class Node
  attr_accessor :name, :msg_q
 
  def initialize(name, &block)
    @name = name
    @block = block      # ← 初期化時のブロックを保持
    @msg_q = {
      ms: [],
      ms_private: []
    }
  end
 
  # --- update：ブロックを実行 ---
  def update
    @block.call(self) if @block
  end
 
  # --- 送信 ---
  def _ms_send_private(msg)
    _ms_send(msg, :ms_private)
  end
 
  def _ms_send(msg, mode = :ms)
    msg[:from]    ||= self.name
    msg[:to]      ||= nil
    msg[:payload] ||= []
    msg[:to].msg_q[mode] << msg
  end
 
  # --- 受信処理 ---
  def _ms_proc_private
    while (msg = self.msg_q[:ms_private].shift)
      yield msg if block_given?
    end
  end
end
 
# ----------- サンプル -----------
 
a = Node.new("A")
 
b = Node.new("B") do |self_node|
  # メッセージ待ち受け 毎ループ実行 .update
  self_node._ms_proc_private do |msg|
    puts "received: #{msg[:type]}, payload=#{msg[:payload].inspect}, from=#{msg[:from]}"
  end
end
 
# bへメッセージ送信
a._ms_send_private({
  from: a.name,
  to: b,
  type: "M_TEST_1",
  payload: ["hello"]
})
 
[a, b].each {|m| m.update }
 

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