feat(nativemem): categorized native-memory accounting — first cut#669
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CI Test ResultsRun: #30087824078 | Commit:
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Legend: ✅ passed | ❌ failed | ⚪ skipped | 🚫 cancelled Summary: Total: 32 | Passed: 32 | Failed: 0 Updated: 2026-07-24 11:12:58 UTC |
Contributor
Benchmark Results (commit e095203)Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/125289326 Commit:
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| Benchmark | JDK | Latest | Dev | Δ (dev vs latest) | Issues L/D |
|---|---|---|---|---|---|
| akka-uct | 21 | ✅ 10287 ms (21 iters) | ✅ 10260 ms (21 iters) | ≈ -0.3% (±10.9%) | — / — |
| akka-uct | 25 | ✅ 8867 ms (24 iters) | ✅ 8805 ms (24 iters) | ≈ -0.7% (±9.8%) | — / — |
| finagle-chirper | 21 | ✅ 5933 ms (33 iters) | ✅ 5935 ms (33 iters) | ≈ +0% (±24.9%) | |
| finagle-chirper | 25 | ✅ 5475 ms (36 iters) | ✅ 5453 ms (36 iters) | ≈ -0.4% (±24.5%) | |
| fj-kmeans | 21 | ✅ 2648 ms (71 iters) | ✅ 2700 ms (69 iters) | ≈ +2% (±2.7%) | — / — |
| fj-kmeans | 25 | ✅ 2825 ms (66 iters) | ✅ 2836 ms (66 iters) | ≈ +0.4% (±2.6%) | — / — |
| future-genetic | 21 | ✅ 2121 ms (88 iters) | ✅ 2045 ms (90 iters) | 🟢 -3.6% | — / — |
| future-genetic | 25 | ✅ 1976 ms (94 iters) | ✅ 2086 ms (89 iters) | 🔴 +5.6% | — / — |
| naive-bayes | 21 | ✅ 1230 ms (139 iters) | ✅ 1259 ms (137 iters) | ≈ +2.4% (±32.9%) | — / — |
| naive-bayes | 25 | ✅ 1015 ms (168 iters) | ✅ 1011 ms (169 iters) | ≈ -0.4% (±31.6%) | — / — |
| reactors | 21 | ✅ 15811 ms (16 iters) | ✅ 16445 ms (15 iters) | ≈ +4% (±7.6%) | — / — |
| reactors | 25 | ✅ 18243 ms (15 iters) | ✅ 18764 ms (15 iters) | ≈ +2.9% (±4.1%) | — / — |
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 / 1 | 2094 / 1933 | ✅ / ✅ | ✅ / ✅ |
| akka-uct | 25 | ✅ / ✅ | ✅ / ✅ | 1 / 3 | 2216 / 2195 | ✅ / ✅ | ✅ / ✅ |
| finagle-chirper | 21 | ✅ / ✅ | ✅ / ✅ | 4 / 2 | 8790 / 8777 | ✅ / ✅ | ✅ / ✅ |
| finagle-chirper | 25 | ✅ / ✅ | ✅ / ✅ | 1 / 3 | 8165 / 8254 | ✅ / ✅ | ✅ / ✅ |
| fj-kmeans | 21 | ✅ / ✅ | ✅ / ✅ | 2 / 2 | 1283 / 1240 | ✅ / ✅ | ✅ / ✅ |
| fj-kmeans | 25 | ✅ / ✅ | ✅ / ✅ | 1 / 2 | 1289 / 1281 | ✅ / ✅ | ✅ / ✅ |
| future-genetic | 21 | ✅ / ✅ | ✅ / ✅ | ✅ / 2 | 2935 / 2926 | ✅ / ✅ | ✅ / ✅ |
| future-genetic | 25 | ✅ / ✅ | ✅ / ✅ | 1 / 2 | 2884 / 2927 | ✅ / ✅ | ✅ / ✅ |
| naive-bayes | 21 | ✅ / ✅ | ✅ / ✅ | 4 / 2 | 3486 / 3580 | ✅ / ✅ | ✅ / ✅ |
| naive-bayes | 25 | ✅ / ✅ | ✅ / ✅ | 5 / ✅ | 3448 / 3533 | ✅ / ✅ | ✅ / ✅ |
| reactors | 21 | ✅ / ✅ | ✅ / ✅ | 1 / ✅ | 1512 / 1844 | ✅ / ✅ | ✅ / ✅ |
| reactors | 25 | ✅ / ✅ | ✅ / ✅ | 1 / 1 | 1866 / 1889 | ✅ / ✅ | ✅ / ✅ |
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Contributor
Reliability & Chaos Results✅ All reliability & chaos checks passed Pipeline: https://gitlab.ddbuild.io/DataDog/java-profiler/-/pipelines/126272097 |
Contributor
Benchmark Results (commit 62b6f2c)Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/125313150 Commit:
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| Benchmark | JDK | Latest | Dev | Δ (dev vs latest) | Issues L/D |
|---|---|---|---|---|---|
| akka-uct | 21 | ✅ 10303 ms (21 iters) | ✅ 10356 ms (21 iters) | ≈ +0.5% (±10.7%) | — / — |
| akka-uct | 25 | ✅ 9028 ms (24 iters) | ✅ 8895 ms (24 iters) | ≈ -1.5% (±9.8%) | — / — |
| finagle-chirper | 21 | ✅ 5921 ms (33 iters) | ✅ 5936 ms (33 iters) | ≈ +0.3% (±25.2%) | |
| finagle-chirper | 25 | ✅ 5537 ms (36 iters) | ✅ 5535 ms (36 iters) | ≈ -0% (±24.4%) | |
| fj-kmeans | 21 | ✅ 2705 ms (70 iters) | ✅ 2667 ms (69 iters) | ≈ -1.4% (±2.6%) | — / — |
| fj-kmeans | 25 | ✅ 2829 ms (66 iters) | ✅ 2824 ms (66 iters) | ≈ -0.2% (±2.6%) | — / — |
| future-genetic | 21 | ✅ 2122 ms (88 iters) | ✅ 2066 ms (90 iters) | 🟢 -2.6% | — / — |
| future-genetic | 25 | ✅ 2071 ms (90 iters) | ✅ 1960 ms (94 iters) | 🟢 -5.4% | — / — |
| naive-bayes | 25 | ✅ 1022 ms (167 iters) | ✅ 1012 ms (169 iters) | ≈ -1% (±31.6%) | — / — |
| reactors | 21 | ✅ 16191 ms (15 iters) | ✅ 15952 ms (15 iters) | ≈ -1.5% (±6.7%) | — / — |
| reactors | 25 | ✅ 18581 ms (15 iters) | ✅ 18426 ms (15 iters) | ≈ -0.8% (±3.8%) | — / — |
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 | 21 | ✅ / ✅ | ✅ / ✅ | 2 / ✅ | 1975 / 2029 | ✅ / ✅ | ✅ / ✅ |
| akka-uct | 25 | ✅ / ✅ | ✅ / ✅ | ✅ / ✅ | 2406 / 2283 | ✅ / ✅ | ✅ / ✅ |
| finagle-chirper | 21 | ✅ / ✅ | ✅ / ✅ | 7 / 7 | 8749 / 8443 | ✅ / ✅ | ✅ / ✅ |
| finagle-chirper | 25 | ✅ / ✅ | ✅ / ✅ | 1 / 2 | 8539 / 8755 | ✅ / ✅ | ✅ / ✅ |
| fj-kmeans | 21 | ✅ / ✅ | ✅ / ✅ | 5 / 3 | 1305 / 1244 | ✅ / ✅ | ✅ / ✅ |
| fj-kmeans | 25 | ✅ / ✅ | ✅ / ✅ | 4 / 1 | 1284 / 1292 | ✅ / ✅ | ✅ / ✅ |
| future-genetic | 21 | ✅ / ✅ | ✅ / ✅ | ✅ / 1 | 3065 / 2961 | ✅ / ✅ | ✅ / ✅ |
| future-genetic | 25 | ✅ / ✅ | ✅ / ✅ | 2 / 4 | 2938 / 2818 | ✅ / ✅ | ✅ / ✅ |
| naive-bayes | 25 | ✅ / ✅ | ✅ / ✅ | 5 / 4 | 3483 / 3485 | ✅ / ✅ | ✅ / ✅ |
| reactors | 21 | ✅ / ✅ | ✅ / ✅ | 1 / ✅ | 1495 / 1554 | ✅ / ✅ | ✅ / ✅ |
| reactors | 25 | ✅ / ✅ | ✅ / ✅ | 1 / ✅ | 1874 / 1984 | ✅ / ✅ | ✅ / ✅ |
Contributor
Benchmark Results (commit bdf9f55)Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/125648678 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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Contributor
Benchmark Results (commit f1a84c6)Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/125658666 Commit:
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| Benchmark | JDK | Latest | Dev | Δ (dev vs latest) | Issues L/D |
|---|---|---|---|---|---|
| akka-uct | 21 | ✅ 10309 ms (21 iters) | ✅ 10323 ms (21 iters) | ≈ +0.1% (±10.8%) | — / — |
| akka-uct | 25 | ✅ 8961 ms (24 iters) | ✅ 8884 ms (24 iters) | ≈ -0.9% (±9.8%) | — / — |
| finagle-chirper | 21 | ✅ 6042 ms (33 iters) | ✅ 5955 ms (33 iters) | ≈ -1.4% (±25.3%) | |
| finagle-chirper | 25 | ✅ 5468 ms (36 iters) | ✅ 5531 ms (36 iters) | ≈ +1.2% (±25%) | |
| fj-kmeans | 21 | ✅ 2649 ms (70 iters) | ✅ 2695 ms (70 iters) | ≈ +1.7% (±2.7%) | — / — |
| fj-kmeans | 25 | ✅ 2800 ms (67 iters) | ✅ 2807 ms (66 iters) | ≈ +0.3% (±2.6%) | — / — |
| future-genetic | 21 | ✅ 2141 ms (87 iters) | ✅ 2039 ms (90 iters) | 🟢 -4.8% | — / — |
| future-genetic | 25 | ✅ 2088 ms (89 iters) | ✅ 2127 ms (87 iters) | ≈ +1.9% (±2.5%) | — / — |
| naive-bayes | 21 | ✅ 1227 ms (139 iters) | ✅ 1280 ms (134 iters) | ≈ +4.3% (±33%) | — / — |
| naive-bayes | 25 | ✅ 1024 ms (167 iters) | ✅ 1022 ms (167 iters) | ≈ -0.2% (±32%) | — / — |
| reactors | 21 | ✅ 16285 ms (15 iters) | ✅ 16003 ms (15 iters) | ≈ -1.7% (±5.7%) | — / — |
| reactors | 25 | ✅ 18050 ms (15 iters) | ✅ 18143 ms (15 iters) | ≈ +0.5% (±6%) | — / — |
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 | ✅ / ✅ | ✅ / ✅ | ✅ / 5 | 2017 / 2009 | ✅ / ✅ | ✅ / ✅ |
| akka-uct | 25 | ✅ / ✅ | ✅ / ✅ | 1 / 1 | 2344 / 2264 | ✅ / ✅ | ✅ / ✅ |
| finagle-chirper | 21 | ✅ / ✅ | ✅ / ✅ | 3 / 5 | 8749 / 8648 | ✅ / ✅ | ✅ / ✅ |
| finagle-chirper | 25 | ✅ / ✅ | ✅ / ✅ | 3 / 4 | 8234 / 8352 | ✅ / ✅ | ✅ / ✅ |
| fj-kmeans | 21 | ✅ / ✅ | ✅ / ✅ | 2 / 2 | 1239 / 1269 | ✅ / ✅ | ✅ / ✅ |
| fj-kmeans | 25 | ✅ / ✅ | ✅ / ✅ | 2 / 2 | 1267 / 1274 | ✅ / ✅ | ✅ / ✅ |
| future-genetic | 21 | ✅ / ✅ | ✅ / ✅ | 3 / 1 | 3072 / 2901 | ✅ / ✅ | ✅ / ✅ |
| future-genetic | 25 | ✅ / ✅ | ✅ / ✅ | ✅ / 1 | 2974 / 2854 | ✅ / ✅ | ✅ / ✅ |
| naive-bayes | 21 | ✅ / ✅ | ✅ / ✅ | 2 / 2 | 3509 / 3545 | ✅ / ✅ | ✅ / ✅ |
| naive-bayes | 25 | ✅ / ✅ | ✅ / ✅ | 3 / ✅ | 3490 / 3444 | ✅ / ✅ | ✅ / ✅ |
| reactors | 21 | ✅ / ✅ | ✅ / ✅ | 1 / ✅ | 1756 / 1751 | ✅ / ✅ | ✅ / ✅ |
| reactors | 25 | ✅ / ✅ | ✅ / ✅ | ✅ / 1 | 1854 / 1753 | ✅ / ✅ | ✅ / ✅ |
Contributor
Benchmark Results (commit 277e2d8)Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/125665685 Commit:
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| Benchmark | JDK | Latest | Dev | Δ (dev vs latest) | Issues L/D |
|---|---|---|---|---|---|
| akka-uct | 21 | ✅ 10393 ms (21 iters) | ✅ 10229 ms (21 iters) | ≈ -1.6% (±11%) | — / — |
| akka-uct | 25 | ✅ 8931 ms (24 iters) | ✅ 8766 ms (24 iters) | ≈ -1.8% (±9.8%) | — / — |
| finagle-chirper | 21 | ✅ 6009 ms (33 iters) | ✅ 5981 ms (33 iters) | ≈ -0.5% (±24.6%) | |
| finagle-chirper | 25 | ✅ 5507 ms (36 iters) | ✅ 5496 ms (36 iters) | ≈ -0.2% (±24.7%) | |
| fj-kmeans | 21 | ✅ 2761 ms (68 iters) | ✅ 2694 ms (70 iters) | ≈ -2.4% (±2.7%) | — / — |
| fj-kmeans | 25 | ✅ 2757 ms (68 iters) | ✅ 2798 ms (67 iters) | ≈ +1.5% (±2.7%) | — / — |
| future-genetic | 21 | ✅ 2159 ms (86 iters) | ✅ 2039 ms (92 iters) | 🟢 -5.6% | — / — |
| future-genetic | 25 | ✅ 2030 ms (91 iters) | ✅ 2111 ms (88 iters) | 🔴 +4% | — / — |
| naive-bayes | 21 | ✅ 1283 ms (133 iters) | ✅ 1258 ms (136 iters) | ≈ -1.9% (±32.4%) | — / — |
| naive-bayes | 25 | ✅ 1019 ms (168 iters) | ✅ 1020 ms (168 iters) | ≈ +0.1% (±31.8%) | — / — |
| reactors | 21 | ✅ 16429 ms (15 iters) | ✅ 14845 ms (17 iters) | 🟢 -9.6% | — / — |
| reactors | 25 | ✅ 18219 ms (15 iters) | ✅ 18034 ms (15 iters) | ≈ -1% (±4.2%) | — / — |
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 | ✅ / ✅ | ✅ / ✅ | 8 / 1 | 1988 / 2062 | ✅ / ✅ | ✅ / ✅ |
| akka-uct | 25 | ✅ / ✅ | ✅ / ✅ | 1 / 9 | 2080 / 2084 | ✅ / ✅ | ✅ / ✅ |
| finagle-chirper | 21 | ✅ / ✅ | ✅ / ✅ | 4 / 3 | 8485 / 8415 | ✅ / ✅ | ✅ / ✅ |
| finagle-chirper | 25 | ✅ / ✅ | ✅ / ✅ | 3 / 2 | 8560 / 8615 | ✅ / ✅ | ✅ / ✅ |
| fj-kmeans | 21 | ✅ / ✅ | ✅ / ✅ | 4 / 2 | 1282 / 1286 | ✅ / ✅ | ✅ / ✅ |
| fj-kmeans | 25 | ✅ / ✅ | ✅ / ✅ | 6 / 1 | 1278 / 1295 | ✅ / ✅ | ✅ / ✅ |
| future-genetic | 21 | ✅ / ✅ | ✅ / ✅ | 2 / 1 | 3002 / 3031 | ✅ / ✅ | ✅ / ✅ |
| future-genetic | 25 | ✅ / ✅ | ✅ / ✅ | 2 / ✅ | 2944 / 2864 | ✅ / ✅ | ✅ / ✅ |
| naive-bayes | 21 | ✅ / ✅ | ✅ / ✅ | 2 / 3 | 3504 / 3524 | ✅ / ✅ | ✅ / ✅ |
| naive-bayes | 25 | ✅ / ✅ | ✅ / ✅ | 2 / 6 | 3485 / 3488 | ✅ / ✅ | ✅ / ✅ |
| reactors | 21 | ✅ / ✅ | ✅ / ✅ | ✅ / ✅ | 1536 / 1691 | ✅ / ✅ | ✅ / ✅ |
| reactors | 25 | ✅ / ✅ | ✅ / ✅ | 1 / ✅ | 1780 / 1837 | ✅ / ✅ | ✅ / ✅ |
Contributor
Benchmark Results (commit ac8c128)Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/125736830 Commit:
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| Benchmark | JDK | Latest | Dev | Δ (dev vs latest) | Issues L/D |
|---|---|---|---|---|---|
| akka-uct | 21 | ✅ 10383 ms (21 iters) | ✅ 10256 ms (21 iters) | ≈ -1.2% (±11.4%) | — / — |
| akka-uct | 25 | ✅ 8923 ms (24 iters) | ✅ 8855 ms (24 iters) | ≈ -0.8% (±10%) | — / — |
| finagle-chirper | 21 | ✅ 5980 ms (33 iters) | ✅ 6028 ms (33 iters) | ≈ +0.8% (±25.1%) | |
| finagle-chirper | 25 | ✅ 5483 ms (36 iters) | ✅ 5498 ms (36 iters) | ≈ +0.3% (±24.1%) | |
| fj-kmeans | 21 | ✅ 2749 ms (68 iters) | ✅ 2717 ms (69 iters) | ≈ -1.2% (±2.7%) | — / — |
| fj-kmeans | 25 | ✅ 2826 ms (66 iters) | ✅ 2762 ms (67 iters) | ≈ -2.3% (±2.6%) | — / — |
| future-genetic | 21 | ✅ 2042 ms (91 iters) | ✅ 2044 ms (90 iters) | ≈ +0.1% (±2.6%) | — / — |
| future-genetic | 25 | ✅ 2130 ms (87 iters) | ✅ 2051 ms (90 iters) | 🟢 -3.7% | — / — |
| naive-bayes | 25 | ✅ 1008 ms (170 iters) | ✅ 1009 ms (169 iters) | ≈ +0.1% (±31.7%) | — / — |
| reactors | 21 | ✅ 16229 ms (15 iters) | ✅ 16543 ms (15 iters) | ≈ +1.9% (±7.5%) | — / — |
| reactors | 25 | ✅ 18332 ms (15 iters) | ✅ 18379 ms (15 iters) | ≈ +0.3% (±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 | ✅ / ✅ | ✅ / ✅ | 2 / 1 | 2019 / 2112 | ✅ / ✅ | ✅ / ✅ |
| akka-uct | 25 | ✅ / ✅ | ✅ / ✅ | 2 / ✅ | 2418 / 2216 | ✅ / ✅ | ✅ / ✅ |
| finagle-chirper | 21 | ✅ / ✅ | ✅ / ✅ | 5 / 4 | 8420 / 8855 | ✅ / ✅ | ✅ / ✅ |
| finagle-chirper | 25 | ✅ / ✅ | ✅ / ✅ | ✅ / 3 | 8622 / 8796 | ✅ / ✅ | ✅ / ✅ |
| fj-kmeans | 21 | ✅ / ✅ | ✅ / ✅ | 6 / 2 | 1266 / 1280 | ✅ / ✅ | ✅ / ✅ |
| fj-kmeans | 25 | ✅ / ✅ | ✅ / ✅ | 1 / ✅ | 1307 / 1266 | ✅ / ✅ | ✅ / ✅ |
| future-genetic | 21 | ✅ / ✅ | ✅ / ✅ | ✅ / 1 | 3019 / 2888 | ✅ / ✅ | ✅ / ✅ |
| future-genetic | 25 | ✅ / ✅ | ✅ / ✅ | 1 / ✅ | 2890 / 2833 | ✅ / ✅ | ✅ / ✅ |
| naive-bayes | 21 | ✅ / ✅ | ✅ / ✅ | ✅ / ✅ | ✅ / ✅ | ✅ / ✅ | ✅ / ✅ |
| naive-bayes | 25 | ✅ / ✅ | ✅ / ✅ | 4 / 3 | 3505 / 3444 | ✅ / ✅ | ✅ / ✅ |
| reactors | 21 | ✅ / ✅ | ✅ / ✅ | ✅ / ✅ | 1626 / 1497 | ✅ / ✅ | ✅ / ✅ |
| reactors | 25 | ✅ / ✅ | ✅ / ✅ | ✅ / 1 | 1806 / 1830 | ✅ / ✅ | ✅ / ✅ |
Contributor
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Pull request overview
Introduces a new NativeMem facility to attribute the profiler’s own native memory usage into a small set of categories, tracking per-category live bytes, a moving-window average, and a precise per-category peak; totals are exported via existing counter/JFR pathways.
Changes:
- Added
NativeMemcore implementation (nativeMem.h/.cpp) with per-category live/avg/max tracking and tests. - Instrumented major native allocation sites (calltrace arena/buffers, dictionaries, thread-local data, thread filter, perf mmap, line tables, JFR recording buffers, native symbols gauge) to record alloc/free deltas.
- Emitted totals through the counters table and per-category metrics through
T_DATADOG_COUNTERevents on chunk finish.
Reviewed changes
Copilot reviewed 17 out of 17 changed files in this pull request and generated 2 comments.
Show a summary per file
| File | Description |
|---|---|
| ddprof-lib/src/test/cpp/stringDictionary_ut.cpp | Adds lifecycle accounting-balance test for StringDictionaryBuffer NM_DICTIONARY instrumentation. |
| ddprof-lib/src/test/cpp/nativeMem_ut.cpp | New unit tests covering live/avg/max semantics, peaks between samples, clamping behavior, and category names. |
| ddprof-lib/src/test/cpp/dictionary_ut.cpp | Adds lifecycle accounting-balance test for Dictionary NM_DICTIONARY instrumentation. |
| ddprof-lib/src/main/cpp/threadLocalData.h | Records NM_THREAD_LOCAL on ProfiledThread creation via forTid. |
| ddprof-lib/src/main/cpp/threadLocalData.cpp | Records NM_THREAD_LOCAL decrements on TLS destruction/release paths. |
| ddprof-lib/src/main/cpp/threadFilter.cpp | Accounts for thread-filter chunk and freelist backing allocations under NM_THREAD_FILTER. |
| ddprof-lib/src/main/cpp/stringDictionary.h | Accounts arena chunks + SBTable allocations/frees under NM_DICTIONARY. |
| ddprof-lib/src/main/cpp/profiler.cpp | Accounts per-shard calltrace buffer allocations/frees under NM_CALLTRACE; mirrors native symbol gauge via setLive. |
| ddprof-lib/src/main/cpp/perfEvents_linux.cpp | Accounts perf ring mmap/unmap under NM_PERF. |
| ddprof-lib/src/main/cpp/nativeMem.h | Defines categories and NativeMem API (record/setLive/sample/live/avg/max/totals). |
| ddprof-lib/src/main/cpp/nativeMem.cpp | Implements totals, sampling window averaging, reset, and category naming. |
| ddprof-lib/src/main/cpp/linearAllocator.cpp | Accounts calltrace arena chunk alloc/free under NM_CALLTRACE. |
| ddprof-lib/src/main/cpp/flightRecorder.h | Declares Recording helpers to sample/export native-mem metrics. |
| ddprof-lib/src/main/cpp/flightRecorder.cpp | Samples native-mem each chunk and emits totals + per-category counter events. |
| ddprof-lib/src/main/cpp/dictionary.h | Accounts root table allocation under NM_DICTIONARY. |
| ddprof-lib/src/main/cpp/dictionary.cpp | Accounts key-string alloc/free and overflow/root table alloc/free under NM_DICTIONARY. |
| ddprof-lib/src/main/cpp/counters.h | Adds total native-mem counters (live/avg/max) to the counter table. |
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Contributor
Benchmark Results (commit 8a9567f)Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/125902089 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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Copilot reviewed 17 out of 17 changed files in this pull request and generated 2 comments.
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ddprof-lib/src/main/cpp/flightRecorder.cpp:1815
- writeNativeMem() serializes values with Buffer::putVar64(u64). If any native-mem gauge goes negative (possible until all free sites are instrumented), the implicit signed->unsigned conversion will emit a huge varint. Clamp to 0 before encoding to keep the JFR/counter stream valid.
auto emit = [&](const char *label, long long value) {
int start = buf->skip(1);
buf->putVar64(T_DATADOG_COUNTER);
buf->putVar64(_start_ticks);
buf->putUtf8(label);
buf->putVar64(value);
writeEventSizePrefix(buf, start);
flushIfNeeded(buf);
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Benchmark Results (commit 3c82245)Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/125929510 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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Pull request overview
Copilot reviewed 17 out of 17 changed files in this pull request and generated no new comments.
Comments suppressed due to low confidence (1)
ddprof-lib/src/main/cpp/flightRecorder.cpp:1801
- NativeMem::sample() explicitly clamps negative per-category live values to 0 when computing totals/averages, but the exported total live counter uses NativeMem::liveTotal(), which can go negative if any category is temporarily negative (the scenario sample() is already designed to tolerate). This can produce a nonsensical negative "native_mem_live_bytes" in the counter stream and makes the totals inconsistent with the sampled/clamped window.
// per-category values are emitted by writeNativeMem().
Counters::set(NATIVE_MEM_LIVE_BYTES, NativeMem::liveTotal());
Counters::set(NATIVE_MEM_AVG_BYTES, NativeMem::avgTotal());
Counters::set(NATIVE_MEM_MAX_BYTES, NativeMem::maxTotal());
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Benchmark Results (commit 19db9d3)Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/125953166 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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kaahos
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Thank you for the work, I've left some comments! let me know what you think.
Add DICTIONARY to the per-category accounting, and remove the CONTEXT category. CONTEXT had no separate backing allocation — the OTel context record is embedded in ProfiledThread and already counted under THREAD_LOCAL — so it would have been a permanently-zero line. Removed rather than left dangling. DICTIONARY is tagged across both implementations, counting physical backing allocations once each (single category; per-role breakdown, if ever wanted, belongs in a nested dimension, not extra top-level categories): - Dictionary (older, per-key malloc; used for symbols/packages): root and overflow DictTables (constant size) and key strings. Key frees are bulk and lose per-item sizes, but keys are null-terminated so the malloc'd size (strlen + 1) is recovered at free — no running total needed. - StringDictionary / StringArena (arena-based): arena chunks and root / overflow SBTables. Keys are bump-allocated inside chunks, so they are NOT counted separately (that would double-count). Chunk and SBTable accounting is unconditional, independent of the diagnostic counters' _counter_offset gate, so anonymous dictionaries are covered too. Tests: lifecycle invariants for both implementations assert the accounting grows on insert, returns exactly to the construction baseline after clear(), and to zero after destruction — directly proving inc/dec pairing (including the strlen-at-free path and arena chunk growth). Full gtestDebug suite green (356 tests). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The class comment implied every record() call needs to be async-signal-safe. In fact most categories allocate via malloc/new off the signal path, where the property is irrelevant. Only the CALLTRACE arena allocates from within the sampling signal handler (via OS::safeAlloc's raw mmap syscall), so that is where record() staying a relaxed atomic add actually matters. Reword accordingly. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The "CodeCache" name is async-profiler's, and collides with the JVM's JIT code cache. This category measures something unrelated: the profiler's own per-native-library symbol tables (used to symbolicate native frames), not JVM-managed code. Rename the NativeMem category and its JFR label to native_symbols so the metric is unambiguous. The existing CODECACHE_NATIVE_SIZE_BYTES counter keeps its name for continuity; only the new NativeMem category is renamed. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The class comment still described record() as "a single relaxed atomic add" from before precise per-category max was added. record() now also does a conditional lock-free high-water update on allocation. Correct the wording; the async-signal-safety guarantee still holds (lock-free atomics). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Two invariants the accounting relies on are now asserted (stripped under NDEBUG, so no release cost and never in a real signal handler): - Per-category live bytes never go negative: record() asserts the post-update value >= 0. A negative means an unbalanced/oversized free. This lets liveTotal() sum without clamping, since each term is >= 0. - Dictionary keys are NUL-free strings of exactly `length`: allocateKey() asserts strlen == length. The NM_DICTIONARY free path recovers a key's size via strlen at clear(), so an embedded NUL would under-count; the assert trips in debug/gtest instead of silently drifting. The sample() clamp is retained as a release-mode safety net for the asserted-impossible negative case, and its comment updated to say so. The old NegativeLiveClampedInSample test is removed: it deliberately drove a category negative, which now (correctly) trips the record() assert. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Review fixes: - Clamp per-category live to 0 at the emit boundary (liveTotal() and writeNativeMem()). These values are serialized via putVar64(u64); a negative gauge would otherwise emit a huge varint and corrupt the counter stream. Matches the clamping sample() already does. The record() invariant asserts non-negative in debug; this guards the release path where the assert is stripped. - Move the NM_JFR_BUFFERS decrement in FlightRecorder::stop() to after `delete rec`: ~Recording() runs finishChunk(), which emits the counters for the final chunk while the buffers are still live, so account the free only once it has happened. - Reword the "lower bound" description of the observed total: the sampled per-category sum is not an atomic snapshot, so it can drift above or below a true instantaneous total; it is an approximate sampled figure, and maxTotal() remains the authoritative ceiling. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
…s on stop Review fixes: - Reallocate the per-shard calltrace buffers in two phases: allocate all CONCURRENCY_LEVEL replacements first, and only swap/free/account if all succeed. A mid-loop allocation failure now leaves the profiler entirely unchanged (old buffers, _max_stack_depth, and NM_CALLTRACE accounting stay consistent), instead of the previous partial-swap + reset of _max_stack_depth to 0 that mis-accounted a later resize. - Extract updateNativeLibMemStats(): read native_libs.memoryUsage() once (was called three times) and publish the CODECACHE counters plus the NM_NATIVE_SYMBOLS gauge. Call it from both dump() and stop() (before _jfr.stop()), so the final chunk reflects native-symbol memory even when stopping without a preceding dump. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The per-thread PerfEvent array (max_events * sizeof(PerfEvent)) is real perf-engine memory that NM_PERF omitted — it counted only the ring mappings. Add paired inc/dec around the calloc/free in start(), guarded on non-null so a prior calloc failure is not mis-accounted. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
- Add two tests proving NM_THREAD_LOCAL balances across the ProfiledThread lifecycle: the decrement lives in freeValue(), reached both via release() -> ThreadLocal::clear() and via the pthread-key destructor on thread exit. Both paths return the gauge to baseline. - dictionary_ut.cpp: update copyright to 2025, 2026. - stringDictionary_ut.cpp: add the missing Datadog copyright header. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Two follow-up review fixes: - ProfiledThread::deleteForTest() (UNIT_TEST helper) deleted the object directly, bypassing freeValue()'s NM_THREAD_LOCAL decrement and leaking live bytes across tests that use it. It stands in for freeValue()'s delete, so mirror the decrement. - In ~ThreadFilter(), record the decrements after the memory is actually freed: delete the chunk before its decrement, and reset the _free_list unique_ptr explicitly before recording (rather than letting it free the array after the destructor body runs). Keeps the gauge from leading the free during teardown. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Consistency: the two-phase resize recorded the NM_CALLTRACE decrement before free(prev); the other decrement sites (FlightRecorder::stop, ~ThreadFilter) account the free after it happens. Reorder to match. Functionally equivalent (free doesn't read the counter), purely for uniformity. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Consistency (same as the calltrace-buffer and ~ThreadFilter sites): record the NM_PERF decrement for the old _events array after free(_events) rather than before. Capture the old size first, since _max_events is overwritten by the reallocation. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Consistency with the other decrement sites (calltrace resize, perf _events, ~ThreadFilter): record the NM_THREAD_LOCAL decrement after delete pt rather than before. sizeof is a compile-time constant, so no value is lost by deleting first. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Sweep the remaining "record before free" decrement sites to record after the free, consistent with the calltrace/perf/thread-local/ThreadFilter sites (avoids a transient underreport if sampling races teardown): - StringArena chunk frees (~StringArena, reset()). - SBTable frees (freeOverflowNodes, ~StringDictionaryBuffer). - Dictionary key strings (capture strlen+1 before free, record after) and overflow DictTable frees. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
jbachorik
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Jul 24, 2026
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Nice work!
Can you plz consider adding some smoke tests? Mybe extending the existing tests to assert the presence of the NM accounting counters and that they are sane?
rkennke
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Add an end-to-end smoke test asserting the always-on native-memory accounting counters (native_mem_live_bytes / _avg_bytes / _max_bytes) are emitted into the recording after a short profiling run and hold their sanity invariants: the peak total (sum of precise per-category peaks) brackets both the live total and the moving-window average. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Replace the full Apache-2.0 boilerplate in nativeMem.{h,cpp} and
nativeMem_ut.cpp with the short-form copyright + SPDX identifier used
across the tree, and normalize the dictionary_ut.cpp copyright line.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Contributor
Benchmark Results (commit 9ebd615)Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/126754088 Commit:
|
| Benchmark | JDK | Latest | Dev | Δ (dev vs latest) | Issues L/D |
|---|---|---|---|---|---|
| akka-uct | 21 | ✅ 10265 ms (21 iters) | ✅ 10278 ms (21 iters) | ≈ +0.1% (±10.6%) | — / — |
| akka-uct | 25 | ✅ 8824 ms (24 iters) | ✅ 8954 ms (24 iters) | ≈ +1.5% (±10.7%) | — / — |
| finagle-chirper | 21 | ✅ 5964 ms (33 iters) | ✅ 5999 ms (33 iters) | ≈ +0.6% (±25.1%) | |
| finagle-chirper | 25 | ✅ 5467 ms (36 iters) | ✅ 5493 ms (36 iters) | ≈ +0.5% (±24.3%) | |
| fj-kmeans | 21 | ✅ 2747 ms (68 iters) | ✅ 2682 ms (70 iters) | ≈ -2.4% (±2.6%) | — / — |
| fj-kmeans | 25 | ✅ 2832 ms (66 iters) | ✅ 2821 ms (66 iters) | ≈ -0.4% (±2.5%) | — / — |
| future-genetic | 21 | ✅ 2050 ms (90 iters) | ✅ 2177 ms (85 iters) | 🔴 +6.2% | — / — |
| future-genetic | 25 | ✅ 2068 ms (90 iters) | ✅ 2074 ms (89 iters) | ≈ +0.3% (±2.7%) | — / — |
| naive-bayes | 21 | ✅ 1260 ms (135 iters) | ✅ 1226 ms (138 iters) | ≈ -2.7% (±32.6%) | — / — |
| naive-bayes | 25 | ✅ 1031 ms (166 iters) | ✅ 1015 ms (168 iters) | ≈ -1.6% (±31.9%) | — / — |
| reactors | 21 | ✅ 16158 ms (15 iters) | ✅ 15977 ms (15 iters) | ≈ -1.1% (±6.3%) | — / — |
| reactors | 25 | ✅ 18443 ms (15 iters) | ✅ 18665 ms (15 iters) | ≈ +1.2% (±4.9%) | — / — |
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 | ✅ / ✅ | ✅ / ✅ | ✅ / 1 | 1952 / 1889 | ✅ / ✅ | ✅ / ✅ |
| akka-uct | 25 | ✅ / ✅ | ✅ / ✅ | 2 / ✅ | 2080 / 2128 | ✅ / ✅ | ✅ / ✅ |
| finagle-chirper | 21 | ✅ / ✅ | ✅ / ✅ | 1 / 2 | 8693 / 8617 | ✅ / ✅ | ✅ / ✅ |
| finagle-chirper | 25 | ✅ / ✅ | ✅ / ✅ | 1 / ✅ | 8629 / 8362 | ✅ / ✅ | ✅ / ✅ |
| fj-kmeans | 21 | ✅ / ✅ | ✅ / ✅ | ✅ / 1 | 1245 / 1246 | ✅ / ✅ | ✅ / ✅ |
| fj-kmeans | 25 | ✅ / ✅ | ✅ / ✅ | 3 / 3 | 1285 / 1291 | ✅ / ✅ | ✅ / ✅ |
| future-genetic | 21 | ✅ / ✅ | ✅ / ✅ | ✅ / ✅ | 2979 / 3063 | ✅ / ✅ | ✅ / ✅ |
| future-genetic | 25 | ✅ / ✅ | ✅ / ✅ | 1 / ✅ | 2971 / 2936 | ✅ / ✅ | ✅ / ✅ |
| naive-bayes | 21 | ✅ / ✅ | ✅ / ✅ | 3 / 3 | 3497 / 3449 | ✅ / ✅ | ✅ / ✅ |
| naive-bayes | 25 | ✅ / ✅ | ✅ / ✅ | 8 / 2 | 3515 / 3457 | ✅ / ✅ | ✅ / ✅ |
| reactors | 21 | ✅ / ✅ | ✅ / ✅ | 2 / ✅ | 1725 / 1589 | ✅ / ✅ | ✅ / ✅ |
| reactors | 25 | ✅ / ✅ | ✅ / ✅ | 1 / ✅ | 1933 / 1891 | ✅ / ✅ | ✅ / ✅ |
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What
Adds a
NativeMemfacility to measure the profiler's own native memory usage — currently we only observe whole-process RSS. Per-category live gauge, moving-window average, and a precise per-category peak, wired through the existing counter/JFR path.Why
We measure the agent's native footprint only as an RSS delta (~150–200 MB) with no breakdown. This gives an in-process, attributable, categorized number we can trend, and a foundation for later pinpointing which code is responsible.
How
NativeMem(nativeMem.h/nativeMem.cpp): aNativeMemCategoryenum whose per-category live gauges partition the total — each backing allocation belongs to exactly one category, so no double-counting.COUNTERSbuild flag:record()is a single relaxed atomic add. Most sites are off the signal path (malloc/new is not async-signal-safe anyway); the exception is CALLTRACE, whose arena allocates inside the sampling signal handler (viaOS::safeAlloc), sorecord()is kept async-signal-safe there.record()maintains each category's high-water mark at allocation time via a relaxed CAS (common path is load+compare; CAS only on a new peak; frees skip it). Spikes between sample ticks are still captured.sample()refreshes the moving-window averages and the observed total, ticked once per JFR chunk finish.NATIVE_MEM_{LIVE,AVG,MAX}_BYTES(JFRT_DATADOG_COUNTER+ JNI debug counters); per-categorynative_mem_{live,avg,max}_bytes.<category>values reuse the same event format — no new event type.Total peak: bracketed, no shared hotspot
A precise total peak would need a single global atomic hit by every allocation (a contention hotspot). Instead the total peak is bracketed:
NATIVE_MEM_MAX_BYTES= upper bound = sum of the precise per-category peaks.native_mem_max_observed_total_bytes= lower bound = the largest instantaneous total seen at a sampling tick.Instrumented categories
Tagged via
record()at their backing alloc/free sites (precise, always-on):LinearAllocatorchunks (call-trace arena) + per-shard calltrace buffers.Dictionary(symbols/packages — root/overflowDictTables + key strings, whose size is recovered viastrlenat bulk-free), and the arenaStringDictionary(arena chunks + root/overflowSBTables; keys live inside chunks so they're not counted separately). Counted unconditionally, independent of the diagnostic counters' offset gate. Single category — a per-role split, if ever wanted, belongs in a nested dimension.ProfiledThreadper thread.Recordingobject (embeds the JFR buffer array).mmap(2 × page_size).ChunkStoragechunks (bounded) + free-list array.Gauge-mirrored (
NativeMem::setLive()at a recompute site):CodeCache; not the JVM code cache). Sourced fromCodeCache::memoryUsage(), which is now accurate onmain(fix(codecache): make memoryUsage() accurate and live #677 merged); the gauge is refreshed at dump/stop, the same cadence as the existingCODECACHE_NATIVE_SIZE_BYTEScounter.Not yet covered (reads 0):
new/mallocacross the remaining files → best captured by malloc interception, not hand-tagging.(
CONTEXTwas removed: the OTel context record is embedded inProfiledThread, already counted underTHREAD_LOCAL; a separate category would double-count or read a permanent 0.)So the total is still a subset of the RSS delta until interception lands, but now covers the major consumers.
Avoiding double-counting
Call-trace bytes appear at three layers (
safeAllocmmap,LINEAR_ALLOCATOR_BYTESreserved chunks,CALLTRACE_STORAGE_BYTESused-within-chunks); summing counters would double/triple-count.NativeMemcounts backing memory once per category; the existing reserved/used/waste counters remain an independent nested diagnostic dimension. The dictionary tagging follows the same rule — e.g. arena keys are inside chunks and are not counted separately.Performance
Designed to be off the hot path. Measured in operations, not observed as a regression in this workload:
CallTraceStorage::putnormally just bump-allocates within an existing arena chunk and touches norecord().record()runs only when the call-trace arena grows a new chunk (8 MiB apart), and there it's a lock-free relaxed atomic add + high-water update — async-signal-safe.record()is one relaxedfetch_add; on allocation it also does a relaxed load + compare, with a CAS only when a new per-category peak is set (rare, since the peak is monotonic). This sits next to amalloc/calloc/mmap/newthat dominates the cost, so it's negligible. These sites (dictionary inserts, chunk/table growth, thread/lib/recording creation) are not per-sample.sample()is O(categories × window) ≈ 9 × 64 folds;writeNativeMem()emits ~28 counter events. This runs once per chunk rotation (seconds–minutes), off the sampling path.clear(): the per-key free now also does astrlento recover the freed size, soclear()cost is O(sum of key lengths) rather than O(key count).clear()already walks every key; this is a marginal constant-factor increase, at dictionary rotation only.No new locks, no shared global counter on the hot path (the total peak is bracketed precisely to avoid one), and the always-on atomics are relaxed.
sample()/writeNativeMem()run within the existing recording flush.Roadmap
Testing
nativeMem_ut(7 tests): live tracking + total partition, single-sample avg==live, moving average, max high-water, precise per-category max catching an inter-sample spike (with the bracket),setLivegauge + peak retention, category names. (The non-negative invariant is enforced by an assert inrecord()rather than a dedicated clamp test.)dictionary_ut,stringDictionary_ut): accounting grows on insert, returns exactly to the construction baseline afterclear(), and to zero after destruction — directly proving inc/dec pairing (incl. the strlen-at-free path and arena chunk growth).thread_teardown_safety_ut, Linux):NM_THREAD_LOCALreturns to baseline after bothrelease()and thread-exit teardown, proving theforTid/freeValuepairing.:ddprof-lib:gtestDebugsuite green (358 cross-platform tests, 0 failures locally; Linux-only perf/thread-teardown coverage runs in CI).🤖 Generated with Claude Code