Go: Broadcast a signal on a channel
When you close a channel, all readers receive a zero value.
In this example the Publish
function returns a channel, which is used to broadcast a signal when a message has been published.
// Print text after the given time has expired.
// When done, the wait channel is closed.
func Publish(text string, delay time.Duration) (wait <-chan struct{}) {
ch := make(chan struct{})
go func() {
time.Sleep(delay)
fmt.Println("BREAKING NEWS:", text)
close(ch) // Broadcast to all receivers
}()
return ch
}
Notice that we use a channel of empty structs: struct{}
. This clearly indicates that the channel will only be used for signalling, not for passing data.
This is how you may use the function.
func main() {
wait := Publish("Channels let goroutines communicate.", 5*time.Second)
fmt.Println("Waiting for the news...")
<-wait
fmt.Println("The news is out, time to leave.")
}
Comments
Be the first to comment!