Golang Concurrency Pattern

gistfile1.go

package main

import (
    "sync"
    "fmt"
)

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

    wg.Add(1)
    go func() {
        for i := 0; i < 10; i++ {
            ch <- i
        }
        wg.Done()
    }()

    wg.Add(1)
    go func() {
        for i := 10; i < 20; i++ {
            ch <- i
        }
        wg.Done()
    }()

    go func() {
        wg.Wait()
        close(ch)
    }()

    for i := range ch {
        fmt.Println(i)
    }
}