go例程，按所需顺序执行的函数

package main

import (
	"fmt"
	"sync"
)

func functionA(wg *sync.WaitGroup, ch chan string) {
	defer wg.Done()
	fmt.Println("Function A")
	ch <- "A"
}

func functionB(wg *sync.WaitGroup, ch chan string) {
	defer wg.Done()
	<-ch
	fmt.Println("Function B")
	ch <- "B"
}

func functionC(wg *sync.WaitGroup, ch chan string) {
	defer wg.Done()
	<-ch
	fmt.Println("Function C")
	ch <- "C"
}

func main() {
	var wg sync.WaitGroup
	ch := make(chan string, 3)

	wg.Add(3)
	go functionA(&wg, ch)
	go functionB(&wg, ch)
	go functionC(&wg, ch)

	wg.Wait()
	close(ch)
}

Function A
Function B
Function C