On Fri, 7 Apr 2023 08:27:18 GMT, Tingjun Yuan <d...@openjdk.org> wrote:
> In the current implementation of `String.join(CharSequence, Iterable)`, the > temp array `elems` is always initialized with a length of 8. It will cause > many array recreations when the `Iterable` contains more than 8 elements. > Furthermore, it's very common that an `Iterable` is also a `Collection`. So > if the `Iterable` is an instance of `Collection`, the initial length of the > array can be `((Collection<?>)elements).size()`. It will not change the > current behavior even if the `Collection` is modified asynchronously. > > I don't know whether this change requires a CSR request. It would be good to show the performance improvement via a few jmh runs. ------------- PR Comment: https://git.openjdk.org/jdk/pull/13383#issuecomment-1500986773
