游戏中渲染线程与更新线程交替执行

private final State mThreadLocker = new State();
 private UpdateThread updateThread;
 private DrawThread drawThread;

 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
  updateThread = new UpdateThread();
  updateThread.start();
  drawThread = new DrawThread();
  drawThread.start();
 }

 protected void onUpdate() throws InterruptedException {
  final State threadLocker = this.mThreadLocker;
  threadLocker.waitUntilCanUpdate();
  System.out.println("Update");
  threadLocker.notifyCanDraw();

 }

 public void onDrawFrame() throws InterruptedException {
  final State threadLocker = this.mThreadLocker;
  threadLocker.waitUntilCanDraw();
  System.out.println("Draw");
  threadLocker.notifyCanUpdate();

 }

 private class UpdateThread extends Thread {
  private boolean flag; // 线程执行标志位

  public UpdateThread() {
   super("UpdateThread");
   this.flag = true;
  }

  @Override
  public void run() {
   try {
    while (flag) {
     onUpdate();
    }
   } catch (final InterruptedException e) {
    this.interrupt();
    e.printStackTrace();
   }
  }

  /*
   * 停止线程
   */
  public void requestStop() {
   flag = false;
  }
 }

 private class DrawThread extends Thread {
  private boolean flag; // 线程执行标志位

  public DrawThread() {
   super("DrawThread");
   this.flag = true;
  }

  @Override
  public void run() {
   try {
    while (flag) {
     onDrawFrame();
    }
   } catch (final InterruptedException e) {
    this.interrupt();
    e.printStackTrace();
   }
  }

  /*
   * 停止线程
   */
  public void requestStop() {
   flag = false;

  }
 }

 private static class State {
  boolean mDrawing = false;

  public synchronized void notifyCanDraw() {
   this.mDrawing = true;
   this.notifyAll();
  }

  public synchronized void notifyCanUpdate() {
   this.mDrawing = false;
   this.notifyAll();
  }

  public synchronized void waitUntilCanDraw() throws InterruptedException {
   while (this.mDrawing == false) {
    this.wait();
   }
  }

  public synchronized void waitUntilCanUpdate()
    throws InterruptedException {
   while (this.mDrawing == true) {
    this.wait();
   }
  }
 }

 @Override
 protected void onStart() {
  super.onStart();
 }

 @Override
 protected void onResume() {
  super.onResume();
 }

 @Override
 protected void onPause() {
  super.onPause();
 }

 @Override
 protected void onStop() {
  super.onStop();
 }

 @Override
 protected void onDestroy() {
  super.onDestroy();
  updateThread.requestStop();
  drawThread.requestStop();
 }

 @Override
 public String toString() {
  return "MultiThreadAndSync";
 }