Hi Christof,

Thanks - this is great information!
>Hi Claude,
>
>>I think a lot of us are curious if there are any real advantages to calling a .VFP. mtdll from a multithreaded client(such as an ISAPI exetension) as opposed to calling a .VFP. EXE COM server(pooled or otherwise) from a multithreaded client. Also in regards to actual dual or multiprocessors? What's your honest opinion??
>
>That depends on a wide variety of factors. A COM call to an EXE is slower than a COM call to another thread. I think it was a factor of 2 in the tests I did a long time ago. It depends on the actual method and the call frequency if that's really an important issue considering that a thread increases risks due to possible crashes.
>
>However, a COM call is not the only possibility to handle communication. AFP, for instance, uses named pipes instead which are faster than COM calls to communicate between the ISAPI extension and the actual server. That's the same mechanism used by ASP.NET. With such a solution the difference between MTDLL and EXE become even less an issue in terms of performance. The biggest difference is resource usage in this case. An EXE solution needs more memory as the runtime is bigger and there's copy of the runtime for each EXE.
>
>I think the reasons to pick MTDLLS over EXEs shouldn't be performance considerations, rather stability, scalability, security, etc.
>
>Christof