[Go] p2 multi-producer-consumer

package main
//2020  Aion Algos#9218 http://discord.futuregadgetlab.net
import (
  "fmt"
  "time"
  "sync"
)

func main() {
  fmt.Println("Multi-Producer-Consumer example starting.")
  quantity_per_producer := 100
  producers := 5
  consumers := 20
  buffer := 1

  queue := make(chan int, buffer)

  var pwg sync.WaitGroup
  pwg.Add(producers)
  for i := 0; i < producers; i++ {
    go producer(i, &pwg, queue, quantity_per_producer)
  }

  var cwg sync.WaitGroup
  cwg.Add(consumers)
  for i := 0; i < consumers; i++ {
    go consumer(i, &cwg, queue)
  }

  pwg.Wait()
  close(queue)
  cwg.Wait()
  fmt.Println("Multi-Producer-Consumer example complete.")
}

func consumer(id int, wg *sync.WaitGroup, queue <-chan int) {
  fmt.Println("Consumer", id, "started.")
  defer wg.Done()
  for q := range queue {
    fmt.Println("Consumer", id, "recieved:", q)
    time.Sleep(time.Millisecond * 200)
  }
  fmt.Println("Consumer", id, "done.")
}

func producer(id int, wg *sync.WaitGroup, queue chan<- int, quantity int) {
  defer wg.Done()
  fmt.Println("Producer", id, "started.")
  for i := 0; i < quantity; i++ {
    queue<- i
    fmt.Println("Producer", id, "produced:", i)
  }
  fmt.Println("Producer", id, "done.")
}