RFR [8014066] Mistake in documentation of ArrayList#removeRange

[Martin Buchholz]

modCount is an imprecise concurrent modification mechanism.  It doesn't
have to be kept transactionally correct.


On Tue, Mar 18, 2014 at 3:12 PM, Ulf Zibis <Ulf.Zibis at cosoco.de> wrote:

> Am 18.03.2014 19:28, schrieb Ivan Gerasimov:
>
>
>> Assuming this last iteration is OK, should the next step be a CCC request?
>>
>
> Do you mean? :
>      /*
>       * ...
> +     * It is assumed that fromIndex <= toIndex, otherwise the behaviour
> of this method is undefined.
>       * ...
>  -     *          toIndex < fromIndex})
>       * ...
>      */
>      protected void removeRange(int fromIndex, int toIndex) {
>          ...
>
> Please remove and replace inline by size - toIndex:
>  621         int numMoved = size - toIndex;
>
>
> About modCount:
>
> Wouldn't it be more correct to code? :
>
>  616         if (fromIndex > toIndex) {
>  617             throw new IndexOutOfBoundsException(
>  618                     outOfBoundsMsg(fromIndex, toIndex));
>  619         }
>  620         try {
>  621             modCount++;
>  622             System.arraycopy(elementData, toIndex, elementData,
> fromIndex,
>  623                     size - toIndex);
>  624         } catch (IndexOutOfBoundsException ioobe) {
>  625             modCount--;
>  626             throw ioobe;
>  627         }
>
> Of even better :
>
>  000     private int[] modCount = { 0 };
>  ...
>  616         if (fromIndex > toIndex) {
>  617             throw new IndexOutOfBoundsException(
>  618                     outOfBoundsMsg(fromIndex, toIndex));
>  619         }
>  620         System.arraycopy(elementData, toIndex, elementData, fromIndex,
>  621                 size - toIndex, modCount);
>
> Or :
>
>  000 public class ArrayList ... implements ModCounter {
>  001     private int modCount = 0;
>  001     void incModCount() {
>  001         modCount++;
>  004    }
>  ...
>  616         if (fromIndex > toIndex) {
>  617             throw new IndexOutOfBoundsException(
>  618                     outOfBoundsMsg(fromIndex, toIndex));
>  619         }
>  620         System.arraycopy(elementData, toIndex, elementData, fromIndex,
>  621                 size - toIndex, this);
>
> -Ulf
>
>
>