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diff --git a/bundles/org.simantics.utils.thread/src/org/simantics/utils/threads/internal/ListenerList.java b/bundles/org.simantics.utils.thread/src/org/simantics/utils/threads/internal/ListenerList.java
new file mode 100644
index 000000000..b1e6b6e2b
--- /dev/null
+++ b/bundles/org.simantics.utils.thread/src/org/simantics/utils/threads/internal/ListenerList.java
@@ -0,0 +1,120 @@
+/*******************************************************************************
+ * Copyright (c) 2007, 2010 Association for Decentralized Information Management
+ * in Industry THTH ry.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     VTT Technical Research Centre of Finland - initial API and implementation
+ *******************************************************************************/
+/*
+ * 12.6.2007
+ */
+package org.simantics.utils.threads.internal;
+
+import java.lang.reflect.Array;
+
+/**
+ * ListenerList is an efficient and synchronized list of listeners.
+ * The class is optimized for quick getListeners and slow add/remove.
+ * 
+ * @author Toni Kalajainen
+ */
+public class ListenerList<T> {
+    
+    /**
+     * Array of listeners
+     */
+    private volatile T [] array;
+    
+    /** 
+     * The class of T
+     */
+    private final Class<T> componentType;
+           
+    /**
+     * Construct new Listener List
+     * @param componentType the class of the listener type
+     */
+    public ListenerList(Class<T> componentType)
+    {
+        this.componentType = componentType;
+        array = createArray(0);
+    }
+    
+    public T[] getListeners()
+    {
+        return array;
+    }
+    
+    public synchronized void add(T listener)
+    {
+        int oldLength = array.length;
+        int newLength = oldLength + 1;
+        T newArray[] = createArray(newLength);
+        System.arraycopy(array, 0, newArray, 0, oldLength);
+        newArray[oldLength] = listener;
+        array = newArray;
+    }
+    
+    /**
+     * Removes the first occurance of listener.
+     * If the listener is added multiple times, then it must be removed
+     * as many times.
+     * 
+     * @param listener a listener
+     * @return the listener that was removed from the list
+     */
+    public synchronized boolean remove(T listener)
+    {
+        int pos = getPos(listener);
+        if (pos<0) return false;
+        
+        int oldLength = array.length;
+        int newLength = oldLength -1;
+        T newArray[] = createArray(newLength);
+        
+        // Copy beginning
+        if (pos>0)
+            System.arraycopy(array, 0, newArray, 0, pos);
+        
+        // Copy ending
+        if (pos<newLength)
+            System.arraycopy(array, pos+1, newArray, pos, newLength-pos);
+        
+        array = newArray;
+        return true;
+    }        
+    
+    private synchronized int getPos(T listener)
+    {
+        for (int i=0; i<array.length; i++)
+            if (array[i] == listener)
+                return i;
+        return -1;
+    }
+    
+    public int size()
+    {
+        return array.length;
+    }
+    
+    public boolean isEmpty()
+    {
+        return array.length == 0;
+    }
+    
+    public void clear()
+    {
+        array = createArray(0);
+    }
+    
+    @SuppressWarnings("unchecked")
+    private T[] createArray(int size)
+    {
+        return (T[]) Array.newInstance(componentType, size);
+    }
+    
+}