From: Paul Lutus <nospam@...>
Date: 2006-09-10T02:20:16+09:00
Subject: Re: Timer Task?

Jason Vinson wrote:

/...

> I guess my real question is the preferred approach
> something like this?
> 
> notifier = SnarlMail.new("imap.mailserver.com", "username", "passwd")
> 
> while(true) do
>   notifier.check
>   sleep 60
> end
> 
> Does sleep cost anything in terms of resources, and if so what is
> "cheaper"?

AFAIK "sleep" is a perfectly adequate way to idle a thread, and it has the
advantage of being trivial to implement. I have recently seen Ruby threads
that used "sleep" be idled by the thread manager, never to be called again,
but this has to do with Ruby threads within a Ruby process, not native
threads represented by particular Ruby applications.

[Somewhat OT]

Have you considered using OS-specific facilities like "cron" instead of
"sleep" for scheduling? I use cron for most of these periodic, relatively
low-powered tasks because it is easy to add a task to cron's list of jobs,
and it burdens the system less than maintaining a bunch of sleeping
processes -- cron loads, runs, and unloads its tasks, while a sleeping
process represents an ongoing use of resources.

-- 
Paul Lutus
http://www.arachnoid.com