Go routines and channels

I’m having a bit of a dabble with Go, as a by product of working with Elastic Search beats.

One thing I’ve been looking at today is the channels to allow two go routines to communicate with each other and I came up with a fairly cheesy way to play with implementing them.

package main

import "fmt"

func ping(c chan string) {
	for {
		msg := <-c
		if msg == "pong" {
			println(" .... " + msg)
			c <- "ping"
		}
	}
}

func pong(c chan string) {
	for {
		msg := <-c
		if msg == "ping" {
			print(msg)
			c <- "pong"
		}
	}
}

func main() {
	var c chan string = make(chan string)

	go ping(c)
	go pong(c)

	c <- "ping"
	var input string
	fmt.Scanln(&input)
}

Using the go keyword to essentially start the ping and pong in the logical processor and run concurrently. They both get passed a special chan string that acts as a shared channel for them to synchronise against.

The code results in an endless game of ping pong.

ping .... pong
ping .... pong
ping .... pong
ping .... pong
ping .... pong
ping .... pong

There you go. Almost certainly not the best Go ever written, but a start.