Skip to content

Instantly share code, notes, and snippets.

@akshaybharambe14
Created July 2, 2021 05:24
Show Gist options
  • Save akshaybharambe14/0a150a8098d11d809757e284bd4e5182 to your computer and use it in GitHub Desktop.
Save akshaybharambe14/0a150a8098d11d809757e284bd4e5182 to your computer and use it in GitHub Desktop.
Simple worker pool in golang/ https://play.golang.org/p/6SRS2KScnuu
// https://play.golang.org/p/6SRS2KScnuu
package main
import (
"fmt"
"sync"
"time"
)
const (
numJobs = 30
numWrks = 4
)
func main() {
run()
}
func run() {
var (
// we should have just enough buffer so that work producer should not block
in = make(chan int, numWrks)
out = make(chan int, numWrks)
wg sync.WaitGroup
)
// create a pool of wrokers
for i := 0; i < numWrks; i++ {
wg.Add(1)
go worker(i, in, out, &wg)
}
// produce some work in background
go func() {
for i := 0; i < numJobs; i++ {
in <- i // this could block if we exhaust the buffer, hence this producer must process in background
}
close(in) // signal that we have finished producing work, so that all workers will return
}()
// wait for all workers to finish
go func() {
wg.Wait()
// all workers returned, we can safely close the out chan
close(out) // signal that we have finished producing output
}()
for i := range out {
fmt.Printf("received %d\n", i)
}
fmt.Println("exiting...")
}
func worker(id int, in <-chan int, out chan<- int, wg *sync.WaitGroup) {
for i := range in {
out <- work(i)
fmt.Printf("worker id %d processed %d\n", id, i)
}
fmt.Printf("worker id %d finished working\n", id)
wg.Done() // signal that this worker has finished working
}
func work(i int) int {
time.Sleep(time.Second)
return i
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment