--- /dev/null
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.log4j.helpers;
+
+import java.util.Hashtable;
+
+/**
+ <code>ThreadLocalMap</code> extends {@link InheritableThreadLocal}
+ to bequeath a copy of the hashtable of the MDC of the parent
+ thread.
+
+ @author Ceki Gülcü
+ @since 1.2
+*/
+final public class ThreadLocalMap extends InheritableThreadLocal {
+
+ public
+ final
+ Object childValue(Object parentValue) {
+ Hashtable ht = (Hashtable) parentValue;
+ if(ht != null) {
+ return ht.clone();
+ } else {
+ return null;
+ }
+ }
+}