> 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 four additional commits since the last revision: - Use identity of thread, some optimizations for single thread case - Merge branch 'master' of https://github.com/openjdk/jdk into fix/classvalue-compute-remove - Track threads on the promise for cheap reentrancy checks - 8351996: Alternative way to ensure no stale values for ClassValue::remove ------------- Changes: - all: https://git.openjdk.org/jdk/pull/24043/files - new: https://git.openjdk.org/jdk/pull/24043/files/70bf2368..74851320 Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=24043&range=01 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24043&range=00-01 Stats: 14260 lines in 293 files changed: 7595 ins; 4232 del; 2433 mod Patch: https://git.openjdk.org/jdk/pull/24043.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/24043/head:pull/24043 PR: https://git.openjdk.org/jdk/pull/24043
