[c++] 获取物理内存和可用虚拟内存、内存使用率、cpu使用率

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获取内存

MEMORYSTATUSEX 函数原型：

typedef struct _MEMORYSTATUSEX {
    DWORD dwLength;
    DWORD dwMemoryLoad;
    DWORDLONG ullTotalPhys;
    DWORDLONG ullAvailPhys;
    DWORDLONG ullTotalPageFile;
    DWORDLONG ullAvailPageFile;
    DWORDLONG ullTotalVirtual;
    DWORDLONG ullAvailVirtual;
    DWORDLONG ullAvailExtendedVirtual;
} MEMORYSTATUSEX, *LPMEMORYSTATUSEX;

	MEMORYSTATUSEX statex;
	statex.dwLength = sizeof(statex);
	GlobalMemoryStatusEx(&statex);

	DWORDLONG physical_memory = statex.ullTotalPhys / (1024 * 1024);
	DWORDLONG virtual_memory = (DWORD)statex.ullAvailVirtual / (1024 * 1024);
	DWORDLONG usePhys = physical_memory - (statex.ullAvailPhys / (1024 * 1024));

	float percent_memory = (float)usePhys / (float)physical_memory;
	cout << "内存使用率: ";
	printf("%.2f", percent_memory * 100);
	cout << "%" << endl;
	cout << "物理内存: " << physical_memory << " MB" << endl;
	cout<<"虚拟内存: " << virtual_memory << " MB" << endl;

计算cpu：

__int64 CompareFileTime(FILETIME time1, FILETIME time2)		//filetime到const filetime的转换函数
{
    __int64 a = time1.dwHighDateTime << 32 | time1.dwLowDateTime;
    __int64 b = time2.dwHighDateTime << 32 | time2.dwLowDateTime;

    return   (b - a);
}
int main()
{
    double cpu;
    double idle, kernel, user;
    FILETIME idleTime1, idleTime2;
    FILETIME kernelTime1, kernelTime2;
    FILETIME userTime1, userTime2;
    GetSystemTimes(&idleTime1, &kernelTime1, &userTime1);
    Sleep(50);
    GetSystemTimes(&idleTime2, &kernelTime2, &userTime2);
    idle = (double)CompareFileTime(idleTime1, idleTime2);
    kernel = (double)CompareFileTime(kernelTime1, kernelTime2);
    user = (double)CompareFileTime(userTime1, userTime2);
    if (kernel + user == 0)
    {
    	cpu = 0.0;
    }
    else
    {
    	cpu = (double)((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		
    }
    cout << "cpu使用率：";
    printf("%.2f", cpu);
    cout << "%" << endl;
    
    return 0;
}