--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/instrument/AdvancedInstrumentRootFactory.java	Wed Jun 17 10:58:08 2015 +0200
@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 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.nodes.*;
+
+/**
+ * Creator of {@linkplain AdvancedInstrumentRoot AST fragments} suitable for efficient execution,
+ * subject to full Truffle optimization, by an
+ * {@linkplain Instrument#create(AdvancedInstrumentResultListener, AdvancedInstrumentRootFactory, Class, String)
+ * Advanced Instrument}.
+ *
+ * @see Instrument
+ * @see AdvancedInstrumentRoot
+ */
+public interface AdvancedInstrumentRootFactory {
+
+    /**
+     * Provider of {@linkplain AdvancedInstrumentRoot AST fragment} instances to be executed by the
+     * Instrumentation Framework at a {@linkplain Probe Probed} site in a guest-language AST.
+     * <p>
+     * <strong>Notes:</strong>
+     * <ul>
+     * <li>Once the factory has produced an AST fragment at a particular {@linkplain Node AST Node},
+     * it will not be called again at that Node.</li>
+     * <li>In some use cases, for example to implement a breakpoint at a specific program location,
+     * the Probe argument will be the same for every call. Each Node argument will represent the
+     * same program location associated with the Probe, but in different clones of the AST.</li>
+     * <li>In other use cases, for example to implement a breakpoint at any Node with a particular
+     * {@linkplain SyntaxTag tag}, both the Probe and Node argument may differ. Implementations that
+     * are sensitive to the lexical context in which the AST fragment will be evaluated must take
+     * care to build a new, possibly different AST fragment for each request.</li>
+     * </ul>
+     *
+     * @param probe the Probe to which the Instrument requesting the AST fragment is attached
+     * @param node the guest-language AST location that is the context in which the requesting
+     *            Instrument must execute the AST fragment.
+     * @return a newly created AST fragment suitable for execution, via instrumentation, in the
+     *         execution context of the specified guest-language AST site.
+     */
+    AdvancedInstrumentRoot createInstrumentRoot(Probe probe, Node node);
+}