Thread blocking issue - AWT

package p5.test_awt_applet;

import java.applet.Applet;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.DisplayMode;
import java.awt.Frame;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.Insets;
import java.awt.Rectangle;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.util.Timer;
import java.util.TimerTask;

import javax.media.opengl.*;
import javax.media.opengl.awt.GLCanvas;

import com.jogamp.opengl.util.AnimatorBase;

// Sample program that relies on JOGL's mechanism to handle the OpenGL context
// and rendering loop when using an AWT canvas attached to an Applet.
public class MiniPApplet extends Applet implements MouseMotionListener,
                                                   KeyListener {
  private static final long serialVersionUID = 1L;

  /////////////////////////////////////////////////////////////
  //
  // Test parameters

  public int frameRate           = 120;
  public int numSamples          = 4;

  public boolean fullScreen      = false;
  public boolean useAnimator     = true;
  public boolean resizeableFrame = true;

  public boolean restartCanvas   = true;
  public int restartTimeout      = 100; // in number of frames.

  public boolean printThreadInfo = false;
  public boolean printEventInfo  = false;

  /////////////////////////////////////////////////////////////
  //
  // Internal variables

  int width;
  int height;

  String OPENGL_VENDOR;
  String OPENGL_RENDERER;
  String OPENGL_VERSION;
  String OPENGL_EXTENSIONS;

  int currentSamples = -1;

  private Frame frame;
  private GLProfile profile;
  private GLCapabilities capabilities;
  private GLCanvas canvas;

  private SimpleListener listener;
  private CustomAnimator animator;

  private long beforeTime;
  private long overSleepTime;
  private long frameRatePeriod = 1000000000L / frameRate;

  private boolean initialized = false;

  private double theta = 0;
  private double s = 0;
  private double c = 0;

  private long millisOffset;
  private int fcount, lastm;
  private float frate;
  private int fint = 3;

  private boolean setFramerate = false;
  private boolean restarted = false;

  private int frameCount = 0;

  void run() {
    Thread loop = new Thread("Animation Thread") {
      public void run() {
        frameCount = 0;
        while (true) {
          if (!initialized) {
            setup();
          }

          if (restartCanvas && restartTimeout == frameCount) {
            restart();
          }

          if (useAnimator) {
            animator.requestRender();
          } else {
            canvas.display();
          }

          clock();

          frameCount++;
        }
      }
    };
    loop.start();
  }

  void setup() {
    if (printThreadInfo) System.out.println("Current thread at setup(): " + Thread.currentThread());

    millisOffset = System.currentTimeMillis();

    // Frame setup ----------------------------------------------------------

    width = 300;
    height = 300;
    MiniPApplet applet = this;
    Rectangle fullScreenRect = null;

    GraphicsEnvironment environment =
      GraphicsEnvironment.getLocalGraphicsEnvironment();
    GraphicsDevice displayDevice = environment.getDefaultScreenDevice();
    frame = new Frame(displayDevice.getDefaultConfiguration());

    frame.setTitle("MiniPApplet");
    if (fullScreen) {
      frame.setUndecorated(true);
      frame.setBackground(Color.GRAY);
      DisplayMode mode = displayDevice.getDisplayMode();
      fullScreenRect = new Rectangle(0, 0, mode.getWidth(), mode.getHeight());
      frame.setBounds(fullScreenRect);
      frame.setVisible(true);
    }
    frame.setLayout(null);
    frame.add(applet);
    if (fullScreen) {
      frame.invalidate();
    } else {
      frame.pack();
    }
    frame.setResizable(resizeableFrame);

    if (fullScreen) {
      // After the pack(), the screen bounds are gonna be 0s
      frame.setBounds(fullScreenRect);
      applet.setBounds((fullScreenRect.width - applet.width) / 2,
                       (fullScreenRect.height - applet.height) / 2,
                       applet.width, applet.height);
    } else {
      Insets insets = frame.getInsets();

      int windowW = applet.width + insets.left + insets.right;
      int windowH = applet.height + insets.top + insets.bottom;
      int locationX = 100;
      int locationY = 100;

      frame.setSize(windowW, windowH);
      frame.setLocation(locationX, locationY);

      int usableWindowH = windowH - insets.top - insets.bottom;
      applet.setBounds((windowW - width)/2, insets.top + (usableWindowH - height)/2, width, height);
    }

    frame.add(this);
    frame.addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
          System.exit(0);
      }
    });

    frame.setVisible(true);

    // Canvas setup ----------------------------------------------------------

    profile = GLProfile.getDefault();
    capabilities = new GLCapabilities(profile);
    capabilities.setSampleBuffers(true);
    capabilities.setNumSamples(numSamples);
    capabilities.setDepthBits(24);
    capabilities.setStencilBits(8);
    capabilities.setAlphaBits(8);

    canvas = new GLCanvas(capabilities);
    canvas.setBounds(0, 0, width, height);

    this.setLayout(new BorderLayout());
    this.add(canvas, BorderLayout.CENTER);
    canvas.addMouseMotionListener(this);
    canvas.addKeyListener(this);

    // Setting up animation
    listener = new SimpleListener();
    canvas.addGLEventListener(listener);
    if (useAnimator) {
      animator = new CustomAnimator(canvas);
      animator.start();
    }
    initialized = true;
  }

  void restart() {
    System.out.println("Restarting surface...");

    // Stopping animation, removing current canvas.
    if (useAnimator) {
      animator.stop();
      animator.remove(canvas);
    }
    canvas.removeGLEventListener(listener);
    this.remove(canvas);

    capabilities = new GLCapabilities(profile);
    capabilities.setSampleBuffers(true);
    capabilities.setNumSamples(numSamples);

    canvas = new GLCanvas(capabilities);
    canvas.setBounds(0, 0, width, height);

    // Setting up animation again
    this.setLayout(new BorderLayout());
    this.add(canvas, BorderLayout.CENTER);
    canvas.addMouseMotionListener(this);
    canvas.addKeyListener(this);

    canvas.addGLEventListener(listener);
    if (useAnimator) {
      animator.add(canvas);
      animator.start();
    }

    setFramerate = false;
    restarted = true;

    System.out.println("Done");
  }

  void draw(GL2 gl) {
    frame.setTitle("frame " + frameCount);

    if (printThreadInfo) System.out.println("Current thread at draw(): " + Thread.currentThread());

    if (OPENGL_VENDOR == null) {
      OPENGL_VENDOR     = gl.glGetString(GL.GL_VENDOR);
      OPENGL_RENDERER   = gl.glGetString(GL.GL_RENDERER);
      OPENGL_VERSION    = gl.glGetString(GL.GL_VERSION);
      OPENGL_EXTENSIONS = gl.glGetString(GL.GL_EXTENSIONS);
      System.out.println(OPENGL_VENDOR);
      System.out.println(OPENGL_RENDERER);
      System.out.println(OPENGL_VERSION);
      System.out.println(OPENGL_EXTENSIONS);

      int[] temp = { 0 };
      gl.glGetIntegerv(GL2.GL_MAX_SAMPLES, temp, 0);
      System.out.println("Maximum number of samples supported by the hardware: " + temp[0]);
    }

    if (currentSamples == -1) {
      int[] temp = { 0 };
      gl.glGetIntegerv(GL.GL_SAMPLES, temp, 0);
      currentSamples = temp[0];
      if (numSamples != currentSamples) {
        System.err.println("Requested sampling level " + numSamples + " not supported. Using " + currentSamples + " samples instead.");
      }
    }

    if (!setFramerate) {
      if (60 < frameRate) {
        // Disables vsync
        gl.setSwapInterval(0);
      } else if (30 < frameRate) {
        gl.setSwapInterval(1);
      } else {
        gl.setSwapInterval(2);
      }
      setFramerate = true;
    }

    if (restarted) {
      int[] temp = { 0 };
      gl.glGetIntegerv(GL.GL_SAMPLES, temp, 0);
      if (numSamples != temp[0]) {
        System.err.println("Multisampling level requested " + numSamples + " not supported. Using " + temp[0] + "samples instead.");
      }
    }

    gl.glClearColor(0, 0, 0, 1);
    gl.glClear(GL.GL_COLOR_BUFFER_BIT);

    theta += 0.01;
    s = Math.sin(theta);
    c = Math.cos(theta);

    gl.glBegin(GL.GL_TRIANGLES);
    gl.glColor3f(1, 0, 0);
    gl.glVertex2d(-c, -c);
    gl.glColor3f(0, 1, 0);
    gl.glVertex2d(0, c);
    gl.glColor3f(0, 0, 1);
    gl.glVertex2d(s, -s);
    gl.glEnd();

    gl.glFlush();

    fcount += 1;
    int m = (int) (System.currentTimeMillis() - millisOffset);
    if (m - lastm > 1000 * fint) {
      frate = (float)(fcount) / fint;
      fcount = 0;
      lastm = m;
      System.err.println("fps: " + frate);
    }
  }

  void clock() {
    long afterTime = System.nanoTime();
    long timeDiff = afterTime - beforeTime;
    long sleepTime = (frameRatePeriod - timeDiff) - overSleepTime;

    if (sleepTime > 0) {  // some time left in this cycle
      try {
        Thread.sleep(sleepTime / 1000000L, (int) (sleepTime % 1000000L));
      } catch (InterruptedException ex) { }

      overSleepTime = (System.nanoTime() - afterTime) - sleepTime;

    } else {    // sleepTime <= 0; the frame took longer than the period
      overSleepTime = 0L;
    }

    beforeTime = System.nanoTime();
  }

  class SimpleListener implements GLEventListener {
    @Override
    public void display(GLAutoDrawable drawable) {
      draw(drawable.getGL().getGL2());
    }

    @Override
    public void dispose(GLAutoDrawable drawable) { }

    @Override
    public void init(GLAutoDrawable drawable) { }

    @Override
    public void reshape(GLAutoDrawable drawable, int x, int y, int w, int h) { }
  }

  public void mouseDragged(MouseEvent ev) {
    if (printEventInfo) {
      System.err.println("Mouse dragged event: " + ev);
    }
  }

  public void mouseMoved(MouseEvent ev) {
    if (printEventInfo) {
      System.err.println("Mouse moved event: " + ev);
    }
  }

  public void keyPressed(KeyEvent ev) {
    if (printEventInfo) {
      System.err.println("Key pressed event: " + ev);
    }
  }

  public void keyReleased(KeyEvent ev) {
    if (printEventInfo) {
      System.err.println("Key released event: " + ev);
    }
  }

  public void keyTyped(KeyEvent ev) {
    if (printEventInfo) {
      System.err.println("Key typed event: " + ev);
    }
  }

  public static void main(String[] args) {
    MiniPApplet mini;
    try {
      Class<?> c = Thread.currentThread().getContextClassLoader().loadClass(MiniPApplet.class.getName());
      mini = (MiniPApplet) c.newInstance();
    } catch (Exception e) {
      throw new RuntimeException(e);
    }
    if (mini != null) {
      mini.run();
    }
  }

  /** An Animator subclass which renders one frame at the time
   *  upon calls to the requestRender() method.
   **/
  public class CustomAnimator extends AnimatorBase {
      private Timer timer = null;
      private TimerTask task = null;
      private volatile boolean shouldRun;

      protected String getBaseName(String prefix) {
          return "Custom" + prefix + "Animator" ;
      }

      /** Creates an CustomAnimator with an initial drawable to
       * animate. */
      public CustomAnimator(GLAutoDrawable drawable) {
          if (drawable != null) {
              add(drawable);
          }
      }

      public synchronized void requestRender() {
          shouldRun = true;
      }

      public final boolean isStarted() {
          stateSync.lock();
          try {
              return (timer != null);
          } finally {
              stateSync.unlock();
          }
      }

      public final boolean isAnimating() {
          stateSync.lock();
          try {
              return (timer != null) && (task != null);
          } finally {
              stateSync.unlock();
          }
      }

      private void startTask() {
          if(null != task) {
              return;
          }

          task = new TimerTask() {
              private boolean firstRun = true;
              public void run() {
                  if (firstRun) {
                    Thread.currentThread().setName("OPENGL");
                    firstRun = false;
                  }
                  if(CustomAnimator.this.shouldRun) {
                     CustomAnimator.this.animThread = Thread.currentThread();
                      // display impl. uses synchronized block on the animator instance
                      display();
                      synchronized (this) {
                        // done with current frame.
                        shouldRun = false;
                      }
                  }
              }
          };

          fpsCounter.resetFPSCounter();
          shouldRun = false;

          timer.schedule(task, 0, 1);
      }

      public synchronized boolean  start() {
          if (timer != null) {
              return false;
          }
          stateSync.lock();
          try {
              timer = new Timer();
              startTask();
          } finally {
              stateSync.unlock();
          }
          return true;
      }

      /** Stops this CustomAnimator. */
      public synchronized boolean stop() {
          if (timer == null) {
              return false;
          }
          stateSync.lock();
          try {
              shouldRun = false;
              if(null != task) {
                  task.cancel();
                  task = null;
              }
              if(null != timer) {
                  timer.cancel();
                  timer = null;
              }
              animThread = null;
              try {
                  Thread.sleep(20); // ~ 1/60 hz wait, since we can't ctrl stopped threads
              } catch (InterruptedException e) { }
          } finally {
              stateSync.unlock();
          }
          return true;
      }

      public final boolean isPaused() { return false; }
      public synchronized boolean resume() { return false; }
      public synchronized boolean pause() { return false; }
  }
}