ch9.go

ch9.go

package main

import (
	"fmt"
	"os"
	"strconv"
	"time"
)

func main() {
	num, _ := strconv.Atoi(os.Args[1])

	first := make(chan bool)
	out := make(chan bool)
	go flipper(first, out)

	then := time.Now()
	fmt.Printf("Building a chain with %d goroutines\n", num)

	var in chan bool
	for i := 0; i < num; i++ {
		in = out
		out = make(chan bool)
		go flipper(in, out)
	}

	fmt.Printf("Chain built in %v\n", time.Now().Sub(then))

	then = time.Now()
	first <- true
	<-out

	fmt.Printf("Sent finished in %v\n", time.Now().Sub(then))
}

func flipper(in chan bool, out chan bool) {
	r := <-in
	out <- !r
}