on_user_channel_message_context.go

func startRedisListener() {
	ctx, cancelFn = context.WithCancel(context.Background())
	defer cancelFn()
	onUserChannelMessage(ctx, r, w)
	for {
		// ...do usual stuff
	}
}

func onUserChannelMessage(ctx context.Context, r <-chan *redis.Message, w chan string) {
	go func() {
		for {
			select{
				case m, ok := <-r:
				if !ok{
					return
				}
				w <- m.Payload
				// ctx.Done returns a channel which is closed when cancel function of that context is called
				case <-ctx.Done():
					return
			}	
		}
	}()
}