| 343 |
|
* When these cases arise, rather than always retraversing the |
| 344 |
|
* entire list to find an actual predecessor to unlink (which |
| 345 |
|
* won't help for case (1) anyway), we record a conservative |
| 346 |
< |
* estimate of possible unsplice failures (in "sweepVotes). We |
| 346 |
> |
* estimate of possible unsplice failures (in "sweepVotes"). We |
| 347 |
|
* trigger a full sweep when the estimate exceeds a threshold |
| 348 |
|
* indicating the maximum number of estimated removal failures to |
| 349 |
|
* tolerate before sweeping through, unlinking cancelled nodes |
| 876 |
|
} |
| 877 |
|
|
| 878 |
|
/** |
| 879 |
< |
* Unlink matched nodes encountered in a traversal from head |
| 879 |
> |
* Unlinks matched nodes encountered in a traversal from head. |
| 880 |
|
*/ |
| 881 |
|
private void sweep() { |
| 882 |
< |
Node p = head, s, n; |
| 883 |
< |
while (p != null && (s = p.next) != null && (n = s.next) != null) { |
| 884 |
< |
if (p == s || s == n) |
| 885 |
< |
p = head; // stale |
| 886 |
< |
else if (s.isMatched()) |
| 887 |
< |
p.casNext(s, n); |
| 888 |
< |
else |
| 882 |
> |
for (Node p = head, s, n; p != null && (s = p.next) != null; ) { |
| 883 |
> |
if (p == s) // stale |
| 884 |
> |
p = head; |
| 885 |
> |
else if (!s.isMatched()) |
| 886 |
|
p = s; |
| 887 |
+ |
else if ((n = s.next) == null) // trailing node is pinned |
| 888 |
+ |
break; |
| 889 |
+ |
else |
| 890 |
+ |
p.casNext(s, n); |
| 891 |
|
} |
| 892 |
|
} |
| 893 |
|
|
| 1125 |
|
* @return {@code true} if this queue contains no elements |
| 1126 |
|
*/ |
| 1127 |
|
public boolean isEmpty() { |
| 1128 |
< |
return firstOfMode(true) == null; |
| 1128 |
> |
for (Node p = head; p != null; p = succ(p)) { |
| 1129 |
> |
if (!p.isMatched()) |
| 1130 |
> |
return !p.isData; |
| 1131 |
> |
} |
| 1132 |
> |
return true; |
| 1133 |
|
} |
| 1134 |
|
|
| 1135 |
|
public boolean hasWaitingConsumer() { |
