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Comparing jsr166/src/main/java/util/ArrayDeque.java (file contents):
Revision 1.25 by jsr166, Sat Sep 17 17:22:17 2005 UTC vs.
Revision 1.27 by jsr166, Tue Feb 7 20:54:24 2006 UTC

# Line 4 | Line 4
4   */
5  
6   package java.util;
7 import java.util.*; // for javadoc (till 6280605 is fixed)
7   import java.io.*;
8  
9   /**
# Line 595 | Line 594 | public class ArrayDeque<E> extends Abstr
594          }
595  
596          public E next() {
598            E result;
597              if (cursor == fence)
598                  throw new NoSuchElementException();
599 +            E result = elements[cursor];
600              // This check doesn't catch all possible comodifications,
601              // but does catch the ones that corrupt traversal
602 <            if (tail != fence || (result = elements[cursor]) == null)
602 >            if (tail != fence || result == null)
603                  throw new ConcurrentModificationException();
604              lastRet = cursor;
605              cursor = (cursor + 1) & (elements.length - 1);
# Line 610 | Line 609 | public class ArrayDeque<E> extends Abstr
609          public void remove() {
610              if (lastRet < 0)
611                  throw new IllegalStateException();
612 <            if (delete(lastRet)) // if left-shifted, undo increment in next()
612 >            if (delete(lastRet)) { // if left-shifted, undo increment in next()
613                  cursor = (cursor - 1) & (elements.length - 1);
614 +                fence = tail;
615 +            }
616              lastRet = -1;
616            fence = tail;
617          }
618      }
619  
620      private class DescendingIterator implements Iterator<E> {
621          /*
622           * This class is nearly a mirror-image of DeqIterator, using
623 <         * (tail-1) instead of head for initial cursor, (head-1)
624 <         * instead of tail for fence, and elements.length instead of -1
625 <         * for sentinel. It shares the same structure, but not many
626 <         * actual lines of code.
623 >         * tail instead of head for initial cursor, and head instead of
624 >         * tail for fence.
625           */
626 <        private int cursor = (tail - 1) & (elements.length - 1);
627 <        private int fence =  (head - 1) & (elements.length - 1);
628 <        private int lastRet = elements.length;
626 >        private int cursor = tail;
627 >        private int fence = head;
628 >        private int lastRet = -1;
629  
630          public boolean hasNext() {
631              return cursor != fence;
632          }
633  
634          public E next() {
637            E result;
635              if (cursor == fence)
636                  throw new NoSuchElementException();
637 <            if (((head - 1) & (elements.length - 1)) != fence ||
638 <                (result = elements[cursor]) == null)
637 >            cursor = (cursor - 1) & (elements.length - 1);
638 >            E result = elements[cursor];
639 >            if (head != fence || result == null)
640                  throw new ConcurrentModificationException();
641              lastRet = cursor;
644            cursor = (cursor - 1) & (elements.length - 1);
642              return result;
643          }
644  
645          public void remove() {
646 <            if (lastRet >= elements.length)
646 >            if (lastRet < 0)
647                  throw new IllegalStateException();
648 <            if (!delete(lastRet))
648 >            if (!delete(lastRet)) {
649                  cursor = (cursor + 1) & (elements.length - 1);
650 <            lastRet = elements.length;
651 <            fence = (head - 1) & (elements.length - 1);
650 >                fence = head;
651 >            }
652 >            lastRet = -1;
653          }
654      }
655  

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