--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.truffle.api/src/com/oracle/truffle/api/instrument/ExecutionEvents.java	Sun Apr 20 20:37:27 2014 -0700
@@ -0,0 +1,179 @@
+/*
+ * Copyright (c) 2013, 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.frame.*;
+import com.oracle.truffle.api.nodes.*;
+
+/**
+ * Normal events during program execution at Truffle AST nodes that are reported via a {@link Probe}
+ * associated with the node, and made available to the probe's attached {@link Instrument}s.
+ * <p>
+ * <strong>Disclaimer:</strong> experimental interface under development.
+ */
+public interface ExecutionEvents {
+
+    /**
+     * Notifies that an AST node's execute method has just been entered. Callers should assure that
+     * a matching call to {@link #leave(Node, VirtualFrame, Object)} always follows.
+     *
+     * @param astNode The AST node on which the execute method is being called
+     * @param frame The frame being passed to the execute method
+     */
+    void enter(Node astNode, VirtualFrame frame);
+
+    /**
+     * Notifies that an AST Node's void-valued execute method is about to exit.
+     * <p>
+     * Callers should assure (via {@code try/finally}) that a matching call to this method always
+     * follows a call to {@link #enter(Node, VirtualFrame)}.
+     *
+     * @param astNode The AST node on which the execute method is being called
+     * @param frame The frame that was passed to the execute method
+     */
+    void leave(Node astNode, VirtualFrame frame);
+
+    /**
+     * Notifies that an AST Node's boolean-valued execute method is about to exit.
+     * <p>
+     * Callers should assure (via {@code try/finally}) that a matching call to this method always
+     * follows a call to {@link #enter(Node, VirtualFrame)}.
+     *
+     * @param astNode The AST node on which the execute method is being called
+     * @param frame The frame that was passed to the execute method
+     * @param result The result of the call to the execute method.
+     */
+    void leave(Node astNode, VirtualFrame frame, boolean result);
+
+    /**
+     * Notifies that an AST Node's byte-valued execute method is about to exit.
+     * <p>
+     * Callers should assure (via {@code try/finally}) that a matching call to this method always
+     * follows a call to {@link #enter(Node, VirtualFrame)}.
+     *
+     * @param astNode The AST node on which the execute method is being called
+     * @param frame The frame that was passed to the execute method
+     * @param result The result of the call to the execute method.
+     */
+    void leave(Node astNode, VirtualFrame frame, byte result);
+
+    /**
+     * Notifies that an AST Node's short-valued execute method is about to exit.
+     * <p>
+     * Callers should assure (via {@code try/finally}) that a matching call to this method always
+     * follows a call to {@link #enter(Node, VirtualFrame)}.
+     *
+     * @param astNode The AST node on which the execute method is being called
+     * @param frame The frame that was passed to the execute method
+     * @param result The result of the call to the execute method.
+     */
+    void leave(Node astNode, VirtualFrame frame, short result);
+
+    /**
+     * Notifies that an AST Node's integer-valued execute method is about to exit.
+     * <p>
+     * Callers should assure (via {@code try/finally}) that a matching call to this method always
+     * follows a call to {@link #enter(Node, VirtualFrame)}.
+     *
+     * @param astNode The AST node on which the execute method is being called
+     * @param frame The frame that was passed to the execute method
+     * @param result The result of the call to the execute method.
+     */
+    void leave(Node astNode, VirtualFrame frame, int result);
+
+    /**
+     * Notifies that an AST Node's long-valued execute method is about to exit.
+     * <p>
+     * Callers should assure (via {@code try/finally}) that a matching call to this method always
+     * follows a call to {@link #enter(Node, VirtualFrame)}.
+     *
+     * @param astNode The AST node on which the execute method is being called
+     * @param frame The frame that was passed to the execute method
+     * @param result The result of the call to the execute method.
+     */
+    void leave(Node astNode, VirtualFrame frame, long result);
+
+    /**
+     * Notifies that an AST Node's float-valued execute method is about to exit.
+     * <p>
+     * Callers should assure (via {@code try/finally}) that a matching call to this method always
+     * follows a call to {@link #enter(Node, VirtualFrame)}.
+     *
+     * @param astNode The AST node on which the execute method is being called
+     * @param frame The frame that was passed to the execute method
+     * @param result The result of the call to the execute method.
+     */
+    void leave(Node astNode, VirtualFrame frame, float result);
+
+    /**
+     * Notifies that an AST Node's double-valued execute method is about to exit.
+     * <p>
+     * Callers should assure (via {@code try/finally}) that a matching call to this method always
+     * follows a call to {@link #enter(Node, VirtualFrame)}.
+     *
+     * @param astNode The AST node on which the execute method is being called
+     * @param frame The frame that was passed to the execute method
+     * @param result The result of the call to the execute method.
+     */
+    void leave(Node astNode, VirtualFrame frame, double result);
+
+    /**
+     * Notifies that an AST Node's char-valued execute method is about to exit.
+     * <p>
+     * Callers should assure (via {@code try/finally}) that a matching call to this method always
+     * follows a call to {@link #enter(Node, VirtualFrame)}.
+     *
+     * @param astNode The AST node on which the execute method is being called
+     * @param frame The frame that was passed to the execute method
+     * @param result The result of the call to the execute method.
+     */
+    void leave(Node astNode, VirtualFrame frame, char result);
+
+    /**
+     * Notifies that an AST Node's object-valued execute method is about to exit.
+     * <p>
+     * Callers should assure (via {@code try/finally}) that a matching call to this method always
+     * follows a call to {@link #enter(Node, VirtualFrame)}.
+     *
+     * @param astNode The AST node on which the execute method is being called
+     * @param frame The frame that was passed to the execute method
+     * @param result The result of the call to the execute method.
+     */
+    void leave(Node astNode, VirtualFrame frame, Object result);
+
+    /**
+     * Notifies that an AST Node's execute method is about to leave under exceptional conditions,
+     * returning no value.
+     * <p>
+     * Callers should assure (via {@code try/finally}) that a matching call to this method always
+     * follows a call to {@link #enter(Node, VirtualFrame)}.
+     *
+     * @param astNode The AST node on which the execute method is being called
+     * @param frame The frame that was passed to the execute method
+     * @param e the exception associated with the unusual return
+     */
+    void leaveExceptional(Node astNode, VirtualFrame frame, Exception e);
+
+}