Question

For example, in language X:

let x = CreateOject( "MyProgID" )
x.LateBoundCall()
x.Release()  // (or setting x to Nothing in VB-like language, etc)

What happens to the DLL MyProgID lives in? Does COM unload DLLs automatically?

EDIT

This is assuming that the code above is in an executable that does not expose any COM.

Answer 1

Yes, but not in a deterministic way. Windows periodically asks every loaded DLL “is it safe to unload you now?” Any DLL that responds “Yes” is unloaded.

Note a remark from MSDN :

If a DLL loaded through a call to
CoGetClassObject fails to export
DllCanUnloadNow, the DLL will not be
unloaded until the application calls
the CoUninitialize function to release
the OLE libraries.

See this Old New Thing article.