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 <stdio.h>
33 #include <string.h>
34 #include <unistd.h>
35
36 #include "private/get_cpu_count_from_string.h"
37 #include "private/ScopedReaddir.h"
38
__matches_cpuN(const char * s)39 static bool __matches_cpuN(const char* s) {
40 // The %c trick is to ensure that we have the anchored match "^cpu[0-9]+$".
41 // We can't use %*c because the return value is how many were *assigned*.
42 unsigned cpu;
43 char unused;
44 return (sscanf(s, "cpu%u%c", &cpu, &unused) == 1);
45 }
46
get_nprocs_conf()47 int get_nprocs_conf() {
48 // On x86 kernels you can use /proc/cpuinfo for this, but on ARM kernels offline CPUs disappear
49 // from there. This method works on both.
50 ScopedReaddir reader("/sys/devices/system/cpu");
51 if (reader.IsBad()) {
52 return 1;
53 }
54
55 int result = 0;
56 dirent* entry;
57 while ((entry = reader.ReadEntry()) != nullptr) {
58 if (entry->d_type == DT_DIR && __matches_cpuN(entry->d_name)) {
59 ++result;
60 }
61 }
62 return result;
63 }
64
get_nprocs()65 int get_nprocs() {
66 int cpu_count = 1;
67 FILE* fp = fopen("/sys/devices/system/cpu/online", "re");
68 if (fp != nullptr) {
69 char* line = nullptr;
70 size_t len = 0;
71 if (getline(&line, &len, fp) != -1) {
72 cpu_count = GetCpuCountFromString(line);
73 free(line);
74 }
75 fclose(fp);
76 }
77 return cpu_count;
78 }
79
get_phys_pages()80 long get_phys_pages() {
81 struct sysinfo si;
82 sysinfo(&si);
83 return (static_cast<int64_t>(si.totalram) * si.mem_unit) / PAGE_SIZE;
84 }
85
get_avphys_pages()86 long get_avphys_pages() {
87 struct sysinfo si;
88 sysinfo(&si);
89 return ((static_cast<int64_t>(si.freeram) + si.bufferram) * si.mem_unit) / PAGE_SIZE;
90 }
91