libjava/testsuite/libjava.lang/Thread_Monitor.java

   1 // Test that monitor locks work and are recursive.
   2 // Origin: Bryce McKinlay <bryce@albatross.co.nz>
   3
   4 class T implements Runnable
   5 {
   6   public int count = 0;
   7   Counter c;
   8
   9   public T (Counter c)
  10   {
  11     this.c = c;
  12   }
  13
  14   public void run()
  15   {
  16     while (true)
  17       {
  18         // NOTE: double-synchronization here.
  19         synchronized (c)
  20         {
  21           if (c.getCount() <= 100000)
  22             count++;
  23           else
  24             break;
  25         }
  26       }
  27   }
  28 }
  29
  30 class Counter
  31 {
  32   int i = 0;
  33   public synchronized int getCount ()
  34   {
  35     return ++i;
  36   }
  37 }
  38
  39 public class Thread_Monitor
  40 {
  41   public static void main(String args[])
  42   {
  43     Counter c = new Counter();
  44     T t1 = new T(c);
  45     T t2 = new T(c);
  46
  47     Thread th1 = new Thread(t1);
  48     Thread th2 = new Thread(t2);
  49     th1.start();
  50     th2.start();
  51     try
  52     {
  53       th1.join();
  54       th2.join();
  55     }
  56     catch (InterruptedException x)
  57     {
  58       System.out.println("failed: Interrupted");
  59     }
  60     if (t1.count + t2.count == 100000)
  61       System.out.println ("ok");
  62     else
  63       System.out.println ("failed: total count incorrect");
  64   }
  65 }