Question

64位电脑获取CPU使用率（使用c语言）

使用32位的电脑的CPU获取可以用:NtQuerySystemInformation(systemPerformanceInformation, &sysPerfInfo, sizeof(sysPerfInfo), NULL);但是64位的就不能使用这个获取了，求高手指点！

Answer 1

GlobalMemoryStatusEx
获得系统时间：
CopyBOOL WINAPI GetSystemTimes(
__out_opt LPFILETIME lpIdleTime, //空闲时间
__out_opt LPFILETIME lpKernelTime, //内核时间
__out_opt LPFILETIME lpUserTime //用户时间
);

#define _WIN32_WINNT 0x0501
#include <Windows.h>
#include <iostream>
using namespace std;

__int64 CompareFileTime ( FILETIME time1, FILETIME time2 )
{
__int64 a = time1.dwHighDateTime << 32 | time1.dwLowDateTime ;
__int64 b = time2.dwHighDateTime << 32 | time2.dwLowDateTime ;

return (b - a);
}
void main()
{
HANDLE hEvent;
BOOL res ;

FILETIME preidleTime;
FILETIME prekernelTime;
FILETIME preuserTime;

FILETIME idleTime;
FILETIME kernelTime;
FILETIME userTime;

res = GetSystemTimes( &idleTime, &kernelTime, &userTime );

preidleTime = idleTime;
prekernelTime = kernelTime;
preuserTime = userTime ;

hEvent = CreateEvent (NULL,FALSE,FALSE,NULL); // 初始值为 nonsignaled ，并且每次触发后自动设置为nonsignaled

while (1){
WaitForSingleObject( hEvent,1000 ); //等待500毫秒
res = GetSystemTimes( &idleTime, &kernelTime, &userTime );

int idle = CompareFileTime( preidleTime,idleTime);
int kernel = CompareFileTime( prekernelTime, kernelTime);
int user = CompareFileTime(preuserTime, userTime);

int cpu = (kernel +user - idle) *100/(kernel+user);//（总的时间-空闲时间）/总的时间=占用cpu的时间就是使用率
int cpuidle = ( idle) *100/(kernel+user);
cout << "CPU利用率:" << cpu << "%" << " CPU空闲率:" <<cpuidle << "%" <<endl;

preidleTime = idleTime;
prekernelTime = kernelTime;
preuserTime = userTime ;
}
}