java
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.locks.ReentrantLock;
class Philosopher implements Runnable{
private final String name;
private final ReentrantLock left;
private final ReentrantLock right;
private final AtomicInteger hunger = new AtomicInteger(3);
public Philosopher(String name, ReentrantLock left, ReentrantLock right) {
this.name = name;
this.left = left;
this.right = right;
}
@Override
public void run() {
while (this.hunger.get() > 0) {
System.out.println(name + " Hungry");
this.left.lock();
this.right.lock();
System.out.println(name + " Eating");
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
this.right.unlock();
this.left.unlock();
System.out.println(name + " Thinking");
this.hunger.decrementAndGet();
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
public class DiningPhilosopher {
public static void main(String[] args) {
ExecutorService executor = Executors.newCachedThreadPool();
String[] philosophers = new String[] {"Mark", "Russell", "Rocky", "Haris", "Root"};
ReentrantLock fork0 = new ReentrantLock();
ReentrantLock forkLeftLock = fork0;
List<Philosopher> philosopherList = new ArrayList<Philosopher>();
for(int i=1;i<philosophers.length;i++) {
String name = philosophers[i];
ReentrantLock forkRightLock = new ReentrantLock();
philosopherList.add(new Philosopher(name, forkLeftLock, forkRightLock));
forkLeftLock = forkRightLock;
}
philosopherList.add(new Philosopher(philosophers[0], fork0, forkLeftLock));
for (Philosopher philosopher : philosopherList) {
executor.submit(philosopher);
}
executor.shutdown();
}
}
go
package main
import (
"hash/fnv"
"log"
"math/rand"
"os"
"sync"
"time"
)
// 初始化5个人
var ph = []string{"Mark", "Russell", "Rocky", "Haris", "Root"}
const hunger = 3 // 每个哲学家吃几次饭
const think = time.Second / 100 // 思考时间
const eat = time.Second / 100 // 吃饭时间
var fmt = log.New(os.Stdout, "", 0)
var dining sync.WaitGroup
func diningProblem(phName string, dominantHand, otherHand *sync.Mutex) {
fmt.Println(phName, "Seated")
h := fnv.New64a()
h.Write([]byte(phName))
rg := rand.New(rand.NewSource(int64(h.Sum64())))
rSleep := func(t time.Duration) {
time.Sleep(t/2 + time.Duration(rg.Int63n(int64(t))))
}
for h := hunger; h > 0; h-- {
fmt.Println(phName, "Hungry")
dominantHand.Lock() // 获取资源
otherHand.Lock()
fmt.Println(phName, "Eating")
rSleep(eat)
dominantHand.Unlock() // 释放资源
otherHand.Unlock()
fmt.Println(phName, "Thinking")
rSleep(think)
}
fmt.Println(phName, "Satisfied")
dining.Done()
fmt.Println(phName, "Left the table")
}
func main() {
fmt.Println("Table empty")
dining.Add(5)
fork0 := &sync.Mutex{}
forkLeft := fork0
for i := 1; i < len(ph); i++ {
forkRight := &sync.Mutex{}
go diningProblem(ph[i], forkLeft, forkRight)
forkLeft = forkRight
}
go diningProblem(ph[0], fork0, forkLeft)
dining.Wait() // 等待结束
fmt.Println("Table empty")
}
