module Fluent::PluginHelper::EventLoop

def event_loop_wait_until_stop
  timeout_at = Fluent::Clock.now + EVENT_LOOP_SHUTDOWN_TIMEOUT
  sleep(0.1) while event_loop_running? && Fluent::Clock.now < timeout_at
  if @_event_loop_running
    puts "terminating event_loop forcedly"
    caller.each{|bt| puts "\t#{bt}" }
    @_event_loop.stop rescue nil
    @_event_loop_running = true
  end
end