8265028: JDWP debug agent thread lookup can be made faster

[plummercj]

Improved thread lookup speeds in the debug agent, especially when there is a large number of threads. See CR for details.

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• Change must be properly reviewed

Issue

• JDK-8265028: JDWP debug agent thread lookup can be made faster

Reviewers

• Serguei Spitsyn (@sspitsyn - Reviewer)
• Alex Menkov (@alexmenkov - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.java.net/jdk pull/3444/head:pull/3444
$ git checkout pull/3444

Update a local copy of the PR:
$ git checkout pull/3444
$ git pull https://git.openjdk.java.net/jdk pull/3444/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 3444

View PR using the GUI difftool:
$ git pr show -t 3444

Using diff file

Download this PR as a diff file:
https://git.openjdk.java.net/jdk/pull/3444.diff

[bridgekeeper]

👋 Welcome back cjplummer! 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.

[openjdk]

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

• serviceability

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[mlbridge]

Webrevs

• 00: Full (1e12a8b2)

[sspitsyn]

Looks good.

[openjdk]

@plummercj 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:

8265028: JDWP debug agent thread lookup can be made faster

Reviewed-by: sspitsyn, amenkov

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 95 new commits pushed to the master branch:

• ff49970: 8265375: Bootcycle builds fail with StackOverflowError in cldrconverter
• c108e7a: 8265154: vinserti128 operand mix up for KNL platforms
• 2c4075c: 8265381: ProblemList runtime/logging/RedefineClasses.java on macos-x64 -Xcomp
• 888d80b: 8265358: ProblemList jdk/jshell/ToolBasicTest.java on macOS-aarch64
• 0bdc3e7: 8262744: Formatter '%g' conversion uses wrong format for BigDecimal rounding up to limits
• 4413dbf: 8263395: Incorrect use of Objects.nonNull
• 74d03ab: 8039270: The background color of the button can't be displayed and when pressed the button, the background color can not be changed in accordance with the case described.
• 7c37c02: 8244190: JFR: When starting a JVM with -XX:StartFlightRecording, output is written to stdout
• 79adc16: 8264152: javax/net/ssl/DTLS/RespondToRetransmit.java timed out
• 1c3fd46: 8265175: (fs) Files.copy(Path,Path,CopyOption...) should use sendfile on Linux
• ... and 85 more: https://git.openjdk.java.net/jdk/compare/d84a7e55be40eae57b6c322694d55661a5053a55...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.

[plummercj]

Thank you Alex and Serguei!

[plummercj]

/integrate

[openjdk]

@plummercj Since your change was applied there have been 121 commits pushed to the master branch:

• 713483c: 8265373: Change to GCC 10.3 for building on Linux at Oracle
• 3990713: 8265463: ProblemList vmTestbase/vm/mlvm/mixed/stress/regression/b6969574/INDIFY_Test.java on Win-X64 -Xcomp
• 5b43b39: 8263154: [macos] DMG builds have finder errors
• 54cb388: 8252600: [JVMCI] remove mx configuration
• b703e0a: 8264569: Remove obsolete error messages from CDSTestUtils.java
• 235daea: 8265285: Unnecessary inclusion of bytecodeHistogram.hpp
• 8bec6fe: 8264277: java.xml.crypto module should be granted FilePermission and SocketPermission
• 5303ccb: 8265135: Reduce work initializing VarForms
• d9e40dd: 8199407: Skip Rebuild Remset Phase if there are no rebuild candidates
• 8dbf7aa: 8241306: Add SignatureMethodParameterSpec subclass for RSASSA-PSS params
• ... and 111 more: https://git.openjdk.java.net/jdk/compare/d84a7e55be40eae57b6c322694d55661a5053a55...master

Your commit was automatically rebased without conflicts.

Pushed as commit e0fd5fc.

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