Hoist local vars for exception probes by jpbempel · Pull Request #11964 · DataDog/dd-trace-java

jpbempel · 2026-07-15T15:56:34Z

What Does This Do

Exception probe instrumentation was not performing hoisting of local vars which is in fact required if we want to capture those locals because the wrapping with try/catch of the whole method body create sub scope preventing locals to be captured in the catch clause.

Motivation

Additional Notes

Contributor Checklist

Format the title according to the contribution guidelines
Assign the type: and (comp: or inst:) labels in addition to any other useful labels
Avoid using close, fix, or any linking keywords when referencing an issue
Use solves instead, and assign the PR milestone to the issue
Update the CODEOWNERS file on source file addition, migration, or deletion
Update public documentation with any new configuration flags or behaviors
Once approved, use merge queue to merge the PR

Jira ticket: DEBUG-5838

dd-octo-sts · 2026-07-15T15:56:53Z

Hi! 👋 Thanks for your pull request! 🎉

To help us review it, please make sure to:

Add at least one type, and one component or instrumentation label to the pull request

If you need help, please check our contributing guidelines.

datadog-datadog-prod-us1-2 · 2026-07-15T16:16:58Z

🎯 Code Coverage (details)
• Patch Coverage: 100.00%
• Overall Coverage: 57.17% (-0.01%)

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

🔗 Commit SHA: e8a8fe1 | Docs | Datadog PR Page | Give us feedback!}

datadog-datadog-prod-us1-2

More details

The hoisting-before-computeFrames ordering in ExceptionInstrumenter is safe: the inserted STORE instructions use node-identity equality in the frames IdentityHashMap so frames for original RETURN nodes are unaffected. The ConfigurationUpdater change is a correct refactoring — injected config and Config.get() are the same singleton in production, and the test mock's stubbed values match the real defaults for every method DebuggerTransformer calls.

Was this helpful? React 👍 or 👎

_{Open Bits AI session}

_{🤖 Datadog Autotest · Commit 154692d · What is Autotest? · Any feedback? Reach out in #autotest}

pr-commenter · 2026-07-15T16:21:04Z

Debugger benchmarks

Parameters

	Baseline	Candidate
baseline_or_candidate	baseline	candidate
ci_job_date	1784139379	1784139726
end_time	2026-07-15T18:17:45	2026-07-15T18:23:31
git_branch	master	jpbempel/add-hoisting-for-er
git_commit_sha	`d3d2e12`	`e8a8fe1`
start_time	2026-07-15T18:16:20	2026-07-15T18:22:07

See matching parameters

	Baseline	Candidate
ci_job_id	1862793250	1862793250
ci_pipeline_id	124839006	124839006
cpu_model	Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz	Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz
git_commit_date	1784138737	1784138737

Summary

Found 0 performance improvements and 0 performance regressions! Performance is the same for 9 metrics, 6 unstable metrics.

See unchanged results

scenario	Δ mean agg_http_req_duration_min	Δ mean agg_http_req_duration_p50	Δ mean agg_http_req_duration_p75	Δ mean agg_http_req_duration_p99	Δ mean throughput
scenario:noprobe	unstable [-36.729µs; +25.676µs] or [-12.226%; +8.547%]	unstable [-53.084µs; +35.293µs] or [-15.399%; +10.238%]	unstable [-64.961µs; +45.168µs] or [-17.952%; +12.482%]	unstable [-128.919µs; +100.371µs] or [-11.026%; +8.584%]	same
scenario:basic	same	same	same	unstable [-103.509µs; +135.445µs] or [-9.716%; +12.714%]	unstable [-108.011op/s; +229.962op/s] or [-4.428%; +9.428%]
scenario:loop	same	same	same	same	same

Request duration reports for reports

gantt
    title reports - request duration [CI 0.99] : candidate=None, baseline=None
    dateFormat X
    axisFormat %s
section baseline
noprobe (344.717 µs) : 294, 395
.   : milestone, 345,
basic (298.792 µs) : 292, 306
.   : milestone, 299,
loop (8.979 ms) : 8957, 9001
.   : milestone, 8979,
section candidate
noprobe (335.821 µs) : 304, 368
.   : milestone, 336,
basic (296.899 µs) : 290, 304
.   : milestone, 297,
loop (8.968 ms) : 8963, 8973
.   : milestone, 8968,

baseline results

Scenario	Request median duration [CI 0.99]
noprobe	344.717 µs [294.474 µs, 394.959 µs]
basic	298.792 µs [291.565 µs, 306.018 µs]
loop	8.979 ms [8.957 ms, 9.001 ms]

candidate results

Scenario	Request median duration [CI 0.99]
noprobe	335.821 µs [304.115 µs, 367.528 µs]
basic	296.899 µs [290.099 µs, 303.698 µs]
loop	8.968 ms [8.963 ms, 8.973 ms]

dd-octo-sts · 2026-07-15T16:27:26Z

🟢 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	13.97 s	14.04 s	[-1.3%; +0.3%] (no difference)
startup:insecure-bank:tracing:Agent	12.90 s	12.96 s	[-1.2%; +0.3%] (no difference)
startup:petclinic:appsec:Agent	15.91 s	16.74 s	[-10.8%; +0.9%] (unstable)
startup:petclinic:iast:Agent	16.96 s	16.96 s	[-1.1%; +1.2%] (no difference)
startup:petclinic:profiling:Agent	16.58 s	16.77 s	[-2.4%; +0.3%] (no difference)
startup:petclinic:sca:Agent	16.85 s	16.72 s	[-0.2%; +1.6%] (no difference)
startup:petclinic:tracing:Agent	16.09 s	16.09 s	[-1.0%; +1.0%] (no difference)

Commit: e8a8fe1d · 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.

datadog-datadog-prod-us1-2 · 2026-07-15T16:31:04Z

View session in Datadog

Bits Code status: ✅ Done

Comment @DataDog to request changes

Exception probe instrumentation was not performing hoisting of local vars which is in fact required if we want to capture those locals because the wrapping with try/catch of the whole method body create sub scope preventing locals to be captured in the catch clause.

dd-octo-sts · 2026-07-22T05:14:44Z

/merge

gh-worker-devflow-routing-ef8351 · 2026-07-22T05:14:48Z

View all feedbacks in Devflow UI.

2026-07-22 05:14:47 UTC ℹ️ Start processing command /merge

2026-07-22 05:14:53 UTC ℹ️ MergeQueue: pull request added to the queue

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

2026-07-22 06:19:08 UTC ℹ️ MergeQueue: This merge request was merged

jpbempel requested a review from a team as a code owner July 15, 2026 15:56

jpbempel requested review from andreimatei and removed request for a team July 15, 2026 15:56

jpbempel added the comp: debugger Dynamic Instrumentation label Jul 15, 2026

jpbempel added the type: feature Enhancements and improvements label Jul 15, 2026

datadog-datadog-prod-us1-2 Bot reviewed Jul 15, 2026

View reviewed changes

jpbempel force-pushed the jpbempel/add-hoisting-for-er branch from 154692d to e8a8fe1 Compare July 15, 2026 18:05

tylfin approved these changes Jul 21, 2026

View reviewed changes

jpbempel added this pull request to the merge queue Jul 22, 2026

github-merge-queue Bot removed this pull request from the merge queue due to failed status checks Jul 22, 2026

gh-worker-dd-mergequeue-cf854d Bot merged commit 27ad2de into master Jul 22, 2026
978 of 985 checks passed

gh-worker-dd-mergequeue-cf854d Bot deleted the jpbempel/add-hoisting-for-er branch July 22, 2026 06:19

github-actions Bot added this to the 1.65.0 milestone Jul 22, 2026

Navigation Menu

Hoist local vars for exception probes - #11964

Hoist local vars for exception probes#11964
gh-worker-dd-mergequeue-cf854d[bot] merged 1 commit into
masterfrom
jpbempel/add-hoisting-for-er

jpbempel commented Jul 15, 2026 •

edited by atlassian Bot

Loading

Uh oh!

dd-octo-sts Bot commented Jul 15, 2026

Uh oh!

datadog-datadog-prod-us1-2 Bot commented Jul 15, 2026 •

edited by datadog-datadog-us1-prod Bot

Loading

Uh oh!

datadog-datadog-prod-us1-2 Bot left a comment

Uh oh!

pr-commenter Bot commented Jul 15, 2026 •

edited

Loading

Uh oh!

dd-octo-sts Bot commented Jul 15, 2026 •

edited

Loading

Uh oh!

datadog-datadog-prod-us1-2 Bot commented Jul 15, 2026 •

edited by datadog-prod-us1-5 Bot

Loading

Uh oh!

dd-octo-sts Bot commented Jul 22, 2026

Uh oh!

gh-worker-devflow-routing-ef8351 Bot commented Jul 22, 2026 •

edited

Loading

Uh oh!

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

Conversation

jpbempel commented Jul 15, 2026 • edited by atlassian Bot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

What Does This Do

Motivation

Additional Notes

Contributor Checklist

Uh oh!

dd-octo-sts Bot commented Jul 15, 2026

Uh oh!

datadog-datadog-prod-us1-2 Bot commented Jul 15, 2026 • edited by datadog-datadog-us1-prod Bot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

datadog-datadog-prod-us1-2 Bot left a comment

Choose a reason for hiding this comment

Uh oh!

pr-commenter Bot commented Jul 15, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Debugger benchmarks

Parameters

Summary

Uh oh!

dd-octo-sts Bot commented Jul 15, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

🟢 Java Benchmark SLOs — All performance SLOs passed

Uh oh!

datadog-datadog-prod-us1-2 Bot commented Jul 15, 2026 • edited by datadog-prod-us1-5 Bot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

dd-octo-sts Bot commented Jul 22, 2026

Uh oh!

gh-worker-devflow-routing-ef8351 Bot commented Jul 22, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

jpbempel commented Jul 15, 2026 •

edited by atlassian Bot

Loading

datadog-datadog-prod-us1-2 Bot commented Jul 15, 2026 •

edited by datadog-datadog-us1-prod Bot

Loading

pr-commenter Bot commented Jul 15, 2026 •

edited

Loading

dd-octo-sts Bot commented Jul 15, 2026 •

edited

Loading

datadog-datadog-prod-us1-2 Bot commented Jul 15, 2026 •

edited by datadog-prod-us1-5 Bot

Loading

gh-worker-devflow-routing-ef8351 Bot commented Jul 22, 2026 •

edited

Loading