On Tue, 15 Jun 2021 12:15:11 GMT, Сергей Цыпанов <d...@openjdk.java.net> wrote:
> In some JDK classes there's still the following hashCode() implementation:
>
> long objNum;
>
> public int hashCode() {
> return (int) objNum;
> }
>
> This outdated expression should be replaced with Long.hashCode(long) as it
>
> - uses all bits of the original value, does not discard any information
> upfront. For example, depending on how you are generating the IDs, the upper
> bits could change more frequently (or the opposite).
>
> - does not introduce any bias towards values with more ones (zeros), as it
> would be the case if the two halves were combined with an OR (AND) operation.
>
> See https://stackoverflow.com/a/4045083
>
> This is related to https://github.com/openjdk/jdk/pull/4309
This pull request has now been integrated.
Changeset: 124f8237
Author: Sergey Tsypanov <sergei.tsypa...@yandex.ru>
Committer: Sergey Bylokhov <s...@openjdk.org>
URL:
https://git.openjdk.java.net/jdk/commit/124f82377ba93359bc59118ee315ba194080fa92
Stats: 21 lines in 9 files changed: 6 ins; 0 del; 15 mod
8268764: Use Long.hashCode() instead of int-cast where applicable
Reviewed-by: kevinw, prr, kizune, serb
-------------
PR: https://git.openjdk.java.net/jdk/pull/4491
