Go Routine Behaviour Controlling using Channel

interview-ques-01.go

package main

// Problem :
// Create a go routine that will loop and sleep for 1 second. When it wakes up it will print out the time.
//The main routine will wait for 20 seconds and then sends a termination signal to the go routine.

import (
	"time"
	"fmt"
)

// work has two channel one for controlling the chanel and other for getting the
// output out of the channel before quiting , like the duration of the routine in this case

func work(quit chan bool, t chan string,  start time.Time, elapse time.Duration) {

	select {
	case <- quit:
		t <- elapse.String()
		return
	default:
		for i :=0 ; i < 10; i++ {
			fmt.Println(i)
		}
    time.Sleep(time.Second)
    
    // It wakes up and prints how many time it slept !
		fmt.Println("1 Sec Sleep")
    
		elapse = time.Since(start)
	}

	// Loop until you get the signal form chanel quit
	work(quit, t, start, elapse)
}

func main(){

	// two channel initialization
	t := make(chan string)
	quit := make(chan bool)

	// start time is now and elapse time is 0
	start := time.Now()
	elapse := 0 * time.Microsecond

	// start the go routine passing all the parameter
	go work(quit, t,  start, elapse)

	// sleep the main routine for 20 sec while the work routine still working
	time.Sleep(20 * time.Second)

	// send quit signal to the work channel
	quit <- true

	// print the result from the work channel , in this case the duration time the channel is up or working
	fmt.Println(<-t)

}