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Go by Example - Select

翻译自 https://gobyexample.com/

Go by Example

Go is an open source programming language designed for building simple, fast, and reliable software.

Go by Example is a hands-on introduction to Go using annotated example programs. Check out the first example or browse the full list below.

Go by Example: Select

select允许程序等待多个管道操作,使用select来组合goroutinechannel是golang的一项重要的功能。

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package main
import "time"
import "fmt"
func main() {
// 定义两个管道用来测试`select`
c1 := make(chan string)
c2 := make(chan string)
// 每个管道变量在独立的goroutine中隔若干时间后接收到一个值,用来模拟阻塞的RPC调用
go func() {
time.Sleep(time.Second * 1)
c1 <- "one"
}()
go func() {
time.Sleep(time.Second * 2)
c2 <- "two"
}()
// 使用`select`同时等待这些管道变量,并且当管道有值时就将其打印出来
for i := 0; i < 2; i++ {
select {
case msg1 <- c1:
fmt.Println("received", msg1)
case msg2 <- c2:
fmt.Println("received", msg2)
}
}
}
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$ time go run select.go
received one
received two
// 由于两个睡眠操作是并行执行的,所以执行时间并没有超过3秒
real 0m2.245s

原文链接:Go by Example: Select