Random

signal
constructor

pp.A1-CondPhilosophers/src/main/java/pp/Philosopher.java

@@ -3,6 +3,7 @@ package pp;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.Condition;
 import static pp.PhilosopherExperiment.*;
+import java.util.Random;
 
 
 public class Philosopher extends Thread implements IPhilosopher {
@@ -13,6 +14,13 @@ public class Philosopher extends Thread implements IPhilosopher {
 	private Condition canEat;
 	private volatile boolean eating = false;
 	private volatile boolean stopped = false;
+	private final Random random;
+
+	public Philosopher() {
+		this.random = new Random();
+		this.seat = 0;
+		this.stopped = false;
+	}
 
 	@Override
 	public void setLeft(IPhilosopher left) {
@@ -71,15 +79,15 @@ public class Philosopher extends Thread implements IPhilosopher {
 		try {
 			eating = false;
 			log(seat, "hat fertig gegessen");
-			left.signal();
-			right.signal();
+			left.canEat.signal();
+			right.canEat.signal();
 		} finally {
 			table.unlock();
 		}
 	}
 
 	private void eat() throws InterruptedException {
-		Thread.sleep((long) (Math.random() * MAX_EATING_DURATION_MS));
+		Thread.sleep(random.nextInt(MAX_EATING_DURATION_MS));
 	}
 
 
@@ -101,22 +109,14 @@ public class Philosopher extends Thread implements IPhilosopher {
 
 	private void think() throws InterruptedException {
 		log(seat, "denkt");
-		Thread.sleep((long) (Math.random() * MAX_THINKING_DURATION_MS));
+		Thread.sleep(random.nextInt(MAX_THINKING_DURATION_MS));
 		table.lock();
 		try {
-			left.signal();
-			right.signal();
+			left.canEat.signal();
+			right.canEat.signal();
 		} finally {
 			table.unlock();
 		}
 	}
 
-	public void signal() {
-		table.lock();
-		try {
-			canEat.signal();
-		} finally {
-			table.unlock();
-		}
-	}
 }