ReadWriteLock examples

winterbe · winterbe · commit 4a8a7e0a3000 · 2015-04-20T07:56:19.000+02:00
diff --git a/src/com/winterbe/java8/samples/concurrent/Lock3.java b/src/com/winterbe/java8/samples/concurrent/Lock3.java
@@ -0,0 +1,70 @@
+package com.winterbe.java8.samples.concurrent;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.locks.ReadWriteLock;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+
+/**
+ * @author Benjamin Winterberg
+ */
+public class Lock3 {
+
+    public static void main(String[] args) {
+        ExecutorService executor = Executors.newFixedThreadPool(2);
+
+        Map<String, String> map = new HashMap<>();
+
+        ReadWriteLock lock = new ReentrantReadWriteLock();
+
+        executor.submit(() -> {
+            lock.writeLock().lock();
+            try {
+                TimeUnit.SECONDS.sleep(1);
+                map.put("foo", "bar");
+            }
+            catch (InterruptedException e) {
+                throw new IllegalStateException(e);
+            }
+            finally {
+                lock.writeLock().unlock();
+            }
+        });
+
+        executor.submit(() -> {
+            lock.readLock().lock();
+            try {
+                String foo = map.get("foo");
+                System.out.println(foo);
+                TimeUnit.SECONDS.sleep(1);
+            }
+            catch (InterruptedException e) {
+                throw new IllegalStateException(e);
+            }
+            finally {
+                lock.readLock().unlock();
+            }
+        });
+
+        executor.submit(() -> {
+            lock.readLock().lock();
+            try {
+                String foo = map.get("foo");
+                System.out.println(foo);
+                TimeUnit.SECONDS.sleep(1);
+            }
+            catch (InterruptedException e) {
+                throw new IllegalStateException(e);
+            }
+            finally {
+                lock.readLock().unlock();
+            }
+        });
+
+        ConcurrentUtils.stop(executor);
+    }
+
+}
