deadlock.go

package main

import (
	"fmt"
	"sync"
)

var m sync.Mutex

func main() {
	cPop := make(chan int, 1)
	cPush := make(chan int, 1)
	cCache := make(chan int, 100)

	go func() {
		for {
			select {
			case cCache <- <-cPush:
				m.Lock()
				fmt.Println("cCache <- <- cPush")
				m.Unlock()
			}
		}
	}()
	go func() {
		for {
			select {
			case cPop <- <-cCache:
				m.Lock()
				fmt.Println("cPop <- <- cCache")
				m.Unlock()
			}
		}
	}()
	go func() {
		for {
			select {
			case cPush <- <-cPop: // throw the ball again
				m.Lock()
				fmt.Println("cPush <- <- cPop")
				m.Unlock()
			}
		}
	}()

	n := 1
	cPush <- n
	fmt.Println("Push:", n) // throw ball in the endless-loop world

	select {}
}