package main

import (
	"log"
	"time"
)

func main() {
	log.SetFlags(log.LstdFlags | log.Lshortfile)

	interval := 20
	sleepTime := time.Second*5
	var a []map[int]int64 // id:lasttime
	for i := 0; i < 15; i++ {
		a = append(a, map[int]int64{i:0})
	}
	fn := func() {
		for id, m := range a {
			now := time.Now().Unix()
			if m[id] == 0 {
				m[id] = now
			} else {
				if int(now - m[id]) >= interval {
					log.Println(id, time.Now())
					m[id] = now
					time.Sleep(sleepTime)
				}
			}
		}
	}
	tk := time.NewTicker(time.Second)
	go func() {
		for range tk.C {
			fn()
		}
	}()
	time.Sleep(sleepTime*100)
}