Add functions in sysinfo.h.
Bug: 17703902
Change-Id: I699d12d76a8fc483c919be730c2ac63641b71a1d
diff --git a/libc/bionic/sysinfo.cpp b/libc/bionic/sysinfo.cpp
new file mode 100644
index 0000000..6f0afb8
--- /dev/null
+++ b/libc/bionic/sysinfo.cpp
@@ -0,0 +1,111 @@
+/*
+ * 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 <limits.h>
+#include <stdio.h>
+#include <string.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(const char* pattern) {
+ FILE* fp = fopen("/proc/meminfo", "re");
+ if (fp == NULL) {
+ return -1;
+ }
+
+ int result = -1;
+ char buf[256];
+ while (fgets(buf, sizeof(buf), fp) != NULL) {
+ long total;
+ if (sscanf(buf, pattern, &total) == 1) {
+ result = (int) (total / (PAGE_SIZE/1024));
+ break;
+ }
+ }
+ fclose(fp);
+ return result;
+}
+
+long get_phys_pages() {
+ return __get_meminfo("MemTotal: %ld kB");
+}
+
+long get_avphys_pages() {
+ return __get_meminfo("MemFree: %ld kB");
+}