アルゴリズム－哲学者食事－アルビトレートソロ
2079 ワード
package com.mzs.demo4;
public class Fork {
private boolean[] forks = new boolean[] {false, false, false, false, false};
private int size = forks.length;
public synchronized void take(int id) throws InterruptedException {
while (forks[id % size] || forks[(id + 1) % size]) {
wait();
}
forks[id % size] = true;
forks[(id + 1) % size] = true;
}
public synchronized void put(int id) {
forks[id % size] = false;
forks[(id + 1) % size] = false;
notifyAll();
}
}
package com.mzs.demo4;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadLocalRandom;
public class Philosopher implements Runnable {
private int id;
private Fork fork;
public Philosopher(int id, Fork fork) {
this.id = id;
this.fork = fork;
}
@Override
public void run() {
while (true) {
try {
think();
fork.take(id);
eat();
fork.put(id);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
private void think() {
int time = (int) (Math.max(0.5, ThreadLocalRandom.current().nextDouble(1)) * 2000);
System.out.println("I am philosopher " + id + ", and I am thinking for " + time + " milliseconds");
try {
Thread.sleep(time);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
private void eat() {
int time = (int) (Math.max(0.5, ThreadLocalRandom.current().nextDouble(1)) * 2000);
System.out.println("I am philosopher " + id + ", and I am eating for " + time + " milliseconds");
try {
Thread.sleep(time);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
ExecutorService service = Executors.newFixedThreadPool(5);
Fork fork = new Fork();
for (int i = 0; i < 5; i++) {
Runnable runnable = new Philosopher(i, fork);
service.execute(runnable);
}
service.shutdown();
}
}