deadlockdemo.java

J2ME高级用户界面的学习代码

//DeadlockDemo.java

import java.lang.*;
import java.util.*;
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;

public class DeadlockDemo extends MIDlet implements Runnable
{
  private Display display;
  A a = new A();
  B b = new B();


  public DeadlockDemo()
  {
    //display = Display.getDisplay(this);
    Thread.currentThread().setPriority(8);
    Thread t = new Thread(this,"RacingThread");
    t.start();

    a.foo(b);
    System.out.println("Back in main thread");
  }

  public void run()
  {
    b.bar(a);
    System.out.println("Back in the other thread");
  }

  protected void startApp()
  {
    //display.setCurrent();
    new DeadlockDemo();
  }

  protected void pauseApp(){}
  protected void destroyApp(boolean unconditional){}

}

class A
{
  synchronized void foo(B b)
  {
    String name = Thread.currentThread().getName();
    System.out.println(name + "entered A.foo");

    try{
      Thread.sleep(1000);
    }catch(Exception e){
      System.out.println("A Interrupted");
    }

    System.out.println(name + "trying to call B.last()");
    b.last();
  }

  synchronized void last()
  {
    System.out.println("Inside A.last");
  }
}

class B
{
  synchronized void bar(A a)
  {
    String name = Thread.currentThread().getName();
    System.out.println(name + "entered B.bar");

    try{
      Thread.sleep(1000);
    }catch(Exception e){
      System.out.println("B Interrupted");
    }

    System.out.println(name + "trying to call A.last()");
    a.last();
  }

  synchronized void last()
  {
    System.out.println("Inside B.last");
  }
}