From: Joel VanderWerf <vjoel@...>
Date: 2007-10-12T16:04:53+09:00
Subject: Re: Inter-Process Messaging

Bill Kelly wrote:
> 
> From: "M. Edward (Ed) Borasky" <znmeb@cesmail.net>
...
>> 2. There are basically two ways to do concurrency/parallelism: shared 
>> memory and message passing. I'm not sure what the *real* tradeoffs are 
>> -- I've pretty much had my brain hammered with "shared memory bad -- 
>> message passing good", but there obviously must be *some* 
>> counter-arguments, or shared memory wouldn't exist. :)
> 
> The way I look at it, Re: trade-offs, message passing is nice
> because the API doesn't change whether the receiver is on localhost
> or over the wire.
> 
> Shared memory is nice for very high bandwidth between processes;
> say process A decodes a 300MB TIFF image into memory and wants
> to make the bitmap available to process B.

And shared memory might also be nice if you don't want queueing, you 
just want the latest data. Sensors in a real-time system, for example.

-- 
       vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407