Producer-Consumer的Ruby实现

Ruby语言中直接提供了Monitor的支持，因此可以如下实现Producer-Consumer：
require 'monitor'

N = 10
BUFFER = Array.new(N)

class ProducerConsumer < Monitor
    def initialize
        @count = 0
        super
    end
    def insert(item)
        if @count == N
            puts "buffer is full"
            Thread.pass
        end
        insert_item(item)
        puts "item inserted"
        @count += 1
    end
    def remove
        if @count == 0
            puts "buffer is empty"
            Thread.pass
        end
        remove_item
        puts "item removed"
        @count -= 1
    end
   
  private
    def insert_item(item)
        BUFFER << item
    end
    def remove_item
        item = BUFFER.delete_at(@count - 1)
    end
end

m = ProducerConsumer.new

producer = Thread.start {
  while true
    m.insert(1)
  end
}

consumer = Thread.start {
  while true
    item = m.remove
  end
}

producer.join
consumer.join


也可以利用Ruby的mixin特性，不继承Monitor：
require 'monitor'

class ProducerConsumer
  include MonitorMixin
  //以下代码同上
...