Bu misolda goroutina va kanallar yordamida worker pool qanday qurilishini ko'ramiz.

package main

import (
    "fmt"
    "time"
)

// Worker — bir nechta nusxada parallel ishlaydi. Ular jobs kanalidan ish olib,
// results kanaliga natijani yuboradilar. Har ish uchun 1 soniya uxlab, qimmat ishni taqlid qilamiz.
func worker(id int, jobs <-chan int, results chan<- int) {
    for j := range jobs {
        fmt.Println("worker", id, "started  job", j)
        time.Sleep(time.Second)
        fmt.Println("worker", id, "finished job", j)
        results <- j * 2
    }
}

func main() {
    // Ishchilarimizga ish yuborish va natijalarni yig'ish uchun 2 ta kanal yaratamiz
    const numJobs = 5
    jobs := make(chan int, numJobs)
    results := make(chan int, numJobs)

    // 3 ta worker ishga tushadi; hozircha jobs bo'lmagani uchun bloklangan
    for w := 1; w <= 3; w++ {
        go worker(w, jobs, results)
    }

    // 5 ta ish yuboramiz va barcha ishlar tugaganini bildirish uchun jobs kanalini yopamiz
    for j := 1; j <= numJobs; j++ {
        jobs <- j
    }
    close(jobs)

    // Natijalarni yig'ib olamiz; shu bilan worker goroutinalarining tugashiga ham ishonch hosil qilamiz
    // Bir nechta goroutinani kutishning yana bir usuli — sync.WaitGroup ishlatish
    for a := 1; a <= numJobs; a++ {
        <-results
    }
}

Ishga tushirganda 5 ta ish turli workerlarda bajarilishini ko'rasiz. 3 ta worker parallel ishlayotgani uchun dastur ~2 soniya ichida tugaydi, garchi ishlar umumiy 5 soniya talab qilsa ham.

Terminalda bajarish:

$ time go run worker-pools.go 
worker 1 started  job 1
worker 2 started  job 2
worker 3 started  job 3
worker 1 finished job 1
worker 1 started  job 4
worker 2 finished job 2
worker 2 started  job 5
worker 3 finished job 3
worker 1 finished job 4
worker 2 finished job 5

real    0m2.358s