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8268297: jdk/jfr/api/consumer/streaming/TestLatestEvent.java times out #68

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@egahlin egahlin commented Dec 23, 2021

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


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

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@bridgekeeper bridgekeeper bot commented Dec 23, 2021

👋 Welcome back egahlin! 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.

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@openjdk openjdk bot commented Dec 23, 2021

@egahlin The following label will be automatically applied to this pull request:

  • hotspot-jfr

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing list. If you would like to change these labels, use the /label pull request command.

@openjdk openjdk bot added the hotspot-jfr label Dec 23, 2021
@egahlin egahlin marked this pull request as ready for review Dec 23, 2021
@openjdk openjdk bot added the rfr label Dec 23, 2021
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@mlbridge mlbridge bot commented Dec 23, 2021

Webrevs

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@mgronlun mgronlun left a comment

Looks good.

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@openjdk openjdk bot commented Dec 23, 2021

@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

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 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.
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@openjdk openjdk bot added the ready label Dec 23, 2021
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@egahlin egahlin commented Dec 23, 2021

/integrate

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@openjdk openjdk bot commented Dec 23, 2021

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 openjdk bot added the integrated label Dec 23, 2021
@openjdk openjdk bot closed this Dec 23, 2021
@openjdk openjdk bot removed ready rfr labels Dec 23, 2021
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@openjdk openjdk bot commented Dec 23, 2021

@egahlin Pushed as commit 730f670.

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

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