Go to Go - Concurrency Part#2

In last part, we talked about goroutines and channels. As discussed there is much more to channels, liked channel direction, by default a channel is bi-directional, but it can be restricted to sending or receiving.

In sender, receiver example from part, sender can only be restricted to sending, by redifining it like

func sender(ch chan <- int) {
  for i := 0; ; i++ {
    ch <- i

Now sender can only send signal to channel ch. Similarly receiver can be restricted just to receive, by redifining it like

func receiver(ch <- chan int) {
  for {
    message := <- ch
    fmt.Println("received: ", message)
    time.Sleep(time.Millisecond * 100)
Buffering in channels

Generally channels are synchronous, but they can have buffer of specified size. Buffer size can be specified by passing a second argument while creating a channel

ch := make(chan int, 10)

Now this channel can buffer at most 10 messages, working as a pub/sub.


Select work like a case switch for channels, basic construct looks like:

select {
case message_from_ch1 := <- ch1:
case message_from_ch2 := <- ch2:

Happy Channeling :)