Thank you Nick for the education. Greatly appreciate it....

>>>>Hello all.
>>>>
>>>>Is there a literature somewhere that I can read to learn how to COM/DCOM in VFP?
>>>>
>>>>Thanks ...
>>>
>>>Dean, try
>>>
>>>http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnfoxgen7/html/vfpandcom.asp
>>>http://msdn.microsoft.com/library/default.asp?url=/library/en-us/fox7help/html/newcontrolling_call_blocking.asp
>>>http://msdn.microsoft.com/library/techart/msdn_raresp.htm
>>>http://msdn.microsoft.com/library/backgrnd/html/msdn_dcomfirewall.htm
>>>http://msdn.microsoft.com/msdnmag/issues/01/10/VFP7/print.asp
>>
>>Hi Nick.
>>
>>I just created my first COM object.
>>I have another question.
>>
>>When you create the DLL, what is the difference between Single-threaded and multi-threaded?
>>
>>Thanks again.
>
>Hi Dean,
>
>In a multi-threaded environment the process of the request execution may be interrupted by other requests.
>
>As an example, three client requests arrive to your multi-threaded COM DLL almost at the same time. First request runs some long calculation method in your COM and other two just want to query some COM property.
>
>In a single-threaded environment the last two requests have to wait until the first one is finished, say in a minute and then the other two requests are executed for one second each. So, all three clients got the result in about one minute each. In a multi-threaded environment the long process can be interrupted with others. The result is that for the first long query the execution time will slightly increase, but two short ones are executed almost at once.
>
>So, the multithreaded COM will have a better performance from the user point of view. It does not mean that several simultaneous calls to COM will take less total time. There is still just one processor to execute all calls, plus it needs the time for the thread switching. The real performance increase can happen only on multiprocessor PC.
>
>Note, that programming for multithreaded COM is different from writing the normal code. You supposed to use the SYS(2336) function which can lock and unlock the critical sections of the program where no any interference from other threads, calling the same code, may be allowed. Programming for multithreaded COM also should be a topic for a separate session. :)
>
>The Multithreaded DLL option first appeared in VFP 6 Service Pack 3 and in order to take advantage of it you are supposed to use a different runtime library - VFP6T.DLL You should refer to the documentation as there is some difference in VFP features supported in normal VFP6R.DLL and VFP6T.DLL
>Multithreaded DLL can be used only with "Multi-Use" option, while single-threaded DLL may be both Single-Use and Multi-Use. Multithreaded DLLs is what you should use, for example, for the heavy load web site programming.