windows-nt/Source/XPSP1/NT/admin/wmi/wbem/providers/wdmprovider/classfac.cpp

////////////////////////////////////////////////////////////////////////////////////////

//

//  CLASSFAC.CPP

//

//  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 "wdmdefs.h"
////////////////////////////////////////////////////////////////////////////////////////
//
// Constructor 
//  
////////////////////////////////////////////////////////////////////////////////////////
CProvFactory::CProvFactory(const CLSID & ClsId)
{
    m_cRef=0L;
    InterlockedIncrement((LONG *) &g_cObj);
    m_ClsId = ClsId;
}
////////////////////////////////////////////////////////////////////////////////////////
//
//  Destructor
//
////////////////////////////////////////////////////////////////////////////////////////
CProvFactory::~CProvFactory(void)
{
    InterlockedDecrement((LONG *) &g_cObj);
}

////////////////////////////////////////////////////////////////////////////////////////
//
// Standard Ole routines needed for all interfaces
//
////////////////////////////////////////////////////////////////////////////////////////
STDMETHODIMP CProvFactory::QueryInterface(REFIID riid, PPVOID ppv)
{
    HRESULT hr = E_NOINTERFACE;

    *ppv=NULL;

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

    if (NULL!=*ppv)
    {
        AddRef();
        hr = NOERROR;
    }

    return hr;
}
/////////////////////////////////////////////////////////////////////////
STDMETHODIMP_(ULONG) CProvFactory::AddRef(void)
{
    return InterlockedIncrement((long*)&m_cRef);
}
/////////////////////////////////////////////////////////////////////////
STDMETHODIMP_(ULONG) CProvFactory::Release(void)
{
	ULONG cRef = InterlockedDecrement( (long*) &m_cRef);
	if ( !cRef ){
		delete this;
		return 0;
	}
	return cRef;
}
////////////////////////////////////////////////////////////////////////////////////////
//
// Instantiates an object returning an interface pointer.
//
////////////////////////////////////////////////////////////////////////////////////////
STDMETHODIMP CProvFactory::CreateInstance(LPUNKNOWN pUnkOuter, REFIID riid, PPVOID ppvObj)
{
    HRESULT   hr = E_OUTOFMEMORY;
    IUnknown* pObj = NULL;

    *ppvObj=NULL;

    //==================================================================
    // This object doesnt support aggregation.
    //==================================================================

    if (NULL!=pUnkOuter)
    {
        hr = CLASS_E_NOAGGREGATION;
    }
    else
    {
        //==============================================================
        //Create the object passing function to notify on destruction.
        //==============================================================
        if (m_ClsId == CLSID_WMIProvider)
        {
            try
			{
		        pObj = (IWbemServices *) new CWMI_Prov;
            }
			catch(...)
			{
				hr = WBEM_E_UNEXPECTED;
			}
        }
        else if (m_ClsId == CLSID_WMIEventProvider)
        {
            try
			{
    		    pObj = (IWbemEventProvider *) new CWMIEventProvider(WMIEVENT);
            }
			catch(...)
			{
				hr = WBEM_E_UNEXPECTED;
			}
        }
        else if (m_ClsId == CLSID_WMIHiPerfProvider)
        {
            try
			{
    		    pObj = (IWbemEventProvider *) new CWMIHiPerfProvider;
            }
			catch(...)
			{
				hr = WBEM_E_UNEXPECTED;
			}
        }
        if(pObj)
        {
            hr = pObj->QueryInterface(riid, ppvObj);
	    }

    }

    //===================================================================
    //Kill the object if initial creation or Init failed.
    //===================================================================
    if (FAILED(hr))
    {
		if( pObj )
		{
			SAFE_DELETE_PTR(pObj);
		}
    }

    return hr;
}

////////////////////////////////////////////////////////////////////////////////////////
//
//  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.
//
////////////////////////////////////////////////////////////////////////////////////////
STDMETHODIMP CProvFactory::LockServer(BOOL fLock)
{
    if (fLock)
        InterlockedIncrement(&g_cLock);
    else
        InterlockedDecrement(&g_cLock);

    return NOERROR;
}