diff --git a/dependencymanager/core/src/main/java/org/apache/felix/dm/impl/BlockingSerialExecutor.java b/dependencymanager/core/src/main/java/org/apache/felix/dm/impl/BlockingSerialExecutor.java
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index 0000000..efcea7a
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+++ b/dependencymanager/core/src/main/java/org/apache/felix/dm/impl/BlockingSerialExecutor.java
@@ -0,0 +1,71 @@
+/*
+ * 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.felix.dm.impl;
+
+import java.util.LinkedList;
+
+/**
+ * This class allows to serialize the execution of tasks on one single/unique thread. 
+ * Other threads are blocked until they are elected for execution. 
+ * 
+ * <p>note I: when one leader thread executes a task, it does not hold any locks
+ * while executing the task, and does not execute tasks scheduled by other threads.
+ * 
+ * <p>note II: this executor is reentrant: when one task executed by a leader thread
+ * reschedule another task, then the task is run immediately.
+ * 
+ * @author <a href="mailto:dev@felix.apache.org">Felix Project Team</a>
+ */
+public class BlockingSerialExecutor {
+    private final LinkedList m_tasksQueue = new LinkedList();
+    private Thread m_executingThread = null;
+
+    /**
+     * Executes a task exclusively without holding any locks (other concurrent tasks are blocked until the current task is executed).
+     * @param task a task to be executed serially, without holding any locks.
+     */
+    public void execute(Runnable task) {
+        boolean releaseLock = false;
+        synchronized (this) {
+            if (m_executingThread != Thread.currentThread()) {
+                m_tasksQueue.addLast(task);
+                while (m_tasksQueue.size() > 0 && m_tasksQueue.get(0) != task) {
+                    try {
+                        // TODO it might make sense to use a maxwait time and throw an exception on timeouts.
+                        wait();
+                    } catch (InterruptedException e) {
+                    }
+                }
+                m_executingThread = Thread.currentThread();
+                releaseLock = true;
+            }
+        }
+        try {
+            task.run();
+        } finally {
+            if (releaseLock) {
+                synchronized (this) {
+                    m_tasksQueue.remove(task);
+                    notifyAll();
+                    m_executingThread = null;
+                }
+            }
+        }
+    }
+}