--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.max.base/src/com/sun/max/util/Registry.java	Sat Dec 17 19:59:18 2011 +0100
@@ -0,0 +1,122 @@
+/*
+ * Copyright (c) 2007, 2011, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.sun.max.util;
+
+import java.util.*;
+
+import com.sun.max.program.*;
+
+/**
+ * The {@code Registry} class implements a type of configuration mechanism
+ * that allows a short string name (called an alias) to refer to a class name.
+ * The short name can be used to quickly look up an internally registered class and
+ * instantiate it (assuming the target class as a public constructor which takes
+ * no parameters). If the alias is not registered, the registry will try to use
+ * the alias as a fully-qualified Java class and load it using reflection.
+ */
+public class Registry<C> {
+
+    protected final boolean loadClass;
+    protected final Class<C> classClass;
+    protected final Map<String, Class<? extends C>> classMap;
+    protected final Map<String, C> objectMap;
+    protected final Map<String, String> stringMap;
+
+    public Registry(Class<C> classType, boolean loadClass) {
+        this.loadClass = loadClass;
+        this.classClass = classType;
+        this.classMap = new HashMap<String, Class<? extends C>>();
+        this.objectMap = new HashMap<String, C>();
+        this.stringMap = new HashMap<String, String>();
+    }
+
+    public void registerObject(String alias, C object) {
+        objectMap.put(alias, object);
+    }
+
+    public void registerClass(String alias, Class<? extends C> classType) {
+        classMap.put(alias, classType);
+    }
+
+    public void registerClass(String alias, String className) {
+        stringMap.put(alias, className);
+    }
+
+    public C getInstance(String alias) {
+        return getInstance(alias, true);
+    }
+
+    public C getInstance(String alias, boolean fatal) {
+        final C object = objectMap.get(alias);
+        if (object != null) {
+            return object;
+        }
+        Class<? extends C> classRef = classMap.get(alias);
+        String className = alias;
+        try {
+            if (classRef == null) {
+                className = stringMap.get(alias);
+                if (className != null) {
+                    classRef = Class.forName(className).asSubclass(classClass);
+                } else if (loadClass) {
+                    classRef = Class.forName(alias).asSubclass(classClass);
+                } else {
+                    return genError(fatal, "cannot find alias", alias, className);
+                }
+            }
+            className = classRef.getName();
+            return classRef.newInstance();
+        } catch (ClassNotFoundException e) {
+            return genError(fatal, "cannot find class", alias, className);
+        } catch (InstantiationException e) {
+            return genError(fatal, "cannot instantiate class", alias, className);
+        } catch (IllegalAccessException e) {
+            return genError(fatal, "cannot instantiate class", alias, className);
+        } catch (ClassCastException e) {
+            return genError(fatal, "not a subclass of " + classClass.getName(), alias, className);
+        }
+    }
+
+    public Iterable<String> getAliases() {
+        final LinkedList<String> lista = new LinkedList<String>();
+        lista.addAll(objectMap.keySet());
+        lista.addAll(classMap.keySet());
+        lista.addAll(stringMap.keySet());
+        return lista;
+    }
+
+    private C genError(boolean fatal, String message, String alias, String className) {
+        if (!fatal) {
+            return null;
+        }
+        String mstr = message + ": " + alias;
+        if (className != null) {
+            mstr = mstr + "(" + className + ")";
+        }
+        throw ProgramError.unexpected(mstr);
+    }
+
+    public static <T> Registry<T> newRegistry(Class<T> cl) {
+        return new Registry<T>(cl, true);
+    }
+}