DiningPhilo

src/praktikum04/BetterPhilosopher.java

+package praktikum04;
+
+public class BetterPhilosopher extends Philosopher{
+
+    public BetterPhilosopher(int id, Fork left, Fork right) {
+        super(id, left, right);
+    }
+
+    public void allocateForks() {
+        Fork fork1 = left;
+        Fork fork2 = right;
+
+        if(left.getId() > right.getId()) {
+            fork1 = right;
+            fork2 = left;
+        }
+
+        System.out.println("Philosopher" + id + "is trying to get a fork" + fork1.getId());
+        while(!fork1.take())
+            Thread.yield();
+        System.out.println("Philosopher" + id + "got a fork" + fork1.getId());
+
+        System.out.println("Philosopher" + id + "is trying to get a fork" + fork2.getId());
+        while(!fork2.take())
+            Thread.yield();
+        System.out.println("Philosopher" + id + "got a fork" + fork2.getId());
+
+    }
+
+}

src/praktikum04/Fork.java

+package praktikum04;
+
+public class Fork {
+
+
+    private boolean inUse = false;
+    private final int id;
+
+    public Fork(int id) {
+        this.id = id;
+    }
+
+    public int getId() {
+
+        return id;
+
+    }
+
+    public boolean take() {
+        synchronized (this) {
+            if(inUse) {
+                return false;
+            }
+            inUse = true;
+            try {
+                Thread.sleep(1000);
+            } catch (InterruptedException e) {
+                System.out.println("Gabel" + id + "konnte nicht angenommen werden");
+
+            }
+            return true;
+        }
+    }
+
+    public void put()  {
+        synchronized (this) {
+            inUse = false;
+        }
+
+    }
+}

src/praktikum04/Philosopher.java

+package praktikum04;
+
+import java.awt.desktop.AppHiddenListener;
+
+public class Philosopher implements Runnable{
+
+    protected int id ;
+    protected final Fork left;
+
+    protected final Fork right;
+
+    public Philosopher(int id, Fork left, Fork right) {
+        this.id = id;
+        this.left = left;
+        this.right = right;
+    }
+
+    @Override
+    public void run() {
+
+        allocateForks();
+        System.out.println("Philosopher " + id + " is eating");
+
+        try {
+            Thread.sleep(2000);
+        } catch (InterruptedException e) {
+            System.out.println("Philosopher" + id + "was interrupted");
+        }
+        left.put();
+        right.put();
+
+        System.out.println("Philosopher" + id + "is done eating");
+
+
+    }
+
+    protected void allocateForks() {
+        System.out.println("Philosopher" + id + "is trying to get a fork." + left.getId());
+        while (!left.take())
+            Thread.yield();
+        System.out.println("Philosopher" + id + "got fork" + left.getId());
+        System.out.println("Philosopher" + id + "is trying to get a fork" + right.getId());
+        while (!right.take())
+            Thread.yield();
+        System.out.println("Philosopher" + id + "got fork" + right.getId());
+    }
+}

src/praktikum04/Table.java

+package praktikum04;
+
+public class Table {
+
+    public static void main(String[] args) {
+        Fork[] forks = { new Fork(0), new Fork(1), new Fork(2),
+                new Fork(3), new Fork(4)};
+        Philosopher[] philosophers = {
+                new Philosopher(0, forks[0], forks[1]),
+                new Philosopher(1, forks[1], forks[2]),
+                new Philosopher(2, forks[2], forks[3]),
+                new Philosopher(3, forks[3], forks[4]),
+                new Philosopher(4, forks[4], forks[0])
+        };
+        for (Philosopher philosopher : philosophers) {
+            Thread t = new Thread(philosopher);
+            t.start();
+        }
+    }
+}

test/praktikum04/ForkTest.java

+package praktikum04;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class ForkTest {
+
+    @Test
+    void getId() {
+
+        Fork fork = new Fork(1);
+        fork.getId();
+    }
+
+    @Test
+    void take() {
+
+        Fork fork = new Fork(1);
+    }
+
+    @Test
+    void put() {
+
+        Fork fork = new Fork(1);
+        fork.take();
+
+        fork.put();
+
+
+    }
+}