如何在C ++中获得每个内核的CPU负载（具有超线程的四核cpu）？ 我在％。的任务管理器中寻找结果。
我现在正试着这样做： 问题是代码识别9个核心（我有8：/）
#define _WIN32_DCOM
#include <iostream>
#include <comdef.h>
#include <Wbemidl.h>
# pragma comment(lib, "wbemuuid.lib")
using namespace std;
bool getCpuLoadInfo() {
HRESULT hres;
// Step 1: --------------------------------------------------
// Initialize COM. ------------------------------------------
hres = CoInitializeEx(0, COINIT_MULTITHREADED);
if (FAILED(hres)) {
cout << "Failed to initialize COM library. Error code = 0x" << hex << hres << endl;
return 0; // Program has failed.
}
// Step 2: --------------------------------------------------
// Set general COM security levels --------------------------
// Note: If you are using Windows 2000, you need to specify -
// the default authentication credentials for a user by using
// a SOLE_AUTHENTICATION_LIST structure in the pAuthList ----
// parameter of CoInitializeSecurity ------------------------
hres = CoInitializeSecurity(
NULL,
-1, // COM authentication
NULL, // Authentication services
NULL, // Reserved
RPC_C_AUTHN_LEVEL_DEFAULT, // Default authentication
RPC_C_IMP_LEVEL_IMPERSONATE, // Default Impersonation
NULL, // Authentication info
EOAC_NONE, // Additional capabilities
NULL // Reserved
);
if (FAILED(hres)) {
cout << "Failed to initialize security. Error code = 0x"
<< hex << hres << endl;
CoUninitialize();
return 0; // Program has failed.
}
// Step 3: ---------------------------------------------------
// Obtain the initial locator to WMI -------------------------
IWbemLocator *pLoc = NULL;
hres = CoCreateInstance(
CLSID_WbemLocator,
0,
CLSCTX_INPROC_SERVER,
IID_IWbemLocator, (LPVOID *)&pLoc);
if (FAILED(hres)) {
cout << "Failed to create IWbemLocator object."
<< " Err code = 0x"
<< hex << hres << endl;
CoUninitialize();
return 0; // Program has failed.
}
// Step 4: -----------------------------------------------------
// Connect to WMI through the IWbemLocator::ConnectServer method
IWbemServices *pSvc = NULL;
// Connect to the root\cimv2 namespace with
// the current user and obtain pointer pSvc
// to make IWbemServices calls.
hres = pLoc->ConnectServer(
_bstr_t(L"ROOT\\CIMV2"), // Object path of WMI namespace
NULL, // User name. NULL = current user
NULL, // User password. NULL = current
0, // Locale. NULL indicates current
NULL, // Security flags.
0, // Authority (e.g. Kerberos)
0, // Context object
&pSvc // pointer to IWbemServices proxy
);
if (FAILED(hres)) {
cout << "Could not connect. Error code = 0x" << hex << hres << endl;
pLoc->Release();
CoUninitialize();
return 0; // Program has failed.
}
cout << "Connected to ROOT\\CIMV2 WMI namespace" << endl;
// Step 5: --------------------------------------------------
// Set security levels on the proxy -------------------------
hres = CoSetProxyBlanket(
pSvc, // Indicates the proxy to set
RPC_C_AUTHN_WINNT, // RPC_C_AUTHN_xxx
RPC_C_AUTHZ_NONE, // RPC_C_AUTHZ_xxx
NULL, // Server principal name
RPC_C_AUTHN_LEVEL_CALL, // RPC_C_AUTHN_LEVEL_xxx
RPC_C_IMP_LEVEL_IMPERSONATE, // RPC_C_IMP_LEVEL_xxx
NULL, // client identity
EOAC_NONE // proxy capabilities
);
if (FAILED(hres)) {
cout << "Could not set proxy blanket. Error code = 0x"
<< hex << hres << endl;
pSvc->Release();
pLoc->Release();
CoUninitialize();
return 0; // Program has failed.
}
// Step 6: --------------------------------------------------
// Use the IWbemServices pointer to make requests of WMI ----
// For example, get the name of the operating system
IEnumWbemClassObject* pEnumerator = NULL;
IWbemClassObject *pclsObj;
int i;
while (1) {
i = 1;
hres = pSvc->ExecQuery(
bstr_t("WQL"),
bstr_t("SELECT * FROM Win32_PerfFormattedData_PerfOS_Processor"),
WBEM_FLAG_FORWARD_ONLY | WBEM_FLAG_RETURN_IMMEDIATELY,
NULL,
&pEnumerator);
if (FAILED(hres)) {
cout << "Query for operating system name failed."
<< " Error code = 0x"
<< hex << hres << endl;
pSvc->Release();
pLoc->Release();
CoUninitialize();
return 0; // Program has failed.
}
// Step 7: -------------------------------------------------
// Get the data from the query in step 6 -------------------
ULONG uReturn = 0;
while (pEnumerator) {
HRESULT hr = pEnumerator->Next(WBEM_INFINITE, 1,
&pclsObj, &uReturn);
if (0 == uReturn) {
break;
}
VARIANT vtProp;
// Get the value of the Name property
//hr = pclsObj->Get(L"Name", 0, &vtProp, 0, 0);
hr = pclsObj->Get(L"PercentProcessorTime", 0, &vtProp, 0, 0);
wcout << " CPU Usage of CPU " << i << " : " << vtProp.bstrVal << endl;
VariantClear(&vtProp);
//IMPORTANT!!
pclsObj->Release();
i++;
}
}
// Cleanup
// ========
pSvc->Release();
pLoc->Release();
pEnumerator->Release();
pclsObj->Release();
CoUninitialize();
return 0; // Program successfully completed.
}
是否有其他（可能更简单）的方法来获得每个核心的CPU负载％？ 或者我是在正确的轨道上，但我的代码有问题？ 如果是这样有什么问题呢？ ：P
答案 0 :(得分：1)
C ++作为一种语言不提供确定此功能的功能。编译器只生成正在执行要求的代码。
其他方面。您的方案广泛使用操作系统的功能，涉及在不同进程和内核中进行处理。您很可能想知道所有活动的总和，而不仅仅是您的特定流程消耗了多少CPU周期。
然而，您可以进行间接测量。我建议你同时在几个线程上运行你的场景（并在每个线程上重复多次）并测量每个线程消耗的天文时间。如果您将监视任务管理器中的CPU /内存/ IO消耗并将此信息与线程所花费的平均时间进行比较，则可以估计您的方案实际上“花费”了什么。
还有一个方面。您的结果只是一个估计值，取决于您的Windows框的实际配置（域的成员与否）等。CoInitializeSecurity取决于各种安全设置和调用它的帐户类型。框中和域中有大量选项如何配置安全性。但是，即使不是非常可靠的估计总比没有好。
答案 1 :(得分：1)
最后一个数字是_Total的值，这就是为什么你看到9个内核而不是8个内核，你可以根据内核数量显示结果。要检索核心数，请使用以下命令：
SYSTEM_INFO systemInfo;
GetSystemInfo( &systemInfo );
numberofCPU = systemInfo.dwNumberOfProcessors;