From: Robert Klemme <bob.news@...>
Date: 2003-02-27T02:36:03+09:00
Subject: Re: Ruby in Performance Testing


"ahoward" <ahoward@fsl.noaa.gov> schrieb im Newsbeitrag
news:Pine.LNX.4.53.0302261440230.14239@eli.fsl.noaa.gov...
> i'm not sure, but accessing stdout/stderr from this many threads at once
may
> be a problem - i've had problems with it before.  one thing i've done in
my
> threaded problems is something like this :
<snip/>

In order to get a grip on ruby threading I implemented a similar version
that does also write the output along the way. Feel free to use and modify
it as you like.

    robert


require 'thread'

class Queue
  def initialize()
    @q     = []
    @mutex = Mutex.new
    @cond  = ConditionVariable.new
  end

  def enqueue(*elems)
    @mutex.synchronize do
      @q.push *elems
      @cond.signal
    end
  end

  def dequeue()
    @mutex.synchronize do
      while @q.empty? do
        @cond.wait(@mutex)
      end

      return @q.shift
    end
  end
end

class Logger
  def initialize(io, close=false)
    @closeOnTerminate = close
    @queue = Queue.new
    @io = io

    @t = Thread.new do
      while true do
        @io.puts(@queue.dequeue)
      end
    end
  end

  def log(*args)
    checkRunning
    @queue.enqueue(*args)
  end

  def terminate()
    checkRunning

    @t.exit
    @t = nil

    @io.close if @closeOnTerminate
    @io = nil

    @queue = nil
  end

  def checkRunning
    raise "Logger already terminated" unless @t
  end
end

l = Logger.new($stdout)

l.log("hello")
l.log("this is it")
l.log(%w{this is it})

l.terminate

sleep(5)