | return 0; |
38 | } |
39 | |
40 | if (INTERNAL_SYSCALL_ERRNO (r, err) == EINVAL) |
41 | { |
42 | /* The clock_getres system call checked the PID for us. */ |
43 | return ESRCH; |
44 | } |
45 | else |
46 | return INTERNAL_SYSCALL_ERRNO (r, err); |
47 | } |
48 | weak_alias (__clock_getcpuclockid, clock_getcpuclockid) |
49 | |