Example of Concurrent Processing With Channels

concurrent.go

package main

import (
    "context"
    "flag"
    "fmt"
    "runtime"

    ipgen "github.com/wahyuhadi/go-ipgen"
)

var (
    workerCount = flag.Int("wk", runtime.NumCPU(), "Worker count")
    subnet      = flag.String("subnet", "192.168.1.1/24", "Subnet Network")
)

func main() {
    flag.Parse()

    ip := ipgen.IpAddressGen(*subnet)
    ctx, cancel := context.WithCancel(context.Background())
    defer cancel()

    doneChan := make(chan bool, *workerCount)
    retChan := make(chan string, *workerCount)
    for i := 0; i < *workerCount; i++ {
        go work(ctx, retChan, doneChan)
    }

    go func() {
        for _, i := range ip {
            retChan <- i
        }
    }()

    for i := 0; i < len(ip); i++ {
        <-doneChan
    }
}

func work(ctx context.Context, retChan <-chan string, doneChan chan<- bool) {
    for {
        select {
        case <-ctx.Done():
            return
        case ip := <-retChan:
            fmt.Println(ip)
            doneChan <- true
        }
    }
}