From fa520c9ac171338aeb0367bfe42fe6f608028e47 Mon Sep 17 00:00:00 2001
From: Yan Wittmann <order@yanwittmann.de>
Date: Sun, 23 Oct 2022 12:03:58 +0200
Subject: [PATCH] Aufgabe 01

---
 .../ffi/parcoord/dining/cond/Philosopher.java | 49 ++++++++++++-------
 .../dining/cond/PhilosopherExperiment.java    | 10 ++--
 2 files changed, 36 insertions(+), 23 deletions(-)

diff --git a/src/main/java/io/dama/ffi/parcoord/dining/cond/Philosopher.java b/src/main/java/io/dama/ffi/parcoord/dining/cond/Philosopher.java
index 0c468c1..218312f 100644
--- a/src/main/java/io/dama/ffi/parcoord/dining/cond/Philosopher.java
+++ b/src/main/java/io/dama/ffi/parcoord/dining/cond/Philosopher.java
@@ -28,8 +28,8 @@ public class Philosopher extends Thread implements IPhilosopher {
     private Lock table;
     private Condition condition;
 
-    private boolean stop = false;
-    private boolean isEating = false;
+    private volatile boolean stop = false;
+    private volatile boolean isEating = false;
 
     private void log(String message) {
         synchronized (Philosopher.class) {
@@ -40,6 +40,15 @@ public class Philosopher extends Thread implements IPhilosopher {
         }
     }
 
+    private void err(String message) {
+        synchronized (Philosopher.class) {
+            for (var i = 1; i <= this.seat; i++) {
+                System.err.print(" ".repeat(40));
+            }
+            System.err.println(message);
+        }
+    }
+
     @Override
     public void setLeft(IPhilosopher left) {
         this.left = (Philosopher) left;
@@ -70,35 +79,39 @@ public class Philosopher extends Thread implements IPhilosopher {
     @Override
     public void run() {
         while (!this.stop) {
+            log("Philosopher " + seat + " is thinking");
             this.sleepRandomDuration(PhilosopherExperiment.MAX_THINKING_DURATION_MS);
+            log("Philosopher " + seat + " is done thinking");
 
+            this.table.lock();
             try {
-                this.table.lock();
                 while (this.left.isEating || this.right.isEating) {
-                    log("Philosopher " + seat + " is waiting for his neighbors to finish eating");
-                    this.left.condition.await();
-                    this.right.condition.await();
+                    log("Philosopher " + seat + " is waiting");
+                    this.condition.await();
+                    log("Philosopher " + seat + " is done waiting");
                 }
 
-                this.isEating = true;
-
                 log("Philosopher " + seat + " is taking chopsticks");
-
                 this.sleepRandomDuration(PhilosopherExperiment.MAX_TAKING_TIME_MS);
-                log("Philosopher " + seat + " is eating");
-
-                this.sleepRandomDuration(PhilosopherExperiment.MAX_EATING_DURATION_MS);
-                log("Philosopher " + seat + " is done eating");
-
-                this.isEating = false;
+                log("Philosopher " + seat + " took chopsticks");
 
+                this.isEating = true;
             } catch (InterruptedException e) {
-                log("Philosopher " + seat + " was interrupted");
-                throw new RuntimeException(e);
+                this.err("Philosopher " + seat + " was interrupted while waiting for the table");
             } finally {
-                this.condition.signalAll();
                 this.table.unlock();
             }
+
+            log("Philosopher " + seat + " is eating");
+            this.sleepRandomDuration(PhilosopherExperiment.MAX_EATING_DURATION_MS);
+            log("Philosopher " + seat + " is done eating");
+
+            this.table.lock();
+            this.isEating = false;
+            this.left.condition.signalAll();
+            this.right.condition.signalAll();
+            log("Philosopher " + seat + " is signaling");
+            this.table.unlock();
         }
 
         log("Philosopher " + seat + " has stopped");
diff --git a/src/main/java/io/dama/ffi/parcoord/dining/cond/PhilosopherExperiment.java b/src/main/java/io/dama/ffi/parcoord/dining/cond/PhilosopherExperiment.java
index 6b4001f..1cf31e9 100644
--- a/src/main/java/io/dama/ffi/parcoord/dining/cond/PhilosopherExperiment.java
+++ b/src/main/java/io/dama/ffi/parcoord/dining/cond/PhilosopherExperiment.java
@@ -4,11 +4,11 @@ import java.util.concurrent.locks.ReentrantLock;
 
 public class PhilosopherExperiment {
 
-    static final int MAX_THINKING_DURATION_MS = 3000; // 3000
-    static final int MAX_EATING_DURATION_MS = 3000; // 3000
-    static final int MAX_TAKING_TIME_MS = 100; // 100
-    static final int PHILOSOPHER_NUM = 5;
-    static final int EXP_DURATION_MS = 20000;
+    public static final int MAX_THINKING_DURATION_MS = 3000; // 3000
+    public static final int MAX_EATING_DURATION_MS = 3000; // 3000
+    public static final int MAX_TAKING_TIME_MS = 100; // 100
+    public static final int PHILOSOPHER_NUM = 5;
+    public static final int EXP_DURATION_MS = 20000;
 
     static IPhilosopher[] philosophers = new Philosopher[PHILOSOPHER_NUM];