8268297: jdk/jfr/api/consumer/streaming/TestLatestEvent.java times out

[egahlin]

Hi,

Could I have a review of a fix that prevents a recording stream from dropping events/chunks.

This occurs when rotation happens quickly, as in TestLatestEvent.java, and the clock is not making progress, on Windows sometimes. The result is a chunk header with duration 0 ns, meaning there could be two chunks with the same start timestamp, which confuses the RecordingStream when determining iteration order.

The fix is to always increase the elapsed time by at least 1 ns. There were similar code prior to JDK 17, but it was removed because a mechanism was added in Java that makes sure a chunk always gets a unique Instant.now() timestamp. Unfortunately, that timestamp does not always correlate with what the JVM writes, which leads to intermittent failures in 2-4% of the time.

I also updated the test, so it can provide better information in case of new failures.

Testing:
test/jdk/jdk/jfr/api/consumer/streaming/TestLatestEvent.java 600 times without failure on Windows
test/jdk/jdk/jfr/ 6 times without failure on Mac, Linux and Windows.

Thanks
Erik

---

Progress

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Issue

• JDK-8268297: jdk/jfr/api/consumer/streaming/TestLatestEvent.java times out

Reviewers

• Markus Grönlund (@mgronlun - Reviewer)

Reviewing

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[mlbridge]

Webrevs

• 00: Full (1733b587)

[mgronlun]

Looks good.

[openjdk]

@egahlin 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:

8268297: jdk/jfr/api/consumer/streaming/TestLatestEvent.java times out

Reviewed-by: mgronlun

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At the time when this comment was updated there had been 5 new commits pushed to the master branch:

• 9d5ae2e: 8279076: C2: Bad AD file when matching SqrtF with UseSSE=0
• 04ee921: 8278967: rmiregistry fails to start because SecurityManager is disabled
• 2be3e7e: 8278239: vmTestbase/nsk/jvmti/RedefineClasses/StressRedefine failed with EXCEPTION_ACCESS_VIOLATION at 0x000000000000000d
• dfb15c3: 8274315: JFR: One closed state per file or stream
• e49d4a9: 8271447: java.nio.file.InvalidPathException: Malformed input or input contains unmappable characters

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.

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[egahlin]

/integrate

[openjdk]

Going to push as commit 730f670.
Since your change was applied there have been 5 commits pushed to the master branch:

• 9d5ae2e: 8279076: C2: Bad AD file when matching SqrtF with UseSSE=0
• 04ee921: 8278967: rmiregistry fails to start because SecurityManager is disabled
• 2be3e7e: 8278239: vmTestbase/nsk/jvmti/RedefineClasses/StressRedefine failed with EXCEPTION_ACCESS_VIOLATION at 0x000000000000000d
• dfb15c3: 8274315: JFR: One closed state per file or stream
• e49d4a9: 8271447: java.nio.file.InvalidPathException: Malformed input or input contains unmappable characters

Your commit was automatically rebased without conflicts.

[openjdk]

@egahlin Pushed as commit 730f670.

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