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 #include "build/build_config.h" 16 17 namespace base { 18 19 #if !defined(OS_ANDROID) 20 21 static const int kLowMemoryDeviceThresholdMB = 512; 22 DetectLowEndDevice()23bool DetectLowEndDevice() { 24 CommandLine* command_line = CommandLine::ForCurrentProcess(); 25 if (command_line->HasSwitch(switches::kEnableLowEndDeviceMode)) 26 return true; 27 if (command_line->HasSwitch(switches::kDisableLowEndDeviceMode)) 28 return false; 29 30 int ram_size_mb = SysInfo::AmountOfPhysicalMemoryMB(); 31 return (ram_size_mb > 0 && ram_size_mb <= kLowMemoryDeviceThresholdMB); 32 } 33 34 static LazyInstance< 35 internal::LazySysInfoValue<bool, DetectLowEndDevice> >::Leaky 36 g_lazy_low_end_device = LAZY_INSTANCE_INITIALIZER; 37 38 // static IsLowEndDevice()39bool SysInfo::IsLowEndDevice() { 40 const std::string group_name = 41 base::FieldTrialList::FindFullName("MemoryReduction"); 42 43 // Low End Device Mode will be enabled if this client is assigned to 44 // one of those EnabledXXX groups. 45 if (StartsWith(group_name, "Enabled", CompareCase::SENSITIVE)) 46 return true; 47 48 return g_lazy_low_end_device.Get().value(); 49 } 50 #endif 51 52 #if (!defined(OS_MACOSX) || defined(OS_IOS)) && !defined(OS_ANDROID) HardwareModelName()53std::string SysInfo::HardwareModelName() { 54 return std::string(); 55 } 56 #endif 57 58 // static Uptime()59base::TimeDelta SysInfo::Uptime() { 60 // This code relies on an implementation detail of TimeTicks::Now() - that 61 // its return value happens to coincide with the system uptime value in 62 // microseconds, on Win/Mac/iOS/Linux/ChromeOS and Android. 63 int64_t uptime_in_microseconds = TimeTicks::Now().ToInternalValue(); 64 return base::TimeDelta::FromMicroseconds(uptime_in_microseconds); 65 } 66 67 } // namespace base 68