Is there a way to do repetitive tasks at intervals?
Is there a way to do repetitive background tasks in Go? I'm thinking of something like Timer.schedule(task, delay, period)
in Java. I know I can do this with a goroutine and Time.sleep()
, but I'd like something that easily stopped.
Here's what I got, but looks ugly to me. Is there a cleaner/better way?
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)
}
Solution 1:
The function time.NewTicker
makes a channel that sends a periodic message, and provides a way to stop it. Use it something like this (untested):
ticker := time.NewTicker(5 * time.Second)
quit := make(chan struct{})
go func() {
for {
select {
case <- ticker.C:
// do stuff
case <- quit:
ticker.Stop()
return
}
}
}()
You can stop the worker by closing the quit
channel: close(quit)
.
Solution 2:
If you do not care about tick shifting (depending on how long did it took previously on each execution) and you do not want to use channels, it's possible to use native range function.
i.e.
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")
}
}
Playground
Solution 3:
How about something like
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")
}
Playground