diff -r 000000000000 -r 08dd52950883 samples/deadlock/src/org/apidesign/javamonitorflaws/Cache.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/samples/deadlock/src/org/apidesign/javamonitorflaws/Cache.java	Tue Feb 10 18:36:21 2009 +0100
@@ -0,0 +1,40 @@
+package org.apidesign.javamonitorflaws;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ *
+ * @author Jaroslav Tulach <jtulach@netbeans.org>
+ */
+public abstract class Cache<From,To> {
+    private Map<From,To> cache;
+
+    public final To get(From f) {
+        for (;;) {
+            synchronized (this) {
+                if (cache == null) {
+                    cache = new HashMap<From, To>();
+                }
+                To t = cache.get(f);
+                if (t != null) {
+                    return t;
+                }
+            }
+
+            To newT = createItem(f);
+
+            synchronized (this) {
+                To t = cache.get(f);
+                if (t == null) {
+                    cache.put(f, newT);
+                    return newT;
+                } else {
+                    return t;
+                }
+            }
+        }
+    }
+
+    protected abstract To createItem(From f);
+}