| 560 |
|
return false; |
| 561 |
|
} |
| 562 |
|
|
| 563 |
< |
/* |
| 564 |
< |
* Possible values for "how" argument in xfer method. |
| 565 |
< |
*/ |
| 563 |
> |
/** |
| 564 |
> |
* Collapse dead (matched) nodes between pred and q. |
| 565 |
> |
* @param pred the last known live node, or null if none |
| 566 |
> |
* @param c the first dead node |
| 567 |
> |
* @param p the last dead node |
| 568 |
> |
* @param q p.next: the next live node, or null if at end |
| 569 |
> |
* @return either old pred or p if pred dead or CAS failed |
| 570 |
> |
*/ |
| 571 |
> |
private Node skipDeadNodes(Node pred, Node c, Node p, Node q) { |
| 572 |
> |
// assert pred != c; |
| 573 |
> |
// assert p != q; |
| 574 |
> |
// assert c.isMatched(); |
| 575 |
> |
// assert p.isMatched(); |
| 576 |
> |
if (q == null) { |
| 577 |
> |
// Never unlink trailing node. |
| 578 |
> |
if (c == p) return pred; |
| 579 |
> |
q = p; |
| 580 |
> |
} |
| 581 |
> |
return (tryCasSuccessor(pred, c, q) |
| 582 |
> |
&& (pred == null || !pred.isMatched())) |
| 583 |
> |
? pred : p; |
| 584 |
> |
} |
| 585 |
> |
|
| 586 |
> |
/* Possible values for "how" argument in xfer method. */ |
| 587 |
> |
|
| 588 |
|
private static final int NOW = 0; // for untimed poll, tryTransfer |
| 589 |
|
private static final int ASYNC = 1; // for offer, put, add |
| 590 |
|
private static final int SYNC = 2; // for transfer, take |
| 1472 |
|
* @return {@code true} if this queue changed as a result of the call |
| 1473 |
|
*/ |
| 1474 |
|
public boolean remove(Object o) { |
| 1475 |
< |
if (o == null) |
| 1454 |
< |
return false; |
| 1475 |
> |
if (o == null) return false; |
| 1476 |
|
restartFromHead: for (;;) { |
| 1477 |
< |
for (Node p = head, c = p, pred = null, q; p != null; ) { |
| 1478 |
< |
final Object item; boolean pAlive; |
| 1479 |
< |
if (pAlive = ((item = p.item) != null && p.isData)) { |
| 1480 |
< |
if (o.equals(item) && p.tryMatchData()) { |
| 1481 |
< |
if ((q = p.next) == null) q = p; |
| 1482 |
< |
if (c != q) tryCasSuccessor(pred, c, q); |
| 1483 |
< |
return true; |
| 1477 |
> |
for (Node p = head, pred = null; p != null; ) { |
| 1478 |
> |
Node q = p.next; |
| 1479 |
> |
final Object item; |
| 1480 |
> |
if ((item = p.item) != null) { |
| 1481 |
> |
if (p.isData) { |
| 1482 |
> |
if (o.equals(item) && p.tryMatchData()) { |
| 1483 |
> |
skipDeadNodes(pred, p, p, q); |
| 1484 |
> |
return true; |
| 1485 |
> |
} |
| 1486 |
> |
pred = p; p = q; continue; |
| 1487 |
|
} |
| 1488 |
|
} |
| 1489 |
< |
else if (!p.isData && item == null) |
| 1489 |
> |
else if (!p.isData) |
| 1490 |
|
break; |
| 1491 |
< |
if ((c != p && !tryCasSuccessor(pred, c, c = p)) || pAlive) { |
| 1492 |
< |
pred = p; |
| 1493 |
< |
c = p = p.next; |
| 1491 |
> |
for (Node c = p;;) { |
| 1492 |
> |
if ((q = p.next) == null || !q.isMatched()) { |
| 1493 |
> |
pred = skipDeadNodes(pred, c, p, q); p = q; break; |
| 1494 |
> |
} |
| 1495 |
> |
if (p == (p = q)) continue restartFromHead; |
| 1496 |
|
} |
| 1471 |
– |
else if (p == (p = p.next)) |
| 1472 |
– |
continue restartFromHead; |
| 1497 |
|
} |
| 1498 |
|
return false; |
| 1499 |
|
} |
| 1508 |
|
* @return {@code true} if this queue contains the specified element |
| 1509 |
|
*/ |
| 1510 |
|
public boolean contains(Object o) { |
| 1511 |
< |
if (o == null) |
| 1488 |
< |
return false; |
| 1511 |
> |
if (o == null) return false; |
| 1512 |
|
restartFromHead: for (;;) { |
| 1513 |
< |
for (Node p = head, c = p, pred = null; p != null; ) { |
| 1514 |
< |
final Object item; final boolean pAlive; |
| 1515 |
< |
if (pAlive = ((item = p.item) != null && p.isData)) { |
| 1516 |
< |
if (o.equals(item)) |
| 1517 |
< |
return true; |
| 1513 |
> |
for (Node p = head, pred = null; p != null; ) { |
| 1514 |
> |
Node q = p.next; |
| 1515 |
> |
final Object item; |
| 1516 |
> |
if ((item = p.item) != null) { |
| 1517 |
> |
if (p.isData) { |
| 1518 |
> |
if (o.equals(item)) |
| 1519 |
> |
return true; |
| 1520 |
> |
pred = p; p = q; continue; |
| 1521 |
> |
} |
| 1522 |
|
} |
| 1523 |
< |
else if (!p.isData && item == null) |
| 1523 |
> |
else if (!p.isData) |
| 1524 |
|
break; |
| 1525 |
< |
if ((c != p && !tryCasSuccessor(pred, c, c = p)) || pAlive) { |
| 1526 |
< |
pred = p; |
| 1527 |
< |
c = p = p.next; |
| 1525 |
> |
for (Node c = p;;) { |
| 1526 |
> |
if ((q = p.next) == null || !q.isMatched()) { |
| 1527 |
> |
pred = skipDeadNodes(pred, c, p, q); p = q; break; |
| 1528 |
> |
} |
| 1529 |
> |
if (p == (p = q)) continue restartFromHead; |
| 1530 |
|
} |
| 1502 |
– |
else if (p == (p = p.next)) |
| 1503 |
– |
continue restartFromHead; |
| 1531 |
|
} |
| 1532 |
|
return false; |
| 1533 |
|
} |
| 1659 |
|
*/ |
| 1660 |
|
@SuppressWarnings("unchecked") |
| 1661 |
|
void forEachFrom(Consumer<? super E> action, Node p) { |
| 1662 |
< |
for (Node c = p, pred = null; p != null; ) { |
| 1663 |
< |
final Object item; final boolean pAlive; |
| 1664 |
< |
if (pAlive = ((item = p.item) != null && p.isData)) |
| 1665 |
< |
action.accept((E) item); |
| 1666 |
< |
else if (!p.isData && item == null) |
| 1662 |
> |
for (Node pred = null; p != null; ) { |
| 1663 |
> |
Node q = p.next; |
| 1664 |
> |
final Object item; |
| 1665 |
> |
if ((item = p.item) != null) { |
| 1666 |
> |
if (p.isData) { |
| 1667 |
> |
action.accept((E) item); |
| 1668 |
> |
pred = p; p = q; continue; |
| 1669 |
> |
} |
| 1670 |
> |
} |
| 1671 |
> |
else if (!p.isData) |
| 1672 |
|
break; |
| 1673 |
< |
if ((c != p && !tryCasSuccessor(pred, c, c = p)) || pAlive) { |
| 1674 |
< |
pred = p; |
| 1675 |
< |
c = p = p.next; |
| 1676 |
< |
} |
| 1677 |
< |
else if (p == (p = p.next)) { |
| 1646 |
< |
pred = null; |
| 1647 |
< |
c = p = head; |
| 1673 |
> |
for (Node c = p;;) { |
| 1674 |
> |
if ((q = p.next) == null || !q.isMatched()) { |
| 1675 |
> |
pred = skipDeadNodes(pred, c, p, q); p = q; break; |
| 1676 |
> |
} |
| 1677 |
> |
if (p == (p = q)) { pred = null; p = head; break; } |
| 1678 |
|
} |
| 1679 |
|
} |
| 1680 |
|
} |
