feat: emit TaskBlock events for JVM blocking states#665
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CI Test ResultsRun: #29839659489 | Commit:
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Legend: ✅ passed | ❌ failed | ⚪ skipped | 🚫 cancelled Summary: Total: 32 | Passed: 32 | Failed: 0 Updated: 2026-07-21 14:56:17 UTC |
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Benchmark Results (commit 38efbf8)Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/125051342 Commit:
|
| Benchmark | JDK | Latest | Dev | Δ (dev vs latest) | Issues L/D |
|---|---|---|---|---|---|
| akka-uct | 21 | ✅ 10365 ms (21 iters) | ✅ 10195 ms (21 iters) | ≈ -1.6% (±11.4%) | — / — |
| akka-uct | 25 | ✅ 8859 ms (24 iters) | ✅ 8925 ms (24 iters) | ≈ +0.7% (±10.1%) | — / — |
| finagle-chirper | 21 | ✅ 5945 ms (33 iters) | ✅ 5953 ms (33 iters) | ≈ +0.1% (±24.9%) | |
| finagle-chirper | 25 | ✅ 5495 ms (36 iters) | ✅ 5431 ms (36 iters) | ≈ -1.2% (±24.2%) | |
| fj-kmeans | 21 | ✅ 2719 ms (68 iters) | ✅ 2830 ms (66 iters) | 🔴 +4.1% | — / — |
| fj-kmeans | 25 | ✅ 2737 ms (68 iters) | ✅ 2815 ms (66 iters) | 🔴 +2.8% | — / — |
| future-genetic | 21 | ✅ 2114 ms (88 iters) | ✅ 2140 ms (87 iters) | ≈ +1.2% (±2.7%) | — / — |
| future-genetic | 25 | ✅ 2080 ms (90 iters) | ✅ 2126 ms (88 iters) | ≈ +2.2% (±2.5%) | — / — |
| naive-bayes | 21 | ✅ 1299 ms (131 iters) | ✅ 1232 ms (139 iters) | ≈ -5.2% (±31.9%) | — / — |
| naive-bayes | 25 | ✅ 997 ms (172 iters) | ✅ 1004 ms (170 iters) | ≈ +0.7% (±31.8%) | — / — |
| reactors | 21 | ✅ 16202 ms (15 iters) | ✅ 15908 ms (15 iters) | ≈ -1.8% (±7.6%) | — / — |
| reactors | 25 | ✅ 18524 ms (15 iters) | ✅ 18484 ms (15 iters) | ≈ -0.2% (±3.9%) | — / — |
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 | ✅ / ✅ | ✅ / ✅ | 2 / ✅ | 2045 / 1958 | ✅ / ✅ | ✅ / ✅ |
| akka-uct | 25 | ✅ / ✅ | ✅ / ✅ | ✅ / 3 | 2353 / 2059 | ✅ / ✅ | ✅ / ✅ |
| finagle-chirper | 21 | ✅ / ✅ | ✅ / ✅ | 6 / 2 | 8437 / 8382 | ✅ / ✅ | ✅ / ✅ |
| finagle-chirper | 25 | ✅ / ✅ | ✅ / ✅ | ✅ / 2 | 8800 / 8439 | ✅ / ✅ | ✅ / ✅ |
| fj-kmeans | 21 | ✅ / ✅ | ✅ / ✅ | 2 / 2 | 1248 / 1279 | ✅ / ✅ | ✅ / ✅ |
| fj-kmeans | 25 | ✅ / ✅ | ✅ / ✅ | 4 / 1 | 1262 / 1271 | ✅ / ✅ | ✅ / ✅ |
| future-genetic | 21 | ✅ / ✅ | ✅ / ✅ | ✅ / ✅ | 2963 / 2980 | ✅ / ✅ | ✅ / ✅ |
| future-genetic | 25 | ✅ / ✅ | ✅ / ✅ | 2 / 3 | 2955 / 2936 | ✅ / ✅ | ✅ / ✅ |
| naive-bayes | 21 | ✅ / ✅ | ✅ / ✅ | 3 / 7 | 3466 / 3539 | ✅ / ✅ | ✅ / ✅ |
| naive-bayes | 25 | ✅ / ✅ | ✅ / ✅ | 5 / 1 | 3478 / 3531 | ✅ / ✅ | ✅ / ✅ |
| reactors | 21 | ✅ / ✅ | ✅ / ✅ | ✅ / ✅ | 1700 / 1609 | ✅ / ✅ | ✅ / ✅ |
| reactors | 25 | ✅ / ✅ | ✅ / ✅ | ✅ / ✅ | 1905 / 1873 | ✅ / ✅ | ✅ / ✅ |
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Reliability & Chaos Results✅ All reliability & chaos checks passed Pipeline: https://gitlab.ddbuild.io/DataDog/java-profiler/-/pipelines/125035442 |
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Benchmark Results (commit cdb8274)Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/125162043 Commit:
|
| Benchmark | JDK | Latest | Dev | Δ (dev vs latest) | Issues L/D |
|---|---|---|---|---|---|
| finagle-chirper | 21 | ✅ 5956 ms (33 iters) | ✅ 6031 ms (33 iters) | ≈ +1.3% (±24.8%) | |
| finagle-chirper | 25 | ✅ 5457 ms (36 iters) | ✅ 5444 ms (36 iters) | ≈ -0.2% (±23.9%) | |
| fj-kmeans | 21 | ✅ 2683 ms (70 iters) | ✅ 2821 ms (66 iters) | 🔴 +5.1% | — / — |
| fj-kmeans | 25 | ✅ 2786 ms (67 iters) | ✅ 2839 ms (66 iters) | ≈ +1.9% (±2.7%) | — / — |
| future-genetic | 21 | ✅ 2063 ms (90 iters) | ✅ 2095 ms (89 iters) | ≈ +1.6% (±2.6%) | — / — |
| future-genetic | 25 | ✅ 2072 ms (90 iters) | ✅ 2125 ms (87 iters) | ≈ +2.6% (±2.6%) | — / — |
| naive-bayes | 21 | ✅ 1257 ms (135 iters) | ✅ 1250 ms (136 iters) | ≈ -0.6% (±32.8%) | — / — |
| reactors | 21 | ✅ 16137 ms (15 iters) | ✅ 15974 ms (15 iters) | ≈ -1% (±7.5%) | — / — |
| reactors | 25 | ✅ 18395 ms (15 iters) | ✅ 18505 ms (15 iters) | ≈ +0.6% (±4.4%) | — / — |
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 | ✅ / ✅ | ✅ / ✅ | 1 / 1 | 2260 / 2182 | ✅ / ✅ | ✅ / ✅ |
| finagle-chirper | 21 | ✅ / ✅ | ✅ / ✅ | 4 / 3 | 8741 / 8673 | ✅ / ✅ | ✅ / ✅ |
| finagle-chirper | 25 | ✅ / ✅ | ✅ / ✅ | 1 / ✅ | 8238 / 8373 | ✅ / ✅ | ✅ / ✅ |
| fj-kmeans | 21 | ✅ / ✅ | ✅ / ✅ | 4 / 2 | 1241 / 1256 | ✅ / ✅ | ✅ / ✅ |
| fj-kmeans | 25 | ✅ / ✅ | ✅ / ✅ | 2 / ✅ | 1287 / 1282 | ✅ / ✅ | ✅ / ✅ |
| future-genetic | 21 | ✅ / ✅ | ✅ / ✅ | 2 / 1 | 2971 / 2981 | ✅ / ✅ | ✅ / ✅ |
| future-genetic | 25 | ✅ / ✅ | ✅ / ✅ | 1 / 1 | 2968 / 2956 | ✅ / ✅ | ✅ / ✅ |
| naive-bayes | 21 | ✅ / ✅ | ✅ / ✅ | 5 / 3 | 3468 / 3474 | ✅ / ✅ | ✅ / ✅ |
| naive-bayes | 25 | ✅ / ✅ | ✅ / ✅ | 9 / 3 | 3464 / 3465 | ✅ / ✅ | ✅ / ✅ |
| reactors | 21 | ✅ / ✅ | ✅ / ✅ | 1 / 2 | 1531 / 1536 | ✅ / ✅ | ✅ / ✅ |
| reactors | 25 | ✅ / ✅ | ✅ / ✅ | 1 / ✅ | 1857 / 1856 | ✅ / ✅ | ✅ / ✅ |
Contributor
Benchmark Results (commit e13ec27)Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/125211559 Commit: ✅ Within expected boundariesNo significant runtime deltas (all within run-to-run noise) and no internal-counter outliers. Runtime details (per benchmark × JDK)
Internal counter details (ddprof)ddprof internal counters, latest / dev (✅ = 0, · = unavailable):
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Benchmark Results (commit c111812)Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/125236325 Commit: ✅ Within expected boundariesNo significant runtime deltas (all within run-to-run noise) and no internal-counter outliers. Runtime details (per benchmark × JDK)
Internal counter details (ddprof)ddprof internal counters, latest / dev (✅ = 0, · = unavailable):
|
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Benchmark Results (commit df472c0)Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/125568035 Commit:
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| Benchmark | JDK | Latest | Dev | Δ (dev vs latest) | Issues L/D |
|---|---|---|---|---|---|
| akka-uct | 25 | ✅ 8806 ms (24 iters) | ✅ 8924 ms (24 iters) | ≈ +1.3% (±11.1%) | — / — |
| finagle-chirper | 21 | ✅ 6033 ms (33 iters) | ✅ 5987 ms (33 iters) | ≈ -0.8% (±25.3%) | |
| finagle-chirper | 25 | ✅ 5500 ms (36 iters) | ✅ 5495 ms (36 iters) | ≈ -0.1% (±24.2%) | |
| fj-kmeans | 21 | ✅ 2692 ms (70 iters) | ✅ 2827 ms (66 iters) | 🔴 +5% | — / — |
| future-genetic | 21 | ✅ 2075 ms (89 iters) | ✅ 2042 ms (91 iters) | ≈ -1.6% (±2.6%) | — / — |
| future-genetic | 25 | ✅ 2036 ms (91 iters) | ✅ 2023 ms (91 iters) | ≈ -0.6% (±2.8%) | — / — |
| naive-bayes | 21 | ✅ 1228 ms (138 iters) | ✅ 1283 ms (133 iters) | ≈ +4.5% (±33.5%) | — / — |
| reactors | 21 | ✅ 16202 ms (15 iters) | ✅ 16354 ms (15 iters) | ≈ +0.9% (±6.6%) | — / — |
| reactors | 25 | ✅ 18212 ms (15 iters) | ✅ 18060 ms (15 iters) | ≈ -0.8% (±4.8%) | — / — |
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 | 25 | ✅ / ✅ | ✅ / ✅ | 2 / 5 | 2176 / 2305 | ✅ / ✅ | ✅ / ✅ |
| finagle-chirper | 21 | ✅ / ✅ | ✅ / ✅ | 1 / 2 | 8602 / 8811 | ✅ / ✅ | ✅ / ✅ |
| finagle-chirper | 25 | ✅ / ✅ | ✅ / ✅ | 1 / ✅ | 8746 / 8149 | ✅ / ✅ | ✅ / ✅ |
| fj-kmeans | 21 | ✅ / ✅ | ✅ / ✅ | ✅ / 2 | 1255 / 1277 | ✅ / ✅ | ✅ / ✅ |
| fj-kmeans | 25 | ✅ / ✅ | ✅ / ✅ | 3 / 3 | 1280 / 1287 | ✅ / ✅ | ✅ / ✅ |
| future-genetic | 21 | ✅ / ✅ | ✅ / ✅ | 4 / ✅ | 2966 / 2985 | ✅ / ✅ | ✅ / ✅ |
| future-genetic | 25 | ✅ / ✅ | ✅ / ✅ | 3 / ✅ | 2906 / 2872 | ✅ / ✅ | ✅ / ✅ |
| naive-bayes | 21 | ✅ / ✅ | ✅ / ✅ | 5 / 3 | 3486 / 3512 | ✅ / ✅ | ✅ / ✅ |
| naive-bayes | 25 | ✅ / ✅ | ✅ / ✅ | 2 / 2 | 3483 / 3521 | ✅ / ✅ | ✅ / ✅ |
| reactors | 21 | ✅ / ✅ | ✅ / ✅ | 1 / ✅ | 1654 / 1756 | ✅ / ✅ | ✅ / ✅ |
| reactors | 25 | ✅ / ✅ | ✅ / ✅ | 1 / ✅ | 1822 / 1798 | ✅ / ✅ | ✅ / ✅ |
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Benchmark Results (commit 46fdadd)Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/125595112 Commit: ✅ Within expected boundariesNo significant runtime deltas (all within run-to-run noise) and no internal-counter outliers. Runtime details (per benchmark × JDK)
Internal counter details (ddprof)ddprof internal counters, latest / dev (✅ = 0, · = unavailable):
|
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Benchmark Results (commit 658df77)Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/125689745 Commit:
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| Benchmark | JDK | Latest | Dev | Δ (dev vs latest) | Issues L/D |
|---|---|---|---|---|---|
| akka-uct | 21 | ✅ 10260 ms (21 iters) | ✅ 10296 ms (21 iters) | ≈ +0.4% (±10.9%) | — / — |
| akka-uct | 25 | ✅ 8840 ms (24 iters) | ✅ 8942 ms (24 iters) | ≈ +1.2% (±10.6%) | — / — |
| finagle-chirper | 21 | ✅ 6010 ms (33 iters) | ✅ 5968 ms (33 iters) | ≈ -0.7% (±25.4%) | |
| finagle-chirper | 25 | ✅ 5480 ms (36 iters) | ✅ 5467 ms (36 iters) | ≈ -0.2% (±24.6%) | |
| fj-kmeans | 21 | ✅ 2679 ms (69 iters) | ✅ 2773 ms (67 iters) | 🔴 +3.5% | — / — |
| fj-kmeans | 25 | ✅ 2769 ms (68 iters) | ✅ 2839 ms (66 iters) | ≈ +2.5% (±2.8%) | — / — |
| future-genetic | 21 | ✅ 2051 ms (90 iters) | ✅ 2133 ms (87 iters) | 🔴 +4% | — / — |
| future-genetic | 25 | ✅ 2047 ms (91 iters) | ✅ 2037 ms (91 iters) | ≈ -0.5% (±2.5%) | — / — |
| naive-bayes | 21 | ✅ 1254 ms (136 iters) | ✅ 1314 ms (131 iters) | ≈ +4.8% (±33.9%) | — / — |
| naive-bayes | 25 | ✅ 1015 ms (169 iters) | ✅ 983 ms (173 iters) | ≈ -3.2% (±31%) | — / — |
| reactors | 21 | ✅ 16594 ms (15 iters) | ✅ 16990 ms (15 iters) | ≈ +2.4% (±9.1%) | — / — |
| reactors | 25 | ✅ 18557 ms (15 iters) | ✅ 18660 ms (15 iters) | ≈ +0.6% (±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 | ✅ / ✅ | ✅ / ✅ | 2 / 1 | 1856 / 2016 | ✅ / ✅ | ✅ / ✅ |
| akka-uct | 25 | ✅ / ✅ | ✅ / ✅ | 2 / 1 | 2373 / 2253 | ✅ / ✅ | ✅ / ✅ |
| finagle-chirper | 21 | ✅ / ✅ | ✅ / ✅ | 5 / 7 | 8704 / 8448 | ✅ / ✅ | ✅ / ✅ |
| finagle-chirper | 25 | ✅ / ✅ | ✅ / ✅ | 2 / 2 | 8503 / 8277 | ✅ / ✅ | ✅ / ✅ |
| fj-kmeans | 21 | ✅ / ✅ | ✅ / ✅ | 1 / 2 | 1260 / 1244 | ✅ / ✅ | ✅ / ✅ |
| fj-kmeans | 25 | ✅ / ✅ | ✅ / ✅ | 4 / 1 | 1282 / 1284 | ✅ / ✅ | ✅ / ✅ |
| future-genetic | 21 | ✅ / ✅ | ✅ / ✅ | 1 / ✅ | 2984 / 2927 | ✅ / ✅ | ✅ / ✅ |
| future-genetic | 25 | ✅ / ✅ | ✅ / ✅ | 1 / 3 | 2889 / 2841 | ✅ / ✅ | ✅ / ✅ |
| naive-bayes | 21 | ✅ / ✅ | ✅ / ✅ | 4 / 3 | 3476 / 3519 | ✅ / ✅ | ✅ / ✅ |
| naive-bayes | 25 | ✅ / ✅ | ✅ / ✅ | 2 / 6 | 3442 / 3468 | ✅ / ✅ | ✅ / ✅ |
| reactors | 21 | ✅ / ✅ | ✅ / ✅ | 2 / 1 | 1680 / 1865 | ✅ / ✅ | ✅ / ✅ |
| reactors | 25 | ✅ / ✅ | ✅ / ✅ | ✅ / 1 | 1868 / 1860 | ✅ / ✅ | ✅ / ✅ |
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Pull request overview
This PR adds first-class TaskBlock emission for common JVM blocking states (park, Object.wait, monitor contention), and reworks wall-clock precheck/suppression to use lifecycle-owned blocked intervals (instead of the prior once-per-run suppression model) while preserving context-window sampling semantics.
Changes:
- Introduces a new
datadog.TaskBlockJFR event and a public paired Java API (beginTaskBlock/endTaskBlock) plus internal park/monitor producers. - Implements native lifecycle ownership + unfiltered-thread registry tracking and a bounded candidate backfill strategy to prevent O(N) wall-tick regressions.
- Adds broad Java + C++ test coverage (including restart/pre-existing-thread scenarios, JVMTI-delegated variants, and benchmark hooks).
Reviewed changes
Copilot reviewed 59 out of 59 changed files in this pull request and generated 4 comments.
Show a summary per file
| File | Description |
|---|---|
| ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/WallclockMitigationsCombinedTest.java | Updates combined mitigation test expectations to ensure context-scoped threads remain sampled. |
| ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/UnfilteredWallPrecheckTest.java | New integration tests for owned-block suppression behavior when filter= samples all threads. |
| ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/UnfilteredWallPrecheckRestartTest.java | New tests ensuring unfiltered tracking/registry state is correctly reset across recording restarts. |
| ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/TaskBlockAssertions.java | New shared assertions for the datadog.TaskBlock event contract. |
| ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/PrecheckTest.java | Refactors precheck tests to the new lifecycle-owned suppression model and unowned blocked weighting counters. |
| ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/PrecheckEfficiencyTest.java | Updates efficiency tests to match lifecycle ownership semantics and explicit unfiltered sampling configuration. |
| ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/ParkTaskBlockTest.java | New tests verifying TaskBlock emission from Java-owned park hooks and suppression counters. |
| ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/MonitorTaskBlockTest.java | New tests verifying TaskBlock emission from JVMTI monitor callbacks and restart recovery. |
| ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JvmtiBasedUnfilteredWallPrecheckTest.java | New subclass to exercise unfiltered precheck via delegated JVMTI stack collection. |
| ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JvmtiBasedPrecheckTest.java | Updates command strings to use explicit filter= under new behavior. |
| ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JvmtiBasedParkTaskBlockTest.java | New JVMTI-delegated variant of park TaskBlock tests. |
| ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JvmtiBasedMonitorTaskBlockTest.java | New JVMTI-delegated variant of monitor TaskBlock tests. |
| ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JavaProfilerTaskBlockPreExistingThreadTest.java | New test covering TaskBlock TLS initialization for threads created before profiler startup. |
| ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JavaProfilerTaskBlockDisabledTest.java | New test verifying TaskBlock API stays inactive outside any sampling scope. |
| ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JavaProfilerTaskBlockApiTest.java | New end-to-end tests for the paired TaskBlock API semantics and rejection rules. |
| ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/J9WallClockPrecheckCapabilityTest.java | New test ensuring J9 wall sampling doesn’t activate unfiltered precheck tracking. |
| ddprof-test/src/test/java/com/datadoghq/profiler/JavaProfilerTest.java | Adds child-JVM agentpath initialization tests and pre-existing monitor callback coverage. |
| ddprof-test/src/test/java/com/datadoghq/profiler/JavaProfilerApiSurfaceTest.java | Updates API-surface assertions: TaskBlock API public, internal hooks stay non-public, monitor delegation APIs are public. |
| ddprof-test/src/test/java/com/datadoghq/profiler/ExternalLauncher.java | Extends launcher scenarios to cover agent compatibility, delegation conflicts, and pre-existing monitor callbacks. |
| ddprof-test/src/test/java/com/datadoghq/profiler/context/OtelContextStorageModeTest.java | Ensures trace context is cleared during cleanup alongside thread context reset. |
| ddprof-test/src/test/java/com/datadoghq/profiler/context/AllNativeContextTest.java | Ensures trace context is cleared during cleanup alongside thread context reset. |
| ddprof-test/src/test/java/com/datadoghq/profiler/AbstractProfilerTest.java | Adds beforeProfilerStart() hook and improves teardown to clear trace context reliably. |
| ddprof-stresstest/src/jmh/java/com/datadoghq/profiler/WallClockPrecheckBenchmarkHooks.java | New helper exposing package-scoped owned-block hooks to JMH benchmarks. |
| ddprof-stresstest/src/jmh/java/com/datadoghq/profiler/stresstest/scenarios/throughput/WallClockPrecheckOverheadBenchmark.java | New benchmark measuring wall-clock timer overhead under growing owned-block populations. |
| ddprof-lib/src/test/cpp/wallprecheck_args_ut.cpp | Adds capability + filter parsing tests relevant to unfiltered tracking (filter omitted vs filter=). |
| ddprof-lib/src/test/cpp/wallClockCounters_ut.cpp | Updates counter tests to the renamed owned-block suppression metric. |
| ddprof-lib/src/test/cpp/wallClockCandidateSelector_ut.cpp | New unit tests for randomized bounded candidate selection/backfill. |
| ddprof-lib/src/test/cpp/taskBlockRecorder_ut.cpp | New unit tests for TaskBlock eligibility, rotation gating, and error accounting. |
| ddprof-lib/src/test/cpp/park_state_ut.cpp | Expands state-machine tests for park and monitor snapshot/exit behavior and owned-block transitions. |
| ddprof-lib/src/test/cpp/jvmSupport_ut.cpp | New unit tests for platform-thread classification (virtual thread rejection) across JNI versions. |
| ddprof-lib/src/test/cpp/frame_ut.cpp | Adds unit test for safe JVMTI->ASGCT frame copying with overlapping buffers. |
| ddprof-lib/src/main/java/com/datadoghq/profiler/JavaProfiler.java | Adds monitor-delegation-aware getInstance, TaskBlock public API, and thread-parameterized native hooks. |
| ddprof-lib/src/main/cpp/wallClockCounters.h | Renames and redefines wall-clock suppression counter to owned-block semantics. |
| ddprof-lib/src/main/cpp/wallClockCandidateSelector.h | New header implementing bounded randomized candidate visitation/backfill. |
| ddprof-lib/src/main/cpp/wallClock.h | Integrates candidate selector into wall timer loop and adds engine capability declaration. |
| ddprof-lib/src/main/cpp/wallClock.cpp | Reworks precheck logic to rely on owned-block registry suppression and bounded slot lookup backfill. |
| ddprof-lib/src/main/cpp/vmEntry.h | Adds monitor delegation ownership model and initialization result enum. |
| ddprof-lib/src/main/cpp/vmEntry.cpp | Implements JVMTI monitor callbacks producing TaskBlocks, plus one-time bridge ownership negotiation. |
| ddprof-lib/src/main/cpp/threadLocalData.h | Adds per-thread state for park/monitor/taskblock lifecycles and snapshotting. |
| ddprof-lib/src/main/cpp/threadFilter.h | Adds unfiltered registry tracking, TID index, recording epochs, and owned-block suppression candidate checks. |
| ddprof-lib/src/main/cpp/threadFilter.cpp | Implements registry activation, per-recording epoch publication, lock-protected indexing, and slot lookup APIs. |
| ddprof-lib/src/main/cpp/taskBlockRecorder.h | New TaskBlock recorder API + eligibility helpers + rotation-safe activity RAII. |
| ddprof-lib/src/main/cpp/taskBlockRecorder.cpp | Implements TaskBlock duration threshold and recording/cleanup at exit paths. |
| ddprof-lib/src/main/cpp/profiler.h | Adds TaskBlock recording API, rotation gating fields, and bootstrap registration hook. |
| ddprof-lib/src/main/cpp/profiler.cpp | Implements TaskBlock recording through JVMTI stack capture, rotation gating, registry bootstrap for existing threads, and start/stop integration. |
| ddprof-lib/src/main/cpp/jvmThread.h | Adds supportsNativeThreadIdLookup() used for registry bootstrap logic. |
| ddprof-lib/src/main/cpp/jvmThread.cpp | Implements native-thread-id lookup capability check. |
| ddprof-lib/src/main/cpp/jvmSupport.h | Adds platform-thread classification API. |
| ddprof-lib/src/main/cpp/jvmSupport.cpp | Implements platform-thread classification (virtual-thread rejection) using JNI version + IsVirtualThread. |
| ddprof-lib/src/main/cpp/jfrMetadata.h | Adds new JFR type id for datadog.TaskBlock. |
| ddprof-lib/src/main/cpp/jfrMetadata.cpp | Defines datadog.TaskBlock metadata schema. |
| ddprof-lib/src/main/cpp/javaApi.cpp | Wires new JNI entrypoints for TaskBlock API and updates park/block hooks to be thread-aware and emit TaskBlocks. |
| ddprof-lib/src/main/cpp/frames.h | Adds copyJvmtiFrames() helper to safely convert overlapping JVMTI frame buffers. |
| ddprof-lib/src/main/cpp/flightRecorder.h | Adds TaskBlock recording API to the JFR writer interface. |
| ddprof-lib/src/main/cpp/flightRecorder.cpp | Implements TaskBlock event serialization and a rotation-safe record path. |
| ddprof-lib/src/main/cpp/event.h | Adds TaskBlockEvent struct and updates wall-clock epoch suppressed counter naming. |
| ddprof-lib/src/main/cpp/engine.h | Adds wall-engine capability hook supportsUnfilteredWallPrecheck(). |
| ddprof-lib/src/main/cpp/counters.h | Adds new counters for registry/backfill and TaskBlock lifecycle/accounting. |
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Benchmark Results (commit 746edc2)Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/125879034 Commit:
|
| Benchmark | JDK | Latest | Dev | Δ (dev vs latest) | Issues L/D |
|---|---|---|---|---|---|
| akka-uct | 21 | ✅ 10315 ms (21 iters) | ✅ 10281 ms (21 iters) | ≈ -0.3% (±11.1%) | — / — |
| akka-uct | 25 | ✅ 8869 ms (24 iters) | ✅ 8962 ms (24 iters) | ≈ +1% (±10%) | — / — |
| finagle-chirper | 21 | ✅ 6014 ms (33 iters) | ✅ 5992 ms (33 iters) | ≈ -0.4% (±25.2%) | |
| finagle-chirper | 25 | ✅ 5449 ms (36 iters) | ✅ 5424 ms (36 iters) | ≈ -0.5% (±24%) | |
| fj-kmeans | 21 | ✅ 2634 ms (72 iters) | ✅ 2749 ms (68 iters) | 🔴 +4.4% | — / — |
| fj-kmeans | 25 | ✅ 2757 ms (68 iters) | ✅ 2825 ms (66 iters) | ≈ +2.5% (±2.8%) | — / — |
| future-genetic | 21 | ✅ 2097 ms (88 iters) | ✅ 2137 ms (87 iters) | ≈ +1.9% (±2.8%) | — / — |
| future-genetic | 25 | ✅ 2067 ms (89 iters) | ✅ 2031 ms (91 iters) | ≈ -1.7% (±2.7%) | — / — |
| naive-bayes | 21 | ✅ 1253 ms (136 iters) | ✅ 1253 ms (137 iters) | ≈ 0% (±32.9%) | — / — |
| naive-bayes | 25 | ✅ 1008 ms (169 iters) | ✅ 1002 ms (170 iters) | ≈ -0.6% (±31.9%) | — / — |
| reactors | 21 | ✅ 17619 ms (15 iters) | ✅ 15712 ms (16 iters) | 🟢 -10.8% | — / — |
| reactors | 25 | ✅ 18550 ms (15 iters) | ✅ 18609 ms (15 iters) | ≈ +0.3% (±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 | ✅ / ✅ | ✅ / ✅ | 3 / ✅ | 1987 / 1971 | ✅ / ✅ | ✅ / ✅ |
| akka-uct | 25 | ✅ / ✅ | ✅ / ✅ | 3 / 2 | 2310 / 2435 | ✅ / ✅ | ✅ / ✅ |
| finagle-chirper | 21 | ✅ / ✅ | ✅ / ✅ | 1 / 3 | 8921 / 8512 | ✅ / ✅ | ✅ / ✅ |
| finagle-chirper | 25 | ✅ / ✅ | ✅ / ✅ | 2 / 1 | 8447 / 8030 | ✅ / ✅ | ✅ / ✅ |
| fj-kmeans | 21 | ✅ / ✅ | ✅ / ✅ | 4 / 1 | 1274 / 1266 | ✅ / ✅ | ✅ / ✅ |
| fj-kmeans | 25 | ✅ / ✅ | ✅ / ✅ | ✅ / 1 | 1280 / 1270 | ✅ / ✅ | ✅ / ✅ |
| future-genetic | 21 | ✅ / ✅ | ✅ / ✅ | 4 / 1 | 2912 / 3053 | ✅ / ✅ | ✅ / ✅ |
| future-genetic | 25 | ✅ / ✅ | ✅ / ✅ | 2 / 1 | 2767 / 2834 | ✅ / ✅ | ✅ / ✅ |
| naive-bayes | 21 | ✅ / ✅ | ✅ / ✅ | 2 / 1 | 3517 / 3509 | ✅ / ✅ | ✅ / ✅ |
| naive-bayes | 25 | ✅ / ✅ | ✅ / ✅ | 6 / 6 | 3483 / 3497 | ✅ / ✅ | ✅ / ✅ |
| reactors | 21 | ✅ / ✅ | ✅ / ✅ | ✅ / ✅ | 1802 / 1666 | ✅ / ✅ | ✅ / ✅ |
| reactors | 25 | ✅ / ✅ | ✅ / ✅ | 1 / ✅ | 1883 / 1920 | ✅ / ✅ | ✅ / ✅ |
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What does this PR do?:
Adds JVM TaskBlock producers for
LockSupport.parkand monitor contention/wait states, wiring JVM state transitions into the synchronous TaskBlock recording API.Motivation:
Common JVM blocking operations can be represented as TaskBlock events instead of relying on wall-clock signals against blocked threads.
Additional Notes:
Virtual threads are not explicitly emitted by this PR. This change focuses on platform-thread JVM blocking states exposed through the existing VM entry paths.
How to test the change?:
Automated coverage includes native park-state tests and Java integration tests for park, monitor wait, monitor contention, JVMTI-backed variants, and combined wall-clock mitigation behavior.
./.claude/commands/build-and-summarize testDebugFor Datadog employees:
dd:platform-security-reviewskill, or file a request via the PSEC review form).bewairealso runs automatically on every PR.