8281289: Improve with List.copyOf

[XueleiFan]

Please review this trivial code clean up, for a little bit better performance.

---

Progress

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• Commit message must refer to an issue
• Change must be properly reviewed

Issue

• JDK-8281289: Improve with List.copyOf

Reviewers

• Jamil Nimeh (@jnimeh - Reviewer)
• Hai-May Chao (@haimaychao - Committer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.java.net/jdk pull/7356/head:pull/7356
$ git checkout pull/7356

Update a local copy of the PR:
$ git checkout pull/7356
$ git pull https://git.openjdk.java.net/jdk pull/7356/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 7356

View PR using the GUI difftool:
$ git pr show -t 7356

Using diff file

Download this PR as a diff file:
https://git.openjdk.java.net/jdk/pull/7356.diff

[bridgekeeper]

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[openjdk]

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[mlbridge]

Webrevs

• 00: Full (f3d1821f)

[jnimeh]

Looks good to me.

[openjdk]

@XueleiFan 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:

8281289: Improve with List.copyOf

Reviewed-by: jnimeh, hchao

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 22 new commits pushed to the master branch:

• 48523b0: 8281049: man page update for jstatd Security Manager dependency removal
• 8e4ef81: 8280767: -XX:ArchiveClassesAtExit does not archive BoundMethodHandle$Species classes
• f5d6fdd: 8280476: [macOS] : hotspot arm64 bug exposed by latest clang
• d4b99bc: 8281120: G1: Rename G1BlockOffsetTablePart::alloc_block to update_for_block
• 66b2c3b: 8280948: [TESTBUG] Write a regression test for JDK-4659800
• 7207f2a: Merge
• 01f93dd: 8279385: [test] Adjust sun/security/pkcs12/KeytoolOpensslInteropTest.java after 8278344
• 3d926dd: 8277795: ldap connection timeout not honoured under contention
• 51b53a8: 8280913: Create a regression test for JRootPane.setDefaultButton() method
• 46c6c6f: 8281043: Intrinsify recursive ObjectMonitor locking for PPC64
• ... and 12 more: https://git.openjdk.java.net/jdk/compare/a95ee5ada230a0177517efd3a417f319066169dd...master

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.

[haimaychao]

Looks good to me.

[XueleiFan]

/integrate

Thank you for the quick code review @jnimeh @haimaychao!

[openjdk]

Going to push as commit 42e272e.
Since your change was applied there have been 22 commits pushed to the master branch:

• 48523b0: 8281049: man page update for jstatd Security Manager dependency removal
• 8e4ef81: 8280767: -XX:ArchiveClassesAtExit does not archive BoundMethodHandle$Species classes
• f5d6fdd: 8280476: [macOS] : hotspot arm64 bug exposed by latest clang
• d4b99bc: 8281120: G1: Rename G1BlockOffsetTablePart::alloc_block to update_for_block
• 66b2c3b: 8280948: [TESTBUG] Write a regression test for JDK-4659800
• 7207f2a: Merge
• 01f93dd: 8279385: [test] Adjust sun/security/pkcs12/KeytoolOpensslInteropTest.java after 8278344
• 3d926dd: 8277795: ldap connection timeout not honoured under contention
• 51b53a8: 8280913: Create a regression test for JRootPane.setDefaultButton() method
• 46c6c6f: 8281043: Intrinsify recursive ObjectMonitor locking for PPC64
• ... and 12 more: https://git.openjdk.java.net/jdk/compare/a95ee5ada230a0177517efd3a417f319066169dd...master

Your commit was automatically rebased without conflicts.

[openjdk]

@XueleiFan Pushed as commit 42e272e.

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

[cl4es]

There's a small compatibility risk with this change, e.g., List.copyOf(...).contains(null) will throw NPE while Collections.unmodifiableList(...).contains(null) won't.

If we accept that compatibility risk (which should probably be decided by CSR) it might also make sense to use List.of() for the empty case, which will reduce the number of List implementation classes returned from the API.

[XueleiFan]

There's a small compatibility risk with this change, e.g., List.copyOf(...).contains(null) will throw NPE while Collections.unmodifiableList(...).contains(null) won't.

If we accept that compatibility risk (which should probably be decided by CSR) it might also make sense to use List.of() for the empty case, which will reduce the number of List implementation classes returned from the API.

All GOOD points! Thanks!

I filed a new JDK-8281298, and a new pull request.