1 /*
2 * Copyright (C) 2014 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/sysinfo.h>
30
31 #include <dirent.h>
32 #include <limits.h>
33 #include <stdio.h>
34 #include <string.h>
35
36 #include "private/ScopedReaddir.h"
37
__matches_cpuN(const char * s)38 static bool __matches_cpuN(const char* s) {
39 // The %c trick is to ensure that we have the anchored match "^cpu[0-9]+$".
40 unsigned cpu;
41 char dummy;
42 return (sscanf(s, "cpu%u%c", &cpu, &dummy) == 1);
43 }
44
get_nprocs_conf()45 int get_nprocs_conf() {
46 // On x86 kernels you can use /proc/cpuinfo for this, but on ARM kernels offline CPUs disappear
47 // from there. This method works on both.
48 ScopedReaddir reader("/sys/devices/system/cpu");
49 if (reader.IsBad()) {
50 return 1;
51 }
52
53 int result = 0;
54 dirent* entry;
55 while ((entry = reader.ReadEntry()) != NULL) {
56 if (entry->d_type == DT_DIR && __matches_cpuN(entry->d_name)) {
57 ++result;
58 }
59 }
60 return result;
61 }
62
get_nprocs()63 int get_nprocs() {
64 FILE* fp = fopen("/proc/stat", "re");
65 if (fp == NULL) {
66 return 1;
67 }
68
69 int result = 0;
70 char buf[256];
71 while (fgets(buf, sizeof(buf), fp) != NULL) {
72 // Extract just the first word from the line.
73 // 'cpu0 7976751 1364388 3116842 469770388 8629405 0 49047 0 0 0'
74 char* p = strchr(buf, ' ');
75 if (p != NULL) {
76 *p = 0;
77 }
78 if (__matches_cpuN(buf)) {
79 ++result;
80 }
81 }
82 fclose(fp);
83 return result;
84 }
85
__get_meminfo_page_count(const char * pattern)86 static int __get_meminfo_page_count(const char* pattern) {
87 FILE* fp = fopen("/proc/meminfo", "re");
88 if (fp == NULL) {
89 return -1;
90 }
91
92 int page_count = -1;
93 char buf[256];
94 while (fgets(buf, sizeof(buf), fp) != NULL) {
95 long total;
96 if (sscanf(buf, pattern, &total) == 1) {
97 page_count = static_cast<int>(total / (PAGE_SIZE / 1024));
98 break;
99 }
100 }
101 fclose(fp);
102 return page_count;
103 }
104
get_phys_pages()105 long get_phys_pages() {
106 return __get_meminfo_page_count("MemTotal: %ld kB");
107 }
108
get_avphys_pages()109 long get_avphys_pages() {
110 return __get_meminfo_page_count("MemFree: %ld kB");
111 }
112