Example of telling multiple go routines to stop and waiting for them to all stop.

multiple-workers-stopping.go

package main

import (
    "fmt"
    "time"
)

func doSomework(imDone chan bool, stopMe chan bool, breakTime int, name string) {
    outer:
        for {
            select {
            case <-stopMe:
                break outer
            default:
                fmt.Printf("Drone-%s is working\n", name)
                time.Sleep(time.Duration(breakTime) * time.Second)
            }	
        }

    imDone <- true
    return
}

func main() {
    stopWorker := make(chan bool)
    workersDone := make(chan bool)

    for i := 0; i < 3; i++ {
        go doSomework(workersDone, stopWorker, i+1, fmt.Sprintf("%d",i))
    }

    go func(breakEmUp chan bool) {
        time.Sleep(10 * time.Second)
        fmt.Println("stopping them")
        breakEmUp <- true
        breakEmUp <- true
        breakEmUp <- true
        return
    }(stopWorker)

    for j := 0; j < 3; j++ {
        <- workersDone
    }
    
    fmt.Println("All stopped.")
}