windows-server-2003/ds/dns/server/wmi/source/provfactory.cpp

/////////////////////////////////////////////////////////////////////
//
//  CopyRight (c) 1999 Microsoft Corporation
//
//  Module Name: provfactory.cpp
//
//  Description:    
//      Implementation of CProvFactory class 
//
//  Author:
//      Henry Wang ( henrywa ) March 8, 2000
//
//////////////////////////////////////////////////////////////////////


#include "DnsWmi.h"


//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////


CProvFactory::CProvFactory()
{
    m_cRef=0L;
    return;
}

CProvFactory::~CProvFactory(void)
{
    return;
}

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


STDMETHODIMP CProvFactory::QueryInterface(REFIID riid
    , PPVOID 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, PPVOID ppvObj)
{
    CInstanceProv *   pObj;
    HRESULT hr;

    *ppvObj=NULL;

    // This object doesnt support aggregation.

    if (NULL!=pUnkOuter)
        return CLASS_E_NOAGGREGATION;

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