RFR: 8318720: G1: Memory leak in G1CodeRootSet after JDK-8315503 [v2]

[Thomas Schatzl]

On Wed, 25 Oct 2023 14:48:47 GMT, Thomas Schatzl <tschatzl at openjdk.org> wrote:

>> That's the first place I looked. But `free_nodes` is not MT-safe, I am not sure it will fit well with other APIs that all seem to be MT-safe.
>> 
>> I also thought about move `G1CodeRootSetHashTable::clear()` implementation to CHT, but likely I would need another version for safepoint? (e.g. use `_table.bulk_delete` instead).
>> 
>> Hope to have a chance to return to JVM development fulltime, so I will have time to think about it. For now, I will let you to worry about the refactoring :-)
>
> I would strongly prefer something like [this](https://github.com/openjdk/jdk/commit/521b66294bc22e7c0760c60e7ce2f1ce31347fc3) after some "worrying about the refactoring" ;)
> Passes gc/g1 testing.

It's small enough to copy it in here:

  void clear() {
    // Remove all entries.
    auto always_true = [] (nmethod** value) {
                         return true;
                       };

    clean(always_true);
  }

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/16352#discussion_r1371903515