On Thu, 20 Aug 2026 13:28:37 GMT, Dušan Bálek <[email protected]> wrote:
> Running two or more `jlink` invocations concurrently in the same JVM through > the `ToolProvider` API causes the simultaneous `run` calls to interfere with > one another, even when each invocation targets a distinct `--output` > directory and the invocations share no inputs. They may fail with errors such > as: > > Error: java.lang.IllegalStateException: stream has already been operated upon > or closed > Error: Resource XYZ already present > > The problem is that Main.run(...) correctly creates a new `JlinkTask` for > each call, but `JlinkTask` defeats this isolation by sharing static > `TaskHelper` and `OptionsHelper` instances. Concurrent invocations can > therefore overwrite one another’s parsed options and plugin pipelines. > > The proposed solution is to make `taskHelper` and `optionsHelper` instance > fields of `JlinkTask`. This preserves actual concurrency. Synchronizing the > provider would unnecessarily serialize image creation and would not protect > separate provider instances or direct calls to `Main.run(...)`. > > --------- > - [x] I confirm that I make this contribution in accordance with the [OpenJDK > Interim AI Policy](https://openjdk.org/legal/ai). Marked as reviewed by alanb (Reviewer). test/jdk/tools/jlink/JLinkToolProviderTest.java line 71: > 69: readyLatch.await(); > 70: } finally { > 71: startLatch.countDown(); FYI, instead of two latches, you could just use a Phaser and use arriveAndAwaitAdvance to have each task attempt the jlink command at around the same time. test/jdk/tools/jlink/JLinkToolProviderTest.java line 86: > 84: checkJlinkOptions("--help"); > 85: checkJlinkOptions("--list-plugins"); > 86: checkConcurrentAccess(3); Future maintainers we will wonder why "3" was picked, maybe Runtime::availableProcessors / 4 would be better. ------------- PR Review: https://git.openjdk.org/jdk/pull/32469#pullrequestreview-4984199509 PR Review Comment: https://git.openjdk.org/jdk/pull/32469#discussion_r3822752250 PR Review Comment: https://git.openjdk.org/jdk/pull/32469#discussion_r3822767367
