gistfile1.rb

class Fiber
  yield_method = method(:yield)
  resume_method = instance_method(:resume)

  singleton_class.send(:define_method, :yield) do |*args|
    puts "yield #{Fiber.current}"
    yield_method.call *args
  end

  define_method(:resume) do |*args|
    puts "resume #{self}"
    resume_method.bind(self).call *args
  end

  def name=(value)
    @name = value
  end

  def to_s
    @name || super
  end

end

f1.name = 'fiber 1'
f2.name = 'fiber 2'
f3.name = 'fiber 3'