JDK-8263426: Reflow JfrNetworkUtilization::send_events

[shipilev]

SonarCloud instance reports a problem in JfrNetworkUtilization::send_events: "Identical sub-expressions on both sides of operator "-"." here:

  const JfrTickspan interval = last_sample_instant == 0 ? cur_time - cur_time : cur_time - last_sample_instant;

Note cur_time - cur_time. It would seem that interval is effectively zero when last_sample_instant is not yet initialized. And I see that the subsequent code checks for interval.value() > 0 for every interface. That can be optimized a bit: when last_sample_instant is not available, do not enter the loop, and don't check interval.value().

Additional testing:

• jdk_jfr on Linux x86_64

---

Progress

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Issue

• JDK-8263426: Reflow JfrNetworkUtilization::send_events

Reviewers

• Markus Grönlund (@mgronlun - Reviewer)

Download

$ git fetch https://git.openjdk.java.net/jdk pull/2935/head:pull/2935
$ git checkout pull/2935

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[openjdk]

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[mlbridge]

Webrevs

• 00: Full (ff648f3)

[mgronlun]

Looks good, thanks.

[openjdk]

@shipilev 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:

8263426: Reflow JfrNetworkUtilization::send_events

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 43 new commits pushed to the master branch:

• 470b150: 8143041: Unify G1CollectorPolicy::PauseKind and G1YCType
• f6b4ba0: 8261931: IGV: quick search fails on multi-line node labels
• 7988c1d: 8262443: GenerateOopMap::do_interpretation can spin for a long time.
• 32cbd19: 8263105: security-libs doclint cleanup
• 6971c23: 8262351: Extra '0' in java.util.Formatter for '%012a' conversion with a sign character
• c6d74bd: 8262910: Cleanup THREAD/TRAPS/naming and typing issues in ObjectMonitor and related code
• 57f16f9: 8262377: Parallel class resolution loses constant pool error
• b482733: 8259218: (fs) Add links in from overloaded methods in java.nio.file.Files
• acda812: 8263333: Improve links from core reflection to JLS and JVMS
• 9399e1b: 8261918: two runtime/cds/appcds/VerifierTest failed with "Unable to use shared archive"
• ... and 33 more: https://git.openjdk.java.net/jdk/compare/17853ee92cfba43d25f3ac984d0d3666bbe9c086...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.

[shipilev]

/integrate

[openjdk]

@shipilev Since your change was applied there have been 54 commits pushed to the master branch:

• e25ad73: 8263430: Uninitialized Method* variables after JDK-8233913
• 9f6b1d7: 8263436: Silly array comparison in GaloisCounterMode.overlapDetection
• ad1f605: 8263353: assert(CompilerOracle::option_matches_type(option, value)) failed: Value must match option type
• cf1c021: 8263480: ProblemList two jpackage tests on Windows
• f3bd801: 8263403: [JVMCI] output written to tty via HotSpotJVMCIRuntime can be garbled
• b92abac: 8263433: Shenandoah: Don't expect forwarded objects in set_concurrent_mark_in_progress()
• 15dacca: 8263465: JDK-8236847 causes tier1 build failure on linux-aarch64
• 7ed46bd: 8241716: Jpackage functionality to let users choose whether to create shortcuts
• 3820ab9: 8236847: CDS archive with 4K alignment unusable on machines with 64k pages
• 273f8bd: 8263248: IGV: accept graphs without node categories
• ... and 44 more: https://git.openjdk.java.net/jdk/compare/17853ee92cfba43d25f3ac984d0d3666bbe9c086...master

Your commit was automatically rebased without conflicts.

Pushed as commit ff25939.

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