/*
* Copyright (c) 2016, 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.instrumentation;
import com.oracle.truffle.api.frame.VirtualFrame;
/**
* A listener attached by an {@link Instrumenter} to specific locations of a guest language program
* to listen to execution events.
*
* @since 0.12
*/
public interface ExecutionEventListener {
/**
* Invoked immediately before the {@link EventContext#getInstrumentedNode() instrumented node}
* is executed. The order in which multiple event listeners are notified matches the order they
* are {@link Instrumenter#attachListener(SourceSectionFilter, ExecutionEventListener) attached}
* .
*
* @param context indicating the current location in the guest language AST
* @param frame the frame that was used for executing instrumented node
* @since 0.12
*/
void onEnter(EventContext context, VirtualFrame frame);
/**
* Invoked immediately after an {@link EventContext#getInstrumentedNode() instrumented node} is
* successfully executed. The order in which multiple event listeners are notified matches the
* order they are
* {@link Instrumenter#attachListener(SourceSectionFilter, ExecutionEventListener) attached}.
*
* @param context indicating the current location in the guest language AST
* @param frame the frame that was used for executing instrumented node
* @since 0.12
*/
void onReturnValue(EventContext context, VirtualFrame frame, Object result);
/**
* Invoked immediately after an {@link EventContext#getInstrumentedNode() instrumented node} did
* not successfully execute. The order in which multiple event listeners are notified matches
* the order they are
* {@link Instrumenter#attachListener(SourceSectionFilter, ExecutionEventListener) attached}.
*
* @param context indicating the current location in the guest language AST
* @param frame the frame that was used for executing instrumented node
* @since 0.12
*/
void onReturnExceptional(EventContext context, VirtualFrame frame, Throwable exception);
}