require "monitor.rb"

$l = Monitor.new
$c = $l.new_cond
$ready = false
$buf = nil

def produce(o)
  $l.synchronize {
    puts "In produce"
    $stdout.flush
    $c.wait_while { $ready }
    $buf = o
    $ready = true
    $c.broadcast
  }
end

def consume
  temp = nil
  $l.synchronize {
    puts "In consume"
    $stdout.flush
    $c.wait_while { !$ready }
    temp = $buf
    $ready = false
    $c.broadcast
  }
  temp
end

def act(a)
  a.each { |x|
    if x == "consume"
      puts "Consumed #{consume}"
      $stdout.flush
    elsif x == "sleep"
      puts "Sleeping"
      $stdout.flush
      sleep 1
    else
      puts "Producing #{x}"
      $stdout.flush
      produce x
    end
  }
end

t1 = Thread.new {
  act ["sleep", 1, 2, 3]
}

t2 = Thread.new {
  act ["consume"]
}

t3 = Thread.new {
  act ["sleep", "sleep", "consume"]
}

t4 = Thread.new {
  act ["sleep", "sleep", "sleep", "consume"]
}

t1.join
t2.join
t3.join
t4.join