| 595 |
|
} |
| 596 |
|
|
| 597 |
|
public E next() { |
| 598 |
– |
E result; |
| 598 |
|
if (cursor == fence) |
| 599 |
|
throw new NoSuchElementException(); |
| 600 |
+ |
E result = elements[cursor]; |
| 601 |
|
// This check doesn't catch all possible comodifications, |
| 602 |
|
// but does catch the ones that corrupt traversal |
| 603 |
< |
if (tail != fence || (result = elements[cursor]) == null) |
| 603 |
> |
if (tail != fence || result == null) |
| 604 |
|
throw new ConcurrentModificationException(); |
| 605 |
|
lastRet = cursor; |
| 606 |
|
cursor = (cursor + 1) & (elements.length - 1); |
| 610 |
|
public void remove() { |
| 611 |
|
if (lastRet < 0) |
| 612 |
|
throw new IllegalStateException(); |
| 613 |
< |
if (delete(lastRet)) // if left-shifted, undo increment in next() |
| 613 |
> |
if (delete(lastRet)) { // if left-shifted, undo increment in next() |
| 614 |
|
cursor = (cursor - 1) & (elements.length - 1); |
| 615 |
+ |
fence = tail; |
| 616 |
+ |
} |
| 617 |
|
lastRet = -1; |
| 616 |
– |
fence = tail; |
| 618 |
|
} |
| 619 |
|
} |
| 620 |
|
|
| 621 |
|
private class DescendingIterator implements Iterator<E> { |
| 622 |
|
/* |
| 623 |
|
* This class is nearly a mirror-image of DeqIterator, using |
| 624 |
< |
* (tail-1) instead of head for initial cursor, (head-1) |
| 625 |
< |
* 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. |
| 624 |
> |
* tail instead of head for initial cursor, and head instead of |
| 625 |
> |
* tail for fence. |
| 626 |
|
*/ |
| 627 |
< |
private int cursor = (tail - 1) & (elements.length - 1); |
| 628 |
< |
private int fence = (head - 1) & (elements.length - 1); |
| 629 |
< |
private int lastRet = elements.length; |
| 627 |
> |
private int cursor = tail; |
| 628 |
> |
private int fence = head; |
| 629 |
> |
private int lastRet = -1; |
| 630 |
|
|
| 631 |
|
public boolean hasNext() { |
| 632 |
|
return cursor != fence; |
| 633 |
|
} |
| 634 |
|
|
| 635 |
|
public E next() { |
| 637 |
– |
E result; |
| 636 |
|
if (cursor == fence) |
| 637 |
|
throw new NoSuchElementException(); |
| 638 |
< |
if (((head - 1) & (elements.length - 1)) != fence || |
| 639 |
< |
(result = elements[cursor]) == null) |
| 638 |
> |
cursor = (cursor - 1) & (elements.length - 1); |
| 639 |
> |
E result = elements[cursor]; |
| 640 |
> |
if (head != fence || result == null) |
| 641 |
|
throw new ConcurrentModificationException(); |
| 642 |
|
lastRet = cursor; |
| 644 |
– |
cursor = (cursor - 1) & (elements.length - 1); |
| 643 |
|
return result; |
| 644 |
|
} |
| 645 |
|
|
| 646 |
|
public void remove() { |
| 647 |
< |
if (lastRet >= elements.length) |
| 647 |
> |
if (lastRet < 0) |
| 648 |
|
throw new IllegalStateException(); |
| 649 |
< |
if (!delete(lastRet)) |
| 649 |
> |
if (!delete(lastRet)) { |
| 650 |
|
cursor = (cursor + 1) & (elements.length - 1); |
| 651 |
< |
lastRet = elements.length; |
| 652 |
< |
fence = (head - 1) & (elements.length - 1); |
| 651 |
> |
fence = head; |
| 652 |
> |
} |
| 653 |
> |
lastRet = -1; |
| 654 |
|
} |
| 655 |
|
} |
| 656 |
|
|
