[boost] Re: async socket i/o [long]

From: Michel André (michel.andre_at_[hidden])
Date: 2005-04-16 13:44:02

Boris wrote:
> Michel André wrote:
> 
>>[...] Another slight mishap is that the things you call acceptor and
>>connector arent acceptors and connectors in the sense of the original
>>pattern (http://www.cs.wustl.edu/~schmidt/PDF/Acc-Con.pdf or POSA 2)
>>as I interpret it.
> 
> 
> I read the 17 pages for a better understanding. And I think you are right 
> that we use different definitions. In the paper acceptor and connector are 
> factories while in the class hierarchy at 
> http://www.highscore.de/boost/net/basic.png they are an endpoint of a 
> communication link. While I understand that the acceptor-connector pattern 
> makes sense I think we should use it in a level > 0. If you look at the 
> connector for example (in the acceptor-connector pattern) it is used to 
> establish a connection and then passes over the connection to a service 
> handler to do the processing. If level 0 should be similar to Berkeley 
> sockets (and as far as I understand this is one goal of level 0) I don't 
> know why the connector shouldn't be able to do the processing after the 
> connection is established. In this level processing basically means calling 
> read() and write(). A service handler in the acceptor-connector pattern is 
> probably something bigger than a socket? Using the acceptor-connector 
> pattern in level 0 would work but would also make the design more 
> complicated as it should be to convince network programmers to switch over 
> to the C++ network library.

It's all in a name ;) . Then I don't think they should be called 
connector and acceptor in level 0 since I was associating it to the 
patterns in POSA2 which I guess a lot of people are familiar with. And 
if we are going to implement these in level 1 it might be confusing to 
have the names with a different implementation in level0. I also think 
there are a lot of good ideas to use from POSA2 and ACE.

The service handler is the implementation of the service and protocol 
over a stream i.e http service handler for an web server that parses and 
responds to http requests.

/Michel