This simple program writen in Golang show how to transfer messages by go chanels, and how to sync the goroutines output

sync-and-chanels.go

package main

/*
	This simple program show how to transfer messages by go chanels,
	and how to sync the goroutines output

*/

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

const workersn int = 50

func main() {
	c := make(chan string)
	var wg sync.WaitGroup

	// Adding 50 wait locks to WaitGroup
	wg.Add(workersn)

	// Start 50 goroutines
	for i := 0; i < workersn; i++ {
		// anonymous function for printing a common message
		go func(i int) {

			// This remove a wait lock
			defer wg.Done()

			d := rand.Intn(5000)
			time.Sleep(time.Duration(d) * time.Millisecond)
			// Printing a common message
			c <- fmt.Sprintf("Go routine %d done.", i)
		}(i)
	}

	// this goroutine print the content of the others
	go func(c chan string) {
		for j := 0; j < workersn; j++ {

			// Receive the message from other goroutines by chanel
			fmt.Println(<-c)
		}
	}(c)

	// Put it in idle until all goroutines are done
	// When all the locks was removed the program go ahead
	wg.Wait()
}