Determine whether a COM is a In-Proc or LocalServer

Question

I got an application that use a COM library, just wondering how can I know whether that application use that COM library as a LocalServer or In-Proc?

I looked at the code being constructed in this way:

DATCOMLib::ITEmulationPtr pTE(__uuidof(DATCOMLib::TEmulation));

Answer 1

It depends partly on what execution context you supply when you create your object - see here for more details: http://msdn.microsoft.com/en-us/library/windows/desktop/ms693716(v=vs.85).aspx

You can look up the class id for your component in the registry and check whether it has a LocalServer sub-key. So in your case you would look for:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{CLSID of DATACOMLib::TEmulation}\LocalServer

If it is an In Proc COM component it will instead have the following key:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{CLSID of DATACOMLib::TEmulation}\InProcServer32

Check this documentation for more details: http://msdn.microsoft.com/en-us/library/aa908849.aspx

Answer 2

It can be find out using multiple ways

1. From looking at the code - check what is the class context passed when calling "CreateInstance" or "CoCreateInstance" - (CLSCTX_INPROC_XXXX then it is inproc server means it is DLL which will be loaded into calling applications process address space. CLSCTX_LOCAL_SERVER, CLSCTX_REMOTE_SERVER - then it is COM server running as a separate process. There are some #defines which combines one or more flags. Just google it)

   ITEmulationPtr.CreateInstance(uuid(TEmulation), 0, CLSCTX_XXX)

2. If you have access to machine on which COM component is installed then you can follow steps given by Peter in above answer