From b5fc96ef94427658e08c401e90d5469d4e582fd3 Mon Sep 17 00:00:00 2001
From: romanschenk37 <84532681+romanschenk37@users.noreply.github.com>
Date: Thu, 7 Apr 2022 13:31:57 +0200
Subject: [PATCH] Solved Task Philosopher

---
 .../zhaw/prog2/philosopher/ForkManager.java   | 25 +++++++++++++------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/code/Philosopher/src/main/java/ch/zhaw/prog2/philosopher/ForkManager.java b/code/Philosopher/src/main/java/ch/zhaw/prog2/philosopher/ForkManager.java
index bbef69e..6c2fa22 100644
--- a/code/Philosopher/src/main/java/ch/zhaw/prog2/philosopher/ForkManager.java
+++ b/code/Philosopher/src/main/java/ch/zhaw/prog2/philosopher/ForkManager.java
@@ -16,7 +16,7 @@ class ForkManager {
     // maximum concurrent threads acquiring forks - used for internal statistics
     private static final LockFreeMax concurrentAcquires = new LockFreeMax();
 
-    private final Lock mutex;       // shared mutex for all forks
+    //private final Lock mutex;       // shared mutex for all forks
     private final int delayTime;    // delay in milliseconds between acquiring / releasing the forks
     private final int numForks;     // amount of forks to be managed
     private final Fork[] forks;     // array of managed forks
@@ -27,12 +27,12 @@ class ForkManager {
      * @param delayTime    delay in milliseconds between acquiring / releasing the forks
      */
     public ForkManager(int numForks, int delayTime) {
-        this.mutex = new ReentrantLock();
+        //this.mutex = new ReentrantLock();
         this.delayTime = delayTime;
         this.numForks = numForks;
         this.forks = new Fork[numForks];
         for (int forkId = 0; forkId < numForks; forkId++)
-            forks[forkId] = new Fork(forkId, mutex);
+            forks[forkId] = new Fork(forkId);
     }
 
     /**
@@ -42,10 +42,15 @@ class ForkManager {
      * @param philosopherId id of the philosopher
      */
     public void acquireForks(int philosopherId) throws InterruptedException {
+        Fork leftFork = leftFork(philosopherId);
+        Fork rightFork = rightFork(philosopherId);
         // acquire forks sequentially
-        leftFork(philosopherId).acquire(philosopherId);
+        while(!(leftFork.getState() == FREE && rightFork.getState() == FREE)){
+            forkDelay();
+        }
+        leftFork.acquire(philosopherId);
         forkDelay();
-        rightFork(philosopherId).acquire(philosopherId);
+        rightFork.acquire(philosopherId);
     }
 
     /**
@@ -136,12 +141,12 @@ class ForkManager {
         /**
          * Constructor for a fork.
          * @param id    unique id of the fork
-         * @param mutex shared mutex to use for wait conditions
+         * //@param mutex shared mutex to use for wait conditions
          */
-        public Fork(int id, Lock mutex) {
+        public Fork(int id) {
             this.id = id;
             this.ownerId = -1;
-            this.mutex = mutex;
+            this.mutex = new ReentrantLock();;
             this.cond = mutex.newCondition();
         }
 
@@ -195,6 +200,10 @@ class ForkManager {
         public String toString() {
             return "Fork {" + "id=" + id + ", state=" + state + ", owner=" + ownerId + '}';
         }
+
+        public ForkState getState(){
+            return state;
+        }
     }
 
     /*