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
23 #include "proc.h"
24
25 static void proc_uptime(int fd, uint64_t *uptime, uint64_t *idle)
26 {
27 uint64_t val1, val2;
28 char buf[64], *p;
29 ssize_t rv;
30
31 /* save "p < end" checks */
32 memset(buf, 0, sizeof(buf));
33 rv = pread(fd, buf, sizeof(buf), 0);
34 assert(0 <= rv && rv <= sizeof(buf));
35 buf[sizeof(buf) - 1] = '\0';
36
37 p = buf;
38
39 val1 = xstrtoull(p, &p);
40 assert(p[0] == '.');
41 assert('0' <= p[1] && p[1] <= '9');
42 assert('0' <= p[2] && p[2] <= '9');
43 assert(p[3] == ' ');
44
45 val2 = (p[1] - '0') * 10 + p[2] - '0';
46 *uptime = val1 * 100 + val2;
47
48 p += 4;
49
50 val1 = xstrtoull(p, &p);
51 assert(p[0] == '.');
52 assert('0' <= p[1] && p[1] <= '9');
53 assert('0' <= p[2] && p[2] <= '9');
54 assert(p[3] == '\n');
55
56 val2 = (p[1] - '0') * 10 + p[2] - '0';
57 *idle = val1 * 100 + val2;
58
59 assert(p + 4 == buf + rv);
60 }