--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.max.base/src/com/sun/max/util/Deferrable.java	Sat Dec 17 19:59:18 2011 +0100
@@ -0,0 +1,94 @@
+/*
+ * 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.*;
+
+/**
+ * Deferred Runnables.
+ *
+ * Creating a Deferrable either causes immediate execution of its 'run()' method
+ * or queues it for deferred execution later on when 'runAll()' is called.
+ */
+public abstract class Deferrable implements Runnable {
+
+    public Deferrable(Queue queue) {
+        queue.handle(this);
+    }
+
+    @Override
+    public String toString() {
+        return super.toString();
+    }
+
+    public static final class Queue {
+
+        private List<Deferrable> deferrables;
+
+        private Queue() {
+        }
+
+        synchronized void handle(Deferrable deferrable) {
+            if (deferrables != null) {
+                deferrables.add(deferrable);
+            } else {
+                deferrable.run();
+            }
+        }
+
+        public synchronized void deferAll() {
+            deferrables = new LinkedList<Deferrable>();
+        }
+
+        public synchronized void runAll() {
+            while (deferrables != null) {
+                final List<Deferrable> oldDeferrables = this.deferrables;
+                this.deferrables = new LinkedList<Deferrable>();
+                for (Deferrable deferrable : oldDeferrables) {
+                    deferrable.run();
+                }
+                if (oldDeferrables.isEmpty()) {
+                    this.deferrables = null;
+                }
+            }
+        }
+    }
+
+    public static Queue createRunning() {
+        return new Queue();
+    }
+
+    public static Queue createDeferred() {
+        final Queue queue = new Queue();
+        queue.deferAll();
+        return queue;
+    }
+
+    public abstract static class Block implements Runnable {
+        public Block(Queue queue) {
+            queue.deferAll();
+            run();
+            queue.runAll();
+        }
+    }
+}