golang中select實現非阻塞及超時控制

摘要： // select.go package main import ( "fmt" "time" //"time" ) func main() { //宣告一個channel ch := make(ch...

// select.go
package main

import (
"fmt"
"time"

//"time"
)

func main() {
//宣告一個channel
ch := make(chan int)

//宣告一個匿名函式，傳入一個引數整型channel型別ch
go func(ch chan int) {
ch <- 1
//往channel寫入一個數據，此時阻塞
}(ch)

//由於goroutine執行太快，先讓它sleep 1秒
time.Sleep(time.Second)

select {
//讀取ch，解除阻塞
case <-ch:
fmt.Print("come to read ch!")
default:
fmt.Print("come to default!")
}
}

// select.go
//整型channel型別ch一直處於讀取狀態，所以處於阻塞,使用select實現超時控制
package main

import (
"fmt"
"time"
)

func main() {
ch := make(chan int)
//buffer channel,1個元素前非阻塞
timeout := make(chan int, 1)

go func() {
time.Sleep(time.Second)
//寫channel
timeout <- 1
}()

select {
//讀channel
case <-ch:
fmt.Print("come to read ch!")
//沒有讀到channel，實現超時控制
case <-timeout:
fmt.Print("come to timeout!")
}

fmt.Print("end of code!")
}

// select.go
//使用time.After實現超時控制
package main

import (
"fmt"
"time"
)

func main() {
ch := make(chan int)

select {
case <-ch:
fmt.Print("come to read ch!")
case <-time.After(time.Second):
fmt.Print("come to timeout!")
}

fmt.Print("end of code!")
}