base/sys_info.cc

   1 // Copyright (c) 2012 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 "base/base_switches.h"
   8 #include "base/command_line.h"
   9 #include "base/lazy_instance.h"
  10 #include "base/metrics/field_trial.h"
  11 #include "base/strings/string_number_conversions.h"
  12 #include "base/strings/string_util.h"
  13 #include "base/sys_info_internal.h"
  14 #include "base/time/time.h"
  15
  16 namespace base {
  17
  18 #if !defined(OS_ANDROID)
  19
  20 static const int kLowMemoryDeviceThresholdMB = 512;
  21
  22 bool DetectLowEndDevice() {
  23   CommandLine* command_line = CommandLine::ForCurrentProcess();
  24   if (command_line->HasSwitch(switches::kEnableLowEndDeviceMode))
  25     return true;
  26   if (command_line->HasSwitch(switches::kDisableLowEndDeviceMode))
  27     return false;
  28
  29   int ram_size_mb = SysInfo::AmountOfPhysicalMemoryMB();
  30   return (ram_size_mb > 0 && ram_size_mb < kLowMemoryDeviceThresholdMB);
  31 }
  32
  33 static LazyInstance<
  34   internal::LazySysInfoValue<bool, DetectLowEndDevice> >::Leaky
  35   g_lazy_low_end_device = LAZY_INSTANCE_INITIALIZER;
  36
  37 // static
  38 bool SysInfo::IsLowEndDevice() {
  39   const std::string group_name =
  40       base::FieldTrialList::FindFullName("MemoryReduction");
  41
  42   // Low End Device Mode will be enabled if this client is assigned to
  43   // one of those EnabledXXX groups.
  44   if (StartsWith(group_name, "Enabled", CompareCase::SENSITIVE))
  45     return true;
  46
  47   return g_lazy_low_end_device.Get().value();
  48 }
  49 #endif
  50
  51 #if (!defined(OS_MACOSX) || defined(OS_IOS)) && !defined(OS_ANDROID)
  52 std::string SysInfo::HardwareModelName() {
  53   return std::string();
  54 }
  55 #endif
  56
  57 // static
  58 int64 SysInfo::Uptime() {
  59   // This code relies on an implementation detail of TimeTicks::Now() - that
  60   // its return value happens to coincide with the system uptime value in
  61   // microseconds, on Win/Mac/iOS/Linux/ChromeOS and Android.
  62   int64 uptime_in_microseconds = TimeTicks::Now().ToInternalValue();
  63   return uptime_in_microseconds / 1000;
  64 }
  65
  66 }  // namespace base