Use ThreadLocal to setup protection longjmp buffer and fix jmp_buf chaining by zhengyu123 · Pull Request #615 · DataDog/java-profiler

zhengyu123 · 2026-06-24T20:23:52Z

What does this PR do?:
This PR intents to resolve some of mysterious crashes seen in later releases, e.g. PROF-15206, although, it might not actually solve this particular problem, but I believe it should have positive impact - Cloude and I believe that overwriting JavaThread's exception field is dangerous, in fact, overwriting any JVM data structures are dangerous, because the writes can result in races and readers may see wrong values, that can lead to crashes.

Before introducing Thread Local Handshake in JVM, thread object is usually only read by 'current` thread, so it is relative safe to alter, then restore values inside signal handler, but not any more - a thread may be able to read other thread's states before it decides how to proceed the handshake, so it may read wrong values.

This PR:
Avoid altering JavaThread for jmp_buf
Uses a thread local for storing longjmp buffer and eliminates the dependency on overwriting JavaThread's exception field, so

Avoiding other thread reads wrong value of the exception field.
longjmp now protects all threads, not just JavaThread - should improve stability.

Chaining jmp_buf
A none signal based sampler can be interrupted by signal based sampler. Therefore, there may be multiple walkVM() calls on stack, each of them sets up a protection jmp_buf for stack walk, the jmp_bufs need to be chained to ensure to jump back to expected location.

Motivation:
Improve profiler's stability.

Additional Notes:
In additional, exception field only exists in JavaThread, but detection code in Profiler is somewhat questionable, especially, for the subclasses of JavaThread

How to test the change?:

CI tests
New unit tests

For Datadog employees:

If this PR touches code that signs or publishes builds or packages, or handles
credentials of any kind, I've requested a security review (run the dd:platform-security-review
skill, or file a request via the PSEC review form).
bewaire also runs automatically on every PR.
This PR doesn't touch any of that.
JIRA: PROF-15206

Unsure? Have a question? Request a review!

dd-octo-sts · 2026-06-24T20:41:37Z

CI Test Results

Run: #28674156900 | Commit: f477580 | Duration: 13m 52s (longest job)

✅ All 32 test jobs passed

Status Overview

JDK	glibc-aarch64/debug	glibc-amd64/debug	musl-aarch64/debug	musl-amd64/debug
8	-	✅	-	-
8-ibm	-	✅	-	-
8-j9	✅	✅	-	-
8-librca	-	-	✅	✅
8-orcl	-	✅	-	-
11	-	✅	-	-
11-j9	✅	✅	-	-
11-librca	-	-	✅	✅
17	✅	✅	-	-
17-graal	✅	✅	-	-
17-j9	✅	✅	-	-
17-librca	-	-	✅	✅
21	✅	✅	-	-
21-graal	✅	✅	-	-
21-librca	-	-	✅	✅
25	✅	✅	-	-
25-graal	✅	✅	-	-
25-librca	-	-	✅	✅

Legend: ✅ passed | ❌ failed | ⚪ skipped | 🚫 cancelled

Summary: Total: 32 | Passed: 32 | Failed: 0

Updated: 2026-07-03 17:22:25 UTC

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

dd-octo-sts · 2026-06-25T01:26:09Z

Reliability & Chaos Results

✅ All reliability & chaos checks passed Pipeline: https://gitlab.ddbuild.io/DataDog/java-profiler/-/pipelines/122611187

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…text

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dd-octo-sts · 2026-07-03T08:12:04Z

Benchmark Results (commit `a7af817`)

Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/122529133 Commit: a7af817920dd5fefb3be3795e0ae4662eb373eb7

⚠️ Significant outliers

🔴 future-genetic (JDK 21): runtime +4.7% (2034→2130 ms)
⚠️ future-genetic (JDK 21): wallclock unwinds skipped — latest 0 → dev 2981 (new)

Runtime details (per benchmark × JDK)

Benchmark	JDK	Latest	Dev	Δ (dev vs latest)	Issues L/D
akka-uct	21	✅ 10262 ms (7 iters)	✅ 10301 ms (7 iters)	≈ +0.4% (±21.2%)	— / —
akka-uct	25	✅ 8886 ms (8 iters)	✅ 9070 ms (8 iters)	≈ +2.1% (±17.7%)	— / —
finagle-chirper	21	✅ 5963 ms (11 iters)	✅ 5986 ms (11 iters)	≈ +0.4% (±47.6%)	⚠️ W:1 / ⚠️ W:1
finagle-chirper	25	✅ 5444 ms (12 iters)	✅ 5383 ms (12 iters)	≈ -1.1% (±42.7%)	⚠️ W:1 / ⚠️ W:1
fj-kmeans	21	✅ 2842 ms (22 iters)	✅ 2832 ms (22 iters)	≈ -0.4% (±4.3%)	— / —
fj-kmeans	25	✅ 2803 ms (22 iters)	✅ 2803 ms (22 iters)	≈ 0% (±4.5%)	— / —
future-genetic	21	✅ 2034 ms (30 iters)	✅ 2130 ms (29 iters)	🔴 +4.7%	— / —
future-genetic	25	✅ 2086 ms (30 iters)	✅ 2022 ms (31 iters)	≈ -3.1% (±4%)	— / —
naive-bayes	21	✅ 1309 ms (44 iters)	✅ 1265 ms (45 iters)	≈ -3.4% (±54.5%)	— / —
naive-bayes	25	✅ 1014 ms (56 iters)	✅ 1019 ms (56 iters)	≈ +0.5% (±55.4%)	— / —
reactors	21	✅ 16988 ms (5 iters)	✅ 17557 ms (5 iters)	≈ +3.3% (±14.2%)	— / —
reactors	25	✅ 18114 ms (5 iters)	✅ 18549 ms (5 iters)	≈ +2.4% (±5.9%)	— / —

Internal counter details (ddprof)

ddprof internal counters, latest / dev (✅ = 0, · = unavailable):

Benchmark	JDK	Dropped rec	Dropped jvmti	Dropped trace	Skipped WC	AGCT fail	Unwind fail
akka-uct	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
akka-uct	25	✅ / ✅	✅ / ✅	3 / 4	2312 / 2219	✅ / ✅	✅ / ✅
finagle-chirper	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
finagle-chirper	25	✅ / ✅	✅ / ✅	1 / 1	8084 / 8011	✅ / ✅	✅ / ✅
fj-kmeans	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
fj-kmeans	25	✅ / ✅	✅ / ✅	3 / 6	1260 / 1266	✅ / ✅	✅ / ✅
future-genetic	21	✅ / ✅	✅ / ✅	✅ / 1	✅ / 2981	✅ / ✅	✅ / ✅
future-genetic	25	✅ / ✅	✅ / ✅	1 / 4	2953 / 2907	✅ / ✅	✅ / ✅
naive-bayes	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
naive-bayes	25	✅ / ✅	✅ / ✅	3 / 5	3440 / 3493	✅ / ✅	✅ / ✅
reactors	21	✅ / ✅	✅ / ✅	2 / ✅	1735 / ✅	✅ / ✅	✅ / ✅
reactors	25	✅ / ✅	✅ / ✅	2 / 1	1845 / 1894	✅ / ✅	✅ / ✅

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dd-octo-sts · 2026-07-03T10:15:17Z

Benchmark Results (commit `2b74f11`)

Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/122551800 Commit: 2b74f11f84ae003f48b61eb1380af84d3ff37ee2

⚠️ Significant outliers

🟢 future-genetic (JDK 21): runtime -5.2% (2193→2079 ms)

Runtime details (per benchmark × JDK)

Benchmark	JDK	Latest	Dev	Δ (dev vs latest)	Issues L/D
akka-uct	21	✅ 10405 ms (7 iters)	✅ 10212 ms (7 iters)	≈ -1.9% (±18.7%)	— / —
akka-uct	25	✅ 8888 ms (8 iters)	✅ 8968 ms (8 iters)	≈ +0.9% (±20.5%)	— / —
finagle-chirper	21	✅ 5982 ms (11 iters)	✅ 6077 ms (11 iters)	≈ +1.6% (±48.3%)	⚠️ W:1 / ⚠️ W:1
finagle-chirper	25	✅ 5483 ms (12 iters)	✅ 5497 ms (12 iters)	≈ +0.3% (±44.1%)	⚠️ W:1 / ⚠️ W:1
fj-kmeans	21	✅ 2825 ms (22 iters)	✅ 2838 ms (22 iters)	≈ +0.5% (±4.4%)	— / —
fj-kmeans	25	✅ 2821 ms (22 iters)	✅ 2834 ms (22 iters)	≈ +0.5% (±4.8%)	— / —
future-genetic	21	✅ 2193 ms (28 iters)	✅ 2079 ms (30 iters)	🟢 -5.2%	— / —
future-genetic	25	✅ 2000 ms (31 iters)	✅ 2046 ms (30 iters)	≈ +2.3% (±4.5%)	— / —
naive-bayes	21	✅ 1406 ms (41 iters)	✅ 1394 ms (41 iters)	≈ -0.9% (±55.8%)	— / —
naive-bayes	25	✅ 995 ms (57 iters)	✅ 1012 ms (56 iters)	≈ +1.7% (±55.1%)	— / —
reactors	21	✅ 17242 ms (5 iters)	✅ 17835 ms (5 iters)	≈ +3.4% (±10.4%)	— / —
reactors	25	✅ 17618 ms (5 iters)	✅ 18524 ms (5 iters)	≈ +5.1% (±12.5%)	— / —

Internal counter details (ddprof)

ddprof internal counters, latest / dev (✅ = 0, · = unavailable):

Benchmark	JDK	Dropped rec	Dropped jvmti	Dropped trace	Skipped WC	AGCT fail	Unwind fail
akka-uct	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
akka-uct	25	✅ / ✅	✅ / ✅	3 / 1	2271 / 2181	✅ / ✅	✅ / ✅
finagle-chirper	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
finagle-chirper	25	✅ / ✅	✅ / ✅	4 / 4	8792 / 8233	✅ / ✅	✅ / ✅
fj-kmeans	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
fj-kmeans	25	✅ / ✅	✅ / ✅	2 / 2	1262 / 1268	✅ / ✅	✅ / ✅
future-genetic	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
future-genetic	25	✅ / ✅	✅ / ✅	1 / ✅	2882 / 2927	✅ / ✅	✅ / ✅
naive-bayes	21	✅ / ✅	✅ / ✅	5 / ✅	3532 / ✅	✅ / ✅	✅ / ✅
naive-bayes	25	✅ / ✅	✅ / ✅	11 / 2	3473 / 3464	✅ / ✅	✅ / ✅
reactors	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
reactors	25	✅ / ✅	✅ / ✅	✅ / ✅	1769 / 1900	✅ / ✅	✅ / ✅

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dd-octo-sts · 2026-07-03T12:25:37Z

Benchmark Results (commit `9afed1d`)

Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/122569372 Commit: 9afed1d10f5814856b7004d2511649abedc015c0

⚠️ Significant outliers

⚠️ future-genetic (JDK 25): wallclock unwinds skipped — latest 0 → dev 2907 (new)

Runtime details (per benchmark × JDK)

Benchmark	JDK	Latest	Dev	Δ (dev vs latest)	Issues L/D
akka-uct	21	✅ 10326 ms (7 iters)	✅ 10399 ms (7 iters)	≈ +0.7% (±19.9%)	— / —
akka-uct	25	✅ 9005 ms (8 iters)	✅ 8860 ms (8 iters)	≈ -1.6% (±21.9%)	— / —
finagle-chirper	21	✅ 5979 ms (11 iters)	✅ 5907 ms (11 iters)	≈ -1.2% (±44.8%)	⚠️ W:1 / ⚠️ W:1
finagle-chirper	25	✅ 5317 ms (12 iters)	✅ 5525 ms (12 iters)	≈ +3.9% (±43%)	⚠️ W:1 / ⚠️ W:1
fj-kmeans	21	✅ 2826 ms (22 iters)	✅ 2806 ms (22 iters)	≈ -0.7% (±4.3%)	— / —
fj-kmeans	25	✅ 2800 ms (22 iters)	✅ 2813 ms (22 iters)	≈ +0.5% (±4.5%)	— / —
future-genetic	21	✅ 2123 ms (29 iters)	✅ 2129 ms (29 iters)	≈ +0.3% (±4.5%)	— / —
future-genetic	25	✅ 2080 ms (30 iters)	✅ 2124 ms (29 iters)	≈ +2.1% (±4.5%)	— / —
naive-bayes	21	✅ 1302 ms (44 iters)	✅ 1258 ms (45 iters)	≈ -3.4% (±56.9%)	— / —
naive-bayes	25	✅ 1005 ms (57 iters)	✅ 1013 ms (56 iters)	≈ +0.8% (±55.3%)	— / —
reactors	21	✅ 17261 ms (5 iters)	✅ 15983 ms (5 iters)	≈ -7.4% (±11%)	— / —
reactors	25	✅ 18647 ms (5 iters)	✅ 18660 ms (5 iters)	≈ +0.1% (±6.9%)	— / —

Internal counter details (ddprof)

ddprof internal counters, latest / dev (✅ = 0, · = unavailable):

Benchmark	JDK	Dropped rec	Dropped jvmti	Dropped trace	Skipped WC	AGCT fail	Unwind fail
akka-uct	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
akka-uct	25	✅ / ✅	✅ / ✅	2 / 2	2338 / 2103	✅ / ✅	✅ / ✅
finagle-chirper	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
finagle-chirper	25	✅ / ✅	✅ / ✅	3 / 5	8000 / 8597	✅ / ✅	✅ / ✅
fj-kmeans	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
fj-kmeans	25	✅ / ✅	✅ / ✅	2 / 3	1270 / 1265	✅ / ✅	✅ / ✅
future-genetic	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
future-genetic	25	✅ / ✅	✅ / ✅	✅ / 2	✅ / 2907	✅ / ✅	✅ / ✅
naive-bayes	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
naive-bayes	25	✅ / ✅	✅ / ✅	5 / 7	3505 / 3465	✅ / ✅	✅ / ✅
reactors	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
reactors	25	✅ / ✅	✅ / ✅	✅ / ✅	1885 / 1891	✅ / ✅	✅ / ✅

dd-octo-sts · 2026-07-03T13:16:07Z

Benchmark Results (commit `0c0e70d`)

Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/122580145 Commit: 0c0e70d656f2f9983e924c08875ff0b271b76775

⚠️ Significant outliers

🔴 future-genetic (JDK 25): runtime +11.1% (1934→2148 ms)
🟢 reactors (JDK 25): runtime -7.4% (18449→17092 ms)

Runtime details (per benchmark × JDK)

Benchmark	JDK	Latest	Dev	Δ (dev vs latest)	Issues L/D
akka-uct	21	✅ 10370 ms (7 iters)	✅ 10370 ms (7 iters)	≈ 0% (±21%)	— / —
akka-uct	25	✅ 8760 ms (8 iters)	✅ 8800 ms (8 iters)	≈ +0.5% (±18.1%)	— / —
finagle-chirper	21	✅ 5986 ms (11 iters)	✅ 5960 ms (11 iters)	≈ -0.4% (±45.8%)	⚠️ W:1 / ⚠️ W:1
finagle-chirper	25	✅ 5436 ms (12 iters)	✅ 5500 ms (12 iters)	≈ +1.2% (±43.6%)	⚠️ W:1 / ⚠️ W:2
fj-kmeans	21	✅ 2823 ms (22 iters)	✅ 2822 ms (22 iters)	≈ -0% (±4.4%)	— / —
fj-kmeans	25	✅ 2842 ms (22 iters)	✅ 2842 ms (22 iters)	≈ 0% (±4.5%)	— / —
future-genetic	21	✅ 2139 ms (29 iters)	✅ 2078 ms (30 iters)	≈ -2.9% (±4.4%)	— / —
future-genetic	25	✅ 1934 ms (32 iters)	✅ 2148 ms (29 iters)	🔴 +11.1%	— / —
naive-bayes	21	✅ 1240 ms (46 iters)	✅ 1378 ms (42 iters)	≈ +11.1% (±59.1%)	— / —
naive-bayes	25	✅ 1018 ms (56 iters)	✅ 1030 ms (55 iters)	≈ +1.2% (±56.3%)	— / —
reactors	21	✅ 16463 ms (5 iters)	✅ 16779 ms (5 iters)	≈ +1.9% (±13.1%)	— / —
reactors	25	✅ 18449 ms (5 iters)	✅ 17092 ms (5 iters)	🟢 -7.4%	— / —

Internal counter details (ddprof)

ddprof internal counters, latest / dev (✅ = 0, · = unavailable):

Benchmark	JDK	Dropped rec	Dropped jvmti	Dropped trace	Skipped WC	AGCT fail	Unwind fail
akka-uct	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
akka-uct	25	✅ / ✅	✅ / ✅	3 / 2	2295 / 2238	✅ / ✅	✅ / ✅
finagle-chirper	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
finagle-chirper	25	✅ / ✅	✅ / ✅	1 / 2	8249 / 8665	✅ / ✅	✅ / ✅
fj-kmeans	21	✅ / ✅	✅ / ✅	1 / ✅	1253 / ✅	✅ / ✅	✅ / ✅
fj-kmeans	25	✅ / ✅	✅ / ✅	4 / 3	1292 / 1285	✅ / ✅	✅ / ✅
future-genetic	21	✅ / ✅	✅ / ✅	✅ / ✅	2986 / ✅	✅ / ✅	✅ / ✅
future-genetic	25	✅ / ✅	✅ / ✅	2 / 3	2854 / 2900	✅ / ✅	✅ / ✅
naive-bayes	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
naive-bayes	25	✅ / ✅	✅ / ✅	4 / 4	3477 / 3462	✅ / ✅	✅ / ✅
reactors	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
reactors	25	✅ / ✅	✅ / ✅	✅ / 1	1885 / 1710	✅ / ✅	✅ / ✅

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dd-octo-sts · 2026-07-03T15:09:48Z

Benchmark Results (commit `321bd18`)

Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/122611145 Commit: 321bd18e84227a2ae8ff62aa761a52a31ebd3df1

⚠️ Significant outliers

🟢 future-genetic (JDK 25): runtime -4.9% (2072→1970 ms)
⚠️ future-genetic (JDK 25): wallclock unwinds skipped — latest 0 → dev 2820 (new)

Runtime details (per benchmark × JDK)

Benchmark	JDK	Latest	Dev	Δ (dev vs latest)	Issues L/D
akka-uct	21	✅ 10366 ms (7 iters)	✅ 10423 ms (7 iters)	≈ +0.5% (±22.2%)	— / —
akka-uct	25	✅ 8898 ms (8 iters)	✅ 8789 ms (8 iters)	≈ -1.2% (±18.5%)	— / —
finagle-chirper	21	✅ 5943 ms (11 iters)	✅ 6022 ms (11 iters)	≈ +1.3% (±47.2%)	⚠️ W:1 / ⚠️ W:1
finagle-chirper	25	✅ 5389 ms (12 iters)	✅ 5334 ms (12 iters)	≈ -1% (±42%)	⚠️ W:1 / ⚠️ W:1
fj-kmeans	21	✅ 2833 ms (22 iters)	✅ 2823 ms (22 iters)	≈ -0.4% (±4.4%)	— / —
fj-kmeans	25	✅ 2816 ms (22 iters)	✅ 2828 ms (22 iters)	≈ +0.4% (±4.8%)	— / —
future-genetic	21	✅ 2101 ms (30 iters)	✅ 2084 ms (30 iters)	≈ -0.8% (±4.6%)	— / —
future-genetic	25	✅ 2072 ms (30 iters)	✅ 1970 ms (31 iters)	🟢 -4.9%	— / —
naive-bayes	21	✅ 1274 ms (45 iters)	✅ 1272 ms (45 iters)	≈ -0.2% (±56.1%)	— / —
naive-bayes	25	✅ 1015 ms (56 iters)	✅ 1008 ms (57 iters)	≈ -0.7% (±54.8%)	— / —
reactors	25	✅ 18282 ms (5 iters)	✅ 17987 ms (5 iters)	≈ -1.6% (±4.3%)	— / —

Internal counter details (ddprof)

ddprof internal counters, latest / dev (✅ = 0, · = unavailable):

Benchmark	JDK	Dropped rec	Dropped jvmti	Dropped trace	Skipped WC	AGCT fail	Unwind fail
akka-uct	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
akka-uct	25	✅ / ✅	✅ / ✅	7 / 1	2210 / 2284	✅ / ✅	✅ / ✅
finagle-chirper	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
finagle-chirper	25	✅ / ✅	✅ / ✅	2 / ✅	8223 / 8078	✅ / ✅	✅ / ✅
fj-kmeans	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
fj-kmeans	25	✅ / ✅	✅ / ✅	3 / 5	1270 / 1282	✅ / ✅	✅ / ✅
future-genetic	21	✅ / ✅	✅ / ✅	✅ / ✅	3036 / ✅	✅ / ✅	✅ / ✅
future-genetic	25	✅ / ✅	✅ / ✅	✅ / ✅	✅ / 2820	✅ / ✅	✅ / ✅
naive-bayes	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
naive-bayes	25	✅ / ✅	✅ / ✅	5 / 7	3468 / 3511	✅ / ✅	✅ / ✅
reactors	25	✅ / ✅	✅ / ✅	1 / ✅	1891 / ✅	✅ / ✅	✅ / ✅

…ofiler into zgu/objmonitor_deflation

dd-octo-sts · 2026-07-03T17:31:47Z

Benchmark Results (commit `e4b9719`)

Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/122633659 Commit: e4b97194a1bd758dfffcb77ab669046e94fe63bc

⚠️ Significant outliers

🟢 fj-kmeans (JDK 21): runtime -5% (2875→2730 ms)
🔴 fj-kmeans (JDK 25): runtime +7.9% (2633→2842 ms)
⚠️ reactors (JDK 21): wallclock unwinds skipped — latest 0 → dev 1597 (new)

Runtime details (per benchmark × JDK)

Benchmark	JDK	Latest	Dev	Δ (dev vs latest)	Issues L/D
akka-uct	21	✅ 10389 ms (7 iters)	✅ 10329 ms (7 iters)	≈ -0.6% (±20.8%)	— / —
akka-uct	25	✅ 8966 ms (8 iters)	✅ 8809 ms (8 iters)	≈ -1.8% (±20.3%)	— / —
finagle-chirper	21	✅ 6023 ms (11 iters)	✅ 6002 ms (11 iters)	≈ -0.3% (±44.9%)	⚠️ W:1 / ⚠️ W:1
finagle-chirper	25	✅ 5457 ms (12 iters)	✅ 5438 ms (12 iters)	≈ -0.3% (±43.4%)	⚠️ W:1 / ⚠️ W:1
fj-kmeans	21	✅ 2875 ms (22 iters)	✅ 2730 ms (23 iters)	🟢 -5%	— / —
fj-kmeans	25	✅ 2633 ms (24 iters)	✅ 2842 ms (22 iters)	🔴 +7.9%	— / —
future-genetic	21	✅ 2133 ms (29 iters)	✅ 2080 ms (30 iters)	≈ -2.5% (±4.2%)	— / —
future-genetic	25	✅ 2070 ms (30 iters)	✅ 2141 ms (29 iters)	≈ +3.4% (±4.3%)	— / —
naive-bayes	21	✅ 1221 ms (46 iters)	✅ 1277 ms (45 iters)	≈ +4.6% (±57.5%)	— / —
naive-bayes	25	✅ 1034 ms (55 iters)	✅ 1018 ms (56 iters)	≈ -1.5% (±55.8%)	— / —
reactors	21	✅ 16041 ms (5 iters)	✅ 15714 ms (5 iters)	≈ -2% (±17.4%)	— / —
reactors	25	✅ 17707 ms (5 iters)	✅ 17823 ms (5 iters)	≈ +0.7% (±11.5%)	— / —

Internal counter details (ddprof)

ddprof internal counters, latest / dev (✅ = 0, · = unavailable):

Benchmark	JDK	Dropped rec	Dropped jvmti	Dropped trace	Skipped WC	AGCT fail	Unwind fail
akka-uct	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
akka-uct	25	✅ / ✅	✅ / ✅	1 / 4	2466 / 2284	✅ / ✅	✅ / ✅
finagle-chirper	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
finagle-chirper	25	✅ / ✅	✅ / ✅	1 / 1	8316 / 8172	✅ / ✅	✅ / ✅
fj-kmeans	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
fj-kmeans	25	✅ / ✅	✅ / ✅	2 / 4	1298 / 1271	✅ / ✅	✅ / ✅
future-genetic	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
future-genetic	25	✅ / ✅	✅ / ✅	3 / 1	2914 / 2977	✅ / ✅	✅ / ✅
naive-bayes	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
naive-bayes	25	✅ / ✅	✅ / ✅	4 / 1	3478 / 3494	✅ / ✅	✅ / ✅
reactors	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / 1597	✅ / ✅	✅ / ✅
reactors	25	✅ / ✅	✅ / ✅	✅ / 2	1765 / 1822	✅ / ✅	✅ / ✅

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jbachorik changed the title ~~Use TheadLocal to setup protection longjmp buffer~~ Use ThreadLocal to setup protection longjmp buffer Jul 2, 2026

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Harden JVM TLS init, crash-handler nesting, and jmp_buf publish/observe #627

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Benchmark Results (commit a7af817)

⚠️ Significant outliers

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Benchmark Results (commit `a7af817`)

Benchmark Results (commit `2b74f11`)

Benchmark Results (commit `9afed1d`)

Benchmark Results (commit `0c0e70d`)

Benchmark Results (commit `321bd18`)

Benchmark Results (commit `e4b9719`)