1、代码
2、运行
3、解析
1、代码
1 package main 2 3 import ( 4 "time" 5 "fmt" 6 ) 7 8 func waitFor(ch chan int) { 9 fmt.Println(time.Now(), "writing ...") 10 time.Sleep(1e9) 11 ch 12 fmt.Println(time.Now(), "wrote ...") 13 } 14 15 func main() { 16 var a chan int = make(chan int) 17 var b chan int = make(chan int) 18 var ch chan int = make(chan int) 19 20 go waitFor(ch) 21 22 var r int = 0 23 fmt.Println(time.Now(), "select ...") 24 select { 25 case x := a : 26 fmt.Println(time.Now(), "read from a...") 27 r = x 28 case x := b : 29 fmt.Println(time.Now(), "read from b...") 30 r = x 31 case x := ch : 32 fmt.Println(time.Now(), "read from ch...") 33 r = x 34 } 35 fmt.Println(time.Now(), "select over.., r = ", r) 36 time.Sleep(1e9) 37 fmt.Println(time.Now(), "over..") 38 }
2、运行
1 $ go run timeout.go
2 2015-07-19 00:35:23.859684465 0800 CST select ...
3 2015-07-19 00:35:23.861022451 0800 CST writing ...
4 2015-07-19 00:35:24.864462549 0800 CST wrote ...
5 2015-07-19 00:35:24.865185396 0800 CST read from ch...
6 2015-07-19 00:35:24.874655353 0800 CST select over.., r = 10
7 2015-07-19 00:35:25.888486739 0800 CST over..
3、解析
1)主线程中的select开始运行,对select中的3个channel进行阻塞等待
2)在线程(协程)waitFor中向ch写入数据
3)select收到数据,进行读取
4)主线程退出
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