windows-server-2003/admin/wmi/wbem/winmgmt/wmicooker/factory.cpp

////////////////////////////////////////////////////////////////////////
//
//    Factory.cpp
//
//    Module:    WMI high performance provider sample code
//
//    This is a standard class factory implementation for the CHiPerfProvider
//    object.  
//
//  History:
//    a-dcrews      12-Jan-99        Created
//
//    
//  Copyright (c) 1999-2001 Microsoft Corporation
//
////////////////////////////////////////////////////////////////////////

#include "precomp.h"
#include "Provider.h"
#include "Factory.h"

extern long g_lObjects;
extern long g_lLocks;

//////////////////////////////////////////////////////////////
//
//
//    CClassFactory
//
//
//////////////////////////////////////////////////////////////

STDMETHODIMP CClassFactory::QueryInterface(REFIID riid, void** ppv)
//////////////////////////////////////////////////////////////
//
//    Standard QueryInterface
//
//    Parameters:
//        riid    - the ID of the requested interface
//        ppv        - a pointer to the interface pointer
//
//////////////////////////////////////////////////////////////
{
    if (NULL == ppv) return E_POINTER;
        
    if(riid == IID_IUnknown)
        *ppv = (LPVOID)(IUnknown*)this;
    else if(riid == IID_IClassFactory)
        *ppv = (LPVOID)(IClassFactory*)this;
    else
    {
        *ppv = NULL;
        return E_NOINTERFACE;
    }

    ((IUnknown*)*ppv)->AddRef();
    return S_OK;
}

STDMETHODIMP_(ULONG) CClassFactory::AddRef()
{
    return InterlockedIncrement(&m_lRef);
}

STDMETHODIMP_(ULONG) CClassFactory::Release()
{
    long lRef = InterlockedDecrement(&m_lRef);
    if(lRef == 0) delete this;
    return lRef;
}

STDMETHODIMP CClassFactory::CreateInstance(
        /* [in] */ IUnknown* pUnknownOuter, 
        /* [in] */ REFIID iid, 
        /* [out] */ LPVOID *ppv)
//////////////////////////////////////////////////////////////
//
//    Standard COM CreateInstance
//
//////////////////////////////////////////////////////////////
{
    HRESULT hRes;
    CHiPerfProvider *pProvider = NULL;

    *ppv = NULL;

    // We do not support aggregation
    if (pUnknownOuter) return CLASS_E_NOAGGREGATION;

    // Create the provider object
    pProvider = new CHiPerfProvider;

    if (NULL == pProvider) return E_OUTOFMEMORY;

    // Retrieve the requested interface
    // ================================

    hRes = pProvider->QueryInterface(iid, ppv);
    if (FAILED(hRes))
    {
        delete pProvider;
        return hRes;
    }

    return S_OK;
}

STDMETHODIMP CClassFactory::LockServer(
        /* [in] */ BOOL bLock)
//////////////////////////////////////////////////////////////
//
//    Standard COM LockServer
//
//////////////////////////////////////////////////////////////
{
    if (bLock)
        InterlockedIncrement(&g_lLocks);
    else
        InterlockedDecrement(&g_lLocks);

    return S_OK;
}