commit Exercise_30_04

csv77 · csv77 · commit 7d733df5cbe6 · 2017-09-30T12:20:43.000+02:00
diff --git a/Chapter_30/exercise_30_04/Exercise_30_04.java b/Chapter_30/exercise_30_04/Exercise_30_04.java
@@ -0,0 +1,57 @@
+package exercise_30_04;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+public class Exercise_30_04 {
+    private int sum = new Integer(0);
+    
+    public Exercise_30_04(boolean isSynchronized) {
+        ExecutorService executor = Executors.newCachedThreadPool();
+        for(int i = 0; i < 1000; i++) {
+            if(isSynchronized) {
+                executor.execute(new SynchronizedSumTask());
+            }
+            else {
+                executor.execute(new SumTask());
+            }
+        }
+        
+        executor.shutdown();
+        
+        while(!executor.isTerminated()) {
+        }
+    }
+    
+    private class SumTask implements Runnable {
+
+        @Override
+        public void run() {
+            increaseSum();
+        }
+    }
+    
+    private class SynchronizedSumTask implements Runnable {
+
+        @Override
+        public void run() {
+            increaseSumWithSync();
+        }
+    }
+    
+    public void increaseSum() {
+        sum++;
+    }
+    
+    public synchronized void increaseSumWithSync() {
+        sum++;
+    }
+    
+    public static void main(String[] args) {
+        Exercise_30_04 sumTestWithoutSync = new Exercise_30_04(false);
+        Exercise_30_04 sumTestWithSync = new Exercise_30_04(true);
+        
+        System.out.println("The sum without synchronization is: " + sumTestWithoutSync.sum);
+        System.out.println("The sum with synchronization is: " + sumTestWithSync.sum);
+    }
+}
