channel.rb

require "sync"
require "blankslate"

class Channel < BlankSlate
  def initialize
    @sync = Sync.new
    @queue = []
  end

  def queue
    @sync.synchronize do
      @queue
    end
  end

  def inspect
    sprintf("#<Channel:%#0x QUEUED:%d>", __id__, self.queue.size)
  end

  def method_missing(method, *params, &block)
    @sync.synchronize do
      @queue.push([method.to_sym, params, block])
    end
    return true
  end

  def receive(object, method=nil)
    (lambda do
      if method.respond_to?(:to_sym)
        method = method.to_sym
        params, block = nil, nil
        found = false
        @sync.synchronize do
          @queue.each_with_index do |(qmethod, qparams, qblock), index|
            if method == qmethod
              method, params, block = qmethod, qparams, qblock
              @queue.delete_at(index)
              found = true
              break
            end
          end
        end
        if found
          return object.send(method, *params, &block)
        else
          Thread.pass
          redo
        end
      elsif method == nil
        @sync.synchronize do
          method, params, block = @queue.shift
        end
        if method
          return object.send(method, *params, &block)
        else
          Thread.pass
          redo
        end
      else
        raise TypeError, "Can't convert #{method.class} into Symbol."
      end
    end).call
  end
end