Find number of Physical CPU Sockets in server machine

Question

I have a system with 4 Physical Processor sockets. Running Windows 2003, I would like to programmatically find the number of sockets using C++. Is this possible and if so, how?

Answer 1

For Windows 7 and 2008 server there is the GetActiveProcessorGroupCount function. But you have 2003 server, so it's not an option.

In C++ this requires to write WMI consumer code, which is a clumsy and boring (D)COM stuff.

One nice solution would be to run systeminfo command and parse the output, but be careful as the output's column header is localized to system's locale.

EDIT

Just found a much nicer solution, which makes use of the command-line interface to WMI.

Run the following command and parse output, there is one line per socket

> wmic.exe cpu get
AddressWidth  Architecture  Availability  Caption                               ConfigManagerErrorCode  ConfigManagerUserConfig  CpuStatus  CreationClassName  CurrentClockSpeed  CurrentVoltage  DataWidth  Description                           DeviceID  ErrorCleared  ErrorDescription  ExtClock  Family  InstallDate  L2CacheSize  L2CacheSpeed  L3CacheSize  L3CacheSpeed  LastErrorCode  Level  LoadPercentage  Manufacturer  MaxClockSpeed  Name                                             NumberOfCores  NumberOfLogicalProcessors  OtherFamilyDescription  PNPDeviceID  PowerManagementCapabilities  PowerManagementSupported  ProcessorId       ProcessorType  Revision  Role  SocketDesignation  Status  StatusInfo  Stepping  SystemCreationClassName  SystemName       UniqueId  UpgradeMethod  Version  VoltageCaps  
64            9             3             Intel64 Family 6 Model 23 Stepping 6                                                   1          Win32_Processor    2532               33              64         Intel64 Family 6 Model 23 Stepping 6  CPU0                                      421       2                                               0            0                            6      1               GenuineIntel  2532           Intel(R) Core(TM)2 Duo CPU     T9400  @ 2.53GHz  2              2                                                                                            FALSE                     BFEBFBFF00010676  3              5894      CPU   CPU Socket #0      OK      3                     Win32_ComputerSystem     CHBROSSO-WIN7VM            1                       2            

Running an exe and parsing output in C++ should the easy part. You can also use POCO library or Boost.Process to have cleaner code.

(this is untested code)

//get wmic program output 
FILE* pipe = _popen("wmic.exe cpu get", "r");
if (!pipe) throw std::exception("error");
char buffer[128];
std::string output;
while(!feof(pipe)) {
  if(fgets(buffer, 128, pipe) != NULL)
      output += buffer;
}
_pclose(pipe);

//split lines to a vector<string>
std::stringstream oss(output);
std::vector<std::string> processor_description; std::string buffer;
while (std::getline(oss, buffer))
  processor_description.push_back(buffer);
//processor_description has n+1 elements, n being nb of sockets, +1 is the header of columns

Answer 2

you will find the number of sockets using C++. https://msdn.microsoft.com/en-us/library/windows/desktop/ms683194(v=vs.85).aspx

#include <windows.h>
#include <malloc.h>    
#include <stdio.h>
#include <tchar.h>

typedef BOOL (WINAPI *LPFN_GLPI)(
    PSYSTEM_LOGICAL_PROCESSOR_INFORMATION, 
    PDWORD);


// Helper function to count set bits in the processor mask.
DWORD CountSetBits(ULONG_PTR bitMask)
{
    DWORD LSHIFT = sizeof(ULONG_PTR)*8 - 1;
    DWORD bitSetCount = 0;
    ULONG_PTR bitTest = (ULONG_PTR)1 << LSHIFT;    
    DWORD i;

    for (i = 0; i <= LSHIFT; ++i)
    {
        bitSetCount += ((bitMask & bitTest)?1:0);
        bitTest/=2;
    }

    return bitSetCount;
}

int _cdecl _tmain ()
{
    LPFN_GLPI glpi;
    BOOL done = FALSE;
    PSYSTEM_LOGICAL_PROCESSOR_INFORMATION buffer = NULL;
    PSYSTEM_LOGICAL_PROCESSOR_INFORMATION ptr = NULL;
    DWORD returnLength = 0;
    DWORD logicalProcessorCount = 0;
    DWORD numaNodeCount = 0;
    DWORD processorCoreCount = 0;
    DWORD processorL1CacheCount = 0;
    DWORD processorL2CacheCount = 0;
    DWORD processorL3CacheCount = 0;
    DWORD processorPackageCount = 0;
    DWORD byteOffset = 0;
    PCACHE_DESCRIPTOR Cache;

    glpi = (LPFN_GLPI) GetProcAddress(
                            GetModuleHandle(TEXT("kernel32")),
                            "GetLogicalProcessorInformation");
    if (NULL == glpi) 
    {
        _tprintf(TEXT("\nGetLogicalProcessorInformation is not supported.\n"));
        return (1);
    }

    while (!done)
    {
        DWORD rc = glpi(buffer, &returnLength);

        if (FALSE == rc) 
        {
            if (GetLastError() == ERROR_INSUFFICIENT_BUFFER) 
            {
                if (buffer) 
                    free(buffer);

                buffer = (PSYSTEM_LOGICAL_PROCESSOR_INFORMATION)malloc(
                        returnLength);

                if (NULL == buffer) 
                {
                    _tprintf(TEXT("\nError: Allocation failure\n"));
                    return (2);
                }
            } 
            else 
            {
                _tprintf(TEXT("\nError %d\n"), GetLastError());
                return (3);
            }
        } 
        else
        {
            done = TRUE;
        }
    }

    ptr = buffer;

    while (byteOffset + sizeof(SYSTEM_LOGICAL_PROCESSOR_INFORMATION) <= returnLength) 
    {
        switch (ptr->Relationship) 
        {
        case RelationNumaNode:
            // Non-NUMA systems report a single record of this type.
            numaNodeCount++;
            break;

        case RelationProcessorCore:
            processorCoreCount++;

            // A hyperthreaded core supplies more than one logical processor.
            logicalProcessorCount += CountSetBits(ptr->ProcessorMask);
            break;

        case RelationCache:
            // Cache data is in ptr->Cache, one CACHE_DESCRIPTOR structure for each cache. 
            Cache = &ptr->Cache;
            if (Cache->Level == 1)
            {
                processorL1CacheCount++;
            }
            else if (Cache->Level == 2)
            {
                processorL2CacheCount++;
            }
            else if (Cache->Level == 3)
            {
                processorL3CacheCount++;
            }
            break;

        case RelationProcessorPackage:
            // Logical processors share a physical package.
            processorPackageCount++;
            break;

        default:
            _tprintf(TEXT("\nError: Unsupported LOGICAL_PROCESSOR_RELATIONSHIP value.\n"));
            break;
        }
        byteOffset += sizeof(SYSTEM_LOGICAL_PROCESSOR_INFORMATION);
        ptr++;
    }

    _tprintf(TEXT("\nGetLogicalProcessorInformation results:\n"));
    _tprintf(TEXT("Number of NUMA nodes: %d\n"), 
            numaNodeCount);
    _tprintf(TEXT("Number of physical processor sockets: %d\n"), 
            processorPackageCount);
    _tprintf(TEXT("Number of processor cores: %d\n"), 
            processorCoreCount);
    _tprintf(TEXT("Number of logical processors: %d\n"), 
            logicalProcessorCount);
    _tprintf(TEXT("Number of processor L1/L2/L3 caches: %d/%d/%d\n"), 
            processorL1CacheCount,
            processorL2CacheCount,
            processorL3CacheCount);

    free(buffer);

    return 0;
}