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CodeBlocksPortable/Borland/BCC55/Include/mspenum.h

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/*
Copyright (c) 1998-1999 Microsoft Corporation
*/
#ifndef _MSPENUM_H_
#pragma option push -b -a8 -pc -A- /*P_O_Push*/
#define _MSPENUM_H_
//////////////////////////////////////////////////////////////////////////////
//
// CSafeComEnum
//
// All TAPI 3.0 system components and MSPs use the CSafeComEnum class instead
// of ATL 2.1's CComEnum class when implementing enumerator objects that are
// accessible to applications. This is needed for the following reasons:
//
// 1. CComEnum does not perform IsBadWritePtr checks on the pointer arguments
// to the enumerator methods. This allows the component exposing the
// enumerator to AV when called with invalid pointer arguments.
//
// 2. CComEnum does not support free thread marshaling, and therefore cannot
// be used from an apartment threaded application.
//
// Note: No debug tracing is done here, to facilitate use of this template
// independent of the rest of the MSP Base Classes.
//
/////////////////////////////////////////////////////////////////////////////
template <class Base, const IID* piid, class T, class Copy,
class ThreadModel = CComObjectThreadModel>
class ATL_NO_VTABLE CSafeComEnum :
public CComEnumImpl<Base, piid, T, Copy>,
public CComObjectRootEx< ThreadModel >
{
typedef CSafeComEnum<Base, piid, T, Copy, ThreadModel> ThisClass;
typedef CComEnumImpl<Base, piid, T, Copy> BaseClass;
STDMETHOD(Next)(ULONG celt, T* rgelt, ULONG* pceltFetched)
{
//
// Check if the return array is valid for as many elements as
// specified. No need to explicitly check if celt is zero here, as
// IsBadWritePtr(p, 0) is valid and returns 0.
// celt itself will be checked in the base class method.
//
if ( IsBadWritePtr(rgelt, celt * sizeof(T) ) )
{
return E_POINTER;
}
//
// Check if the return dword is bad, but if pceltFetched == NULL,
// this may still be a valid call. pceltFetched == NULL implies that
// celt should be equal to 1, but that will be checked in the
// base class method.
//
if ( ( pceltFetched != NULL ) &&
IsBadWritePtr(pceltFetched, sizeof(ULONG) ) )
{
return E_POINTER;
}
//
// Everything OK so far; proceed with base class method.
//
return BaseClass::Next(celt, rgelt, pceltFetched);
}
STDMETHOD(Clone)(Base** ppEnum)
{
//
// Check if the return pointer is valid.
//
if ( IsBadWritePtr(ppEnum, sizeof(Base *) ) )
{
return E_POINTER;
}
//
// Everything OK so far; proceed with base class method.
//
return BaseClass::Clone(ppEnum);
}
//
// We do not override Skip or Reset as they have no pointer arguments.
//
//
// The rest of this class involves support for free thread marshaling.
//
BEGIN_COM_MAP( ThisClass )
COM_INTERFACE_ENTRY_IID( *piid, BaseClass )
COM_INTERFACE_ENTRY_AGGREGATE( IID_IMarshal, m_pFTM )
END_COM_MAP()
DECLARE_GET_CONTROLLING_UNKNOWN()
HRESULT Init(T* begin, T* end, IUnknown* pUnk,
CComEnumFlags flags = AtlFlagNoCopy)
{
//
// We do not check the pointer arguments in this method because this
// method is not exposed to the application (it is not a COM interface
// method).
//
HRESULT hr;
IUnknown * pIU = GetControllingUnknown();
hr = CoCreateFreeThreadedMarshaler( pIU,
& m_pFTM );
if ( FAILED(hr) )
{
return hr;
}
return BaseClass::Init(begin, end, pUnk, flags);
}
CSafeComEnum()
{
m_pFTM = NULL;
}
void FinalRelease(void)
{
if ( m_pFTM )
{
m_pFTM->Release();
}
CComObjectRootEx< ThreadModel >::FinalRelease();
}
protected:
IUnknown * m_pFTM; // pointer to free thread marshaler
};
#pragma option pop /*P_O_Pop*/
#endif // _MSPENUM_H_