class EventMachine::SpawnedProcess

def notify *x
  me = self
  EM.next_tick {
    # A notification executes in the context of this
    # SpawnedProcess object. That makes self and notify
    # work as one would expect.
    #
    y = me.call(*x)
    if y and y.respond_to?(:pull_out_yield_block)
      a,b = y.pull_out_yield_block
      set_receiver a
      self.notify if b
    end
  }
end

def set_receiver blk
  (class << self ; self ; end).class_eval do
    remove_method :call if method_defined? :call
    define_method :call, blk
  end
end