base/sys_info_linux.cc

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/sys_info.h"
   6
   7 #include <limits>
   8
   9 #include "base/file_util.h"
  10 #include "base/logging.h"
  11 #include "base/string_number_conversions.h"
  12
  13 namespace base {
  14
  15 int64 SysInfo::AmountOfPhysicalMemory() {
  16   long pages = sysconf(_SC_PHYS_PAGES);
  17   long page_size = sysconf(_SC_PAGE_SIZE);
  18   if (pages == -1 || page_size == -1) {
  19     NOTREACHED();
  20     return 0;
  21   }
  22
  23   return static_cast<int64>(pages) * page_size;
  24 }
  25
  26 // static
  27 size_t SysInfo::MaxSharedMemorySize() {
  28   static int64 limit;
  29   static bool limit_valid = false;
  30   if (!limit_valid) {
  31     std::string contents;
  32     file_util::ReadFileToString(FilePath("/proc/sys/kernel/shmmax"), &contents);
  33     DCHECK(!contents.empty());
  34     if (!contents.empty() && contents[contents.length() - 1] == '\n') {
  35       contents.erase(contents.length() - 1);
  36     }
  37     if (base::StringToInt64(contents, &limit)) {
  38       DCHECK(limit >= 0);
  39       DCHECK(static_cast<uint64>(limit) <= std::numeric_limits<size_t>::max());
  40       limit_valid = true;
  41     } else {
  42       NOTREACHED();
  43       return 0;
  44     }
  45   }
  46   return static_cast<size_t>(limit);
  47 }
  48
  49 }  // namespace base