On Thu, 26 May 2022 07:17:12 GMT, Jaikiran Pai <j...@openjdk.org> wrote:
> Can I please get a review of this change which addresses the issue noted in > https://bugs.openjdk.java.net/browse/JDK-8287318? > > The `ServerImpl` has a `Dispatcher` thread which uses a `Selector` to select > keys of interested. The selected keys is then iterated over and each key is > removed through the iterator. This is fine as long as the selector isn't then > used to invoke select operation(s) while the iterator is still in use. Doing > so leads to the underlying Set being potentially modified with updates to the > selected keys. As a result any subsequent use of the iterator will lead to > `ConcurrentModificationException` as seen in the linked issue. > > The commit here fixes that by creating a copy of the selected keys and > iterating over it so that any subsequent select operation on the selector > won't have impact on the Set that is being iterated upon. > > No new tests have been added given the intermittent nature of this issue. > Existing tier1, tier2 and tier3 tests passed without any related failures, > after this change. Marked as reviewed by dfuchs (Reviewer). src/jdk.httpserver/share/classes/sun/net/httpserver/ServerImpl.java line 384: > 382: final Set<SelectionKey> copy = new > HashSet<>(selected); > 383: // iterate over the copy > 384: for (final SelectionKey key : copy) { Another possibility would be to call toArray() - since we're simply going to iterate we don't need a full copy of the hashset - e.g.: `for (var key : selected.toArray(SelectionKey[]::new)) {` ------------- PR: https://git.openjdk.java.net/jdk/pull/8898
