How would you define a pool of goroutines to be executed at once?

Question

TL;DR: Please just go to the last part and tell me how you would solve this problem.

I\'ve begun using Go this morning coming from Python. I want to call a closed-sou

Answer 1

I would spawn 4 worker goroutines that read the tasks from a common channel. Goroutines that are faster than others (because they are scheduled differently or happen to get simple tasks) will receive more task from this channel than others. In addition to that, I would use a sync.WaitGroup to wait for all workers to finish. The remaining part is just the creation of the tasks. You can see an example implementation of that approach here:

package main

import (
    "os/exec"
    "strconv"
    "sync"
)

func main() {
    tasks := make(chan *exec.Cmd, 64)

    // spawn four worker goroutines
    var wg sync.WaitGroup
    for i := 0; i < 4; i++ {
        wg.Add(1)
        go func() {
            for cmd := range tasks {
                cmd.Run()
            }
            wg.Done()
        }()
    }

    // generate some tasks
    for i := 0; i < 10; i++ {
        tasks <- exec.Command("zenity", "--info", "--text='Hello from iteration n."+strconv.Itoa(i)+"'")
    }
    close(tasks)

    // wait for the workers to finish
    wg.Wait()
}

There are probably other possible approaches, but I think this is a very clean solution that is easy to understand.