RFR: 8338411: Implement JEP 486: Permanently Disable the Security Manager

[Sean Mullan]

On Tue, 15 Oct 2024 15:52:13 GMT, David M. Lloyd <duke at openjdk.org> wrote:

>> OK
>
> While I disagree with this change on the principle of "the system should operate as if no security manager were installed", the workaround for callers is actually rather simple:
> 
> 
> if (System.getSecurityManager() != null) {
>     foo.checkAccess();
> }
> 
> 
> I assume the justification for having these methods throw is consistency with the `check*` methods defined on `SecurityManager`. I agree that those methods should throw, because nobody should be handling instances of `SecurityManager` after this change. However, having other `checkAccess` methods throw (as opposed to being a no-op, as they would behave previously when no security manager is installed) doesn't really fulfill this spirit in my opinion.
> 
> But since the workaround is so simple, it doesn't really matter. It would be different if we (library authors) would have to resort to MR JARs for example, but that is not the case.

While making `LogManager.checkAccess` be a no-op might be more convenient, it could unconditionally
permit operations that formerly required a permission check: clearly a bad idea. Always throwing a `SecurityException` is the safest option.

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PR Review Comment: https://git.openjdk.org/jdk/pull/21498#discussion_r1801518838