class Concurrent::AbstractExecutorService

def fallback_action(*args)
  case fallback_policy
  when :abort
    lambda { raise RejectedExecutionError }
  when :discard
    lambda { false }
  when :caller_runs
    lambda {
      begin
        yield(*args)
      rescue => ex
        # let it fail
        log DEBUG, ex
      end
      true
    }
  else
    lambda { fail "Unknown fallback policy #{fallback_policy}" }
  end
end