使用 C++ 在 Windows 中检索 CPU 总负载百分比

I'm showing a Unit Test for Jeremy Friesner's code, as well as the completed logging tool that I was working on.

测试以监控 CPU 负载

#include <Windows.h>
#include <iostream>
using namespace std;

static float CalculateCPULoad();
static unsigned long long FileTimeToInt64();
float GetCPULoad();


int main()
{   
    int _c = 0;

    while (_c == 0)
    {
        cout << GetCPULoad() * 100 << "
";
        Sleep(1000);
    }

    return 0;
}


static float CalculateCPULoad(unsigned long long idleTicks, unsigned long long totalTicks)
{
    static unsigned long long _previousTotalTicks = 0;
    static unsigned long long _previousIdleTicks = 0;

    unsigned long long totalTicksSinceLastTime = totalTicks - _previousTotalTicks;
    unsigned long long idleTicksSinceLastTime = idleTicks - _previousIdleTicks;


    float ret = 1.0f - ((totalTicksSinceLastTime > 0) ? ((float)idleTicksSinceLastTime) / totalTicksSinceLastTime : 0);

    _previousTotalTicks = totalTicks;
    _previousIdleTicks = idleTicks;
    return ret;
}

static unsigned long long FileTimeToInt64(const FILETIME & ft)
{
    return (((unsigned long long)(ft.dwHighDateTime)) << 32) | ((unsigned long long)ft.dwLowDateTime);
}

// Returns 1.0f for "CPU fully pinned", 0.0f for "CPU idle", or somewhere in between
// You'll need to call this at regular intervals, since it measures the load between
// the previous call and the current one.  Returns -1.0 on error.
float GetCPULoad()
{
    FILETIME idleTime, kernelTime, userTime;
    return GetSystemTimes(&idleTime, &kernelTime, &userTime) ? CalculateCPULoad(FileTimeToInt64(idleTime), FileTimeToInt64(kernelTime) + FileTimeToInt64(userTime)) : -1.0f;
}

完成的工具(都进入你的Source.cpp，然后编译运行):

/*
Resource Links:
Calling memory info in c++:                             http://msdn.microsoft.com/en-us/library/aa366589%28VS.85%29.aspx
I/O file handling in c++:                               http://www.cplusplus.com/doc/tutorial/files/
Date and Time in c++:                                   http://www.tutorialspoint.com/cplusplus/cpp_date_time.htm
CPU Load Percent (Credit to Jeremy Friesner):           https://stackoverflow.com/questions/23143693/retrieving-cpu-load-percent-total-in-windows-with-c
Everything else (too many to list):                     https://stackoverflow.com/
*/


/*
Performance Snapshot Tool

Grabs CPU load percent and basic Memory info from the system,
and or the Windows Task manager

Designed to work with specifically Windows 7 and beyond

Ideology: Create a small executable program to retrieve and
write to a log file a data sample from system performance
in a single snapshot -- robust enough to be called multiple
times per boot

The compiled .exe will be called by another program to run at
an exact, specified time relative to the program that is
calling it

Does 5 checks per second, every 200 milliseconds for a "Snapshot"
of performance

Initial Code Author:    Anonymous
Current Author: Anonymous
Revision:           0.01
Date:               18/4/2014
*/


//included libraries/functionality for input/output
#include <iostream>
#include <fstream>
#include <windows.h>
using namespace std;

//creates a static variable to convert Bytes to Megabytes
#define MB 1048576

//functions to calculate and retrieve CPU Load information
static float CalculateCPULoad();
static unsigned long long FileTimeToInt64();
float GetCPULoad();


//main program code loop
int main()
{
    //Code block initialization for the memory referenced in the Kernel
    MEMORYSTATUSEX memStat;
    memStat.dwLength = sizeof (memStat);
    GlobalMemoryStatusEx(&memStat);


    //loads the SYSTEMTIME
    SYSTEMTIME sysTime;
    //Retrieves data so that we have a way to Get it to output when using the pointers
    GetSystemTime(&sysTime);


    //setting the I/O for our log file to be "myfile"
    ofstream myfile;
    // ios::out means that we're outputting data to the file
    // ios::app means that all the data we're outputting goes to the end of that log file instead of the start
    myfile.open("log.csv", ios::out | ios::app);


    //a while loop that gathers and logs data every quarter of a second to gather 4 data points in one second
    int counter = 0;
    while (counter < 5)
    {
        //Timestamp + Memory Info, and eventually CPU Load percentage
        myfile << sysTime.wHour << "." << sysTime.wMinute << "." << sysTime.wSecond << ", " << GetCPULoad() * 100 << "%, " << memStat.dwMemoryLoad << "%, " << memStat.ullTotalPhys / MB << ", " << memStat.ullAvailPhys / MB << ", " << memStat.ullTotalPageFile / MB << ", " << memStat.ullAvailPageFile / MB << ", " << memStat.ullTotalVirtual / MB << ", " << memStat.ullAvailVirtual / MB << ", " << memStat.ullAvailExtendedVirtual / MB << "
";
        //250 millisecond sleep delay 
        Sleep(200);
        counter = counter + 1;
    }
        //close the log file before terminating the program
        myfile.close();

    return 0; //standard main() end of program terminator
}

static float CalculateCPULoad(unsigned long long idleTicks, unsigned long long totalTicks)
{
    static unsigned long long _previousTotalTicks = 0;
    static unsigned long long _previousIdleTicks = 0;

    unsigned long long totalTicksSinceLastTime = totalTicks - _previousTotalTicks;
    unsigned long long idleTicksSinceLastTime = idleTicks - _previousIdleTicks;


    float ret = 1.0f - ((totalTicksSinceLastTime > 0) ? ((float)idleTicksSinceLastTime) / totalTicksSinceLastTime : 0);

    _previousTotalTicks = totalTicks;
    _previousIdleTicks = idleTicks;
    return ret;
}

static unsigned long long FileTimeToInt64(const FILETIME & ft)
{
    return (((unsigned long long)(ft.dwHighDateTime)) << 32) | ((unsigned long long)ft.dwLowDateTime);
}

// Returns 1.0f for "CPU fully pinned", 0.0f for "CPU idle", or somewhere in between
// You'll need to call this at regular intervals, since it measures the load between
// the previous call and the current one.  Returns -1.0 on error.
float GetCPULoad()
{
    FILETIME idleTime, kernelTime, userTime;
    return GetSystemTimes(&idleTime, &kernelTime, &userTime) ? CalculateCPULoad(FileTimeToInt64(idleTime), FileTimeToInt64(kernelTime) + FileTimeToInt64(userTime)) : -1.0f;
}

推荐答案

计算负载百分比随时间推移而流行的原因是因为 CPU 并没有真正的可变速度――在任何给定时刻，CPU 内核要么是以额定时钟速率处理指令，或者它处于空闲状态，因此即时测量只会给您 0% 或 100% (*)，这并不是您真正想要的.因此，为了计算有意义的负载百分比，您必须检查 CPU 在特定时间间隔内空闲的时间百分比.

#include <Windows.h>

static float CalculateCPULoad(unsigned long long idleTicks, unsigned long long totalTicks)
{
   static unsigned long long _previousTotalTicks = 0;
   static unsigned long long _previousIdleTicks = 0;

   unsigned long long totalTicksSinceLastTime = totalTicks-_previousTotalTicks;
   unsigned long long idleTicksSinceLastTime  = idleTicks-_previousIdleTicks;

   float ret = 1.0f-((totalTicksSinceLastTime > 0) ? ((float)idleTicksSinceLastTime)/totalTicksSinceLastTime : 0);

   _previousTotalTicks = totalTicks;
   _previousIdleTicks  = idleTicks;
   return ret;
}

static unsigned long long FileTimeToInt64(const FILETIME & ft) {return (((unsigned long long)(ft.dwHighDateTime))<<32)|((unsigned long long)ft.dwLowDateTime);}

// Returns 1.0f for "CPU fully pinned", 0.0f for "CPU idle", or somewhere in between
// You'll need to call this at regular intervals, since it measures the load between
// the previous call and the current one.  Returns -1.0 on error.
float GetCPULoad()
{
   FILETIME idleTime, kernelTime, userTime;
   return GetSystemTimes(&idleTime, &kernelTime, &userTime) ? CalculateCPULoad(FileTimeToInt64(idleTime), FileTimeToInt64(kernelTime)+FileTimeToInt64(userTime)) : -1.0f;
}