package main

import (
	"time"
)

var forks [5]chan int

func main() {
	for i := 0; i < 5; i++ {
		forks[i] = make(chan int, 1)
	}

	for i := 0; i < 4; i++ {
		go philosopher(i, &forks[i], &forks[i+1])
	}

	go philosopher(4, &forks[0], &forks[4])

	//just to keep main thread alive long enough
	for {

	}
}

func philosopher(id int, lower *chan int, higher *chan int) {
	for {
		if tryAcquire(lower) {
			if tryAcquire(higher) {
				println(id, "is eating")
				time.Sleep(time.Millisecond * 1000)

				<-*higher
				<-*lower
			} else {
				<-*lower
				println(id, "is thinking")
				time.Sleep(time.Millisecond * 1000)
			}
		}
	}
}

func tryAcquire(channel *chan int) bool {
	select {
	case *channel <- 1:
		return true

	default:
		return false
	}

}