Mercurial > hg > truffle
view truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/instrument/WrapperNode.java @ 22226:c896a8e70777
Truffle/Instrumentation:
Redesign instrumentation node classes to reduce the public API exposure.
- ProbeNode is no longer public
- Public interface InstrumentationNode.TruffleEvents is now abstract class EventHandlerNode with package private constructor
- Interface ProbeNode.WrapperNode is no longer inside ProbeNode and has been expanded slightly so ProbeNode can be package private
author | Michael Van De Vanter <michael.van.de.vanter@oracle.com> |
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date | Sun, 20 Sep 2015 15:51:39 -0700 |
parents | |
children | c1c9c6d79f40 |
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/* * Copyright (c) 2013, 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.TruffleLanguage; import com.oracle.truffle.api.nodes.Node; /** * A {@link Node} instance that must be inserted into a Truffle AST in order to enable * {@linkplain Instrument instrumentation} at a particular Guest Language (GL) node. Implementations * must ensure that {@link TruffleLanguage#isInstrumentable(Node)} returns {@code false}. * <p> * The implementation must be GL-specific. A wrapper <em>decorates</em> a GL AST node (the wrapper's * <em>child</em>) by acting as a transparent <em>proxy</em> with respect to the GL's execution * semantics. * <p> * Instrumentation at the wrapped node is implemented by an instance of {@link EventHandlerNode} * attached as a second child of the {@link WrapperNode}. * <p> * A wrapper is obliged to notify its attached {@link EventHandlerNode} when execution events occur * at the wrapped AST node during program execution. * <p> * When a GL AST is cloned, the {@link WrapperNode}, its {@link EventHandlerNode} and any * {@linkplain Instrument instrumentation} are also cloned; they are in effect part of the GL AST. * An instance of {@link Probe} represents abstractly the instrumentation at a particular location * in a GL AST; it tracks all the copies of the Wrapper and attached instrumentation, and acts as a * single point of access for tools. * <p> * Implementation guidelines: * <ol> * <li>Each GL implementation must implement a WrapperNode implementation for each AST context in * which Instrumentation is to be supported.</li> * <li>The wrapper type should descend from the <em>GL-specific node class</em>.</li> * <li>Must have a field: {@code @Child private <GL>Node child;}</li> * <li>Must have a field: {@code @Child private EventHandlerNode eventHandlerNode;}</li> * <li>The wrapper must act as a <em>proxy</em> for its child, which means implementing every * possible <em>execute-</em> method that gets called on guest language AST node types by their * parents, and passing along each call to its child.</li> * <li>Method {@code Probe getProbe()} should be implemented as {@code eventHandlerNode.getProbe();} * <li>Method {@code insertProbe(EventHandlerNode)} should be implemented as * {@code this.eventHandlerNode=insert(eventHandlerNode);}</li> * <li>Most importantly, Wrappers must be implemented so that Truffle optimization will reduce their * runtime overhead to zero when there are no attached {@link Instrument}s.</li> * </ol> * <p> * * @see Instrument */ public interface WrapperNode extends InstrumentationNode { /** * Gets the node being "wrapped", i.e. the AST node for which * {@linkplain InstrumentationNode.EventHandlerNode execution events} will be reported through * the Instrumentation Framework. */ Node getChild(); /** * Gets the {@link Probe} responsible for installing this wrapper. */ Probe getProbe(); /** * Implementation support for completing a newly created wrapper node. */ void insertEventHandlerNode(EventHandlerNode eventHandlerNode); }