WaitGroup够程,我从博客https://nathanleclaire.com/blog/2014/02/15/how-to-wait-for-all-goroutines-to-finish-executing-before-continuing/与渠道
学习WaitGroup
代码:
package main
import (
"fmt"
"sync"
"time"
)
func main() {
messages := make(chan int)
var wg sync.WaitGroup
// you can also add these one at
// a time if you need to
wg.Add(3)
go func() {
defer wg.Done()
time.Sleep(time.Second * 3)
messages <- 1
}()
go func() {
defer wg.Done()
time.Sleep(time.Second * 2)
messages <- 2
}()
go func() {
defer wg.Done()
time.Sleep(time.Second * 1)
messages <- 3
}()
go func() {
for i := range messages {
fmt.Println(i)
}
}()
wg.Wait()
}
我认为应该以打印3,2和1。但它只打印3,2,但1丢失,问题是什么?
您可以树它https://play.golang.org/p/kZCvDhykYM
或者,使它成为'wg.Add(4)',并在打印例程中放置一个'wg.Done()'作为好。也就是说,我个人更喜欢把'wg.Wait()'放在goroutine中,并使用通道闭包作为“完成”信号:https://play.golang.org/p/o-EYS_fK2k – Kaedys