CODEWITHSUNDEEP
c++cpu-usageram
tunnuz
tunnuz

Reputation: 24018

How to get current CPU and RAM usage in C++?

is it possible, in C++, to get the current RAM and CPU usage? Is there a platform-indepentent function call?

Upvotes: 32

Views: 55611

Answers (9)

GoFaster
GoFaster

Reputation: 905

I notice that ACE is ported to vcpkg which would make it easy to compile & link a cross-platform C++ app.

In C++ I'd like to monitor available system CPU and memory resources, so that my app can flex its consumption in response to resource availability.

Is anyone please able to offer an ACE code snippet to get started on this?

Upvotes: 0

ididak
ididak

Reputation: 5868

There is an open source library that gives these (and more system info stuff) across many platforms: SIGAR API

I've used it in fairly large projects and it works fine (except for certain corner cases on OS X etc.)

Upvotes: 12

Bartosz Pachołek
Bartosz Pachołek

Reputation: 1318

If that is still the case please check:

http://sourceforge.net/projects/cpp-cpu-monitor/

It gives you an example how to get CPU and RAM usage of a Linux (tested on Debian and CentOS) and a quite simple instruction of how to install.

Please feel free to ask if you have any questions regarding this small project.

Upvotes: 0

Aaron McDaid
Aaron McDaid

Reputation: 27173

On Linux, this will use /proc/self/status . More work is required to turn this into a number. I find this useful as it is though, just to print the memory usage directly to the screen as a string.

static string memory_usage() {
        ostringstream mem;
        PP("hi");
        ifstream proc("/proc/self/status");
        string s;
        while(getline(proc, s), !proc.fail()) {
                if(s.substr(0, 6) == "VmSize") {
                        mem << s;
                        return mem.str();
                }
        }
        return mem.str();
}

Upvotes: 4

jheriko
jheriko

Reputation: 3113

There is not a platform independent function for this that I know of. IF you plan to target multiple versions of Windows be aware that the implementation differs across some versions. I hit this problem when testing an app under NT 3.51 for instance... (archaic, I know).

Here is some code I used for the memory side of things. This doesn't work across platforms other than windows, and will just return 0 when compiled without the WIN32 define:

EDIT: I forgot to mention, this code divides and rounds down to the nearest MB, hence the >> 20 all over the place.

// get memory info...
int getTotalRAM()
{
    int ret = 0;
#ifdef WIN32
    DWORD v = GetVersion();
    DWORD major =  (DWORD)(LOBYTE(LOWORD(v)));
    DWORD minor =  (DWORD)(HIBYTE(LOWORD(v)));
    DWORD build;
    if (v < 0x80000000) build = (DWORD)(HIWORD(v));
    else build = 0;

    // because compiler static links the function...
    BOOL (__stdcall*GMSEx)(LPMEMORYSTATUSEX) = 0;

    HINSTANCE hIL = LoadLibrary(L"kernel32.dll");
    GMSEx = (BOOL(__stdcall*)(LPMEMORYSTATUSEX))GetProcAddress(hIL, "GlobalMemoryStatusEx");

    if(GMSEx)
    {
        MEMORYSTATUSEX m;
        m.dwLength = sizeof(m);
        if(GMSEx(&m))
        {
            ret = (int)(m.ullTotalPhys>>20);
        }
    }
    else
    {
        MEMORYSTATUS m;
        m.dwLength = sizeof(m);
        GlobalMemoryStatus(&m);
        ret = (int)(m.dwTotalPhys>>20);
    }
#endif
    return ret;
}

int getAvailRAM()
{
    int ret = 0;
#ifdef WIN32
    DWORD v = GetVersion();
    DWORD major =  (DWORD)(LOBYTE(LOWORD(v)));
    DWORD minor =  (DWORD)(HIBYTE(LOWORD(v)));
    DWORD build;
    if (v < 0x80000000) build = (DWORD)(HIWORD(v));
    else build = 0;

    // because compiler static links the function...
    BOOL (__stdcall*GMSEx)(LPMEMORYSTATUSEX) = 0;

    HINSTANCE hIL = LoadLibrary(L"kernel32.dll");
    GMSEx = (BOOL(__stdcall*)(LPMEMORYSTATUSEX))GetProcAddress(hIL, "GlobalMemoryStatusEx");

    if(GMSEx)
    {
        MEMORYSTATUSEX m;
        m.dwLength = sizeof(m);
        if(GMSEx(&m))
        {
            ret = (int)(m.ullAvailPhys>>20);
        }
    }
    else
    {
        MEMORYSTATUS m;
        m.dwLength = sizeof(m);
        GlobalMemoryStatus(&m);
        ret = (int)(m.dwAvailPhys>>20);
    }
#endif
    return ret;
}

int getTotalMemory()
{
    int ret = 0;
#ifdef WIN32
    DWORD v = GetVersion();
    DWORD major =  (DWORD)(LOBYTE(LOWORD(v)));
    DWORD minor =  (DWORD)(HIBYTE(LOWORD(v)));
    DWORD build;
    if (v < 0x80000000) build = (DWORD)(HIWORD(v));
    else build = 0;

    // because compiler static links the function...
    BOOL (__stdcall*GMSEx)(LPMEMORYSTATUSEX) = 0;

    HINSTANCE hIL = LoadLibrary(L"kernel32.dll");
    GMSEx = (BOOL(__stdcall*)(LPMEMORYSTATUSEX))GetProcAddress(hIL, "GlobalMemoryStatusEx");

    if(GMSEx)
    {
        MEMORYSTATUSEX m;
        m.dwLength = sizeof(m);
        if(GMSEx(&m))
        {
            ret = (int)(m.ullTotalPhys>>20) + (int)(m.ullTotalVirtual>>20);
        }
    }
    else
    {
        MEMORYSTATUS m;
        m.dwLength = sizeof(m);
        GlobalMemoryStatus(&m);
        ret = (int)(m.dwTotalPhys>>20) + (int)(m.dwTotalVirtual>>20);
    }
#endif
    return ret;
}

int getAvailMemory()
{
    int ret = 0;
#ifdef WIN32
    DWORD v = GetVersion();
    DWORD major =  (DWORD)(LOBYTE(LOWORD(v)));
    DWORD minor =  (DWORD)(HIBYTE(LOWORD(v)));
    DWORD build;
    if (v < 0x80000000) build = (DWORD)(HIWORD(v));
    else build = 0;

    // because compiler static links the function...
    BOOL (__stdcall*GMSEx)(LPMEMORYSTATUSEX) = 0;

    HINSTANCE hIL = LoadLibrary(L"kernel32.dll");
    GMSEx = (BOOL(__stdcall*)(LPMEMORYSTATUSEX))GetProcAddress(hIL, "GlobalMemoryStatusEx");

    if(GMSEx)
    {
        MEMORYSTATUSEX m;
        m.dwLength = sizeof(m);
        if(GMSEx(&m))
        {
            ret = (int)(m.ullAvailPhys>>20) + (int)(m.ullAvailVirtual>>20);
        }
    }
    else
    {
        MEMORYSTATUS m;
        m.dwLength = sizeof(m);
        GlobalMemoryStatus(&m);
        ret = (int)(m.dwAvailPhys>>20) + (int)(m.dwAvailVirtual>>20);
    }
#endif
    return ret;
}

Upvotes: 11

Samrat Patil
Samrat Patil

Reputation: 798

There is no platform independent way to do this. Although for windows, you can get the CPU usage and performance metrics by using PDH.dll(Performance Data Helper) and its related APIs in your code.

Here's more on how to use it.

Upvotes: 1

Loki Astari
Loki Astari

Reputation: 264639

Not directly.

But you can use a library that abstracts the OS (such as ACE).
Though this might by a bit heavy if you just want CPU and Memory.

Upvotes: 0

Kosi2801
Kosi2801

Reputation: 23135

Sadly these things rely heavily on the underlying OS, so there are no platform-independent calls. (Maybe there are some wrapper frameworks, but I don't know of any.)

On Linux you could have a look at the getrusage() function call, on Windows you can use GetProcessMemoryInfo() for RAM Usage. Have also a look at the other functions in the Process Status API of Windows.

Upvotes: 30

HUAGHAGUAH
HUAGHAGUAH

Reputation: 1846

No, there isn't, not in the standard.

If you truly need this information, you will have to write platform-specific #ifdefs or link against a library that provides it.

Upvotes: 5

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