Golang context cancel multiple sleep

main.go

package main

import (
	"context"
	"fmt"
	"time"
)

func main() {
	ctx, cancel := context.WithCancel(context.Background())

	for i := 1; i <= 5; i++ {
		go SleepCanBreak(ctx, 5, i)
	}
	fmt.Println("finish for")

	time.Sleep(1 * time.Second)
	cancel()
	fmt.Println("cancel ed")

	// wait all goroutine finish
	time.Sleep(1 * time.Second)

	fmt.Println("all finish")
}

func SleepCanBreak(ctx context.Context, sleep int, i int) (isBreak bool) {
	select {
	case <-ctx.Done():
		isBreak = true
		fmt.Printf("ctx.Done(), i: %d\n", i)
	case <-time.After(time.Duration(sleep) * time.Second):
		isBreak = false
		fmt.Printf("sleep, i: %d\n", i)
	}
	return
}

// may print like:
// --------------------
// finish for
// cancel ed
// ctx.Done(), i: 1
// ctx.Done(), i: 5
// ctx.Done(), i: 3
// ctx.Done(), i: 4
// ctx.Done(), i: 2
// finish
// --------------------