8302849: SurfaceManager might expose partially constructed object

[minborg]

This PR proposes to add volatile to a variable declaration in order to prevent partially initialized objects to be observed by threads.

SurfaceManager is using a lazily initialized cacheMap that is initialized using a double-checked locking mechanism. Generally, objects initialized using such constructs need to be declared volatile.

See https://en.wikipedia.org/wiki/Double-checked_locking#Usage_in_Java

---

Progress

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Issue

• JDK-8302849: SurfaceManager might expose partially constructed object

Reviewers

• Sergey Bylokhov (@mrserb - Reviewer)

Reviewing

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[bridgekeeper]

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[openjdk]

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[mlbridge]

Webrevs

• 00: Full (0b351891)

[openjdk]

@minborg 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:

8302849: SurfaceManager might expose partially constructed object

Reviewed-by: serb

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 16 new commits pushed to the master branch:

• 9a79722: 8299234: JMX Repository.query performance
• e47e9ec: 8300658: memory_and_swap_limit() reporting wrong values on systems with swapaccount=0
• 7cf7e0a: 8302070: Factor null-check into load_klass() calls
• e731695: 8302882: Newly added test javax/swing/JFileChooser/JFileChooserFontReset.java fails with HeadlessException
• b5a7426: 8301749: Tracking malloc pooled memory size
• 6ac5e05: 8302068: Serial: Refactor oop closures used in Young GC
• 71cf7c4: 8302518: Add missing Op_RoundDoubleMode in VectorNode::vector_operands()
• 98716e2: 8302709: Remove explicit remembered set verification in G1
• 303c61f: 8302776: RISC-V: Fix typo CSR_INSTERT to CSR_INSTRET
• 7c40c8a: 8302312: Make ParGCRareEvent_lock G1 specific
• ... and 6 more: https://git.openjdk.org/jdk/compare/432cf68c4dd1dcce478fccb85163aa0d824474d7...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.

[minborg]

/integrate

[openjdk]

Going to push as commit 63ef214.
Since your change was applied there have been 60 commits pushed to the master branch:

• 30b2ac4: 8302873: ZGC: dump barrier data in C2 Mach nodes
• 861eea9: 8302858: Polish FlightRecorderMXBeanImpl
• 60a3581: 8302856: Typo in FlightRecorderMXBeanImpl
• 3f3a1f5: 8302815: Use new Math.clamp method in core libraries
• 5e1d1b7: 8302870: More information needed from failures in vmTestbase ThreadUtils.waitThreadState
• 7f35389: 8302888: containers/docker/TestJcmd.java fails when run as root under podman
• b6ecca1: 8280113: (dc) DatagramSocket.receive does not always throw when the channel is closed
• f54e108: 8302831: PPC: compiler/codecache/TestStressCodeBuffers.java fails after JDK-8301819
• cba817a: 8302838: jabswitch main() should avoid calling exit explicitly
• 2c52cf0: 8041447: Test javax/swing/dnd/7171812/bug7171812.java fails with java.lang.RuntimeException: Test failed, scroll on drag doesn't work
• ... and 50 more: https://git.openjdk.org/jdk/compare/432cf68c4dd1dcce478fccb85163aa0d824474d7...master

Your commit was automatically rebased without conflicts.

[openjdk]

@minborg Pushed as commit 63ef214.

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

[turbanoff]

Copyright year update seems forgotten.