8371748: Remove the (empty) ThreadPoolExecutor.finalize() method

[bchristi-git]

From the bug report:
Prior to JDK 11, ThreadPoolExecutor.finalize() was specified to
"[invoke] shutdown() when this executor is no longer referenced and it has no threads."

In JDK 11, ThreadPoolExecutor.finalize() was re-specified to do nothing, leaving the finalize() method empty. (JDK-8190324).

In JDK 18, finalize() was deprecated for removal (JDK-8276447), after first being "standard" deprecated in JDK 9 (JDK-8165641).

The finalize() method can safely be removed from ThreadPoolExecutor.

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Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
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• Commit message must refer to an issue
• Change requires CSR request JDK-8371856 to be approved

Issues

• JDK-8371748: Remove the (empty) ThreadPoolExecutor.finalize() method (Sub-task - P4)
• JDK-8371856: Remove the (empty) ThreadPoolExecutor.finalize() method (CSR)

Reviewers

• Viktor Klang (@viktorklang-ora - Reviewer)
• Jaikiran Pai (@jaikiran - Reviewer)
• Alan Bateman (@AlanBateman - Reviewer)

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[bchristi-git]

/csr

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[openjdk]

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[openjdk]

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[mlbridge]

Webrevs

• 00: Full (f166b51a)

[viktorklang-ora]

Thanks @bchristi-git!

[jaikiran]

The failures in the GitHub actions job appear related:

/home/runner/work/jdk/jdk/test/jdk/java/util/concurrent/tck/ThreadPoolExecutorSubclassTest.java:2011: error: unreported exception Throwable; must be caught or declared to be thrown
                super.finalize();
                              ^

[bchristi-git]

The failures in the GitHub actions job appear related:

/home/runner/work/jdk/jdk/test/jdk/java/util/concurrent/tck/ThreadPoolExecutorSubclassTest.java:2011: error: unreported exception Throwable; must be caught or declared to be thrown
                super.finalize();
                              ^

Indeed.
My understanding is that that is being handled by JDK-8371682.

[bchristi-git]

Thank you, reviewers. :)
Can I also get a review on the CSR? TIA.

[AlanBateman]

Indeed. My understanding is that that is being handled by JDK-8371682.

It might make more sense for this PR to remove testFinalizeMethodCallsSuperFinalize as it's part of the removal.

[sendaoYan]

Indeed. My understanding is that that is being handled by JDK-8371682.

It might make more sense for this PR to remove testFinalizeMethodCallsSuperFinalize as it's part of the removal.

Should I close #28278 as duplicated to this PR.

[ExE-Boss]

Wrt. the CSR’s “Compatibility Risk Description”:

Subclasses that @⁠Override finalize, call super.finalize() or call finalize() directly will continue to compile and execute.

This isn’t completely correct, as super.finalize() will now have throws Throwable, where it previously didn’t, causing a source incompatibility, as seen in ThreadPoolExecutorSubclassTest:

/home/runner/work/jdk/jdk/test/jdk/java/util/concurrent/tck/ThreadPoolExecutorSubclassTest.java:2011:
error: unreported exception Throwable; must be caught or declared to be thrown
                super.finalize();
                              ^

[AlanBateman]

super.finalize() will now have throws Throwable, where it previously didn’t, causing a source incompatibility, as seen in ThreadPoolExecutorSubclassTest:

Indeed, there is a source compatibility issue here. @bchristi-git Have you done corpus searches yet to see if there are cases that extend TPE and invoke super.finalize? It wouldn't any in code written in recent years, but maybe older code that needs updating. The overall risk here is low though and the migration would be to just drop the super.finalize() as it doesn't do anything since JDK 11.

[sendaoYan]

@bchristi-git I have integrated #28278, I think you should merge the master to fix the GHA test failures.