Thank you Claes!
The mutator methods normally first update the modCount and then change
the size of ArrayList.
Then, in other methods the modCount is copied to a local variable first,
and after that the size is copied.
This is not true for equalsRange(List<?> other, int from, int to) when
it is called from ArrayList.equals: the size is first copied to the
argument and then the modCount is checked inside of equalsRange(). If
the size and modCount are changed in between, then equals may produce a
wrong results.
It seems to be more accurate to store this.modCount prior calling to
equalsRange((List<?>) o, 0, size); and do
checkForComodification(expectedModCount); after it is done.
Checking for modCount inside equalsRange() can probably be safely removed.
There's another call to equalsRange() from SubList.equals(). In this
case checkForComodification(); is already called after calling to
equalsRange(), so everything seems to be fine here.
With kind regards,
Ivan
On 5/14/18 6:37 AM, Claes Redestad wrote:
Hi Ivan,
right, checkForComodification() alone should be sufficient here.
Updated in-place: http://cr.openjdk.java.net/~redestad/8196340/open.01/
Thanks!
/Claes
On 2018-05-12 03:38, Ivan Gerasimov wrote:
Hi Claes!
One thing I can't figure out is why both these two checks are necessary:
1303 checkForComodification();
1304 root.checkForComodification(expectedModCount);
The former compares the current root.modCount with the one at the
time this subList was created.
The later one compares the current root.modCount with the one at the
time the method was called.
If the later fails, wouldn't it imply the former should also have
failed?
With kind regards,
Ivan
--
With kind regards,
Ivan Gerasimov
