libjava/testsuite/libjava.lang/TLtest.java

   1 class TLtest extends Thread {
   2
   3     public static void main (String [] args) {
   4         Data d = new Data ();
   5         new ThreadTest (d, "A").start ();
   6         new ThreadTest (d, "B").start ();
   7     }
   8 }
   9
  10 class Data {
  11
  12     private static ThreadLocal owner = new ThreadLocal () {
  13             public Object initialValue () { return ("0"); }
  14         };
  15     /* A thread will call `set' to set a value it wants an instance
  16        of Data to associate with it and only it. */
  17     synchronized public void set (String v){owner.set (v);}
  18     /* A thread will call `get' to get a value it wants an instance
  19        of Data to associate with it and only it. */
  20     synchronized public String get (){return (String)owner.get();}
  21 }
  22
  23 class ThreadTest extends Thread {
  24
  25     public Data d;
  26
  27     ThreadTest (Data d, String name) {
  28         super (name);
  29         this.d = d;
  30     }
  31
  32     public void run () {
  33
  34         int value = 0;
  35         int ref = 0;
  36
  37         for (int i = 0; i < 20; i++) {
  38
  39             int rand = (int)(Math.random ()*20);
  40
  41             /* Read `value', ref is kept for comparison */
  42             value = Integer.parseInt (d.get());
  43
  44             /* change `value' and ref by a random number, store `value'. */
  45             value += rand; ref += rand;
  46             d.set (Integer.toString (value));
  47
  48             try {
  49                 sleep((int)(Math.random() * 500));
  50             } catch (InterruptedException e) {}
  51         }
  52
  53         /* If a thread didn't have private value to attach to the
  54            instance of Data, results wouldn't be the same */
  55         if (ref == value)
  56             System.out.println ("test OK.");
  57         else
  58             System.out.println ("test failed.");
  59     }
  60 }