platform_bionic/libc/bionic/sysinfo.cpp
Elliott Hughes 36443fd542 Remove PAGE_SIZE from <limits.h>.
It turns out that everyone's still getting PAGE_SIZE from <sys/user.h> via
<sys/ucontext.h> via <signal.h> anyway.

glibc has PAGE_SIZE in <sys/user.h> rather than <limits.h> so this part is
good. The bad part is that we have such wide transitive inclusion of
<sys/user.h>!

Bug: http://b/22735893
Change-Id: I363adffe4a27b4ca1eedf695ea621f5dd2d5ca10
2015-07-28 19:54:53 -07:00

111 lines
3.2 KiB
C++

/*
* Copyright (C) 2014 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/sysinfo.h>
#include <dirent.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "private/ScopedReaddir.h"
static bool __matches_cpuN(const char* s) {
// The %c trick is to ensure that we have the anchored match "^cpu[0-9]+$".
unsigned cpu;
char dummy;
return (sscanf(s, "cpu%u%c", &cpu, &dummy) == 1);
}
int get_nprocs_conf() {
// On x86 kernels you can use /proc/cpuinfo for this, but on ARM kernels offline CPUs disappear
// from there. This method works on both.
ScopedReaddir reader("/sys/devices/system/cpu");
if (reader.IsBad()) {
return 1;
}
int result = 0;
dirent* entry;
while ((entry = reader.ReadEntry()) != NULL) {
if (entry->d_type == DT_DIR && __matches_cpuN(entry->d_name)) {
++result;
}
}
return result;
}
int get_nprocs() {
FILE* fp = fopen("/proc/stat", "re");
if (fp == NULL) {
return 1;
}
int result = 0;
char buf[256];
while (fgets(buf, sizeof(buf), fp) != NULL) {
// Extract just the first word from the line.
// 'cpu0 7976751 1364388 3116842 469770388 8629405 0 49047 0 0 0'
char* p = strchr(buf, ' ');
if (p != NULL) {
*p = 0;
}
if (__matches_cpuN(buf)) {
++result;
}
}
fclose(fp);
return result;
}
static int __get_meminfo_page_count(const char* pattern) {
FILE* fp = fopen("/proc/meminfo", "re");
if (fp == NULL) {
return -1;
}
int page_count = -1;
char buf[256];
while (fgets(buf, sizeof(buf), fp) != NULL) {
long total;
if (sscanf(buf, pattern, &total) == 1) {
page_count = static_cast<int>(total / (sysconf(_SC_PAGE_SIZE) / 1024));
break;
}
}
fclose(fp);
return page_count;
}
long get_phys_pages() {
return __get_meminfo_page_count("MemTotal: %ld kB");
}
long get_avphys_pages() {
return __get_meminfo_page_count("MemFree: %ld kB");
}