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Comparing jsr166/src/main/java/util/ArrayList.java (file contents):
Revision 1.38 by jsr166, Sat Nov 12 20:51:59 2016 UTC vs.
Revision 1.42 by jsr166, Mon Nov 14 21:16:43 2016 UTC

# Line 423 | Line 423 | public class ArrayList<E> extends Abstra
423          return (E) elementData[index];
424      }
425  
426 +    @SuppressWarnings("unchecked")
427 +    static <E> E elementAt(Object[] es, int index) {
428 +        return (E) es[index];
429 +    }
430 +
431      /**
432       * Returns the element at the specified position in this list.
433       *
# Line 496 | Line 501 | public class ArrayList<E> extends Abstra
501                           s - index);
502          elementData[index] = element;
503          size = s + 1;
504 +        // checkInvariants();
505      }
506  
507      /**
# Line 519 | Line 525 | public class ArrayList<E> extends Abstra
525                               numMoved);
526          elementData[--size] = null; // clear to let GC do its work
527  
528 +        // checkInvariants();
529          return oldValue;
530      }
531  
# Line 552 | Line 559 | public class ArrayList<E> extends Abstra
559          return false;
560      }
561  
562 <    /*
562 >    /**
563       * Private remove method that skips bounds checking and does not
564       * return the value removed.
565       */
# Line 571 | Line 578 | public class ArrayList<E> extends Abstra
578       */
579      public void clear() {
580          modCount++;
581 <
575 <        // clear to let GC do its work
576 <        for (int i = 0; i < size; i++)
577 <            elementData[i] = null;
578 <
581 >        Arrays.fill(elementData, 0, size, null);
582          size = 0;
583      }
584  
# Line 604 | Line 607 | public class ArrayList<E> extends Abstra
607              elementData = grow(s + numNew);
608          System.arraycopy(a, 0, elementData, s, numNew);
609          size = s + numNew;
610 +        // checkInvariants();
611          return true;
612      }
613  
# Line 642 | Line 646 | public class ArrayList<E> extends Abstra
646                               numMoved);
647          System.arraycopy(a, 0, elementData, index, numNew);
648          size = s + numNew;
649 +        // checkInvariants();
650          return true;
651      }
652  
# Line 664 | Line 669 | public class ArrayList<E> extends Abstra
669                      outOfBoundsMsg(fromIndex, toIndex));
670          }
671          modCount++;
672 <        int numMoved = size - toIndex;
673 <        System.arraycopy(elementData, toIndex, elementData, fromIndex,
674 <                         numMoved);
675 <
676 <        // clear to let GC do its work
672 <        int newSize = size - (toIndex-fromIndex);
673 <        for (int i = newSize; i < size; i++) {
674 <            elementData[i] = null;
675 <        }
676 <        size = newSize;
672 >        final Object[] es = elementData;
673 >        final int oldSize = size;
674 >        System.arraycopy(es, toIndex, es, fromIndex, oldSize - toIndex);
675 >        Arrays.fill(es, size -= (toIndex - fromIndex), oldSize, null);
676 >        // checkInvariants();
677      }
678  
679      /**
# Line 716 | Line 716 | public class ArrayList<E> extends Abstra
716       * @see Collection#contains(Object)
717       */
718      public boolean removeAll(Collection<?> c) {
719 <        return batchRemove(c, false);
719 >        return batchRemove(c, false, 0, size);
720      }
721  
722      /**
# Line 736 | Line 736 | public class ArrayList<E> extends Abstra
736       * @see Collection#contains(Object)
737       */
738      public boolean retainAll(Collection<?> c) {
739 <        return batchRemove(c, true);
739 >        return batchRemove(c, true, 0, size);
740      }
741  
742 <    private boolean batchRemove(Collection<?> c, boolean complement) {
742 >    boolean batchRemove(Collection<?> c, boolean complement,
743 >                        final int from, final int end) {
744          Objects.requireNonNull(c);
745          final Object[] es = elementData;
745 –        final int size = this.size;
746          final boolean modified;
747          int r;
748          // Optimize for initial run of survivors
749 <        for (r = 0; r < size && c.contains(es[r]) == complement; r++)
749 >        for (r = from; r < end && c.contains(es[r]) == complement; r++)
750              ;
751 <        if (modified = (r < size)) {
751 >        if (modified = (r < end)) {
752              int w = r++;
753              try {
754 <                for (Object e; r < size; r++)
754 >                for (Object e; r < end; r++)
755                      if (c.contains(e = es[r]) == complement)
756                          es[w++] = e;
757              } catch (Throwable ex) {
758                  // Preserve behavioral compatibility with AbstractCollection,
759                  // even if c.contains() throws.
760 <                System.arraycopy(es, r, es, w, size - r);
761 <                w += size - r;
760 >                System.arraycopy(es, r, es, w, end - r);
761 >                w += end - r;
762                  throw ex;
763              } finally {
764 <                modCount += size - w;
765 <                Arrays.fill(es, (this.size = w), size, null);
764 >                final int oldSize = size, deleted = end - w;
765 >                modCount += deleted;
766 >                System.arraycopy(es, end, es, w, oldSize - end);
767 >                Arrays.fill(es, size -= deleted, oldSize, null);
768              }
769          }
770 +        // checkInvariants();
771          return modified;
772      }
773  
# Line 1114 | Line 1117 | public class ArrayList<E> extends Abstra
1117              return true;
1118          }
1119  
1120 +        public boolean removeAll(Collection<?> c) {
1121 +            return batchRemove(c, false);
1122 +        }
1123 +
1124 +        public boolean retainAll(Collection<?> c) {
1125 +            return batchRemove(c, true);
1126 +        }
1127 +
1128 +        private boolean batchRemove(Collection<?> c, boolean complement) {
1129 +            checkForComodification();
1130 +            int oldSize = root.size;
1131 +            boolean modified =
1132 +                root.batchRemove(c, complement, offset, offset + size);
1133 +            if (modified)
1134 +                updateSizeAndModCount(root.size - oldSize);
1135 +            return modified;
1136 +        }
1137 +
1138 +        public boolean removeIf(Predicate<? super E> filter) {
1139 +            checkForComodification();
1140 +            int oldSize = root.size;
1141 +            boolean modified = root.removeIf(filter, offset, offset + size);
1142 +            if (modified)
1143 +                updateSizeAndModCount(root.size - oldSize);
1144 +            return modified;
1145 +        }
1146 +
1147          public Iterator<E> iterator() {
1148              return listIterator();
1149          }
# Line 1177 | Line 1207 | public class ArrayList<E> extends Abstra
1207                          consumer.accept((E) elementData[offset + (i++)]);
1208                      }
1209                      // update once at end of iteration to reduce heap write traffic
1210 <                    lastRet = cursor = i;
1210 >                    cursor = i;
1211 >                    lastRet = i - 1;
1212                      checkForComodification();
1213                  }
1214  
# Line 1345 | Line 1376 | public class ArrayList<E> extends Abstra
1376      public void forEach(Consumer<? super E> action) {
1377          Objects.requireNonNull(action);
1378          final int expectedModCount = modCount;
1379 <        @SuppressWarnings("unchecked")
1349 <        final E[] elementData = (E[]) this.elementData;
1379 >        final Object[] es = elementData;
1380          final int size = this.size;
1381 <        for (int i=0; modCount == expectedModCount && i < size; i++) {
1382 <            action.accept(elementData[i]);
1383 <        }
1354 <        if (modCount != expectedModCount) {
1381 >        for (int i = 0; modCount == expectedModCount && i < size; i++)
1382 >            action.accept(elementAt(es, i));
1383 >        if (modCount != expectedModCount)
1384              throw new ConcurrentModificationException();
1356 –        }
1385      }
1386  
1387      /**
# Line 1414 | Line 1442 | public class ArrayList<E> extends Abstra
1442          private int fence; // -1 until used; then one past last index
1443          private int expectedModCount; // initialized when fence set
1444  
1445 <        /** Create new spliterator covering the given  range */
1445 >        /** Create new spliterator covering the given range */
1446          ArrayListSpliterator(ArrayList<E> list, int origin, int fence,
1447                               int expectedModCount) {
1448              this.list = list; // OK if null unless traversed
# Line 1492 | Line 1520 | public class ArrayList<E> extends Abstra
1520          }
1521      }
1522  
1523 <    @SuppressWarnings("unchecked")
1523 >    // A tiny bit set implementation
1524 >
1525 >    private static long[] nBits(int n) {
1526 >        return new long[((n - 1) >> 6) + 1];
1527 >    }
1528 >    private static void setBit(long[] bits, int i) {
1529 >        bits[i >> 6] |= 1L << i;
1530 >    }
1531 >    private static boolean isClear(long[] bits, int i) {
1532 >        return (bits[i >> 6] & (1L << i)) == 0;
1533 >    }
1534 >
1535      @Override
1536      public boolean removeIf(Predicate<? super E> filter) {
1537 +        return removeIf(filter, 0, size);
1538 +    }
1539 +
1540 +    boolean removeIf(Predicate<? super E> filter,
1541 +                     final int from, final int end) {
1542          Objects.requireNonNull(filter);
1543          int expectedModCount = modCount;
1544          final Object[] es = elementData;
1501 –        final int size = this.size;
1545          final boolean modified;
1546 <        int r;
1546 >        int i;
1547          // Optimize for initial run of survivors
1548 <        for (r = 0; r < size && !filter.test((E) es[r]); r++)
1548 >        for (i = from; i < end && !filter.test(elementAt(es, i)); i++)
1549              ;
1550 <        if (modified = (r < size)) {
1550 >        // Tolerate predicates that reentrantly access the collection for
1551 >        // read (but writers still get CME), so traverse once to find
1552 >        // elements to delete, a second pass to physically expunge.
1553 >        if (modified = (i < end)) {
1554              expectedModCount++;
1555              modCount++;
1556 <            int w = r++;
1557 <            try {
1558 <                for (E e; r < size; r++)
1559 <                    if (!filter.test(e = (E) es[r]))
1560 <                        es[w++] = e;
1561 <            } catch (Throwable ex) {
1562 <                // copy remaining elements
1563 <                System.arraycopy(es, r, es, w, size - r);
1564 <                w += size - r;
1565 <                throw ex;
1566 <            } finally {
1567 <                Arrays.fill(es, (this.size = w), size, null);
1568 <            }
1556 >            final int beg = i;
1557 >            final long[] deathRow = nBits(end - beg);
1558 >            deathRow[0] = 1L;   // set bit 0
1559 >            for (i = beg + 1; i < end; i++)
1560 >                if (filter.test(elementAt(es, i)))
1561 >                    setBit(deathRow, i - beg);
1562 >            if (modCount != expectedModCount)
1563 >                throw new ConcurrentModificationException();
1564 >            int w = beg;
1565 >            for (i = beg; i < end; i++)
1566 >                if (isClear(deathRow, i - beg))
1567 >                    es[w++] = es[i];
1568 >            final int oldSize = size;
1569 >            System.arraycopy(es, end, es, w, oldSize - end);
1570 >            Arrays.fill(es, size -= (end - w), oldSize, null);
1571          }
1572          if (modCount != expectedModCount)
1573              throw new ConcurrentModificationException();
1574 +        // checkInvariants();
1575          return modified;
1576      }
1577  
1578      @Override
1530 –    @SuppressWarnings("unchecked")
1579      public void replaceAll(UnaryOperator<E> operator) {
1580          Objects.requireNonNull(operator);
1581          final int expectedModCount = modCount;
1582 +        final Object[] es = elementData;
1583          final int size = this.size;
1584 <        for (int i=0; modCount == expectedModCount && i < size; i++) {
1585 <            elementData[i] = operator.apply((E) elementData[i]);
1586 <        }
1538 <        if (modCount != expectedModCount) {
1584 >        for (int i = 0; modCount == expectedModCount && i < size; i++)
1585 >            es[i] = operator.apply(elementAt(es, i));
1586 >        if (modCount != expectedModCount)
1587              throw new ConcurrentModificationException();
1540 –        }
1588          modCount++;
1589 +        // checkInvariants();
1590      }
1591  
1592      @Override
# Line 1546 | Line 1594 | public class ArrayList<E> extends Abstra
1594      public void sort(Comparator<? super E> c) {
1595          final int expectedModCount = modCount;
1596          Arrays.sort((E[]) elementData, 0, size, c);
1597 <        if (modCount != expectedModCount) {
1597 >        if (modCount != expectedModCount)
1598              throw new ConcurrentModificationException();
1551 –        }
1599          modCount++;
1600 +        // checkInvariants();
1601 +    }
1602 +
1603 +    void checkInvariants() {
1604 +        // assert size >= 0;
1605 +        // assert size == elementData.length || elementData[size] == null;
1606      }
1607   }

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