golang--使用channel来同步goroutine

系统管理员 2022-01-15 01:11 224阅读 0赞

[2019独角兽企业重金招聘Python工程师标准>>> ][2019_Python_] ![hot3.png][]

在golang中同步goroutine有2种方法，要么使用channel，要么使用sync.WaitGroup，本文就是介绍如何通过channel来同步goroutine。先看代码。

1 package main 2 
     3 import ( 4     "os"
     5     "os/signal"
     6     "runtime"
     7     "log"
     8     "syscall"
     9 ) 10 
    11 const NUM_OF_QUIT int = 100
    12 
    13 func main() { 14 runtime.GOMAXPROCS(runtime.NumCPU()) 15     done := make(chan bool) 16     receive_channel := make(chan chan bool) 17     finish := make(chan bool) 18 
    19 
    20     for i := 0; i < NUM_OF_QUIT; i++ { 21 go do_while_select(i, receive_channel, finish) 22 } 23 
    24 go handle_exit(done, receive_channel, finish) 25 
    26     <-done 27     os.Exit(0) 28 
    29 } 30 func handle_exit(done chan bool, receive_channel chan chan bool, finish chan bool) { 31     sigs := make(chan os.Signal, 1) 32 signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM) 33     chan_slice := make([]chan bool, 0) 34     for { 35         select { 36         case  <-sigs: 37             for _, v := range chan_slice { 38                 v <- true
    39 } 40             for i := 0; i < len(chan_slice); i++ { 41                 <-finish 42 } 43             done <- true
    44 runtime.Goexit() 45         case single_chan := <-receive_channel: 46             log.Println("the single_chan is ", single_chan) 47             chan_slice = append(chan_slice, single_chan) 48 } 49 } 50 } 51 func do_while_select(num int, rece chan chan bool, done chan bool) { 52     quit := make(chan bool) 53     rece <- quit 54     for { 55         select { 56         case <-quit: 57             done <- true
    58 runtime.Goexit() 59         default: 60             //简单输出
    61             log.Println("the ", num, "is running") 62 } 63 } 64 }

上面的代码保存为example.go，通过gotool编译代码：

go build example.go

在当前目录下有example文件，在终端运行这个文件

2013/03/19 21:17:14 the  0 is running 2013/03/19 21:17:14 the  0 is running 2013/03/19 21:17:14 the  0 is running 2013/03/19 21:17:14 the  0 is running 2013/03/19 21:17:14 the  0 is running 2013/03/19 21:17:14 the  0 is running 2013/03/19 21:17:14 the  0 is running 2013/03/19 21:17:14 the  0 is running 2013/03/19 21:17:14 the  0 is running 2013/03/19 21:17:14 the  0 is running 2013/03/19 21:17:14 the  0 is running 2013/03/19 21:17:14 the  0 is running 2013/03/19 21:17:14 the  0 is running 2013/03/19 21:17:14 the  0 is running
    ......

上面不断输出goroutine中的数字，等待退出信号。

新打开一个终端，通过ps找到这个进程名，通过kill工具干掉这个进程：

$ps aux | grep example user 4026 77.9  0.0  39436  1716 pts/1    Sl+  21:19   0:17 ./example $kill 4026

不久就可以看到在第一个终端里面不再打印，至此演示完毕。

代码思想：

新建NUM\_OF\_QUIT个goroutine，这些个goroutine里面新建1个chan bool，通过这个channel来接受退出的信号，这些channel在新建的时候，已经发给了handle\_exit。在handle\_exit这个goroutine里面，1方面监控由系统发过来的退出信号，然后再通知其他的goroutin优雅地退出；另一方面通过slice收集其他goroutine发过来的channel。handle\_exit通知其他的goroutine优雅退出后，再发信号给main进程主动退出。

可以修改NUM\_OF\_QUIT值，例如改为10000，这个时候，kill命令发出去后，要等待相当长的一段时间才能看到第一个终端停止打印。

参考：

## [Go by Example][]: Signals ##

[https://gobyexample.com/signals][https_gobyexample.com_signals]

**转贴请注明来自：[格通][Link 1]**

转载于:https://my.oschina.net/u/191928/blog/618675

[2019_Python_]: https://my.oschina.net/u/2663968/blog/3061697
[hot3.png]: /images/20220114/32bd70feaa184bc29bdcd1ab405cbe59.png
[Go by Example]: https://gobyexample.com/
[https_gobyexample.com_signals]: https://gobyexample.com/signals
[Link 1]: http://www.cnblogs.com/getong