package main
 
import (
    "log"
    "math/rand"
    "os"
    "time"
)
 
// Number of philosophers is simply the length of this list.
// It is not otherwise fixed in the program.
var ph = []string{"Aristotle", "Kant", "Spinoza", "Marx", "Russell"}
 
const nBites = 3 // number of times each philosopher eats
 
var fmt = log.New(os.Stdout, "", 0) // for thread-safe output
 
// This solution uses channels to implement synchronization.
// Sent over channels are "forks."
type fork byte
 
// A fork object in the program obviously models a physical fork in the
// philosopher simulation.  In the more general context of resource
// sharing, the object would represent exclusive control of a resource.
// A separate channel represents each fork place.  Two philosophers
// have access to each fork.  The channels are buffered with capacity = 1,
// representing a place for a single fork.
 
// Goroutine for philosopher actions.  An instance is run for each
// philosopher.  Instances run concurrently.
func philosopher(phName string,
    dominantHand, otherHand chan fork, done chan bool) {
    fmt.Println(phName, "seated")
    rg := rand.New(rand.NewSource(time.Now().UnixNano()))
    for i := 0; i < nBites; i++ {
        fmt.Println(phName, "hungry")
        <-dominantHand // pick up forks
        <-otherHand
        fmt.Println(phName, "eating")
        time.Sleep(time.Duration(rg.Int63n(1e8)))
        dominantHand <- 'f' // put down forks
        otherHand <- 'f'
        fmt.Println(phName, "thinking")
        time.Sleep(time.Duration(rg.Int63n(1e8)))
    }
    fmt.Println(phName, "satisfied")
    done <- true
    fmt.Println(phName, "left the table")
}
 
func main() {
    fmt.Println("table empty")
    // Create fork channels and start philosopher goroutines,
    // supplying each goroutine with the appropriate channels
    done := make(chan bool)
    place0 := make(chan fork, 1)
    place0 <- 'f' // byte in channel represents a fork on the table.
    placeLeft := place0
    for i := 1; i < len(ph); i++ {
        placeRight := make(chan fork, 1)
        placeRight <- 'f'
        go philosopher(ph[i], placeLeft, placeRight, done)
        placeLeft = placeRight
    }
    // Make one philosopher left handed by reversing fork place
    // supplied to philosopher's dominant hand.
    // This makes precedence acyclic, preventing deadlock.
    go philosopher(ph[0], place0, placeLeft, done)
    // they are all now busy eating
    for _ = range ph {
        <-done // wait for philosphers to finish
    }
    fmt.Println("table empty")
}

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