On Tue, 29 Apr 2025 19:03:08 GMT, Chen Liang <li...@openjdk.org> wrote:
>> The recent patch #23866 makes calling `ClassValue::remove()` from >> `ClassValue::computeValue()` end up in infinite loops while fixing the stale >> value risk from the method. >> >> The proposed fix is to preserve the stale value risk fix, and update the >> remove-from-compute behavior from the original designated no-op behavior to >> throwing an exception, as the original behavior conflicts with the stale >> value fix. >> >> The implementation track the owner thread in promises (accessed in locked >> section); as a result, we can fail-fast on recursive removals from >> `computeValue`. I did not choose to use `ThreadTracker` as it is designed >> for single tracker and multiple threads, while this case here sees often >> just one thread, and the threads outlive the promise objects. >> >> Also updated the API specs for `remove` to more concisely describe the >> memory effects. Please review the associated CSR as well. > > Chen Liang has updated the pull request with a new target base due to a merge > or a rebase. The incremental webrev excludes the unrelated changes brought in > by the merge/rebase. The pull request contains 17 additional commits since > the last revision: > > - Rewrite impl to follow the new simplified spec > - Merge branch 'master' of https://github.com/openjdk/jdk into > fix/classvalue-compute-remove > - Try to simplify the model - use the finish of computeValue > > - Test updates - remove repetition, test case for no stale installation > - Fix incorrect promise removal when unnecessary and add regression test > - Cannot test for recursion eagerly - add test case > - More spec, eager exception, finish with existing, thanks John > - Merge branch 'master' of https://github.com/openjdk/jdk into > fix/classvalue-compute-remove > - docs > - Remove the throwing behavior due to shallow reentrancy > - ... and 7 more: https://git.openjdk.org/jdk/compare/91761352...221d51e7 Excellent. Much better documented and more clearly correct. ------------- Marked as reviewed by jrose (Reviewer). PR Review: https://git.openjdk.org/jdk/pull/24043#pullrequestreview-2805399165
