检查点同步是同步多个任务的问题。考虑一个车间，几个工人组装一些机制的细节。当他们每个人都完成他的工作时，他们会把细节放在一起。没有商店，所以先完成部分的工人必须等待其他人才能开始另一个。将细节放在一起是任务在路径分开之前自我同步的检查点。

示例代码：

package main

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

func worker(part string) {
	log.Println(part, "worker begins part")
	time.Sleep(time.Duration(rand.Int63n(1e6)))
	log.Println(part, "worker completes part")
	wg.Done()
}

var (
	partList    = []string{"A", "B", "C", "D"}
	nAssemblies = 3
	wg          sync.WaitGroup
)

func main() {
	rand.Seed(time.Now().UnixNano())
	for c := 1; c <= nAssemblies; c++ {
		log.Println("begin assembly cycle", c)
		wg.Add(len(partList))
		for _, part := range partList {
			go worker(part)
		}
		wg.Wait()
		log.Println("assemble.  cycle", c, "complete")
	}
}

输出：

2019/07/15 16:10:32 begin assembly cycle 1
2019/07/15 16:10:32 D worker begins part
2019/07/15 16:10:32 A worker begins part
2019/07/15 16:10:32 B worker begins part
........
2019/07/15 16:10:32 D worker completes part
2019/07/15 16:10:32 C worker completes part
2019/07/15 16:10:32 assemble.  cycle 3 complete