golang-range-ticker-with-looper2.go

package main

import (
	"fmt"
	"runtime"
	"time"
)

type LED struct {
	state  bool
	ticker *time.Ticker
}

func toggle(led *LED) {
	led.state = !led.state
}

func looper(led *LED) {
	for range led.ticker.C {
		toggle(led)
	}
}

func looper2(led *LED, q chan bool) {
	for {
		select {
		case <-led.ticker.C:
			toggle(led)
		case <-q:
			fmt.Println("Exiting the goroutine")
			return
		}
	}
}

func main() {

	fmt.Println("Initial number of GoRoutines: ", runtime.NumGoroutine())

	led := &LED{state: true, ticker: time.NewTicker(time.Millisecond * 500)}
	q := make(chan bool)
	go looper2(led, q)
	// go looper(led)
	fmt.Println("Number of GoRoutines after a call to looper: ", runtime.NumGoroutine())

	time.Sleep(2 * time.Second)

	led.ticker.Stop()
	fmt.Println("Number of GoRoutines after stopping the ticker: ", runtime.NumGoroutine())

	q <- true
	fmt.Println("Number of GoRoutines after sending a message on the quit channel: ", runtime.NumGoroutine())
}