fix

pp.A4-HandOverHandLocking/src/main/java/pp/Main.java

@@ -18,25 +18,25 @@ public class Main {
     }
 
     public static void main(String... args) throws InterruptedException {
-        list = new ThreadsafeSimplifiedList<>();
+    	  list = new ThreadsafeSimplifiedList<>();
-        for (int i = 0; i < 5000; i++) {
+          for (int i = 0; i < 5000; i++) {
-            list.add(i);
+              list.add(i);
-        }
+          }
-        var thread0 = new Thread(sliceSum(0, 1250, 780625));
+          var thread0 = new Thread(sliceSum(0, 1250, 780625));
-        var thread1 = new Thread(sliceSum(1250, 2500, 2343125));
+          var thread1 = new Thread(sliceSum(1250, 2500, 2343125));
-        var thread2 = new Thread(sliceSum(2500, 3750, 3905625));
+          var thread2 = new Thread(sliceSum(2500, 3750, 3905625));
-        var thread3 = new Thread(sliceSum(3750, 5000, 5468125));
+          var thread3 = new Thread(sliceSum(3750, 5000, 5468125));
-        var start = System.currentTimeMillis();
+          var start = System.currentTimeMillis();
-        thread0.start();
+          thread0.start();
-        thread1.start();
+          thread1.start();
-        thread2.start();
+          thread2.start();
-        thread3.start();
+          thread3.start();
-        thread0.join();
+          thread0.join();
-        thread1.join();
+          thread1.join();
-        thread2.join();
+          thread2.join();
-        thread3.join();
+          thread3.join();
-        System.out.printf("%s: %d ms\n", list.getClass().toString(),
+          System.out.printf("%s: %d ms\n", list.getClass().toString(),
-                System.currentTimeMillis() - start);
+                  System.currentTimeMillis() - start);
     }
 
 }

pp.A4-HandOverHandLocking/src/main/java/pp/ThreadsafeSimplifiedList.java

@@ -52,9 +52,8 @@ public class ThreadsafeSimplifiedList<T> implements SimplifiedList<T> {
 			}
 		}
 		try {
-			return (ptr.element);
+			return delay(ptr.element);
-		}
+		} finally {
-		finally {
 			ptr.lock.unlock();
 		}
 	}
@@ -113,10 +112,13 @@ public class ThreadsafeSimplifiedList<T> implements SimplifiedList<T> {
 				throw new IndexOutOfBoundsException(index + " out of bounds");
 			}
 		}
-		var prevElement = ptr.element;
+		try {
-		ptr.element = element;
+			var prevElement = ptr.element;
-		ptr.lock.unlock();
+			ptr.element = element;
-		return prevElement;
+			return prevElement;
+		} finally {
+			ptr.lock.unlock();
+		}
 	}
 
 	/**