Please review this change to replace the finalizer in `AbstractLdapNamingEnumeration` with Cleaner.
(The [first PR](https://github.com/openjdk/jdk/pull/8311) for this fix started some substantial discussions, leading to, among other things, the [8314480](https://bugs.openjdk.org/browse/JDK-8314480) `java.lang.ref` memory ordering spec update.) In standard fashion, pieces of state required for cleanup (`LdapCtx homeCtx`, `LdapResult res`, and `LdapClient enumClnt`) are moved into a _Context_ object. From there, the change is fairly mechanical. Details of note: 1. Some operations need to change the state values (the `update()` method is probably the most interesting). Use of `reachabilityFence()` ensures memory visibility on the Cleaner thread (per the aforementioned spec update). 2. Subclasses need to access `homeCtx`; I added a `homeCtx()` method to read `homeCtx` from the superclass's state. The test case is based on a copy of `com/sun/jndi/ldap/blits/AddTests/AddNewEntry.java`. It confirms that the use of Cleaner does not keep an `LdapSearchEnumeration` object reachable. The other `AbstractLdapNamingEnumeration` subclasses (`LdapNamingEnumeration` and `LdapBindingEnumeration`) can be expected to behave the same. Thanks. ------------- Commit messages: - small comment update - simplify test - update test to use WhiteBox, and use volatile read for enumCount - improve test to give cleaning action a chance to run - remove unneeded fullFence()s, fix copyright years, update some comments - more hasMoreReferrals() merge error fixing - fix hasMoreReferrals() merge error - update EnumCtx comment - remove fullFence() calls, fix reachabilityFence() arguments, remove some unneeded comments - simplify some comments - ... and 19 more: https://git.openjdk.org/jdk/compare/b6b5ac1e...e36cf5db Changes: https://git.openjdk.org/jdk/pull/25242/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=25242&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8283660 Stats: 718 lines in 7 files changed: 391 ins; 90 del; 237 mod Patch: https://git.openjdk.org/jdk/pull/25242.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/25242/head:pull/25242 PR: https://git.openjdk.org/jdk/pull/25242
