alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

What this is

This file is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Other links

The source code

/*
 *                 Sun Public License Notice
 * 
 * The contents of this file are subject to the Sun Public License
 * Version 1.0 (the "License"). You may not use this file except in
 * compliance with the License. A copy of the License is available at
 * http://www.sun.com/
 * 
 * The Original Code is NetBeans. The Initial Developer of the Original
 * Code is Sun Microsystems, Inc. Portions Copyright 1997-2000 Sun
 * Microsystems, Inc. All Rights Reserved.
 */

package org.netbeans.core.execution;

import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import org.openide.windows.InputOutput;

/** Simple class for executing tasks in extra threads */
final class RunClassThread extends Thread implements IOThreadIfc {

    /** InputOutput that is to be used */
    private InputOutput io;
    /** name */
    String allName; // used in innerclass Runnable
    /** reference to outer class */
    private final ExecutionEngine engine;
    /** ref to a Task */
    private final ExecutorTaskImpl task;
    /** Task to run */
    private /*final*/ Runnable run;

    /** generated names */
    static int number = 0;

    /** Created group */
    TaskThreadGroup mygroup;
    
    /** Is finalized? */
    boolean finalized;

    /**
    * @param base is a ThreadGroup we want to be in
    * @param m is a method to invoke
    * @param argv are params for the method
    */
    public RunClassThread(TaskThreadGroup base,
                    String name,
                    int number,
                    InputOutput io,
                    org.netbeans.core.execution.ExecutionEngine engine,
                    ExecutorTaskImpl task,
                    Runnable run) {
        super(base, "exec_" + name + "_" + number); // NOI18N
        mygroup = base;
        mygroup.setRunClassThread(this);
        this.allName = name;
        this.io = io;
        this.engine = engine;
        this.task = task;
        this.run = run;
        this.finalized = false;
        // #33789 - this thread must not be daemon otherwise it is immediately destroyed
        setDaemon(false);
        this.start();
    }

    /** runs the thread
    */
    public void run() {
        mygroup.setFinalizable(); // mark it finalizable - after the completetion of the current thread it will be finalized

        boolean fire = true;

        if (allName ==  null) {
            allName = generateName();
            fire = false;
        }

        String ioname = java.text.MessageFormat.format(
                            ProcessNode.getBundle().getString("CTL_ProgramIO"),
                            new Object[] { allName }
                        );

        // prepare environment (threads, In/Out, atd.)
        DefaultSysProcess def;
        if (io != null) {
            def = new DefaultSysProcess(this, mygroup, io, allName);
            TaskIO tIO = new TaskIO(io, ioname, true);
            io.select();
            engine.getTaskIOs ().put (io, tIO);
        } else {   // advance TaskIO for this process
            TaskIO tIO = null;
            tIO = engine.getTaskIOs().getTaskIO(ioname);
            if (tIO == null) { // executed for the first time
                io = org.openide.windows.IOProvider.getDefault().getIO(ioname, true);
                tIO = new TaskIO(io, ioname);
            } else {
                io = tIO.getInout();
            }
            io.select();
            io.setFocusTaken(true);
            engine.getTaskIOs().put(io, tIO);
            def = new DefaultSysProcess(this, mygroup, io, allName);
        }

        ExecutionEvent ev = null;
        try {

            ev = new ExecutionEvent(engine, def, isUserImportant(run));
            if (fire) {
                engine.fireExecutionStarted(ev);
            }

            synchronized (task.lock) {
                task.proc = def;
                task.lock.notifyAll();
            }

            // exec foreign Runnable
            run.run();
            // throw away user runnable
            run = null;

            int result = 2;
            try {
                result = def.result();
            } catch (ThreadDeath err) { // terminated while executing
            } catch (IllegalMonitorStateException e) {
                // killed while leaving synchronized section, ignore
            }
            task.result = result;

        } finally {
            Thread.interrupted(); // Clear the interruption status at first.
            if (ev != null) {
                if (fire) {
                    engine.fireExecutionFinished(ev);
                }
            }

            engine.closeGroup(mygroup); // free windows
            task.finished();
            engine.getTaskIOs().free(mygroup, io); // closes output

            /* Disable for now unless really needed. Cf. #36395, #36393.
            cleanUpHack(mygroup);
            */
            mygroup = null;
            io = null;
            synchronized (this) {
                finalized = true;
                notifyAll();
            }
        }
    } // run method

    public InputOutput getInputOutput() {
        return io;
    }
    
    public synchronized boolean waitForEnd() throws InterruptedException {
        if (finalized) {
            return true;
        }
        
        this.wait(1000);
        return finalized;
    }
    
    /** @return false for inner processes like compilation, true otherwise */
    private boolean isUserImportant (Runnable run) {
        return !"org.openide.compiler.CompilerExecutor$CERunnable".equals(run.getClass().getName()); // NOI18N
    }

    static String generateName() {
        return java.text.MessageFormat.format(
                   ProcessNode.getBundle().getString("CTL_GeneratedName"),
                   new Object[] {new Integer(number++)}
               );
    }
    
    /**
     * Workaround for a JRE bug that unstarted threads are not GC'd.
     * @see http://www.netbeans.org/issues/show_bug.cgi?id=36395
     * @see http://developer.java.sun.com/developer/bugParade/bugs/4533087.html
     * /
    private static void cleanUpHack(ThreadGroup tg) {
        try {
            Field f = ThreadGroup.class.getDeclaredField("threads"); // NOI18N
            f.setAccessible(true);
            Method m = ThreadGroup.class.getDeclaredMethod("remove", new Class[] {Thread.class}); // NOI18N
            m.setAccessible(true);
            Set stillborn = new HashSet(); // Set
            synchronized (tg) {
                Thread[] ts = (Thread[])f.get(tg);
                if (ts == null) {
                    return;
                }
                for (int j = 0; j < ts.length; j++) {
                    Thread t = ts[j];
                    if (t == null) {
                        continue;
                    }
                    if (!t.isAlive()) {
                        stillborn.add(t);
                    }
                }
            }
            Iterator it = stillborn.iterator();
            while (it.hasNext()) {
                Thread t = (Thread)it.next();
                m.invoke(tg, new Object[] {t});
            }
            // Handle child thread groups, too:
            ThreadGroup[] kids = new ThreadGroup[tg.activeGroupCount()];
            tg.enumerate(kids);
            for (int i = 0; i < kids.length; i++) {
                if (kids[i] != null) {
                    cleanUpHack(kids[i]);
                }
            }
        } catch (Exception e) {
            // Oh well.
            e.printStackTrace();
        }
    }
    */
    
}

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.