The hot replacement method of Golang's Channel

chan_hotrepl_fixed.go

package main

import (
	"fmt"
	"sync"
	"time"
)

const CHANGE_SIGN = -1 // The last element of the useless chan1

var chan1 chan int
var chanLength int = 18
var interval time.Duration = 1500 * time.Millisecond

var rwmutex sync.RWMutex // The mutex for protect chan1

func main() {
	chan1 = make(chan int, chanLength)
	go func() {
		for i := 0; i < chanLength; i++ {

			if i > 0 && i%3 == 0 {
				rwmutex.Lock()
				fmt.Println("Reset chan1...")
				chan1 <- CHANGE_SIGN
				chan1 = make(chan int, chanLength)
				rwmutex.Unlock()
			}
			fmt.Printf("Send element %d...\n", i)
			getChan() <- i
			time.Sleep(interval)
		}
		fmt.Println("Close chan1...")
		close(chan1)
	}()
	receive()
}

func receive() {
	fmt.Println("Begin to receive elements from chan1...")
	timer := time.After(30 * time.Second)
Loop:
	for {
		chan2 := getChan()
		select {
		case e, ok := <-chan2:
			if !ok {
				fmt.Println("--chan1 closed.")
				break Loop
			}
			if e == CHANGE_SIGN {
				close(chan2)
				continue
			}
			fmt.Printf("Received an element: %d\n", e)
			time.Sleep(interval)
		case <-timer:
			fmt.Println("Timeout!")
			break Loop
		}
	}
	fmt.Println("--End.")
}

func getChan() chan int {
	rwmutex.RLock()
	defer rwmutex.RUnlock()
	return chan1
}

chan_hotrepl_go1.4.go

package main

import (
	"fmt"
	"time"
)

var chan1 chan int
var chanLength int = 18
var interval time.Duration = 1500 * time.Millisecond

func main() {
	chan1 = make(chan int, chanLength)
	go func() {
		for i := 0; i < chanLength; i++ {
			if i > 0 && i%3 == 0 {
				fmt.Println("Reset chan1...")
				chan1 = make(chan int, chanLength)
			}
			fmt.Printf("Send element %d...\n", i)
			chan1 <- i
			time.Sleep(interval)
		}
		fmt.Println("Close chan1...")
		close(chan1)
	}()
	receive()
}

func receive() {
	fmt.Println("Begin to receive elements from chan1...")
	timer := time.After(30 * time.Second)
Loop:
	for {
		select {
		case e, ok := <-getChan():
			if !ok {
				fmt.Println("--chan1 closed.")
				break Loop
			}
			fmt.Printf("Received an element: %d\n", e)
			time.Sleep(interval)
		case <-timer:
			fmt.Println("Timeout!")
			break Loop
		}
	}
	fmt.Println("--End.")
}

func getChan() chan int {
	return chan1
}

chan_hotrepl_go1.5.go

package main

import (
	"fmt"
	"time"
)

var chan1 chan int
var chanLength int = 18
var interval time.Duration = 1500 * time.Millisecond

func main() {
	chan1 = make(chan int, chanLength)
	go func() {
		for i := 0; i < chanLength; i++ {
			if i > 0 && i%3 == 0 {
				go func() {
					fmt.Println("Reset chan1...")
					chan1 = make(chan int, chanLength)
				}()
			}
			fmt.Printf("Send element %d...\n", i)
			chan1 <- i
			time.Sleep(interval)
		}
		fmt.Println("Close chan1...")
		close(chan1)
	}()
	receive()
}

func receive() {
	fmt.Println("Begin to receive elements from chan1...")
	timer := time.After(30 * time.Second)
Loop:
	for {
		select {
		case e, ok := <-getChan():
			if !ok {
				fmt.Println("--chan1 closed.")
				break Loop
			}
			fmt.Printf("Received an element: %d\n", e)
			time.Sleep(interval)
		case <-timer:
			fmt.Println("Timeout!")
			break Loop
		}
	}
	fmt.Println("--End.")
}

func getChan() chan int {
	return chan1
}