gistfile1.rb

require 'monitor'

obj = Object.new
obj.extend(MonitorMixin)
condition = obj.new_cond
duration = 4

class Signaler
  def initialize(duration, obj, condition)
    @duration = duration
    @obj = obj
    @condition = condition
    @stop = false
  end

  def start
    @t = Thread.new do
      loop do
        break if @stop
        sleep @duration
        signal
      end
    end
  end

  def signal
    @obj.synchronize do
      @condition.signal
    end
  end

  def stop
    @stop = true
    signal
    @t.join
  end
end

class Worker
  def initialize(duration, obj, condition, signaler)
    @duration = duration
    @obj = obj
    @condition = condition
    @signaler = signaler
    @stop = false
  end

  def work
    @t = Thread.new do
      loop do
        puts 'working...'
        sleep 0.2
        puts 'done'

        @obj.synchronize do
          puts 'waiting...'
          @condition.wait(100000)
        end

        break if @stop
      end
      puts 'Stopped'
    end
  end

  def stop
    puts 'Stopping...'
    @stop = true
    @signaler.stop
  end

  def wait
    @t.join
  end
end

s = Signaler.new(duration, obj, condition)
s.start

w = Worker.new(duration, obj, condition, s)
w.work

read_io, write_io = IO.pipe

Thread.new do
  loop do
    read_io.read(1)
    w.stop
  end
end

Signal.trap('INT') do
  write_io.write(1)
end

w.wait