def run
      trap_signals
      log "starting #{display_work_unit}"
      if @unit['options']['benchmark']
        log("ran #{display_work_unit} in " + Benchmark.measure { run_work_unit }.to_s)
      else
        run_work_unit
      end
      Process.exit!
    end
def run
      trap_signals
      log "starting #{display_work_unit}"
      if @unit['options']['benchmark']
        log("ran #{display_work_unit} in " + Benchmark.measure { run_work_unit }.to_s)
      else
        run_work_unit
      end
      Process.exit!
    end
Run this worker inside of a fork. Attempts to exit cleanly.
 Wraps run_work_unit to benchmark the execution time, if requested.