001/* A parser for MoML (modeling markup language)
002
003 Copyright (c) 2006 The Regents of the University of California.
004 All rights reserved.
005 Permission is hereby granted, without written agreement and without
006 license or royalty fees, to use, copy, modify, and distribute this
007 software and its documentation for any purpose, provided that the above
008 copyright notice and the following two paragraphs appear in all copies
009 of this software.
010
011 IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
012 FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
013 ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
014 THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
015 SUCH DAMAGE.
016
017 THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
018 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
019 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
020 PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
021 CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
022 ENHANCEMENTS, OR MODIFICATIONS.
023
024 PT_COPYRIGHT_VERSION_2
025 COPYRIGHTENDKEY
026
027 */
028package ptolemy.moml.test;
029
030import ptolemy.kernel.CompositeEntity;
031import ptolemy.moml.MoMLParser;
032
033//////////////////////////////////////////////////////////////////////////
034//// MoMLParserLeak
035
036/**
037 Leak memory in MoMLParser by throwing an Exception.
038 <p> Under Java 1.4, run this with:
039 <pre>
040 java -Xrunhprof:depth=15 -classpath "$PTII;." ptolemy.moml.test.MoMLParserLeak
041 </pre>
042 and then look in java.hprof.txt.
043
044 @author Christopher Brooks
045 @version $Id$
046 @since Ptolemy II 5.2
047 @Pt.ProposedRating Red (cxh)
048 @Pt.AcceptedRating Red (cxh)
049 */
050public class MoMLParserLeak {
051
052    /** Attempt to leak code by parsing MoML that looks for a class
053     *  that does not exist.
054     *  @return the top level that would be found if the class that
055     *  does not exist was present
056     *  @exception Exception If the class does not exist.
057     */
058    public static CompositeEntity leak() throws Exception {
059        //MoMLParser parser = new MoMLParser();
060        CompositeEntity toplevel = (CompositeEntity) parser
061                .parse("<?xml version=\"1.0\" standalone=\"no\"?>\n"
062                        + "<!DOCTYPE entity PUBLIC \"-//UC Berkeley//DTD MoML 1//EN\"\n"
063                        + "\"http://ptolemy.eecs.berkeley.edu/xml/dtd/MoML_1.dtd\">\n"
064                        + "<entity name=\"top\" class=\"ptolemy.kernel.CompositeEntity\">\n"
065                        + "<entity name=\"myRamp\" class=\"ptolemy.actor.lib.Ramp\"/>\n"
066                        + "<entity name=\"notaclass\" class=\"Not.A.Class\"/>\n"
067                        + "</entity>\n");
068        return toplevel;
069    }
070
071    /** Attempt to leak code by parsing MoML that looks for a class
072     *  that does not exist.
073     *  @param args Ignored.
074     *  @exception Exception if there is a problem parsing
075     */
076    public static void main(String[] args) throws Exception {
077        parser = new MoMLParser();
078        //CompositeEntity toptop = new CompositeEntity();
079        //parser.setContext(toptop);
080        try {
081            CompositeEntity toplevel = leak();
082            toplevel.setContainer(null);
083            toplevel = null;
084            // If we don't set parser to null or otherwise force it to
085            // go out of scope, then we leak memory.
086            System.out.println("Setting parser to null");
087            parser = null;
088        } catch (Exception ex) {
089            // If we don't gc here, then references to Ramp might exist
090            // if if we _don't_ throw an exception.
091            System.gc();
092            System.out.println("Sleeping for 2 seconds for any possible gc.");
093            try {
094                Thread.sleep(2000);
095            } catch (InterruptedException e) {
096            }
097            ex.printStackTrace();
098            throw ex;
099        }
100    }
101
102    /** Note that the parser is what actually leaks here. */
103    public static MoMLParser parser;
104}