Lockdown Learning – Day #45– WaitGroup & Goroutines in GoLang (Music Only)

Continuing with our lockdown learning of Go language. Here’s a video on WaitGroup in goroutines in Golang

A goroutine may have to wait for another goroutine to complete. Using time.Sleep() is a very crude way to wait. Here’s where WaitGroup comes to picture. This is similar to CountDownLatch in Java

package main

import (
	"fmt"
	"math/rand"
	"sync"
	"time"
)

func main() {
	//We need to ask main goroutine to wait for fixIssues() goroutine to complete its task
	wg := sync.WaitGroup{}
	wg.Add(1) //WaitGroup is like a countdown system. It will wait till the count is 1
	go fixIssues(&wg)

	//time.Sleep(time.Second * 5)//Not intuitive and correct too

	//Main go routine is waiting now
	//Blocking statement
	wg.Wait()
	fmt.Println("***Enough! I am done waiting")
}

func fixIssues(wg *sync.WaitGroup)  {
	defer wg.Done() //When the goroutine is completed, it sends a signal ie., it has completed for the lock to release
	i := 0
	rand.Seed(time.Now().UnixNano())
	iterations := rand.Intn(20)
	fmt.Println("Time required:", iterations, "seconds")
	for i < iterations {
		fmt.Println("Fixing Issues ...")
		time.Sleep(time.Second * 1)
		i++
	}

}