Re: operator new[] fails in DLL when being called from within VB6 process

In lieu of showing code, you might need to call CoInitialize() or
CoInitializeEx() when the DLL is first loaded.

I can't remember the details, and our DLL is a complex multi-threaded RPC
client/server wire handler for client applications, but I recall running
into similar memory related GPFs when 3rd party VB6 applications were
importing our standard client/server WINAPI based dlls. Every native
language applications (C/C++, Delphi, etc) worked fine except VB6-based
applets.

You would call CoInitialize() in DLL_PROCESS_ATTACH and you would call
CoUninitialize() in DLL_PROCESS_DETACH.

PS: You didn't mention it, but if your DLL uses threads, you definitely need
to call CoInitialize().

--
Hector Santos, Santronics Software, Inc.
http://www.santronics.com


"Jo Siffert" <jo.siffert@xxxxxxx> wrote in message
news:eVdyCYm1FHA.1028@xxxxxxxxxxxxxxxxxxxxxxx
> Hi,
>
> I have written a DLL in C/C++ which is used by a VB6 program. Everything
> works fine unless the DLL uses the operator new[] - e.g.
>
> m_pBuffer = new CHAR[ dwApproxPayloadLen ];
>
> then an Access Violation Exception is thrown within ntdll!_RtlAllocHeap.
>
> Calling
> CFoo *f = new Cfoo()
> works just fine - only arrays will not work.
>
> The same code works just fine when being called from a C/C++ program.
>
> Is there something special about calling CRT functions when my lib is
> loaded into a VB6 process? Maybe VB6 does not initialize the CRT as it
> does not use it or something like that?
>
> Thanks in advance,
> Jo

.

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