Énumération d’objets process

L’exemple suivant appelle la fonction PdhEnumObjectItems pour énumérer les instances et les compteurs des objets process sur l’ordinateur local.

Conseil

Windows 11 et versions ultérieures inclut l’ensemble de compteurs Process V2. L’ensemble de compteurs Process V2 résout plusieurs problèmes liés à l’ensemble de compteurs Process et doit être privilégié lors de la collecte d’informations sur les processus à partir d’ordinateurs exécutant Windows 11 ou version ultérieure.

// This program needs only the essential Windows header files.
#define WIN32_LEAN_AND_MEAN 1

#include <windows.h>
#include <malloc.h>
#include <stdio.h>
#include <pdh.h>
#include <pdhmsg.h>

#pragma comment(lib, "pdh.lib")

CONST PWSTR COUNTER_OBJECT = L"Process";

void main(void)
{
    PDH_STATUS status = ERROR_SUCCESS;
    LPWSTR pwsCounterListBuffer = NULL;
    DWORD dwCounterListSize = 0;
    LPWSTR pwsInstanceListBuffer = NULL;
    DWORD dwInstanceListSize = 0;
    LPWSTR pTemp = NULL;

    // Determine the required buffer size for the data. 
    status = PdhEnumObjectItems(
        NULL,                   // real-time source
        NULL,                   // local machine
        COUNTER_OBJECT,         // object to enumerate
        pwsCounterListBuffer,   // pass NULL and 0
        &dwCounterListSize,     // to get required buffer size
        pwsInstanceListBuffer, 
        &dwInstanceListSize, 
        PERF_DETAIL_WIZARD,     // counter detail level
        0); 

    if (status == PDH_MORE_DATA) 
    {
        // Allocate the buffers and try the call again.
        pwsCounterListBuffer = (LPWSTR)malloc(dwCounterListSize * sizeof(WCHAR));
        pwsInstanceListBuffer = (LPWSTR)malloc(dwInstanceListSize * sizeof(WCHAR));

        if (NULL != pwsCounterListBuffer && NULL != pwsInstanceListBuffer) 
        {
            status = PdhEnumObjectItems(
                NULL,                   // real-time source
                NULL,                   // local machine
                COUNTER_OBJECT,         // object to enumerate
                pwsCounterListBuffer, 
                &dwCounterListSize,
                pwsInstanceListBuffer, 
                &dwInstanceListSize, 
                PERF_DETAIL_WIZARD,     // counter detail level
                0); 
     
            if (status == ERROR_SUCCESS) 
            {
                wprintf(L"Counters that the Process objects defines:\n\n");

                // Walk the counters list. The list can contain one
                // or more null-terminated strings. The list is terminated
                // using two null-terminator characters.
                for (pTemp = pwsCounterListBuffer; *pTemp != 0; pTemp += wcslen(pTemp) + 1) 
                {
                     wprintf(L"%s\n", pTemp);
                }

                wprintf(L"\nInstances of the Process object:\n\n");

                // Walk the instance list. The list can contain one
                // or more null-terminated strings. The list is terminated
                // using two null-terminator characters.
                for (pTemp = pwsInstanceListBuffer; *pTemp != 0; pTemp += wcslen(pTemp) + 1) 
                {
                     wprintf(L"%s\n", pTemp);
                }
            }
            else 
            {
                wprintf(L"Second PdhEnumObjectItems failed with %0x%x.\n", status);
            }
        } 
        else 
        {
            wprintf(L"Unable to allocate buffers.\n");
            status = ERROR_OUTOFMEMORY;
        }
    } 
    else 
    {
        wprintf(L"\nPdhEnumObjectItems failed with 0x%x.\n", status);
    }

    if (pwsCounterListBuffer != NULL) 
        free (pwsCounterListBuffer);

    if (pwsInstanceListBuffer != NULL) 
        free (pwsInstanceListBuffer);
}