Java example source code file (JDIEventSource.java)

This example Java source code file (JDIEventSource.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

abstracteventset, dispatcher, eventqueue, executionmanager, firstlistener, gui, interruptedexception, jdi, jdieventsource, jdilistener, override, runnable, swing, threaddeatheventset, threadreference, vmdisconnectedexception, vmdisconnecteventset

The JDIEventSource.java Java example source code

/*
 * Copyright (c) 1999, 2011, 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.
 */

/*
 * This source code is provided to illustrate the usage of a given feature
 * or technique and has been deliberately simplified. Additional steps
 * required for a production-quality application, such as security checks,
 * input validation and proper error handling, might not be present in
 * this sample code.
 */


package com.sun.tools.example.debug.bdi;

import com.sun.jdi.*;
import com.sun.jdi.event.*;

import com.sun.tools.example.debug.event.*;

import javax.swing.SwingUtilities;

/**
 */
class JDIEventSource extends Thread {

    private /*final*/ EventQueue queue;
    private /*final*/ Session session;
    private /*final*/ ExecutionManager runtime;
    private final JDIListener firstListener = new FirstListener();

    private boolean wantInterrupt;  //### Hack

    /**
     * Create event source.
     */
    JDIEventSource(Session session) {
        super("JDI Event Set Dispatcher");
        this.session = session;
        this.runtime = session.runtime;
        this.queue = session.vm.eventQueue();
    }

    @Override
    public void run() {
        try {
            runLoop();
        } catch (Exception exc) {
            //### Do something different for InterruptedException???
            // just exit
        }
        session.running = false;
    }

    private void runLoop() throws InterruptedException {
        AbstractEventSet es;
        do {
            EventSet jdiEventSet = queue.remove();
            es = AbstractEventSet.toSpecificEventSet(jdiEventSet);
            session.interrupted = es.suspendedAll();
            dispatchEventSet(es);
        } while(!(es instanceof VMDisconnectEventSet));
    }

    //### Gross foul hackery!
    private void dispatchEventSet(final AbstractEventSet es) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                boolean interrupted = es.suspendedAll();
                es.notify(firstListener);
                boolean wantInterrupt = JDIEventSource.this.wantInterrupt;
                for (JDIListener jl : session.runtime.jdiListeners) {
                    es.notify(jl);
                }
                if (interrupted && !wantInterrupt) {
                    session.interrupted = false;
                    //### Catch here is a hack
                    try {
                        session.vm.resume();
                    } catch (VMDisconnectedException ee) {}
                }
                if (es instanceof ThreadDeathEventSet) {
                    ThreadReference t = ((ThreadDeathEventSet)es).getThread();
                    session.runtime.removeThreadInfo(t);
                }
            }
        });
    }

    private void finalizeEventSet(AbstractEventSet es) {
        if (session.interrupted && !wantInterrupt) {
            session.interrupted = false;
            //### Catch here is a hack
            try {
                session.vm.resume();
            } catch (VMDisconnectedException ee) {}
        }
        if (es instanceof ThreadDeathEventSet) {
            ThreadReference t = ((ThreadDeathEventSet)es).getThread();
            session.runtime.removeThreadInfo(t);
        }
    }

    //### This is a Hack, deal with it
    private class FirstListener implements JDIListener {

        @Override
        public void accessWatchpoint(AccessWatchpointEventSet e) {
            session.runtime.validateThreadInfo();
            wantInterrupt = true;
        }

        @Override
        public void classPrepare(ClassPrepareEventSet e)  {
            wantInterrupt = false;
            runtime.resolve(e.getReferenceType());
        }

        @Override
        public void classUnload(ClassUnloadEventSet e)  {
            wantInterrupt = false;
        }

        @Override
        public void exception(ExceptionEventSet e)  {
            wantInterrupt = true;
        }

        @Override
        public void locationTrigger(LocationTriggerEventSet e)  {
            session.runtime.validateThreadInfo();
            wantInterrupt = true;
        }

        @Override
        public void modificationWatchpoint(ModificationWatchpointEventSet e)  {
            session.runtime.validateThreadInfo();
            wantInterrupt = true;
        }

        @Override
        public void threadDeath(ThreadDeathEventSet e)  {
            wantInterrupt = false;
        }

        @Override
        public void threadStart(ThreadStartEventSet e)  {
            wantInterrupt = false;
        }

        @Override
        public void vmDeath(VMDeathEventSet e)  {
            //### Should have some way to notify user
            //### that VM died before the session ended.
            wantInterrupt = false;
        }

        @Override
        public void vmDisconnect(VMDisconnectEventSet e)  {
            //### Notify user?
            wantInterrupt = false;
            session.runtime.endSession();
        }

        @Override
        public void vmStart(VMStartEventSet e)  {
            //### Do we need to do anything with it?
            wantInterrupt = false;
        }
    }
}