| 950 |
|
; i = 0, to = end) { |
| 951 |
|
for (; i < to; i++) |
| 952 |
|
if (filter.test(elementAt(es, i))) |
| 953 |
< |
return bulkRemoveModified(filter, i, to); |
| 953 |
> |
return bulkRemoveModified(filter, i); |
| 954 |
|
if (to == end) { |
| 955 |
|
if (end != tail) throw new ConcurrentModificationException(); |
| 956 |
|
break; |
| 959 |
|
return false; |
| 960 |
|
} |
| 961 |
|
|
| 962 |
+ |
// A tiny bit set implementation |
| 963 |
+ |
|
| 964 |
+ |
private static long[] nBits(int n) { |
| 965 |
+ |
return new long[((n - 1) >> 6) + 1]; |
| 966 |
+ |
} |
| 967 |
+ |
private static void setBit(long[] bits, int i) { |
| 968 |
+ |
bits[i >> 6] |= 1L << i; |
| 969 |
+ |
} |
| 970 |
+ |
private static boolean isClear(long[] bits, int i) { |
| 971 |
+ |
return (bits[i >> 6] & (1L << i)) == 0; |
| 972 |
+ |
} |
| 973 |
+ |
|
| 974 |
|
/** |
| 975 |
|
* Helper for bulkRemove, in case of at least one deletion. |
| 976 |
< |
* @param i valid index of first element to be deleted |
| 976 |
> |
* Tolerate predicates that reentrantly access the collection for |
| 977 |
> |
* read (but writers still get CME), so traverse once to find |
| 978 |
> |
* elements to delete, a second pass to physically expunge. |
| 979 |
> |
* |
| 980 |
> |
* @param beg valid index of first element to be deleted |
| 981 |
|
*/ |
| 982 |
|
private boolean bulkRemoveModified( |
| 983 |
< |
Predicate<? super E> filter, int i, int to) { |
| 983 |
> |
Predicate<? super E> filter, final int beg) { |
| 984 |
|
final Object[] es = elements; |
| 985 |
|
final int capacity = es.length; |
| 970 |
– |
// a two-finger algorithm, with hare i reading, tortoise j writing |
| 971 |
– |
int j = i++; |
| 986 |
|
final int end = tail; |
| 987 |
< |
try { |
| 988 |
< |
for (;; j = 0) { // j rejoins i on second leg |
| 989 |
< |
E e; |
| 990 |
< |
// In this loop, i and j are on the same leg, with i > j |
| 991 |
< |
for (; i < to; i++) |
| 992 |
< |
if (!filter.test(e = elementAt(es, i))) |
| 993 |
< |
es[j++] = e; |
| 994 |
< |
if (to == end) break; |
| 995 |
< |
// In this loop, j is on the first leg, i on the second |
| 996 |
< |
for (i = 0, to = end; i < to && j < capacity; i++) |
| 997 |
< |
if (!filter.test(e = elementAt(es, i))) |
| 998 |
< |
es[j++] = e; |
| 999 |
< |
if (i >= to) { |
| 1000 |
< |
if (j == capacity) j = 0; // "corner" case |
| 1001 |
< |
break; |
| 1002 |
< |
} |
| 987 |
> |
final long[] deathRow = nBits(sub(end, beg, capacity)); |
| 988 |
> |
deathRow[0] = 1L; // set bit 0 |
| 989 |
> |
for (int i = beg + 1, to = (i <= end) ? end : es.length, k = beg; |
| 990 |
> |
; i = 0, to = end, k -= capacity) { |
| 991 |
> |
for (; i < to; i++) |
| 992 |
> |
if (filter.test(elementAt(es, i))) |
| 993 |
> |
setBit(deathRow, i - k); |
| 994 |
> |
if (to == end) break; |
| 995 |
> |
} |
| 996 |
> |
// a two-finger traversal, with hare i reading, tortoise w writing |
| 997 |
> |
int w = beg; |
| 998 |
> |
for (int i = beg + 1, to = (i <= end) ? end : es.length, k = beg; |
| 999 |
> |
; w = 0) { // w rejoins i on second leg |
| 1000 |
> |
// In this loop, i and w are on the same leg, with i > w |
| 1001 |
> |
for (; i < to; i++) |
| 1002 |
> |
if (isClear(deathRow, i - k)) |
| 1003 |
> |
es[w++] = es[i]; |
| 1004 |
> |
if (to == end) break; |
| 1005 |
> |
// In this loop, w is on the first leg, i on the second |
| 1006 |
> |
for (i = 0, to = end, k -= capacity; i < to && w < capacity; i++) |
| 1007 |
> |
if (isClear(deathRow, i - k)) |
| 1008 |
> |
es[w++] = es[i]; |
| 1009 |
> |
if (i >= to) { |
| 1010 |
> |
if (w == capacity) w = 0; // "corner" case |
| 1011 |
> |
break; |
| 1012 |
|
} |
| 990 |
– |
return true; |
| 991 |
– |
} catch (Throwable ex) { |
| 992 |
– |
// copy remaining elements |
| 993 |
– |
for (; i != end; i = inc(i, capacity), j = inc(j, capacity)) |
| 994 |
– |
es[j] = es[i]; |
| 995 |
– |
throw ex; |
| 996 |
– |
} finally { |
| 997 |
– |
if (end != tail) throw new ConcurrentModificationException(); |
| 998 |
– |
circularClear(es, tail = j, end); |
| 999 |
– |
// checkInvariants(); |
| 1013 |
|
} |
| 1014 |
+ |
if (end != tail) throw new ConcurrentModificationException(); |
| 1015 |
+ |
circularClear(es, tail = w, end); |
| 1016 |
+ |
// checkInvariants(); |
| 1017 |
+ |
return true; |
| 1018 |
|
} |
| 1019 |
|
|
| 1020 |
|
/** |
