chrome/browser/extensions/api/system_cpu/cpu_info_provider_win.cc

   1 // Copyright 2014 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 "chrome/browser/extensions/api/system_cpu/cpu_info_provider.h"
   6
   7 #include <windows.h>
   8 #include <winternl.h>
   9
  10 #include "base/sys_info.h"
  11
  12 namespace extensions {
  13
  14 namespace {
  15
  16 const wchar_t kNtdll[] = L"ntdll.dll";
  17 const char kNtQuerySystemInformationName[] = "NtQuerySystemInformation";
  18
  19 // See MSDN about NtQuerySystemInformation definition.
  20 typedef DWORD (WINAPI *NtQuerySystemInformationPF)(DWORD system_info_class,
  21                                                    PVOID system_info,
  22                                                    ULONG system_info_length,
  23                                                    PULONG return_length);
  24
  25 }  // namespace
  26
  27 bool CpuInfoProvider::QueryCpuTimePerProcessor(
  28     std::vector<linked_ptr<api::system_cpu::ProcessorInfo> >* infos) {
  29   DCHECK(infos);
  30
  31   HMODULE ntdll = GetModuleHandle(kNtdll);
  32   CHECK(ntdll != NULL);
  33   NtQuerySystemInformationPF NtQuerySystemInformation =
  34       reinterpret_cast<NtQuerySystemInformationPF>(
  35           ::GetProcAddress(ntdll, kNtQuerySystemInformationName));
  36
  37   CHECK(NtQuerySystemInformation != NULL);
  38
  39   int num_of_processors = base::SysInfo::NumberOfProcessors();
  40   scoped_ptr<SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION[]> processor_info(
  41       new SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION[num_of_processors]);
  42
  43   ULONG returned_bytes = 0, bytes =
  44       sizeof(SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION) * num_of_processors;
  45   if (!NT_SUCCESS(NtQuerySystemInformation(
  46           SystemProcessorPerformanceInformation,
  47           processor_info.get(), bytes, &returned_bytes)))
  48     return false;
  49
  50   int returned_num_of_processors =
  51       returned_bytes / sizeof(SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION);
  52
  53   if (returned_num_of_processors != num_of_processors)
  54     return false;
  55
  56   DCHECK_EQ(num_of_processors, static_cast<int>(infos->size()));
  57   for (int i = 0; i < returned_num_of_processors; ++i) {
  58     double kernel = static_cast<double>(processor_info[i].KernelTime.QuadPart),
  59         user = static_cast<double>(processor_info[i].UserTime.QuadPart),
  60         idle = static_cast<double>(processor_info[i].IdleTime.QuadPart);
  61
  62     // KernelTime needs to be fixed-up, because it includes both idle time and
  63     // real kernel time.
  64     infos->at(i)->usage.kernel = kernel - idle;
  65     infos->at(i)->usage.user = user;
  66     infos->at(i)->usage.idle = idle;
  67     infos->at(i)->usage.total = kernel + user;
  68   }
  69
  70   return true;
  71 }
  72
  73 }  // namespace extensions