class Concurrent::FixedThreadPool::Worker

def dead?
  return @mutex.synchronize do
    @thread.nil? ? false : ! @thread.alive?
  end
end

def initialize(queue, parent)
  @queue = queue
  @parent = parent
  @mutex = Mutex.new
end

def kill
  @mutex.synchronize do
    Thread.kill(@thread) unless @thread.nil?
    @thread = nil
  end
end

def run(thread = Thread.current)
  @mutex.synchronize do
    raise StandardError.new('already running') unless @thread.nil?
    @thread = thread
  end
  loop do
    task = @queue.pop
    if task == :stop
      @thread = nil
      @parent.on_worker_exit(self)
      break
    end
    @parent.on_start_task(self)
    begin
      task.last.call(*task.first)
    rescue
      # let it fail
    ensure
      @parent.on_end_task(self)
    end
  end
end