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. When waiting for multiple goroutines to finish, you may prefer to use a WaitGroup.

 
package main
 
import (
    "fmt"
    "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.

Next example: Channel Directions.

by Mark McGranaghan and Eli Bendersky | source | license