// select.go
package main

import (
    "fmt"
    "time"

    //"time"
)

func main() {
    //聲明一個(gè)channel
    ch := make(chan int)

    //聲明一個(gè)匿名函數(shù)，傳入一個(gè)參數(shù)整型channel類型ch
    go func(ch chan int) {
        ch <- 1
        //往channel寫入一個(gè)數(shù)據(jù)，此時(shí)阻塞
    }(ch)

    //由于goroutine執(zhí)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類型ch一直處于讀取狀態(tài)，所以處于阻塞,使用select實(shí)現(xiàn)超時(shí)控制
package main

import (
    "fmt"
    "time"
)

func main() {
    ch := make(chan int)
    //buffer channel,1個(gè)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(méi)有讀到channel，實(shí)現(xiàn)超時(shí)控制
    case <-timeout:
        fmt.Print("come to timeout!")
    }

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

// select.go
//使用time.After實(shí)現(xiàn)超時(shí)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!")
}