--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.truffle.api/src/com/oracle/truffle/api/debug/DefaultDebugManager.java	Mon Feb 03 20:58:23 2014 -0800
@@ -0,0 +1,111 @@
+/*
+ * 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.debug;
+
+import java.util.*;
+
+import com.oracle.truffle.api.*;
+import com.oracle.truffle.api.frame.*;
+import com.oracle.truffle.api.nodes.*;
+import com.oracle.truffle.api.nodes.instrument.InstrumentationProbeNode.ProbeChain;
+import com.oracle.truffle.api.source.*;
+
+/**
+ * A minimal, language-agnostic implementation that tracks loaded sources, and keeps maps describing
+ * what locations in the source have instrumentation available. This implementation will do nothing
+ * unless there are calls to it during AST construction, notably {@link #notifyStartLoading(Source)}
+ * and {@link #notifyFinishedLoading(Source)} <em>and</em> there are at least some AST nodes being
+ * instrumented.
+ */
+public class DefaultDebugManager implements DebugManager {
+
+    private final Set<Source> loadedSources = new HashSet<>();
+
+    private Source beingLoaded = null;
+
+    /**
+     * Map: SourceSection ==> probe chain associated with that source section in an AST.
+     */
+    private final Map<SourceSection, ProbeChain> srcToProbeChain = new HashMap<>();
+
+    /**
+     * Map: Source lines ==> probe chains associated with source sections starting on the line.
+     */
+    private final Map<SourceLineLocation, Set<ProbeChain>> lineToProbeChains = new HashMap<>();
+
+    private final ExecutionContext context;
+
+    public DefaultDebugManager(ExecutionContext context) {
+        this.context = context;
+    }
+
+    /**
+     * Gets the {@linkplain ProbeChain probe} associated with a particular {@link SourceSection
+     * source location}, creating a new one if needed. There should only be one probe associated
+     * with each {@linkplain SourceSection source location}.
+     */
+    public ProbeChain getProbeChain(SourceSection sourceSection) {
+        assert sourceSection != null;
+        assert sourceSection.getSource().equals(beingLoaded);
+
+        ProbeChain probeChain = srcToProbeChain.get(sourceSection);
+
+        if (probeChain != null) {
+            return probeChain;
+        }
+        probeChain = new ProbeChain(context, sourceSection, null);
+
+        // Register new ProbeChain by unique SourceSection
+        srcToProbeChain.put(sourceSection, probeChain);
+
+        // Register new ProbeChain by source line, there may be more than one
+        // Create line location for map key
+        final SourceLineLocation lineLocation = new SourceLineLocation(sourceSection.getSource(), sourceSection.getStartLine());
+
+        Set<ProbeChain> probeChains = lineToProbeChains.get(lineLocation);
+        if (probeChains == null) {
+            probeChains = new HashSet<>();
+            lineToProbeChains.put(lineLocation, probeChains);
+        }
+        probeChains.add(probeChain);
+
+        return probeChain;
+    }
+
+    public void notifyStartLoading(Source source) {
+        assert beingLoaded == null;
+        beingLoaded = source;
+    }
+
+    public void notifyFinishedLoading(Source source) {
+        assert source == beingLoaded;
+        loadedSources.add(source);
+        beingLoaded = null;
+    }
+
+    public void haltedAt(Node astNode, VirtualFrame frame) {
+    }
+
+}