001/**
002 * Copyright (c) 2011, The University of Southampton and the individual contributors.
003 * All rights reserved.
004 *
005 * Redistribution and use in source and binary forms, with or without modification,
006 * are permitted provided that the following conditions are met:
007 *
008 *   *  Redistributions of source code must retain the above copyright notice,
009 *      this list of conditions and the following disclaimer.
010 *
011 *   *  Redistributions in binary form must reproduce the above copyright notice,
012 *      this list of conditions and the following disclaimer in the documentation
013 *      and/or other materials provided with the distribution.
014 *
015 *   *  Neither the name of the University of Southampton nor the names of its
016 *      contributors may be used to endorse or promote products derived from this
017 *      software without specific prior written permission.
018 *
019 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
020 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
021 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
022 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
023 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
024 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
025 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
026 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
027 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
028 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029 */
030package org.openimaj.experiment.agent;
031
032import java.io.IOException;
033import java.lang.instrument.Instrumentation;
034
035import org.openimaj.aop.MultiTransformClassFileTransformer;
036import org.openimaj.aop.agent.AgentLoader;
037import org.openimaj.citation.CitationAgent;
038import org.openimaj.citation.ReferencesClassTransformer;
039
040/**
041 * Java instrumentation agent for instrumenting experiments.
042 *
043 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
044 *
045 */
046public class ExperimentAgent {
047        private static boolean isLoaded = false;
048        private static Instrumentation instrumentation;
049
050        /**
051         * JVM hook to statically load the javaagent at startup.
052         *
053         * After the Java Virtual Machine (JVM) has initialized, the premain method
054         * will be called. Then the real application main method will be called.
055         *
056         * @param args
057         * @param inst
058         * @throws Exception
059         */
060        public static void premain(String args, Instrumentation inst) throws Exception {
061                agentmain(args, inst);
062        }
063
064        /**
065         * JVM hook to dynamically load javaagent at runtime.
066         *
067         * The agent class may have an agentmain method for use when the agent is
068         * started after VM startup.
069         *
070         * @param args
071         * @param inst
072         * @throws Exception
073         */
074        public static void agentmain(String args, Instrumentation inst) throws Exception {
075                instrumentation = inst;
076                instrumentation.addTransformer(new MultiTransformClassFileTransformer(
077                                new ReferencesClassTransformer(),
078                                new TimeClassTransformer()
079                                ));
080        }
081
082        /**
083         * Programmatic hook to dynamically load {@link CitationAgent} at runtime.
084         *
085         * @throws IOException
086         *             if an error occurs
087         */
088        public static synchronized void initialise() throws IOException {
089                if (!isLoaded) {
090                        AgentLoader.loadAgent(ExperimentAgent.class);
091                        isLoaded = true;
092                }
093        }
094
095        /**
096         * Is the agent loaded?
097         *
098         * @return true if the agent is already loaded; false otherwise
099         */
100        public synchronized static boolean isLoaded() {
101                return isLoaded;
102        }
103}