Execute Go Goroutines in Order

goroutines_order.go

package main

import (
	"fmt"
	"sync"
)

var wg sync.WaitGroup

func first(wait <-chan struct{}) {
	defer wg.Done()
	<-wait
	fmt.Println("first")
}

func second(wait <-chan struct{}) {
	defer wg.Done()
	<-wait
	fmt.Println("second")
}

func third(wait <-chan struct{}) {
	defer wg.Done()
	<-wait
	fmt.Println("third")
}

func main() {
	wg = sync.WaitGroup{}
	wg.Add(3)

	wait1 := make(chan struct{})
	wait2 := make(chan struct{})
	wait3 := make(chan struct{})

	go third(wait3)
	go first(wait1)
	go second(wait2)

	wait1 <- struct{}{}
	wait2 <- struct{}{}
	wait3 <- struct{}{}

	wg.Wait()
}