Go by Example: Channel Synchronization

We can use channels to synchronize execution across goroutines. Here’s an example of using a blocking receive to wait for a goroutine to finish.

package main
import "fmt"
import "time"

This is the function we’ll run in a goroutine. The done channel will be used to notify another goroutine that this function’s work is done.

func worker(done chan bool) {
	fmt.Print("working...")
	time.Sleep(time.Second)
	fmt.Println("done")

Send a value to notify that we’re done.

	done <- true
}
func main() {

Start a worker goroutine, giving it the channel to notify on.

	done := make(chan bool, 1)
	go worker(done)

Block until we receive a notification from the worker on the channel.

	<-done
}
$ go run channel-synchronization.go      
working...done                  

If you removed the <- done line from this program, the program would exit before the worker even started.

Previous example: Channel Buffering.

Next example: Channel Directions.