consumer-producer.go

package main

import (
	crypto "crypto/rand"
	"fmt"
	"math/big"
	"time"
)

func main() {
	producer := make(chan int64)

	// producer
	go func() {
		for {
			var bigN *big.Int
			val := *big.NewInt(4)

			bigN, _ = crypto.Int(crypto.Reader, &val)
			time.Sleep(time.Duration(bigN.Int64()) * time.Second)
			newN, _ := crypto.Int(crypto.Reader, &val)
			producer <- newN.Int64()
		}
	}()

	// the consumer is the main itself
	for {
		select {
		case got := <-producer:
			fmt.Println("Producer sent in something: ", got)

		case <-time.After(3 * time.Second):
			fmt.Println("you're too slow, feed me faster!")
			return

		}
	}
}