1 | /* |
2 | * Copyright © 2018 Alexey Dobriyan <adobriyan@gmail.com> |
3 | * |
4 | * Permission to use, copy, modify, and distribute this software for any |
5 | * purpose with or without fee is hereby granted, provided that the above |
6 | * copyright notice and this permission notice appear in all copies. |
7 | * |
8 | * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
9 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
10 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
11 | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
12 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
13 | * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
14 | * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
15 | */ |
16 | #undef NDEBUG |
17 | #include <assert.h> |
18 | #include <errno.h> |
19 | #include <string.h> |
20 | #include <stdlib.h> |
21 | #include <unistd.h> |
22 | #include <time.h> |
23 | |
24 | #include "proc.h" |
25 | |
26 | static uint64_t clock_boottime(void) |
27 | { |
28 | struct timespec ts; |
29 | int err; |
30 | |
31 | err = clock_gettime(CLOCK_BOOTTIME, &ts); |
32 | assert(err >= 0); |
33 | |
34 | return (ts.tv_sec * 100) + (ts.tv_nsec / 10000000); |
35 | } |
36 | |
37 | static uint64_t proc_uptime(int fd) |
38 | { |
39 | uint64_t val1, val2; |
40 | char buf[64], *p; |
41 | ssize_t rv; |
42 | |
43 | /* save "p < end" checks */ |
44 | memset(buf, 0, sizeof(buf)); |
45 | rv = pread(fd, buf, sizeof(buf), 0); |
46 | assert(0 <= rv && rv <= sizeof(buf)); |
47 | buf[sizeof(buf) - 1] = '\0'; |
48 | |
49 | p = buf; |
50 | |
51 | val1 = xstrtoull(p, &p); |
52 | assert(p[0] == '.'); |
53 | assert('0' <= p[1] && p[1] <= '9'); |
54 | assert('0' <= p[2] && p[2] <= '9'); |
55 | assert(p[3] == ' '); |
56 | |
57 | val2 = (p[1] - '0') * 10 + p[2] - '0'; |
58 | |
59 | return val1 * 100 + val2; |
60 | } |
61 | |