ran-proc/pkgtest/run-group-test-2023-0125-0410/task.go

package main

import (
	"context"
	"fmt"
	"io"
	"math/rand"
	"time"
)

type Task struct {
	id     int
	ctx    context.Context
	cncl   context.CancelFunc
	writer io.Writer
}

func NewTask(id int, ctx context.Context, writer io.Writer) *Task {
	nctx, cncl := context.WithCancel(ctx)
	t := &Task{
		id:     id,
		ctx:    nctx,
		cncl:   cncl,
		writer: writer,
	}
	return t
}

func (t *Task) Task() error {
	tstr := time.Now().Format(time.RFC3339Nano)
LabelLoop:
	for {
		_, _ = fmt.Fprintf(t.writer, "[Task %d] printing, time=%s.\n", t.id, tstr)
		jitter := rand.Int31n(1000)
		sltime := time.Duration(jitter+1000) * time.Millisecond
		time.Sleep(sltime)
		select {
		case <-t.ctx.Done():
			{
				break LabelLoop
			}
		default:
			continue LabelLoop
		}
	}
	_, _ = fmt.Fprintf(t.writer, "[Task %d] printing task end.\n", t.id)
	return nil
}

func (t *Task) Cancel(_ error) {
	t.cncl()
}