From: Alex Young <alex@...>
Date: 2007-04-27T16:59:43+09:00
Subject: Re: Timer Class

Hussain wrote:
> Hai Dude
> 
> I want to write one class that class should act as a Timer
> On that class , i will check the database every second for database
> field called Diaplay_time ,if the current system time matched with
> database Display_Time field data then i will show the message in
> console,That class should terminate only when i press "Ctrl+C" key
> otherwise that wont stop

You can write a very simple while loop for this:

while true do
   start_time = Time.now
   #do database stuff
   total_time = Time.now - start_time
   sleep(1.0 - total_time) # ignoring the possibility of total_time > 1
end

Alternatively, to make it more Rubyish, use a block or two (untested):

def time_block
   start_time = Time.now
   yield
   return Time.now - start_time
end

def repeat_every(seconds)
   while true do
     sleep( seconds - time_block { yield } ) # again ignoring time > seconds
   end
end

Use it like this:

repeat_every(1.0) do
   # do database stuff
end

-- 
Alex