Re: Cost of constructing a communication path vs. sending a message

On 09/16/2010 04:03 AM, Mike Kristoffersen wrote:
> Looking at the code it seems like constructing a protocol is much more
> expensive than just sending a message - so in a case like this where we
> have two objects communicating over time, is it then the best choice to
> create the connection between them once, and use this connection to
> communicate over time - or is it really better to (re-)create the
> connection each time it is needed? - Is there a significant cost to
> having a connection open all the time?

There's not a general answer to that question. it depends on the 
problem.  I don't know exactly what problem you're solving here, but the 
"request protocol" pattern with Constructor/__delete__ encapsulating the 
request might be what you want.  Depending on what start/stop really 
mean, tracking nested and overlapping requests can become tricky, and 
you'd likely end up duplicating the actor-management logic.

Creating/destroying an actor is cheap, essentially |new 
FooActor()/delete actor|| and a hash table insert/delete on both sides. 
  Sending a message with IPC is much much more expensive than 
constructing/registering/unregistering/deleting an actor.

Cheers,
Chris