Lock examples

winterbe · winterbe · commit 83db0821847b · 2015-04-19T08:27:56.000+02:00
diff --git a/src/com/winterbe/java8/samples/concurrent/Lock1.java b/src/com/winterbe/java8/samples/concurrent/Lock1.java
@@ -0,0 +1,46 @@
+package com.winterbe.java8.samples.concurrent;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.locks.ReentrantLock;
+import java.util.stream.IntStream;
+
+/**
+ * @author Benjamin Winterberg
+ */
+public class Lock1 {
+
+    private static final int NUM_INCREMENTS = 10000;
+
+    private static ReentrantLock lock = new ReentrantLock();
+
+    private static int count = 0;
+
+    private static void increment() {
+        lock.lock();
+        try {
+            count++;
+        }
+        finally {
+            lock.unlock();
+        }
+    }
+
+    public static void main(String[] args) {
+        testLock();
+    }
+
+    private static void testLock() {
+        count = 0;
+
+        ExecutorService executor = Executors.newFixedThreadPool(2);
+
+        IntStream.range(0, NUM_INCREMENTS)
+                .forEach(i -> executor.submit(Lock1::increment));
+
+        ConcurrentUtils.stop(executor);
+
+        System.out.println(count);
+    }
+
+}
diff --git a/src/com/winterbe/java8/samples/concurrent/Lock2.java b/src/com/winterbe/java8/samples/concurrent/Lock2.java
@@ -0,0 +1,29 @@
+package com.winterbe.java8.samples.concurrent;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.locks.ReentrantLock;
+
+/**
+ * @author Benjamin Winterberg
+ */
+public class Lock2 {
+
+    public static void main(String[] args) {
+        ExecutorService executor = Executors.newFixedThreadPool(2);
+
+        ReentrantLock lock = new ReentrantLock();
+
+        executor.submit(() -> {
+            lock.lock();
+            try {
+                System.out.println(lock.isLocked());
+            } finally {
+                lock.unlock();
+            }
+        });
+
+        ConcurrentUtils.stop(executor);
+    }
+
+}
