On 24/02/2013 15:49, Peter Levart wrote:
Hi Alan,
I checked and it seems all 3 IHM views [keySet|values|entrySet] have a
fail-fast iterator implementation
(IdentityHashMap.IdentityHashMapIterator) and all 3 are (were) using
the iterator for .toArray implementations. So this patch tries to
preserve the behavior when there is a concurrent modification (which
is only possible from other thread and is illegal usage anyway since
IHM is not thread-safe) while executing the toArray methods on the
views...
Do you see something I don't see?
My apologies, I see it does check the modification count in
IdentityHashMapIterator.nextIndex.
However, as this forced me to looks at the changes-set again then the
copy loop in Values.toArray has caught by eye:
for (int si = 0; si < tab.length; si += 2) {
if (tab[si++] != null) { // key present ?
// more elements than expected -> concurrent
modification from other thread
if (ti >= size) {
throw new ConcurrentModificationException();
}
a[ti++] = (T) tab[si]; // copy value
}
}
Looks like si is incrementing by 3 rather than 2 (which ironically will
cause a CME later because there will be fewer elements copied than
expected).
Do you concur? If so then we can create a bug to change this to test
tab[si] and copy in tab[si+1].
-Alan
