add demo for custom CLH

src/main/java/threaddemo/lock/CLH.java

@@ -5,7 +5,6 @@ import java.util.concurrent.atomic.AtomicReference;
 /**
  * demo class for CLH. code from
  * <a href="https://mp.weixin.qq.com/s/jEx-4XhNGOFdCo4Nou5tqg">Java AQS 核心数据结构-CLH 锁</a>
- * This is only for demo, do not run the code this node class is not workable
  */
 public class CLH {
     private final ThreadLocal<Node> node = ThreadLocal.withInitial(Node::new);
@@ -15,14 +14,14 @@ public class CLH {
         private volatile boolean locked;
     }
 
-    private void lock() {
+    public void lock() {
         Node node = this.node.get();
         node.locked = true;
         Node pre = this.tail.getAndSet(node);
-        while (!pre.locked) ;
+        while (pre.locked) ;
     }
 
-    private void unlock() {
+    public void unlock() {
         final Node node = this.node.get();
         node.locked = false;
         this.node.set(new Node());

src/main/java/threaddemo/lock/CLHDemo.java

@@ -0,0 +1,36 @@
+package threaddemo.lock;
+
+public class CLHDemo {
+
+    public static void main(String[] args) throws InterruptedException {
+        CLH clh = new CLH();
+        Thread t1 = new Thread(() -> {
+            System.out.println("t1 start");
+            clh.lock();
+            try {
+                System.out.println("t1 get lock");
+                Thread.sleep(1000L);
+                System.out.println("t1 release lock");
+                clh.unlock();
+                System.out.println("t1 end");
+            } catch (InterruptedException e) {
+                throw new RuntimeException("interrupted");
+            }
+         });
+        t1.start();
+        Thread.sleep(10L);
+
+        Thread t2 = new Thread(() -> {
+            System.out.println("t2 start");
+            clh.lock();
+            System.out.println("t2 get lock");
+            clh.unlock();
+            System.out.println("t2 release lock");
+            System.out.println("t2 end");
+        });
+        t2.start();
+        t1.join();
+        t2.join();
+        System.out.println("main end");
+    }
+}