Changeset 131

Timestamp:

05/24/06 07:31:27 (2 years ago)

Author:

blackhedd

Message:

notes

Files:

• experiments/machine/test/NOTES (modified) (1 diff)

experiments/machine/test/NOTES

@@ -1 +1 @@
-$Id$
+
+----------------------------------------------------------------------
+24May06:
+
+Implementation notes:
+
+An EventDispatcher is an event queue plus a manager for a chain
+of handlers, plus a method for iterating over the queue (which
+consumes the events by feeding them into the handler chain).
+
+How are callbacks defined in such a model? We've been assuming
+we need them because Twisted has them, but most of their functionality
+is probably present in the handler mechanism we already have.
+The exception: sending responses to events, but we still haven't defined
+any event types that need to be responded to. (That will come soon enough.)
+Rather than a callback, we may want to send another event that is somehow
+correlated with the first one.
+
+The Timeout class defines a straightforward Dispatcher, but it bothers
+me that it adds a custom implementation of add_handler. Did you do this
+only to sugar the :timer_expired event type? Or is there a more fundamental
+reason?
+
+Timeout adds an construct that is orthogonal to EventDispatcher in
+order to get the timing basis. This is the combination of register_timer,
+the priority queue, and the fire_timers method which has to be invoked by
+the reactor. Something analogous has to be defined for I/O Dispatchers.
+
+Why do you need the external PQueue implementation? For one thing, it's
+GPL and we need EventMachine to be either Ruby-licensed or LGPL.
+But what does PQueue give you that couldn't get simply by adding timers to
+a Ruby array and then calling sort! {|a,b| a.expiration <=> b.expiration}?
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