--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.truffle.api/src/com/oracle/truffle/api/instrument/Instrumentable.java	Thu Aug 21 13:28:22 2014 -0700
@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2014, 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.*;
+
+public interface Instrumentable {
+
+    /**
+     * Optionally applies <em>instrumentation</em> at a Truffle AST node, depending on guest
+     * language characteristics and use-case policy. Ideally, the parent node of the guest language
+     * implements this interface.
+     * <ul>
+     * <li>if no instrumentation is to be applied, returns the AST node unmodified;</li>
+     * <li>if an AST node is to be instrumented, then creates a new Wrapper that <em>decorates</em>
+     * the AST node. Additionally, this creates a probe on the wrapper that is to be used for
+     * attaching instruments. This {@link Probe} is notified of all {@link ExecutionEvents} at the
+     * wrapped AST node.</li>
+     * </ul>
+     *
+     * @param context The {@link ExecutionContext} of the guest language used to create probes on
+     *            the wrapper.
+     * @return The probe that was created.
+     */
+    public Probe probe(ExecutionContext context);
+}