Worker Pool Concurrency Pattern in Go

workerpool.go

package main

import (
	"fmt"
	"sync"
)

const (
	NUM_WORKERS = 10
	NUM_JOBS    = 10000
)

func main() {
	jobs := make(chan int)
	var wg sync.WaitGroup

	go Run(jobs, &wg)
	Dispatch(jobs, &wg)

	wg.Wait()
}

func Dispatch(jobs chan<- int, wg *sync.WaitGroup) {
	defer close(jobs)

	for i := 1; i <= NUM_JOBS; i++ {
		wg.Add(1)
		fmt.Printf("Sending %d\n", i)
		jobs <- i
	}
}

func Run(jobs <-chan int, wg *sync.WaitGroup) {

	for i := 1; i <= NUM_WORKERS; i++ {

		// Spin up a new worker
		k := i
		go func() {
			for job := range jobs {
				fmt.Printf("%d th Worker received %d\n", k, job)
				wg.Done()
			}
		}()
	}
}