C++ – How to get Windows data like CPU usage, etc.

bandwidthcwindows

How can I get Windows data like CPU usage, physical memory, and network utilization and bandwidth, similar to what I see in Task Manager? I'm using C++.

Best Answer

You can get CPU usage using the performance data. If you want data for only one (or a few processes) it may be simpler to call GetProcessTimes every few seconds.

It's generally difficult to pin down exactly what physical memory usage even means. Until you do, trying to describe how to measure it is pretty pointless.

You can get some information about network utilization with GetIpStatistics.

You can get the rated bandwidths of the installed network adapters with GetIfTable.

New answer, powershell

TCP

Get-Process -Id (Get-NetTCPConnection -LocalPort YourPortNumberHere).OwningProcess

UDP

Get-Process -Id (Get-NetUDPEndpoint -LocalPort YourPortNumberHere).OwningProcess

Old answer, cmd

 C:\> netstat -a -b

(Add -n to stop it trying to resolve hostnames, which will make it a lot faster.)

Note Dane's recommendation for TCPView. It looks very useful!

-a Displays all connections and listening ports.

-b Displays the executable involved in creating each connection or listening port. In some cases well-known executables host multiple independent components, and in these cases the sequence of components involved in creating the connection or listening port is displayed. In this case the executable name is in [] at the bottom, on top is the component it called, and so forth until TCP/IP was reached. Note that this option can be time-consuming and will fail unless you have sufficient permissions.

-n Displays addresses and port numbers in numerical form.

-o Displays the owning process ID associated with each connection.

C++ – How to determine CPU and memory consumption from inside a process

Windows

Some of the above values are easily available from the appropriate Win32 API, I just list them here for completeness. Others, however, need to be obtained from the Performance Data Helper library (PDH), which is a bit "unintuitive" and takes a lot of painful trial and error to get to work. (At least it took me quite a while, perhaps I've been only a bit stupid...)

Note: for clarity all error checking has been omitted from the following code. Do check the return codes...!

Total Virtual Memory:
```
#include "windows.h"

MEMORYSTATUSEX memInfo;
memInfo.dwLength = sizeof(MEMORYSTATUSEX);
GlobalMemoryStatusEx(&memInfo);
DWORDLONG totalVirtualMem = memInfo.ullTotalPageFile;
```
Note: The name "TotalPageFile" is a bit misleading here. In reality this parameter gives the "Virtual Memory Size", which is size of swap file plus installed RAM.

Virtual Memory currently used:

Same code as in "Total Virtual Memory" and then

 DWORDLONG virtualMemUsed = memInfo.ullTotalPageFile - memInfo.ullAvailPageFile;

Virtual Memory currently used by current process:

#include "windows.h"
#include "psapi.h"

PROCESS_MEMORY_COUNTERS_EX pmc;
GetProcessMemoryInfo(GetCurrentProcess(), (PROCESS_MEMORY_COUNTERS*)&pmc, sizeof(pmc));
SIZE_T virtualMemUsedByMe = pmc.PrivateUsage;

Total Physical Memory (RAM):

Same code as in "Total Virtual Memory" and then
```
DWORDLONG totalPhysMem = memInfo.ullTotalPhys;
```
Physical Memory currently used:

Same code as in "Total Virtual Memory" and then
```
DWORDLONG physMemUsed = memInfo.ullTotalPhys - memInfo.ullAvailPhys;
```
Physical Memory currently used by current process:

Same code as in "Virtual Memory currently used by current process" and then
```
SIZE_T physMemUsedByMe = pmc.WorkingSetSize;
```

CPU currently used:

#include "TCHAR.h"
#include "pdh.h"

static PDH_HQUERY cpuQuery;
static PDH_HCOUNTER cpuTotal;

void init(){
    PdhOpenQuery(NULL, NULL, &cpuQuery);
    // You can also use L"\\Processor(*)\\% Processor Time" and get individual CPU values with PdhGetFormattedCounterArray()
    PdhAddEnglishCounter(cpuQuery, L"\\Processor(_Total)\\% Processor Time", NULL, &cpuTotal);
    PdhCollectQueryData(cpuQuery);
}

double getCurrentValue(){
    PDH_FMT_COUNTERVALUE counterVal;

    PdhCollectQueryData(cpuQuery);
    PdhGetFormattedCounterValue(cpuTotal, PDH_FMT_DOUBLE, NULL, &counterVal);
    return counterVal.doubleValue;
}

CPU currently used by current process:

#include "windows.h"

static ULARGE_INTEGER lastCPU, lastSysCPU, lastUserCPU;
static int numProcessors;
static HANDLE self;

void init(){
    SYSTEM_INFO sysInfo;
    FILETIME ftime, fsys, fuser;

    GetSystemInfo(&sysInfo);
    numProcessors = sysInfo.dwNumberOfProcessors;

    GetSystemTimeAsFileTime(&ftime);
    memcpy(&lastCPU, &ftime, sizeof(FILETIME));

    self = GetCurrentProcess();
    GetProcessTimes(self, &ftime, &ftime, &fsys, &fuser);
    memcpy(&lastSysCPU, &fsys, sizeof(FILETIME));
    memcpy(&lastUserCPU, &fuser, sizeof(FILETIME));
}

double getCurrentValue(){
    FILETIME ftime, fsys, fuser;
    ULARGE_INTEGER now, sys, user;
    double percent;

    GetSystemTimeAsFileTime(&ftime);
    memcpy(&now, &ftime, sizeof(FILETIME));

    GetProcessTimes(self, &ftime, &ftime, &fsys, &fuser);
    memcpy(&sys, &fsys, sizeof(FILETIME));
    memcpy(&user, &fuser, sizeof(FILETIME));
    percent = (sys.QuadPart - lastSysCPU.QuadPart) +
        (user.QuadPart - lastUserCPU.QuadPart);
    percent /= (now.QuadPart - lastCPU.QuadPart);
    percent /= numProcessors;
    lastCPU = now;
    lastUserCPU = user;
    lastSysCPU = sys;

    return percent * 100;
}

Linux

On Linux the choice that seemed obvious at first was to use the POSIX APIs like getrusage() etc. I spent some time trying to get this to work, but never got meaningful values. When I finally checked the kernel sources themselves, I found out that apparently these APIs are not yet completely implemented as of Linux kernel 2.6!?

In the end I got all values via a combination of reading the pseudo-filesystem /proc and kernel calls.

Total Virtual Memory:

#include "sys/types.h"
#include "sys/sysinfo.h"

struct sysinfo memInfo;

sysinfo (&memInfo);
long long totalVirtualMem = memInfo.totalram;
//Add other values in next statement to avoid int overflow on right hand side...
totalVirtualMem += memInfo.totalswap;
totalVirtualMem *= memInfo.mem_unit;

Virtual Memory currently used:

Same code as in "Total Virtual Memory" and then

long long virtualMemUsed = memInfo.totalram - memInfo.freeram;
//Add other values in next statement to avoid int overflow on right hand side...
virtualMemUsed += memInfo.totalswap - memInfo.freeswap;
virtualMemUsed *= memInfo.mem_unit;

Virtual Memory currently used by current process:

#include "stdlib.h"
#include "stdio.h"
#include "string.h"

int parseLine(char* line){
    // This assumes that a digit will be found and the line ends in " Kb".
    int i = strlen(line);
    const char* p = line;
    while (*p <'0' || *p > '9') p++;
    line[i-3] = '\0';
    i = atoi(p);
    return i;
}

int getValue(){ //Note: this value is in KB!
    FILE* file = fopen("/proc/self/status", "r");
    int result = -1;
    char line[128];

    while (fgets(line, 128, file) != NULL){
        if (strncmp(line, "VmSize:", 7) == 0){
            result = parseLine(line);
            break;
        }
    }
    fclose(file);
    return result;
}

Total Physical Memory (RAM):

Same code as in "Total Virtual Memory" and then

long long totalPhysMem = memInfo.totalram;
//Multiply in next statement to avoid int overflow on right hand side...
totalPhysMem *= memInfo.mem_unit;

Physical Memory currently used:

Same code as in "Total Virtual Memory" and then

long long physMemUsed = memInfo.totalram - memInfo.freeram;
//Multiply in next statement to avoid int overflow on right hand side...
physMemUsed *= memInfo.mem_unit;

Physical Memory currently used by current process:

Change getValue() in "Virtual Memory currently used by current process" as follows:

int getValue(){ //Note: this value is in KB!
    FILE* file = fopen("/proc/self/status", "r");
    int result = -1;
    char line[128];

    while (fgets(line, 128, file) != NULL){
        if (strncmp(line, "VmRSS:", 6) == 0){
            result = parseLine(line);
            break;
        }
    }
    fclose(file);
    return result;
}

CPU currently used:

#include "stdlib.h"
#include "stdio.h"
#include "string.h"

static unsigned long long lastTotalUser, lastTotalUserLow, lastTotalSys, lastTotalIdle;

void init(){
    FILE* file = fopen("/proc/stat", "r");
    fscanf(file, "cpu %llu %llu %llu %llu", &lastTotalUser, &lastTotalUserLow,
        &lastTotalSys, &lastTotalIdle);
    fclose(file);
}

double getCurrentValue(){
    double percent;
    FILE* file;
    unsigned long long totalUser, totalUserLow, totalSys, totalIdle, total;

    file = fopen("/proc/stat", "r");
    fscanf(file, "cpu %llu %llu %llu %llu", &totalUser, &totalUserLow,
        &totalSys, &totalIdle);
    fclose(file);

    if (totalUser < lastTotalUser || totalUserLow < lastTotalUserLow ||
        totalSys < lastTotalSys || totalIdle < lastTotalIdle){
        //Overflow detection. Just skip this value.
        percent = -1.0;
    }
    else{
        total = (totalUser - lastTotalUser) + (totalUserLow - lastTotalUserLow) +
            (totalSys - lastTotalSys);
        percent = total;
        total += (totalIdle - lastTotalIdle);
        percent /= total;
        percent *= 100;
    }

    lastTotalUser = totalUser;
    lastTotalUserLow = totalUserLow;
    lastTotalSys = totalSys;
    lastTotalIdle = totalIdle;

    return percent;
}

CPU currently used by current process:

#include "stdlib.h"
#include "stdio.h"
#include "string.h"
#include "sys/times.h"
#include "sys/vtimes.h"

static clock_t lastCPU, lastSysCPU, lastUserCPU;
static int numProcessors;

void init(){
    FILE* file;
    struct tms timeSample;
    char line[128];

    lastCPU = times(&timeSample);
    lastSysCPU = timeSample.tms_stime;
    lastUserCPU = timeSample.tms_utime;

    file = fopen("/proc/cpuinfo", "r");
    numProcessors = 0;
    while(fgets(line, 128, file) != NULL){
        if (strncmp(line, "processor", 9) == 0) numProcessors++;
    }
    fclose(file);
}

double getCurrentValue(){
    struct tms timeSample;
    clock_t now;
    double percent;

    now = times(&timeSample);
    if (now <= lastCPU || timeSample.tms_stime < lastSysCPU ||
        timeSample.tms_utime < lastUserCPU){
        //Overflow detection. Just skip this value.
        percent = -1.0;
    }
    else{
        percent = (timeSample.tms_stime - lastSysCPU) +
            (timeSample.tms_utime - lastUserCPU);
        percent /= (now - lastCPU);
        percent /= numProcessors;
        percent *= 100;
    }
    lastCPU = now;
    lastSysCPU = timeSample.tms_stime;
    lastUserCPU = timeSample.tms_utime;

    return percent;
}

TODO: Other Platforms

I would assume, that some of the Linux code also works for the Unixes, except for the parts that read the /proc pseudo-filesystem. Perhaps on Unix these parts can be replaced by getrusage() and similar functions?

Best Answer

Related Solutions

Windows – How to you find out which process is listening on a TCP or UDP port on Windows

New answer, powershell

TCP

UDP

Old answer, cmd

C++ – How to determine CPU and memory consumption from inside a process

Windows

Linux

TODO: Other Platforms

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