Retrieving CPU Load Percent total in Windows with C++

Question

I\'ve been working on this tool to quickly log some system stats, like memory info, and cpu load percentage (like what\'s shown in the Task Manager). I seem

Answer 1

This code is take for Cpu Usage

FILETIME prevSysIdle, prevSysKernel, prevSysUser;

int getUsage(double &val)
{
    FILETIME sysIdle, sysKernel, sysUser;
    // sysKernel include IdleTime
    if (GetSystemTimes(&sysIdle, &sysKernel, &sysUser) == 0) // GetSystemTimes func FAILED return value is zero;
        return 0;

    if (prevSysIdle.dwLowDateTime != 0 && prevSysIdle.dwHighDateTime != 0)
    {
        ULONGLONG sysIdleDiff, sysKernelDiff, sysUserDiff;
        sysIdleDiff = SubtractTimes(sysIdle, prevSysIdle);
        sysKernelDiff = SubtractTimes(sysKernel, prevSysKernel);
        sysUserDiff = SubtractTimes(sysUser, prevSysUser);

        ULONGLONG sysTotal = sysKernelDiff + sysUserDiff;
        ULONGLONG kernelTotal = sysKernelDiff - sysIdleDiff; // kernelTime - IdleTime = kernelTime, because sysKernel include IdleTime

        if (sysTotal > 0) // sometimes kernelTime > idleTime
            val = (double)(((kernelTotal + sysUserDiff) * 100.0) / sysTotal);
    }

    prevSysIdle = sysIdle;
    prevSysKernel = sysKernel;
    prevSysUser = sysUser;

    return 1;
}


// TIME DIFF FUNC
ULONGLONG SubtractTimes(const FILETIME one, const FILETIME two)
{
    LARGE_INTEGER a, b;
    a.LowPart = one.dwLowDateTime;
    a.HighPart = one.dwHighDateTime;

    b.LowPart = two.dwLowDateTime;
    b.HighPart = two.dwHighDateTime;

    return a.QuadPart - b.QuadPart;
}