diff -r 000000000000 -r 3905a2e66b9b samples/reentrant/src/org/apidesign/reentrant/NonReentrantLock.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/samples/reentrant/src/org/apidesign/reentrant/NonReentrantLock.java	Sat Jun 14 09:54:36 2008 +0200
@@ -0,0 +1,22 @@
+package org.apidesign.reentrant;
+
+import java.util.concurrent.locks.ReentrantLock;
+
+final class NonReentrantLock extends ReentrantLock {
+    @Override
+    public void lock() {
+        if (isHeldByCurrentThread()) {
+            throw new IllegalStateException("Attempt to reentrant lock");
+        }
+        super.lock();
+    }
+
+    @Override
+    public void lockInterruptibly() throws InterruptedException {
+        if (isHeldByCurrentThread()) {
+            throw new IllegalStateException("Attempt to reentrant lock");
+        }
+        super.lockInterruptibly();
+    }
+    
+}