ReadWriteLock examples

Author: winterbe

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);
+ }
+
+}