> Please review a tiny fix in the ForkJoinPool. Since JDK 9 (JDK-8134852 [1]) > in one case when TC subfield in ctl field is decremented, the applied masking > (UMASK, upper bits) may not preserve neighbor RC subfield sometimes. In JDKs > prior to 19 FJP may stop executing tasks, which requires a long running > application restart [2]. Since 19 it is even harder to reproduce because of > the separate parallelism field. > > The fix is to replace 'UMASK & (c - TC_UNIT)' with '(c & RC_MASK) | ((c - > TC_UNIT) & TC_MASK)' which preserves the RC part of the compareAndSetCtl() > candidate argument. On 17u and 11u that repairs known tests and applications. > This PR is for the mainline, and I intend to backport it to 21u, 17u and 11u. > > [1] https://bugs.openjdk.org/browse/JDK-8134852 > [2] https://bugs.openjdk.org/browse/JDK-8330017
Dmitry Chuyko has updated the pull request incrementally with one additional commit since the last revision: Aligned with JDK-8319447 ------------- Changes: - all: https://git.openjdk.org/jdk/pull/24034/files - new: https://git.openjdk.org/jdk/pull/24034/files/e5517c7d..973c84cd Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=24034&range=01 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24034&range=00-01 Stats: 2 lines in 1 file changed: 1 ins; 0 del; 1 mod Patch: https://git.openjdk.org/jdk/pull/24034.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/24034/head:pull/24034 PR: https://git.openjdk.org/jdk/pull/24034
