--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/instrument/InstrumentationNode.java	Wed Jun 17 10:58:08 2015 +0200
@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2014, 2015, 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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.oracle.truffle.api.instrument;
+
+import com.oracle.truffle.api.frame.*;
+import com.oracle.truffle.api.nodes.*;
+
+/**
+ * A marker interface for Truffle {@linkplain Node nodes} that internally implement the
+ * <em>Instrumentation Framework</em>. Such nodes should not be part of any Guest Language execution
+ * semantics, and should in general not be visible to ordinary Instrumentation clients.
+ */
+public interface InstrumentationNode {
+
+    /**
+     * A short description of the particular role played by the node, intended to support debugging.
+     */
+    String instrumentationInfo();
+
+    /**
+     * Events that propagate through the {@linkplain InstrumentationNode implementation nodes} of
+     * the Instrumentation Framework, not visible in this form to Instrumentation clients.
+     */
+    interface TruffleEvents {
+
+        /**
+         * An AST node's execute method is about to be called.
+         */
+        void enter(Node node, VirtualFrame vFrame);
+
+        /**
+         * An AST Node's {@code void}-valued execute method has just returned.
+         */
+        void returnVoid(Node node, VirtualFrame vFrame);
+
+        /**
+         * An AST Node's execute method has just returned a value (boxed if primitive).
+         */
+        void returnValue(Node node, VirtualFrame vFrame, Object result);
+
+        /**
+         * An AST Node's execute method has just thrown an exception.
+         */
+        void returnExceptional(Node node, VirtualFrame vFrame, Exception exception);
+    }
+}