On Wednesday 18 February 2004 19:39, Leo Simons wrote: > This is a request/response architecture, and its not general enough. It > seems we need an "event bus" or listener approach, where there can be > multiple publishers of the same message, and multiple recipients. we can > ath this point drift into the realm of JINI, JavaSpaces, and the like. > Since I don't fully understand most of that I won't go there.
You should... That's where the fun starts ;o) Thanks for the long RT on what constitutes a Request/Response architecture, but IMHV, isn't this just an generalization (i.e. using something else than the heap and stack, as transport) of normal call/returns of most programming languages? When I think of "Event-Driven" programming patterns, it boils down to exactly what you have described in your essay about why Loggers are no good (I loved that one, and a real eye-opener of something one have taken for granted!). "Event-Driven" (call it publish/subscribe, notification or whatever) patterns are introducing a very nice extension to the familiar call/return concept. Unfortunately, the benefits are rather subtle, and not easily appreciated until you scale up the complexity of a system. And I think Alex has noticed that, and seen that the next level is the 'router'/'hub', gives even more decoupling benefits. NOTE; There are some traps in "Event-Driven" patterns, where the Events has the 'trend' of moving from the low-level towards the higher levels, and the "Call/Return"s are made in the opposite direction in the object hierarchy, causing some really serious trouble in multi-threaded environments. People interested; Join my Advanced Course ;o) Cheers Niclas --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
