windows-server-2003/admin/wmi/wbem/providers/msiprovider/dll/classfac.cpp

//***************************************************************************

//

//  CLASSFAC.CPP

//

//  Module: WBEM Instance provider sample code

//

//  Purpose: Contains the class factory.  This creates objects when

//           connections are requested.

//

// Copyright (c) 1997-2001 Microsoft Corporation, All Rights Reserved
//
//***************************************************************************

#include "precomp.h"
#include <objbase.h>
#include "classfac.h"

//***************************************************************************
//
// CProvFactory::CProvFactory
// CProvFactory::~CProvFactory
//
// Constructor Parameters:
//  None
//***************************************************************************

CProvFactory::CProvFactory()
{
    InterlockedIncrement(&g_cObj);

    m_cRef=0L;
    return;
}

CProvFactory::~CProvFactory(void)
{
	InterlockedDecrement(&g_cObj);

    return;
}

//***************************************************************************
//
// CProvFactory::QueryInterface
// CProvFactory::AddRef
// CProvFactory::Release
//
// Purpose: Standard Ole routines needed for all interfaces
//
//***************************************************************************


STDMETHODIMP CProvFactory::QueryInterface(REFIID riid
    , LPVOID * ppv)
{
    *ppv=NULL;

    if (IID_IUnknown==riid || IID_IClassFactory==riid) *ppv=this;

    if (NULL!=*ppv){
        ((LPUNKNOWN)*ppv)->AddRef();
        return NOERROR;
    }

    return E_NOINTERFACE;
}

STDMETHODIMP_(ULONG) CProvFactory::AddRef(void)
{
    return ++m_cRef;
}

STDMETHODIMP_(ULONG) CProvFactory::Release(void)
{
    ULONG nNewCount = InterlockedDecrement((long *)&m_cRef);
    if (0L == nNewCount) delete this;
    
    return nNewCount;
}

//***************************************************************************
//
// CProvFactory::CreateInstance
//
// Purpose: Instantiates a Locator object returning an interface pointer.
//
// Parameters:
//  pUnkOuter       LPUNKNOWN to the controlling IUnknown if we are
//                  being used in an aggregation.
//  riid            REFIID identifying the interface the caller
//                  desires to have for the new object.
//  ppvObj          PPVOID in which to store the desired
//                  interface pointer for the new object.
//
// Return Value:
//  HRESULT         NOERROR if successful, otherwise E_NOINTERFACE
//                  if we cannot support the requested interface.
//***************************************************************************

STDMETHODIMP CProvFactory::CreateInstance(LPUNKNOWN pUnkOuter
    , REFIID riid, LPVOID * ppvObj)
{
    CMSIProv *pObj;
    HRESULT hr = WBEM_S_NO_ERROR;

    *ppvObj=NULL;
    hr = E_OUTOFMEMORY;

    // This object doesnt support aggregation.

    if(NULL!=pUnkOuter) return CLASS_E_NOAGGREGATION;

    // Create the locator object.
    pObj=new CMSIProv();

    if (NULL==pObj)
        return E_OUTOFMEMORY;

    hr=pObj->QueryInterface(riid, ppvObj);

    //Kill the object if initial creation or Init failed.

    if(FAILED(hr)) delete pObj;
    return hr;
}

//***************************************************************************
//
// CProvFactory::LockServer
//
// Purpose:
//  Increments or decrements the lock count of the DLL.  If the
//  lock count goes to zero and there are no objects, the DLL
//  is allowed to unload.  See DllCanUnloadNow.
//
// Parameters:
//  fLock           BOOL specifying whether to increment or
//                  decrement the lock count.
//
// Return Value:
//  HRESULT         NOERROR always.
//***************************************************************************


STDMETHODIMP CProvFactory::LockServer(BOOL fLock)
{
    if (fLock) InterlockedIncrement(&g_cLock);
    else InterlockedDecrement(&g_cLock);
    return NOERROR;
}