8260621: (jrtfs) ThreadLocal memory leak in ImageBufferCache when using jrtfs

[sundararajana]

Instead of BufferReference class, Map.Entry is used as pair implementation.
This avoids the metaspace leak seen via thread local.

---

Progress

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Issue

• JDK-8260621: (jrtfs) ThreadLocal memory leak in ImageBufferCache when using jrtfs

Reviewers

• Jim Laskey (@JimLaskey - Reviewer)
• Vyom Tewari (@vyommani - Committer)

Reviewing

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$ git checkout pull/3849

Update a local copy of the PR:
$ git checkout pull/3849
$ git pull https://git.openjdk.java.net/jdk pull/3849/head

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$ git pr checkout 3849

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https://git.openjdk.java.net/jdk/pull/3849.diff

[bridgekeeper]

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[openjdk]

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[mlbridge]

Webrevs

• 00: Full (3fc941fc)

[openjdk]

@sundararajana 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:

8260621: (jrtfs) ThreadLocal memory leak in ImageBufferCache when using jrtfs

Reviewed-by: jlaskey, vtewari

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 23 new commits pushed to the master branch:

• 770dfc1: 8265279: Remove unused RandomGeneratorFactory.all(Class category)
• ee5bba0: 8265767: compiler/eliminateAutobox/TestIntBoxing.java crashes on arm32 after 8264649 in debug VMs
• 05e6017: 8265137: java.util.Random suddenly has new public methods nowhere documented
• aa90df6: 8266187: Memory leak in appendBootClassPath()
• b651904: 8266438: Compile::remove_useless_nodes does not remove opaque nodes
• 141cc2f: 8261527: Record page size used for underlying mapping in ReservedSpace
• 8e071c4: 8265784: [C2] Hoisting of DecodeN leaves MachTemp inputs behind
• ce1bc9d: 8266432: ZGC: GC allocation stalls can trigger deadlocks
• 30ccd80: 8264950: Set opaque for JTooltip in config file of NimbusLookAndFeel
• cfdf4a7: 8266449: cleanup jtreg tags in compiler/intrinsics/sha/cli tests
• ... and 13 more: https://git.openjdk.java.net/jdk/compare/c5dc657f0be90bd594663dcc612f40a930c2bbe7...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.

[vyommani]

looks OK to me.

[sundararajana]

/integrate

[openjdk]

@sundararajana Since your change was applied there have been 37 commits pushed to the master branch:

• 82768d9: 8221503: vmTestbase/nsk/jdb/eval/eval001/eval001.java fails with: com.sun.jdi.InvalidTypeException: Can't assign double[][][] to double[][][]
• b71f85a: 8264398: BevelBorderUIResource​(int, Color, Color) and BevelBoder(int, Color, Color) spec should clarify about usage of highlight and shadow color
• b172555: 8266171: -Warray-bounds happens in imageioJPEG.c
• 8bcebe7: 8265505: findsym does not work on remote debug server
• b88785d: 8266038: Move newAddress() to JVMDebugger
• 2c53654: 8266179: [macos] jpackage should specify architecture for produced pkg files
• d282799: 8255566: Add size validation when parsing values from VersionProps
• 61365d5: 8266465: Add wildcard to JTwork/JTreport exclude in jib-profiles.js
• f00b70e: 8266527: RandomTestCoverage.java failing due to API removal
• c53dee7: 8266227: Fix help text for --mac-signing-keychain
• ... and 27 more: https://git.openjdk.java.net/jdk/compare/c5dc657f0be90bd594663dcc612f40a930c2bbe7...master

Your commit was automatically rebased without conflicts.

Pushed as commit c9873c4.

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

[AlanBateman]

I think this comment needs to be re-worded to drop "We used to have ...", "Solution is ..." and the other history. Instead it should provide a clear paragraph that explains the value of the TL for anyone reading this code.