From: Joel VanderWerf <vjoel@...>
Date: 2006-01-17T11:26:13+09:00
Subject: Re: Resetting ruby

Luc Heinrich wrote:
...
> Another (different) aspect of Tcl which I really like is how event loops
> are used to provide ultra-simple interthreads communication with message
> queuing and all that jazz:
> 
> % package require Thread
> % set worker [thread::create]
> % thread::send -async $worker {...some longish calculation...}
> % thread::send -async $worker {...some other longish calculation...}
> % ...continue on the main thread...
> 
> Rite is supposed to be reentrant, so I guess that it shouldn't be very
> hard to build such things upon Ruby 2.0. Oh my, I am *so* looking
> forward to it... :)

Aside from the use of native threads in this tcl example (IIRC), this is
not hard to do in ruby. And with 2.0, we'll have native threads...

Anyway here's one way to do worker threads:

require 'thread'

class WorkerThread < Thread
  def initialize
    super do
      @queue = Queue.new
      loop do
        @queue.pop.call
      end
    end
  end

  def push(&bl)
    @queue << bl
  end
end

def very_long_calculation; (10**10000).to_s.size; end

qt = WorkerThread.new
results = Queue.new

qt.push do
  results.push(very_long_calculation)
end

p results.pop

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