8335007: Inline OopMapCache table

[shipilev]

Almost clean backport to improve OopMapCache footprint and performance.

The conflict is in copyright header years, bots still think this is clean.

Additionally, this is one of few backports that gets OopMapCache behavior similar to mainline. This makes JDK-8335409 backport easier, because it avoids lots of conflicts, resolving which might introduce surprising bugs. Aligning this code with mainline makes accidents less likely.

Additional testing:

• Linux x86_64 server fastdebug, all

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• JDK-8335007 needs maintainer approval

Issue

• JDK-8335007: Inline OopMapCache table (Enhancement - P4 - Approved)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk21u-dev.git pull/936/head:pull/936
$ git checkout pull/936

Update a local copy of the PR:
$ git checkout pull/936
$ git pull https://git.openjdk.org/jdk21u-dev.git pull/936/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 936

View PR using the GUI difftool:
$ git pr show -t 936

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk21u-dev/pull/936.diff

Webrev

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[bridgekeeper]

👋 Welcome back shade! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

@shipilev This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8335007: Inline OopMapCache table

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 3 new commits pushed to the master branch:

• 846962d: 8334078: RISC-V: TestIntVect.java fails after JDK-8332153 when running without RVV
• cd5ac19: 8299813: java/nio/channels/DatagramChannel/Disconnect.java fails with jtreg test timeout due to lost datagram
• 4c86bf5: 8309067: gtest/AsyncLogGtest.java fails again in stderrOutput_vm

Please see this link for an up-to-date comparison between the source branch of this pull request and the master branch.
As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[openjdk]

This backport pull request has now been updated with issue from the original commit.

[openjdk]

⚠️ @shipilev This change is now ready for you to apply for maintainer approval. This can be done directly in each associated issue or by using the /approval command.

[mlbridge]

Webrevs

• 00: Full (a0d400d1)

[shipilev]

/approval request Clean backport to improve OopMapCache footprint and performance, and provide a safer ground for OopMapCache backports, including JDK-8335409 bugfix. All tests pass. The change is simple, so the risk is on the lower side.

[openjdk]

@shipilev
8335007: The approval request has been created successfully.

[shipilev]

/integrate

[openjdk]

Going to push as commit 38eeb50.
Since your change was applied there have been 4 commits pushed to the master branch:

• affb895: 8336926: jdk/internal/util/ReferencedKeyTest.java can fail with ConcurrentModificationException
• 846962d: 8334078: RISC-V: TestIntVect.java fails after JDK-8332153 when running without RVV
• cd5ac19: 8299813: java/nio/channels/DatagramChannel/Disconnect.java fails with jtreg test timeout due to lost datagram
• 4c86bf5: 8309067: gtest/AsyncLogGtest.java fails again in stderrOutput_vm

Your commit was automatically rebased without conflicts.

[openjdk]

@shipilev Pushed as commit 38eeb50.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.