Bug ID: JDK-8246585 ForkJoin updates

JDK-8246585 : ForkJoin updates

Type: Enhancement
Component: core-libs
Sub-Component: java.util.concurrent
Affected Version: 13

Priority: P3
Status: Resolved
Resolution: Fixed

Submitted: 2020-06-04
Updated: 2023-09-06
Resolved: 2021-01-09

Versions (Unresolved/Resolved/Fixed)

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JDK 17
17 b05Fixed

Related Reports

CSR :	JDK-8246587 - ForkJoin updates
Relates :	JDK-8315740 - ForkJoinPool starvation in commonPool/newWorkStealingPool since java 17
Relates :	JDK-8284504 - ForkJoinPool never terminates if shutdownNow() is called at the wrong moment.
Relates :	JDK-8285638 - Unexpected change of behavior of ForkJoin common pool clearing thread locals
Relates :	JDK-8274349 - ForkJoinPool.commonPool() does not work with 1 CPU
Relates :	JDK-8229253 - forkjoin/FJExceptionTableLeak.java fails "AssertionError: failed to satisfy condition"
Relates :	JDK-8299768 - No. of running threads may exceed parallelism when using timed ForkJoinTask.get
Relates :	JDK-8259800 - timeout in tck test testForkJoin(ForkJoinPool8Test)
Relates :	JDK-8259518 - Fixes for rare test failures due to 8246585: ForkJoin updates

Description

This is a followup to JDK13 updates to refresh internal java.util.concurrent lock usages and support. Quoting internal documentation:
     * * ForkJoinTask now uses field "aux" to support blocking joins
     *   and/or record exceptions, replacing reliance on builtin
     *   monitors and side tables.
     * * Scans probe slots (vs compare indices), along with related
     *   changes that reduce performance differences across most
     *   garbage collectors, and reduce contention.
     * * Refactoring for better integration of special task types and
     *   other capabilities that had been incrementally tacked on. Plus
     *   many minor reworkings to improve consistency.

Comments

Changeset: 5cfa8c94 Author: Martin Buchholz <martin@openjdk.org> Date: 2021-01-09 20:57:52 +0000 URL: https://git.openjdk.java.net/jdk/commit/5cfa8c94

09-01-2021

Logistics note: After sitting in jsr166 repo since January 2020, integration was planned for March, but got delayed by world events.

04-06-2020