From: khaines@...
Date: 2007-01-29T01:21:41+09:00
Subject: Re: Benefits of Multi-Threading?

On Sun, 28 Jan 2007, NanoStuff wrote:

> I'm slowly going through the pickaxe, and i've hit the multi-threading
> chapter. Despite all the juicy information, I can't seem to gather what
> the actual benefits of multi-threading on a single processor are.
>
> Is performance improved despite the limitations of one processor, or is
> there a completely performance unrelated purpose to multi-threading that
> I missed entirely?

Sometimes it is convenience.  For instance, if there's an action that you 
want to have repeated every 5 minutes, you might create a thread just runs 
in a loop, sleeping for 300 seconds, then performing the action.

Threads can also be a useful strategy when accepting outside events.  For 
instance, with a web server one might want to spawn a thread for each 
connection.

The only time you will realize a performance boost from Ruby threads, 
though, is when there is some time consuming, but non-blocking delay in 
one thread that allows other threads to use that time in order to get 
something done.

In my experience, they are less about performance than they are about 
implementation convenience.


Kirk Haines