package lip6.jikesrvm.bench;

import java.util.Random;
import lip6.jikesrvm.bench.Cell;

public class Main
{
	private static final long NB_ELEM = 10000;
	private static Random randomInt; // random int to put into the cells
	private static Cell head;

	public static void main(String args[])
	{
		randomInt = new Random(424242424242L);
		{
			Cell oldCell, newCell;

			newCell = null;
			head = new Cell(randomInt.nextInt());
			oldCell = head;
			for (int i = 0; i < NB_ELEM - 1; i++)
			{
				if (i == NB_ELEM / 2)
					Runtime.getRuntime().gc();
				newCell = new Cell(randomInt.nextInt());
				newCell.setPrev(oldCell);
				oldCell.setNext(newCell);
				oldCell = newCell;
			}
			newCell.setNext(head);
			head.setPrev(newCell);
		}
		bubbleSort();
		/* Only the 6 store in the if of the bubbleSort call the write barrier */
		System.out.println("Number of loop: "+ NB_ELEM);
		System.out.println("Number of writes per loop: 6");
	}

	private static void bubbleSort()
	{
		Cell cell, nextCell;

		/* We suppose the list disordered */
		boolean ordered = false;

		/* We stop after NB_ELEM loop or if a loop has been done without inversion */
		for(int i = 0 ; (i < NB_ELEM) && !ordered; i++)
		{
			/* We suppose the list ordered */
			ordered = true;

			/* New tracing of the list: we start to examine the first 2 cells */
			cell = head;
			nextCell = cell.getNext();
			for(int j = 1 ;j < NB_ELEM - i; j++)
			{
				/* If the 2 cells aren't ordered */
				if (nextCell.getValue() < cell.getValue())
				{
					/* We invert the 2 cells */
					cell.getPrev().setNext(nextCell);
					nextCell.getNext().setPrev(cell);
					cell.setNext(nextCell.getNext());
					nextCell.setPrev(cell.getPrev());
					cell.setPrev(nextCell);
					nextCell.setNext(cell);
					Cell.incCounter(6);


					/* We made an inversion: the list isn't ordered */
					ordered = false;
				}
				else
					cell = nextCell; /* Get ready for the next loop: we make a one cell shift (1) */

				/* Get ready for the next loop: we make a one cell shift (2) */
				nextCell = cell.getNext();
			}
		}
		System.out.println("ctr: " + Cell.getCounter());
	}
};