worker_rpc.go

func (wk *Worker) DoTask(arg *DoTaskArgs, _ *struct{}) error {
	fmt.Printf("%s: given %v task #%d on file %s (nois: %d)\n",
		wk.name, arg.Phase, arg.TaskNumber, arg.File, arg.NumOtherPhase)

	switch arg.Phase {
	case mapPhase:
		doMap(arg.JobName, arg.TaskNumber, arg.File, arg.NumOtherPhase, wk.Map)
	case reducePhase:
		doReduce(arg.JobName, arg.TaskNumber, arg.NumOtherPhase, wk.Reduce)
	}

	fmt.Printf("%s: %v task #%d done\n", wk.name, arg.Phase, arg.TaskNumber)
	return nil
}

func (wk *Worker) Shutdown(_ *struct{}, res *ShutdownReply) error {
	debug("Shutdown %s\n", wk.name)
	wk.Lock()
	defer wk.Unlock()
	res.Ntasks = wk.nTasks
	wk.nRPC = 1
	wk.nTasks--
	return nil
}