The notable features of DCOM whose purpose and design you should understand include:
The interface definition language with its use of annotated C types.
The mechanism for distinguishing interfaces based on UUID.
The mechanism for opening a stream between the client and the server based on pipes.
The model of composable components with multiple interfaces.
The approach to lifecycle management with factories and reference counting.
References.
Robert Antonio: Component Object Model. http://www.antonio.cz/com/index.html
Questions.
Microsoft DCOM rozlišuje in process a out of process servery podle toho, zda běží v procesu klienta nebo ve vlastním procesu. Vysvětlete, proč Microsoft DCOM tyto druhy procesů nabízí.
Consider how the options differ in their impact of the communication efficiency, state sharing, stability. Can you come up with examples of servers that fit one of the options well ?
Microsoft DCOM uses a combination of keepalive pinging and reference counting to garbage collect unused objects. Evaluate this approach from the scalability point of view.
The IUnknown interface in Microsoft DCOM has the following methods:
interface IUnknown
{
HRESULT QueryInterface (REFIID iid, void **ppvObject);
ULONG AddRef (void);
ULONG Release (void);
};
Explain the semantics of the methods.