Replace ThreadPoolExecutor context-store with ClassValue cache by mcculls · Pull Request #12105 · DataDog/dd-trace-java

mcculls · 2026-07-29T21:46:40Z

Motivation

The flag being stored in the TPE context-store is constant, based on whether the class is listed in the 'excludedClasses' set provided via static config. This is better suited to being stored as a ClassValue, especially for AOT scenarios where context-stores are more likely to use the global weak-map.

Additional Notes

Found while looking into #10479

Contributor Checklist

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Use solves instead, and assign the PR milestone to the issue
Update the CODEOWNERS file on source file addition, migration, or deletion
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Jira ticket: [PROJ-IDENT]

mcculls · 2026-07-29T21:46:55Z

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Pull request overview

This PR updates the Java-concurrent ThreadPoolExecutor instrumentation to stop using a ContextStore<ThreadPoolExecutor, Boolean> for a per-executor “propagate?” flag, and instead uses a ClassValue<Boolean> cache keyed by executor class to better fit AOT scenarios where context-stores may fall back to global weak-maps.

Changes:

Removed the ThreadPoolExecutor -> Boolean context-store entry and the constructor advice that populated it.
Added a ClassValue<Boolean> (PROPAGATE) in TPEHelper and switched advice sites to call TPEHelper.shouldPropagate(tpe) directly.
Simplified ThreadPoolExecutorInstrumentation to no longer depend on Platform / constructor instrumentation for propagation decisions.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
dd-java-agent/instrumentation/java/java-concurrent/java-concurrent-1.8/src/main/java/datadog/trace/instrumentation/java/concurrent/executor/ThreadPoolExecutorInstrumentation.java	Removes constructor advice + switches propagation checks to `TPEHelper.shouldPropagate(tpe)`
dd-java-agent/instrumentation/java/java-concurrent/java-concurrent-1.8/src/main/java/datadog/trace/instrumentation/java/concurrent/executor/ExecutorModule.java	Drops the `ThreadPoolExecutor -> Boolean` context-store mapping
dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/instrumentation/java/concurrent/TPEHelper.java	Replaces per-instance context-store flagging with a `ClassValue<Boolean>` cache

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datadog-datadog-prod-us1-2 · 2026-07-29T21:59:08Z

🎯 Code Coverage (details)
• Patch Coverage: 0.00%
• Overall Coverage: 61.96% (+4.10%)

_{This comment will be updated automatically if new data arrives.

🔗 Commit SHA: 585e962 | Docs | Datadog PR Page | Give us feedback!}

dd-octo-sts · 2026-07-29T22:06:02Z

🟢 Java Benchmark SLOs — All performance SLOs passed

Suite	Status
Startup	🟢 pass

SLO thresholds are defined here based on automatically generated metrics. A warning is raised when results are within 5% of the threshold.

PR vs. master results

Scenario	Candidate	master	Δ (95% CI of mean)
startup:insecure-bank:iast:Agent	13.98 s	14.03 s	[-1.1%; +0.5%] (no difference)
startup:insecure-bank:tracing:Agent	12.92 s	13.04 s	[-1.7%; -0.2%] (maybe better)
startup:petclinic:appsec:Agent	16.85 s	16.63 s	[+0.3%; +2.3%] (maybe worse)
startup:petclinic:iast:Agent	16.85 s	16.93 s	[-1.2%; +0.2%] (no difference)
startup:petclinic:profiling:Agent	16.63 s	16.78 s	[-2.0%; +0.2%] (no difference)
startup:petclinic:sca:Agent	16.55 s	16.85 s	[-2.7%; -0.8%] (maybe better)
startup:petclinic:tracing:Agent	16.12 s	16.22 s	[-1.4%; +0.2%] (no difference)

Commit: 585e962f · CI Pipeline · Benchmarking Platform UI

Load and DaCapo benchmarks can be triggered manually in the GitLab pipeline. Results will appear in the Benchmarking Platform UI after completion.

The flag being stored in the TPE context-store is constant, based on whether the class is listed in the 'excludedClasses' set provided via static config. This is better suited to being stored as a ClassValue, especially for AOT scenarios where context-stores are more likely to use the global weak-map.

mcculls · 2026-07-29T23:06:41Z

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Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated no new comments.

chatgpt-codex-connector · 2026-07-29T23:11:41Z

Codex Review: Didn't find any major issues. Nice work!

Reviewed commit: 585e962fb3

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datadog-datadog-prod-us1-2

More details

The ClassValue replacement preserves the previous exact executor-class exclusion decision while removing per-executor context-store state, and native-image build-time propagation remains disabled. Existing tests cover the meaningful propagation, exclusion, custom-subclass, cancellation, and legacy-mode paths; execution was blocked by the unavailable Java 25 toolchain.

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PerfectSlayer

Looking good, thanks!

dd-octo-sts · 2026-07-30T08:44:08Z

/merge

gh-worker-devflow-routing-ef8351 · 2026-07-30T08:44:12Z

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2026-07-30 08:44:11 UTC ℹ️ Start processing command /merge

2026-07-30 08:44:16 UTC ℹ️ MergeQueue: pull request added to the queue

The expected merge time in master is approximately 1h (p90).

2026-07-30 10:02:07 UTC ℹ️ MergeQueue: This merge request was merged

bric3

TIL, it's clever !

mcculls added tag: performance Performance related changes type: refactoring inst: java Core Java language instrumentation labels Jul 29, 2026

mcculls requested a review from Copilot July 29, 2026 21:46

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Comment thread ...otstrap/src/main/java/datadog/trace/bootstrap/instrumentation/java/concurrent/TPEHelper.java Outdated

mcculls force-pushed the mcculls/remove-tpe-context-store branch from 6515e4b to 585e962 Compare July 29, 2026 23:04

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mcculls marked this pull request as ready for review July 29, 2026 23:16

mcculls requested review from a team as code owners July 29, 2026 23:16

mcculls requested review from AlexeyKuznetsov-DD and dougqh and removed request for a team July 29, 2026 23:16

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mcculls requested a review from PerfectSlayer July 29, 2026 23:22

PerfectSlayer approved these changes Jul 30, 2026

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mcculls added this pull request to the merge queue Jul 30, 2026

github-merge-queue Bot removed this pull request from the merge queue due to failed status checks Jul 30, 2026

gh-worker-dd-mergequeue-cf854d Bot merged commit 8fdab02 into master Jul 30, 2026
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gh-worker-dd-mergequeue-cf854d Bot deleted the mcculls/remove-tpe-context-store branch July 30, 2026 10:02

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mcculls mentioned this pull request Jul 31, 2026

Traces do not appear in Datadog Web UI when AOT Cache is enabled, #10479

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mcculls commented Jul 29, 2026

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🟢 Java Benchmark SLOs — All performance SLOs passed

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