Go Fan In and Restoring Sequence

faninseq.go

package main

import (
	"fmt"
	"math/rand"
	"time"
)

type Message struct {
	msg  string
	wait chan bool
}

func main() {

	c := FanIn(Msg("Tic"), Msg("Tac"))

	for i := 0; i <= 20; i++ {
		msg1 := <-c
		msg2 := <-c
		fmt.Printf("%q\n", msg1.msg)
		fmt.Printf("%q\n", msg2.msg)
		msg1.wait <- true
		msg2.wait <- true
	}

	fmt.Println("Main Program Exit!!!")
}

func Msg(msg string) <-chan Message {
	var waitForIt = make(chan bool)
	c := make(chan Message)
	go func() {
		for i := 0; ; i++ {
			c <- Message{fmt.Sprintf("%s %d", msg, i), waitForIt}
			time.Sleep(time.Duration(rand.Intn(1e3)) * time.Millisecond)
			<-waitForIt
		}
	}()
	return c
}

func FanIn(c1, c2 <-chan Message) <-chan Message {
	c := make(chan Message)
	go func() {
		for {
			c <- <-c1
		}
	}()
	go func() {
		for {
			c <- <-c2
		}
	}()
	return c
}

func FanInSelect(c1, c2 <-chan Message) <-chan Message {
	c := make(chan Message)
	go func() {
		for {
			select {
			case s := <-c1:
				c <- s
			case s := <-c2:
				c <- s
			}
		}
	}()
	return c
}