funthread.java

gistfile1.txt

class FunThread extends Thread {
  Object first[];
  Object second[];
  int size;

  public FunThread(Object _first[], Object _second[], int _size) {
    first = _first;
    second = _second;
    size = _size;
  }

  public void run() {
/*    System.out.println("copying " + size +
      " on thread " + Thread.currentThread() + " from " +
      first + " to " + second);*/

    if(first.hashCode() == second.hashCode()) {
      System.exit(1);
    }

    Thread.yield();
    System.arraycopy(first, 0, second, 0, size);
  }
}


class Fun {
  static int MEM_PRINT_INT = 100;
  static int NUM_PAR_THREADS = 8;
  static int NUM_LEN_INC = 1;
  static int INC_BYTES = 32;

  public static void main(String[] args) {
    int len = INC_BYTES;

    for(int i = 0;;i++) { 
      Object[] sObj = new Object[len];
      Object[] dObj = new Object[len];

      for(int j = 0; j < NUM_PAR_THREADS; ++j) {
        FunThread ft = new FunThread(sObj, dObj, len);
        ft.start();
      }

      System.gc();

      if(i % MEM_PRINT_INT == 0) {
        System.out.println(Runtime.getRuntime().freeMemory() + "b free");
      }

      if(i % NUM_LEN_INC == 0) {
        len += INC_BYTES;
      }
    }
  }
}