Applet freezing.. Problem with thread?

[Jon Mattson]

Well I've made this really simple game where you need to shoot terrorists.
You can try it here

The problem is it freezes at random times. Sometimes not at all. I suspect it's something wrong with the way i use threads but I haven't been able to find the problem.

Any other suggestions to make it work better are appriciated.

Here is my code:

  import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Timer;
import java.util.TimerTask;
 
public class EpexShooter extends JApplet implements Runnable, MouseListener{

Image backImage;
Image terrorist1;
Image terrorist2;
Image terrorist3;
Image cursorImg;

Graphics bufferGraphics; 
Image offscreen;

Dimension dim; 

double random;
 
int score = 0;
int hp = 100;

Rectangle rectangle1 = new Rectangle(366,285,45,100);
Rectangle rectangle2 = new Rectangle(190,308,68,150);
Rectangle rectangle3 = new Rectangle(623,320,32,70);
Rectangle rectangle4 = new Rectangle(740,320,32,70);
boolean spawn = false;
boolean ter1dead = true;
boolean ter2dead = true;
boolean ter3dead = true;
boolean ter4dead = true;
int previousTer = 0;

Cursor cursor;

HP HPThread = new HP();
private volatile Thread thread = null;


public void init(){
addMouseListener(this); 
dim = getSize(); 
backImage = getImage (getCodeBase (), "EpexShooter.gif");
terrorist1 = getImage (getCodeBase (), "Terrorist2.png");
terrorist2 = getImage (getCodeBase (), "Terrorist3.png");
terrorist3 = getImage (getCodeBase (), "Terrorist4.png");
cursorImg = getImage (getCodeBase (), "Cursor.png");
offscreen = createImage(dim.width,dim.height);
bufferGraphics = offscreen.getGraphics();
 
Toolkit tk = Toolkit.getDefaultToolkit();
cursor = tk.createCustomCursor(cursorImg, new Point(15, 15),"CrossHair");
setCursor(cursor);

        new Reminder(2);
}

class HP implements Runnable{
    
private Thread thread = null;
public int HP = 100;
public boolean allDone = false;
 

    public void start() {
System.out.println("HP thread start");
System.out.println(thread);
        if (thread == null) {
    System.out.println("HP thread started");
            thread = new Thread(this);
            thread.start();
        }
    }
 
public synchronized void run(){
while (thread != null){
hp--;
System.out.println("HP thread running");
if(hp == 0){
stop();
return;
}
            if (allDone==true) {
            thread = null;
                return;
            }
        try {
            Thread.sleep(100);
        } catch (InterruptedException e) {
        }
}
 
}

public synchronized int getHP(){
return HP;
}
}

public class Reminder {
    Timer timer;
 
    public Reminder(int seconds) {
        timer = new Timer();
        timer.schedule(new RemindTask(), seconds*1000);
}
 
    class RemindTask extends TimerTask {
        public void run() {
        spawn = true;
            timer.cancel();
        }
    }
}

 public void mouseClicked (MouseEvent me) {}
 public void mouseEntered (MouseEvent me) {}
 public void mouseReleased (MouseEvent me) {} 
 public void mouseExited (MouseEvent me) {}  

public void mousePressed (MouseEvent me) {

int seconds = (int)(Math.random() * 5);
if (rectangle1.contains(me.getX(),me.getY()) && ter1dead == false){
System.out.println("HIT!1");
ter1dead = true;
spawn = false;
HPThread.allDone = true;
score++;
        new Reminder(seconds);
}
if (rectangle2.contains(me.getX(),me.getY()) && ter2dead == false){
System.out.println("HIT!2");
ter2dead = true;
spawn = false;
HPThread.allDone = true;
score++;
        new Reminder(seconds);
}
if (rectangle3.contains(me.getX(),me.getY()) && ter3dead == false){
System.out.println("HIT!3");
ter3dead = true;
spawn = false;
HPThread.allDone = true;
score++;
        new Reminder(seconds);
}
if (rectangle4.contains(me.getX(),me.getY()) && ter4dead == false){
System.out.println("HIT!4");
ter4dead = true;
spawn = false;
HPThread.allDone = true;
score++;
        new Reminder(seconds);
}
if(me.getX() == 0 && me.getY() == 0){
score = score + 10;
}
if(me.getX() == 1198 && me.getY() == 0){
score = score + 100;
}
if(me.getX() == 0 && me.getY() == 801){
score = score + 1000;
}
if(me.getX() == 1198 && me.getY() == 801){
score = score + 10000;
}

if(hp==0){
if (new Rectangle(400,600,115,40).contains(me.getX(),me.getY())){
hp = 100;
HPThread.allDone = false;
start();
}
}
/*
System.out.println("Duration:" + seconds);
System.out.println("Spawn:" + spawn);
System.out.println("PreviousTer:" + previousTer);
System.out.println("Ter1dead:" + ter1dead);
System.out.println("Ter2dead:" + ter2dead);
System.out.println("Ter3dead:" + ter3dead);
System.out.println("Ter4dead:" + ter4dead);
*/
}

public void update (Graphics g){
if (hp != 0){
bufferGraphics.clearRect(0,0,dim.width,dim.width); 
bufferGraphics.drawImage(backImage, 0, 0, this);

if (ter1dead == false){
bufferGraphics.drawImage(terrorist1, 366, 285, this);
previousTer = 1;
}
if (ter2dead == false){
bufferGraphics.drawImage(terrorist2, 190, 308, this);
previousTer = 2;
}
if (ter3dead == false){
bufferGraphics.drawImage(terrorist3, 623, 320, this);
previousTer = 3;
}
if (ter4dead == false){
bufferGraphics.drawImage(terrorist3, 740, 320, this);
previousTer = 4;
}
bufferGraphics.setColor(Color.red);
bufferGraphics.setFont(new Font("Arial", Font.BOLD, 20));
bufferGraphics.drawString("Score: " + score, 1020,790);
bufferGraphics.fillRect(50,760,100,20);
bufferGraphics.setColor(Color.green);
bufferGraphics.fillRect(50,760,hp,20);
}
else{
bufferGraphics.setColor(Color.black);
bufferGraphics.fillRect(0,0,1199,802);
bufferGraphics.setColor(Color.red);
bufferGraphics.setFont(new Font("Arial", Font.BOLD, 30));
bufferGraphics.drawString("You were owned... ", 400, 500);
bufferGraphics.drawString("Score: " + score , 400, 550);
bufferGraphics.fillRect(400,600,115,40);
bufferGraphics.setColor(Color.white);
bufferGraphics.drawString("RETRY", 405, 632);
}
g.drawImage(offscreen,0,0,this);
}

public void paint(Graphics g){
update(g);
 
}

    public void start() {
        if (thread == null) {
        System.out.println("main thread started");
           thread = new Thread(this, "Thread");
           thread.start();
        }
      }

public synchronized void run(){
      Thread myThread = Thread.currentThread();
      System.out.println("Main thread started");
        while (thread == myThread) {
        if(spawn && ter1dead && ter2dead && ter3dead && ter4dead){
        //System.out.println("spawn && ter1dead && ter2dead && ter3dead && ter4dead == true");
        random = Math.random();
        
        if(random <= 1 && random > 0.75){
        if (previousTer != 1){
        ter1dead = false;
        HPThread.allDone = false;
        HPThread.start();
        }
        }
        if(random <= 0.75 && random > 0.5){
        if (previousTer != 2){
        ter2dead = false;
        HPThread.allDone = false;
        HPThread.start();
        }
        }
        if(random <= 0.5 && random > 0.25){
        if (previousTer != 3){
        ter3dead = false;
        HPThread.allDone = false;
        HPThread.start();
        }
        }
        if(random <= 0.25 && random >= 0){
        if (previousTer != 4){
        ter4dead = false;
        HPThread.allDone = false;
        HPThread.start();
        }
        }
        }
        if (hp == 0){
        stop();
        HPThread.allDone = true;
        repaint();
        }
repaint();
        }
}

    public void stop() {
    System.out.println("main thread stopped");
        thread = null;
    }
    
}  

[ February 07, 2006: Message edited by: Jon Mattson ]

[Jon Mattson]

I've uploaded a new version here

I've been trying to solve this problem by placing System.out.println statements in different parts of the program. Remember you might have to run the applet a few times before it freezes and don't use the retry button to try again. Just refresh the page.

Here's the code again with some small modifications like adding the println statements. I'm sorry I have to post the whole code but I don't really know where the problem is so I post it all. I put bold on all println statements and some lines of code that got to do with what happens when hp reaches 0, theese stop or start threads.

  import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Timer;
import java.util.TimerTask;
 
public class EpexShooter extends JApplet implements Runnable, MouseListener{

Image backImage;
Image terrorist1;
Image terrorist2;
Image terrorist3;
Image cursorImg;

Graphics bufferGraphics; 
Image offscreen;

Dimension dim; 

double random;
 
int score = 0;
int hp = 100;

Rectangle rectangle1 = new Rectangle(366,285,45,100);
Rectangle rectangle2 = new Rectangle(190,308,68,150);
Rectangle rectangle3 = new Rectangle(623,320,32,70);
Rectangle rectangle4 = new Rectangle(740,320,32,70);
boolean spawn = false;
boolean ter1dead = true;
boolean ter2dead = true;
boolean ter3dead = true;
boolean ter4dead = true;
int previousTer = 0;

Cursor cursor;

HP HPThread = new HP();
private volatile Thread thread = null;


public void init(){
addMouseListener(this); 
dim = getSize(); 
backImage = getImage (getCodeBase (), "EpexShooter.gif");
terrorist1 = getImage (getCodeBase (), "Terrorist2.png");
terrorist2 = getImage (getCodeBase (), "Terrorist3.png");
terrorist3 = getImage (getCodeBase (), "Terrorist4.png");
cursorImg = getImage (getCodeBase (), "Cursor.png");
offscreen = createImage(dim.width,dim.height);
bufferGraphics = offscreen.getGraphics();
 
Toolkit tk = Toolkit.getDefaultToolkit();
cursor = tk.createCustomCursor(cursorImg, new Point(15, 15),"CrossHair");
setCursor(cursor);

        new Reminder(2);
}

class HP implements Runnable{
    
private Thread thread = null;
public int HP = 100;
public boolean allDone = false;
 

    public void start() {
[B]System.out.println("HP thread start");[/B]
[B]System.out.println(thread);[/B]
        if (thread == null) {
    [B]System.out.println("HP thread started");[/B]
            thread = new Thread(this);
            thread.start();
        }
    }
 
public synchronized void run(){
while (thread != null){
hp--;
[B]System.out.println("HP thread running. HP:" + hp);[/B]
if(hp == 0){
stop();
return;
}
            if (allDone==true) {
            thread = null;
                return;
            }
        try {
            Thread.sleep(100);
        } catch (InterruptedException e) {
        }
}
 
}

public synchronized int getHP(){
return HP;
}
}

public class Reminder {
    Timer timer;
 
    public Reminder(int seconds) {
        timer = new Timer();
        timer.schedule(new RemindTask(), seconds*1000);
        [B]System.out.println("New Timer");[/B]
}
 
    class RemindTask extends TimerTask {
        public void run() {
        spawn = true;
        [B]System.out.println("Timer, spawn = " + spawn);
System.out.println("Ter1dead:" + ter1dead);
System.out.println("Ter2dead:" + ter2dead);
System.out.println("Ter3dead:" + ter3dead);
System.out.println("Ter4dead:" + ter4dead);[/B]
            timer.cancel();
        }
    }
}

 public void mouseClicked (MouseEvent me) {}
 public void mouseEntered (MouseEvent me) {}
 public void mouseReleased (MouseEvent me) {} 
 public void mouseExited (MouseEvent me) {}  

public void mousePressed (MouseEvent me) {

int seconds = (int)(Math.random() * 5);
if (rectangle1.contains(me.getX(),me.getY()) && ter1dead == false){
[B]System.out.println("HIT!1");[/B]
ter1dead = true;
spawn = false;
HPThread.allDone = true;
score++;
        new Reminder(seconds);
}
if (rectangle2.contains(me.getX(),me.getY()) && ter2dead == false){
[B]System.out.println("HIT!2");[/B]
ter2dead = true;
spawn = false;
HPThread.allDone = true;
score++;
        new Reminder(seconds);
}
if (rectangle3.contains(me.getX(),me.getY()) && ter3dead == false){
[B]System.out.println("HIT!3");[/B]
ter3dead = true;
spawn = false;
HPThread.allDone = true;
score++;
        new Reminder(seconds);
}
if (rectangle4.contains(me.getX(),me.getY()) && ter4dead == false){
[B]System.out.println("HIT!4");[/B]
ter4dead = true;
spawn = false;
HPThread.allDone = true;
score++;
        new Reminder(seconds);
}
if(me.getX() == 0 && me.getY() == 0){
score = score + 10;
}
if(me.getX() == 1198 && me.getY() == 0){
score = score + 100;
}
if(me.getX() == 0 && me.getY() == 801){
score = score + 1000;
}
if(me.getX() == 1198 && me.getY() == 801){
score = score + 10000;
}

if(hp==0){
if (new Rectangle(400,600,115,40).contains(me.getX(),me.getY())){
[B]hp = 100;
HPThread.allDone = false;
start();[/B]
}
}
}

public void update (Graphics g){
if (hp != 0){
bufferGraphics.clearRect(0,0,dim.width,dim.width); 
bufferGraphics.drawImage(backImage, 0, 0, this);

if (ter1dead == false){
bufferGraphics.drawImage(terrorist1, 366, 285, this);
previousTer = 1;
}
if (ter2dead == false){
bufferGraphics.drawImage(terrorist2, 190, 308, this);
previousTer = 2;
}
if (ter3dead == false){
bufferGraphics.drawImage(terrorist3, 623, 320, this);
previousTer = 3;
}
if (ter4dead == false){
bufferGraphics.drawImage(terrorist3, 740, 320, this);
previousTer = 4;
}
bufferGraphics.setColor(Color.red);
bufferGraphics.setFont(new Font("Arial", Font.BOLD, 20));
bufferGraphics.drawString("Score: " + score, 1020,790);
bufferGraphics.fillRect(50,760,100,20);
bufferGraphics.setColor(Color.green);
bufferGraphics.fillRect(50,760,hp,20);
}
else{[B]
bufferGraphics.setColor(Color.black);
bufferGraphics.fillRect(0,0,1199,802);
bufferGraphics.setColor(Color.red);
bufferGraphics.setFont(new Font("Arial", Font.BOLD, 30));
bufferGraphics.drawString("You were owned... ", 400, 500);
bufferGraphics.drawString("Score: " + score , 400, 550);
bufferGraphics.fillRect(400,600,115,40);
bufferGraphics.setColor(Color.white);
bufferGraphics.drawString("RETRY", 405, 632);[/B]
}
g.drawImage(offscreen,0,0,this);
}

public void paint(Graphics g){
update(g);
 
}

    public void start() {
        if (thread == null) {
        [B]System.out.println("main thread started");[/B]
           thread = new Thread(this, "Thread");
           thread.start();
        }
      }

public synchronized void run(){
      Thread myThread = Thread.currentThread();
      [B]System.out.println("Main thread started");[/B]
        while (thread == myThread) {
        if(spawn && ter1dead && ter2dead && ter3dead && ter4dead){
        [B]System.out.println("spawn && ter1dead && ter2dead && ter3dead && ter4dead == true");[/B]
        random = Math.random();
        System.out.println(random);
        
        if(random <= 1 && random > 0.75){
        if (previousTer != 1){
        ter1dead = false;
        HPThread.allDone = false;
        HPThread.start();
        }
        }
        if(random <= 0.75 && random > 0.5){
        if (previousTer != 2){
        ter2dead = false;
        HPThread.allDone = false;
        HPThread.start();
        }
        }
        if(random <= 0.5 && random > 0.25){
        if (previousTer != 3){
        ter3dead = false;
        HPThread.allDone = false;
        HPThread.start();
        }
        }
        if(random <= 0.25 && random >= 0){
        if (previousTer != 4){
        ter4dead = false;
        HPThread.allDone = false;
        HPThread.start();
        }
        }
        }
        if (hp == 0){
        [B]repaint();
        try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
            }
        stop();
        HPThread.allDone = true;[/B]
        }
repaint();
        }
}

    public void stop() {
    [B]System.out.println("main thread stopped");[/B]
        thread = null;
    }
    
}  

Here is the last lines in console after a freeze. It always ends in Ter1dead:true
Ter2dead:true
Ter3dead:true
Ter4dead:true
You can also try the applet yourself and check the console the println statements are there.

  HIT!4
New Timer
HP thread running. HP:92
Timer, spawn = true
Ter1dead:true
Ter2dead:true
Ter3dead:true
spawn && ter1dead && ter2dead && ter3dead && ter4dead == true
Ter4dead:true
0.5023988734381781
HP thread start
null
HP thread started
HP thread running. HP:91
HP thread running. HP:90
HP thread running. HP:89
HP thread running. HP:88
HP thread running. HP:87
HP thread running. HP:86
HP thread running. HP:85
HP thread running. HP:84
HP thread running. HP:83
HIT!2
New Timer
HP thread running. HP:82
Timer, spawn = true
Ter1dead:true
Ter2dead:true
Ter3dead:true
Ter4dead:true
  

  Dump thread list ...
Group main,ac=13,agc=2,pri=10
    main,5,alive
    Java2D Disposer,10,alive,daemon
    AWT-Shutdown,5,alive
    AWT-Windows,6,alive,daemon
    traceMsgQueueThread,5,alive,daemon
    AWT-EventQueue-0,6,alive
    Thread-55,5,alive
Group Plugin Thread Group,ac=3,agc=0,pri=10
    AWT-EventQueue-1,6,alive
    ConsoleWriterThread,6,alive,daemon
    TimerQueue,5,alive,daemon
Group <a href="http://www.freewebs.com/blobber/-threadGroup,ac=3,agc=0,pri=4" target="_blank" rel="nofollow">http://www.freewebs.com/blobber/-threadGroup,ac=3,agc=0,pri=4</a>
    thread applet-EpexShooter.class,4,alive
    TimerQueue,4,alive,daemon
    AWT-EventQueue-3,4,alive
Done.
  

  Dump thread stack ...
----------------------------------------------------
Full thread dump Java HotSpot(TM) Client VM (1.5.0_06-b05 mixed mode, sharing):
 
"TimerQueue" daemon prio=6 tid=0x05bdfa48 nid=0xab0 in Object.wait() [0x061bf000..0x061bfbe8]
at java.lang.Object.wait(Native Method)
- waiting on <0x23886f68> (a javax.swing.TimerQueue)
at javax.swing.TimerQueue.run(Unknown Source)
- locked <0x23886f68> (a javax.swing.TimerQueue)
at java.lang.Thread.run(Unknown Source)
 
"ConsoleWriterThread" daemon prio=6 tid=0x05bd28b8 nid=0xed0 in Object.wait() [0x01d4f000..0x01d4fc68]
at java.lang.Object.wait(Native Method)
- waiting on <0x23014408> (a java.lang.Object)
at java.lang.Object.wait(Unknown Source)
at com.sun.deploy.util.ConsoleTraceListener$ConsoleWriterThread.run(Unknown Source)
- locked <0x23014408> (a java.lang.Object)
 
"AWT-EventQueue-1" prio=6 tid=0x05c5ff20 nid=0x6a0 runnable [0x0103f000..0x0103fce8]
at sun.plugin.JavaRunTime.dumpAllStacks(Native Method)
at sun.plugin.util.PluginConsoleController.dumpAllStacks(Unknown Source)
at com.sun.deploy.util.ConsoleWindow$1.actionPerformed(Unknown Source)
at javax.swing.JComponent$ActionStandin.actionPerformed(Unknown Source)
at javax.swing.SwingUtilities.notifyAction(Unknown Source)
at javax.swing.JComponent.processKeyBinding(Unknown Source)
at javax.swing.KeyboardManager.fireBinding(Unknown Source)
at javax.swing.KeyboardManager.fireKeyboardAction(Unknown Source)
at javax.swing.JComponent.processKeyBindingsForAllComponents(Unknown Source)
at javax.swing.JComponent.processKeyBindings(Unknown Source)
at javax.swing.JComponent.processKeyEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.KeyboardFocusManager.redispatchEvent(Unknown Source)
at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(Unknown Source)
at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(Unknown Source)
at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(Unknown Source)
at java.awt.DefaultKeyboardFocusManager.dispatchEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
 
"Thread-55" prio=6 tid=0x05c7c030 nid=0xb3c runnable [0x00000000..0x0597f71c]
 
"AWT-EventQueue-3" prio=4 tid=0x05c602a8 nid=0x9ac in Object.wait() [0x0707f000..0x0707fce8]
at java.lang.Object.wait(Native Method)
at java.lang.Object.wait(Unknown Source)
at java.awt.EventQueue.getNextEvent(Unknown Source)
- locked <0x23586748> (a java.awt.EventQueue)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
 
"TimerQueue" daemon prio=4 tid=0x05be2210 nid=0x4b4 in Object.wait() [0x062bf000..0x062bfd68]
at java.lang.Object.wait(Native Method)
- waiting on <0x235867e0> (a javax.swing.TimerQueue)
at javax.swing.TimerQueue.run(Unknown Source)
- locked <0x235867e0> (a javax.swing.TimerQueue)
at java.lang.Thread.run(Unknown Source)
 
"thread applet-EpexShooter.class" prio=4 tid=0x05151920 nid=0xe9c in Object.wait() [0x060bf000..0x060bfa68]
at java.lang.Object.wait(Native Method)
- waiting on <0x23586850> (a sun.plugin.AppletViewer)
at java.lang.Object.wait(Unknown Source)
at sun.applet.AppletPanel.getNextEvent(Unknown Source)
- locked <0x23586850> (a sun.plugin.AppletViewer)
at sun.applet.AppletPanel.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
 
"AWT-EventQueue-0" prio=6 tid=0x05144c28 nid=0xf6c in Object.wait() [0x05a7f000..0x05a7fb68]
at java.lang.Object.wait(Native Method)
at java.lang.Object.wait(Unknown Source)
at java.awt.EventQueue.getNextEvent(Unknown Source)
- locked <0x22fc95d8> (a java.awt.EventQueue)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
 
"traceMsgQueueThread" daemon prio=6 tid=0x0513dd80 nid=0xb30 in Object.wait() [0x0587f000..0x0587fc68]
at java.lang.Object.wait(Native Method)
- waiting on <0x22fd55c0> (a java.util.ArrayList)
at java.lang.Object.wait(Unknown Source)
at com.sun.deploy.util.Trace$TraceMsgQueueChecker.run(Unknown Source)
- locked <0x22fd55c0> (a java.util.ArrayList)
at java.lang.Thread.run(Unknown Source)
 
"AWT-Windows" daemon prio=6 tid=0x05137db0 nid=0xec4 runnable [0x0566f000..0x0566fce8]
at sun.awt.windows.WToolkit.eventLoop(Native Method)
at sun.awt.windows.WToolkit.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
 
"AWT-Shutdown" prio=6 tid=0x05137930 nid=0x2d4 in Object.wait() [0x0556f000..0x0556fd68]
at java.lang.Object.wait(Native Method)
- waiting on <0x22fd5268> (a java.lang.Object)
at java.lang.Object.wait(Unknown Source)
at sun.awt.AWTAutoShutdown.run(Unknown Source)
- locked <0x22fd5268> (a java.lang.Object)
at java.lang.Thread.run(Unknown Source)
 
"Java2D Disposer" daemon prio=10 tid=0x05136570 nid=0x1e4 in Object.wait() [0x0546f000..0x0546f9e8]
at java.lang.Object.wait(Native Method)
- waiting on <0x22fd52f0> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(Unknown Source)
- locked <0x22fd52f0> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(Unknown Source)
at sun.java2d.Disposer.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
 
"Low Memory Detector" daemon prio=6 tid=0x029a8a58 nid=0x218 runnable [0x00000000..0x00000000]
 
"CompilerThread0" daemon prio=10 tid=0x029a74e8 nid=0xc58 waiting on condition [0x00000000..0x04f0f94c]
 
"Signal Dispatcher" daemon prio=10 tid=0x029a67d0 nid=0x418 runnable [0x00000000..0x00000000]
 
"Finalizer" daemon prio=8 tid=0x02978e00 nid=0xf50 in Object.wait() [0x04d0f000..0x04d0fbe8]
at java.lang.Object.wait(Native Method)
- waiting on <0x22fd5498> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(Unknown Source)
- locked <0x22fd5498> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(Unknown Source)
at java.lang.ref.Finalizer$FinalizerThread.run(Unknown Source)
 
"Reference Handler" daemon prio=10 tid=0x029a1a90 nid=0xec0 in Object.wait() [0x04c0f000..0x04c0fce8]
at java.lang.Object.wait(Native Method)
- waiting on <0x22fd51a0> (a java.lang.ref.Reference$Lock)
at java.lang.Object.wait(Unknown Source)
at java.lang.ref.Reference$ReferenceHandler.run(Unknown Source)
- locked <0x22fd51a0> (a java.lang.ref.Reference$Lock)
 
"main" prio=6 tid=0x0003ea78 nid=0xcf8 runnable [0x00000000..0x0013e85c]
 
"VM Thread" prio=10 tid=0x02976f90 nid=0xa6c runnable 
 
"VM Periodic Task Thread" prio=10 tid=0x029a9c70 nid=0xfdc waiting on condition 
 
----------------------------------------------------
Done.

Those I took when the applet had freezed.

Help will be appriciated

[ February 08, 2006: Message edited by: Jon Mattson ]

[ February 08, 2006: Message edited by: Jon Mattson ]
[ February 08, 2006: Message edited by: Jon Mattson ]

[Jeremy Tartaglia]

There are a few things which concern me. Why do you have your run methods as synchronized? They should only be called once, so there's no need to have them synchronized. Plus, synchronization causes the JVM to lock objects, which could cause some problems. I stay away from synchronized until I notice deadlocks occuring.

Another is the volatile Thread property. Why? Volatile is used when the property will be changed by an outside source, ie: not in the program. A hardware register changes, like the VBlank bit on a video card, or the address where the hardware timer stores the current time. Those are all volatile.

I don't think those are the problems, but I'd start there.

[Jon Mattson]

Sorry haven't been able to post been busy in school.

I uploaded yet another version of the applet. Now I somehow managed to get the retry button work and I removed the volatile and synchronized statements. This freezing problem is annoying cuz it seems to happen pretty randomly. But now there seems to be less of it. Didn't manage to make it freeze in the web browser but it did freeze in Eclipse. I still hope someone could find something in my code that could cause freezing.

Now I'm planning to make a hiscore system to that game which displays the scores on a webpage. I've been searching on google about it but haven't found that much info about it. I read somewhere about someone who used a php page which the applet updated with some command. Could someone lead me to the right direction about this issue? To a tutorial or class I should use. :roll: