有没有办法在Golang中每隔一段时间做一次重复的任务？

Question

有没有办法在Go中执行重复的后台任务？我在考虑类似Timer.schedule(task, delay, period)Java 的东西.我知道我可以用goroutine做到这一点Time.sleep(),但是我想要一些容易停止的东西.

这是我得到的,但看起来很难看.有更干净/更好的方式吗？

func oneWay() {
    var f func()
    var t *time.Timer

    f = func () {
        fmt.Println("doing stuff")
        t = time.AfterFunc(time.Duration(5) * time.Second, f)
    }

    t = time.AfterFunc(time.Duration(5) * time.Second, f)

    defer t.Stop()

    //simulate doing stuff
    time.Sleep(time.Minute)
}

Answer 1

该函数time.NewTicker创建一个发送周期性消息的通道,并提供一种停止它的方法.使用它像这样(未经测试):

ticker := time.NewTicker(5 * time.Second)
quit := make(chan struct{})
go func() {
    for {
       select {
        case <- ticker.C:
            // do stuff
        case <- quit:
            ticker.Stop()
            return
        }
    }
 }()

您可以通过关闭quit频道来停止工作人员:close(quit).

Answer 2

怎么样的

package main

import (
    "fmt"
    "time"
)

func schedule(what func(), delay time.Duration) chan bool {
    stop := make(chan bool)

    go func() {
        for {
            what()
            select {
            case <-time.After(delay):
            case <-stop:
                return
            }
        }
    }()

    return stop
}

func main() {
    ping := func() { fmt.Println("#") }

    stop := schedule(ping, 5*time.Millisecond)
    time.Sleep(25 * time.Millisecond)
    stop <- true
    time.Sleep(25 * time.Millisecond)

    fmt.Println("Done")
}

操场

Answer 3

如果你不关心滴答移位(取决于每次执行之前花了多长时间)并且你不想使用通道,则可以使用原生范围功能.

即

package main

import "fmt"
import "time"

func main() {
    go heartBeat()
    time.Sleep(time.Second * 5)
}

func heartBeat() {
    for range time.Tick(time.Second * 1) {
        fmt.Println("Foo")
    }
}

操场

Answer 4

看看这个库:https://github.com/robfig/cron

示例如下:

c := cron.New()
c.AddFunc("0 30 * * * *", func() { fmt.Println("Every hour on the half hour") })
c.AddFunc("@hourly",      func() { fmt.Println("Every hour") })
c.AddFunc("@every 1h30m", func() { fmt.Println("Every hour thirty") })
c.Start()

Answer 5

如果您想随时停止它

ticker := time.NewTicker(500 * time.Millisecond)
go func() {
    for range ticker.C {
        fmt.Println("Tick")
    }
}()
time.Sleep(1600 * time.Millisecond)
ticker.Stop()

如果您不想停止它，请勾选：

tick := time.Tick(500 * time.Millisecond)
for range tick {
    fmt.Println("Tick")
}