Direct RGBA receive: native write CPU and elapsed time

Method

This diagnostic measures calling-thread CPU time around the existing native HTTP packet write call.

Noisedeck A sends 1920 × 1080 RGBA packets through Sync to Noisedeck B. Native camera publication remains active.

B uses the existing HTTP BYOB reader. The source limit remains two packets, or 16,588,928 bytes. Receiver credit remains one.

The browser, source encoder, renderer and queue policy retain their frozen BUDGET2 bytes. Only the native timing diagnostic changes.

The tests use GLSL and synth.testPattern. Timing uses pattern 0 with gridSize 4. Pixel controls use pattern 5 with gridSize 16.

Retained host metadata identifies an Apple M2, eight logical CPUs, 24 GiB of memory and Darwin 23.6.0.

Observed power samples show AC power. They do not prove continuous AC power between reads. The tests include no in-run thermal or frequency measurements.

ContextGateStatusNative callsNative slow callsResult SHA256
webpositivePass5770238479620f001af4b2098bf9880fb3cb53df8a29c4b286a95174a5ad871817b2
webnegativePass52710b4c57e3f0b3d94b365a7a726a9273c3776a7a1492d7cc772732f7568564b220
webobserve5Pass5810865997ff65101c84485c26340e1d40c0acaece6dfb6a932fd71a43f0924ec5b9
webobserve180Pass1017674dade0ebba66bfd51e69e3a7c4f4a2cc2513224be3a44321264ba093d884644c
desktoppositivePass5800e79194134af9a8631d4c1d844959647bc74a2cc45a0d15863368ce74fb5f868b
desktopnegativePass5820bb789d0969bacbc405dc187482352dc086dc1538fad7f3e92d5cd78d0e1a3d3c
desktopobserve5Pass59601527b56d0b8a8ac1a137c92982c40f66597f61c58c5394e213c321c514907f30
desktopobserve180Pass10827206eb8c2d7725d438d1cc1ae27f85d005c1f69883b6b732079d64d55410df5d84
ContextA browserB browserStart UTCEnd UTCObserved AC samples
webChrome/152.0.7977.83Chrome/152.0.7977.832026-09-09T09:33:51.967Z2026-09-09T09:37:21.155Z5
desktopChrome/148.0.7778.180Chrome/148.0.7778.1802026-09-09T09:37:21.389Z2026-09-09T09:40:54.268Z5

Delivery observations

Four fresh pixel controls and four observations passed. The observations include two five-second and two three-minute runs.

The long observations retain all 360 complete B seconds and both partial tails. The short observations retain ten complete seconds and both tails.

Input and final markers must match within the same render. Rates use the full measurement span, including the tail.

Web averaged 54.863649 unique pairs/s, with 41 complete seconds below 50. Desktop averaged 58.467740, with four below 50.

These instrumented sequential runs do not establish sustained 60 frames/s, a causal ranking or released-product performance.

ContextRunUnique pairsElapsed msPairs/sInput minFinal minInput below50Final below50
webobserve52935024.79999923706158.310779565600
webobserve1809876180009.9000015258854.86364932324141
desktopobserve52955006.90000152587958.918692545400
desktopobserve18010525180013.800001144458.467740363644
ContextRunTail msInput tailFinal tail
webobserve524.79999923706054722
webobserve1809.90000152587890600
desktopobserve56.90000152587890611
desktopobserve18013.8000011444091800
Open full-size diagramSeparate B clocks. Solid blue: final. Dashed orange: input. All 360 complete seconds use 0–66. Dotted lines mark 50 and 60. The table retains partial tails.
Separate B clocks. Solid blue: final. Dashed orange: input. All 360 complete seconds use 0–66. Dotted lines mark 50 and 60. The table retains partial tails.

Native CPU and elapsed time

Native records cover each entire native lifetime, including setup and cleanup. Their clocks have no measured alignment to either page clock.

The original elapsed timer surrounds uv_write. A calling-thread CPU read precedes that timer and another follows it.

The CPU difference includes calling-thread user and kernel execution. It is not the exact CPU time of the inner write interval.

The CPU clock advances only while the calling thread executes. The elapsed clock-read brackets can include scheduling delay.

Web recorded 10,176 calls and seven elapsed calls of at least 25 ms. Desktop recorded 10,827 calls and two such calls.

The longest web call took 227.731292 ms elapsed and 4.019 ms outer-window CPU. The longest desktop call took 42.512834 ms and 3.087167 ms.

The difference between elapsed and CPU time does not identify the cause. These records do not distinguish descheduling from a system wait.

CPU records have no clock errors, rejected records or overwritten events. All retained slow records and the separate worst record remain in the numeric data.

ContextLifetime sCallsMean elapsed msMean outer CPU msSlow callsCPU events overwritten
web188.336557166101764.9229483.46739070
desktop188.203864333108275.1197713.49621020
Open full-size diagramEach mean divides its complete native-lifetime total by its own call count. The CPU interval surrounds the elapsed interval. These totals include setup and cleanup. This is not a B measurement interval.
Each mean divides its complete native-lifetime total by its own call count. The CPU interval surrounds the elapsed interval. These totals include setup and cleanup. This is not a B measurement interval.
Open full-size diagramThe diagram shows all seven web and two desktop slow calls. Both panels use the same 0–240 ms scale. Labels give frame sequence and time from each native origin. No page-clock alignment exists.
The diagram shows all seven web and two desktop slow calls. Both panels use the same 0–240 ms scale. Labels give frame sequence and time from each native origin. No page-clock alignment exists.
ContextCall indexSequenceNative start sElapsed msOuter CPU msBefore bracket usAfter bracket us
web2232225037.577803227.7312924.0190001.6673.583
web70187447124.17407826.4804173.3034591.1661.917
web70687520125.46504229.9382923.0392081.6251.917
web71237618127.07292642.2021673.1303332.2081.583
web923110022167.15472531.4729593.2152081.4162.916
web941010241170.73627945.2719172.0774171.2921.958
web954310409173.63058629.7720001.6372501.8752.125
desktop3752388964.92750042.5128343.0871671.251.5
desktop1005810314172.18991829.9635002.8457501.252.292

Clock-read brackets and native event loss

The fixed recorder uses 22,744 bytes and permits 20,000 calls. That recorder adds no per-call dynamic allocation.

The bracket measurements include the CPU clock reads and surrounding elapsed time. They exclude later recorder validation and storage.

The diagnostic subtracts no overhead. The brackets do not measure total instrumentation overhead.

The existing write-callback elapsed measurement now includes the added CPU reads and recorder work after submission.

The older six-stage ring overwrote 785 of 1,041 web events and 92 of 348 desktop events. Each retained 256 records.

Its aggregate counts, elapsed totals and maxima remain available. Individual lost records cannot be reconstructed.

The web maximum has no retained individual native callback record. Its separate CPU record remains available.

ContextBefore total nsBefore mean usBefore max usAfter total nsAfter mean usAfter max us
web203305161.997889643.167379593373.7302812919.833
desktop238440462.202276528.208393900613.638133467.791
ContextStageCountMean elapsed msMax elapsed msAll-stage slow eventsAll-stage overwritten
webingestGap1074217.519238257.4261041785
webtapCopy105630.97936924.3211041785
webcameraPublish107421.23169742.7081041785
webwriteSubmit101764.922469227.7311041785
webwriteCallback101765.049630227.7511041785
webackCallback1017517.530103255.8671041785
desktopingestGap1113416.892118190.0134892
desktoptapCopy109520.75496146.86434892
desktopcameraPublish111340.95990063.84634892
desktopwriteSubmit108275.11929042.51234892
desktopwriteCallback108275.23191942.51934892
desktopackCallback1082616.712800173.25234892

Source intervals

The source pressure recorder keeps positive checks and actual drops. It does not record continuous socket occupancy.

Measured A intervals recorded 541 web drops and 152 desktop drops, all at admission or before encoding.

These source intervals use their own page clocks. Their durations differ from the B measurement spans and native lifetimes.

Frame sequences can join identities across processes. They do not establish latency or simultaneous clock readings.

ContextA elapsed sOffersAcceptedSentAdmission dropsPre-encode dropsPost-encode dropsAll pressure drops
web180.087100000381471080610508102652982430541
desktop180.0912999992370710806107131065493590152

Rejected web attempt

The first web five-second attempt was not accepted. The source renderer was not running before cleanup.

The source pattern identity and sender/bridge checks remained available. The stop caller was not recorded.

The attempt retained 71 matched pairs with no invalid markers. It has no accepted rate or accepted cell journal.

All actual browser and native processes exited. Source, pressure and cell journals are incomplete. A and B telemetry journals are complete.

The native lifetime independently passed CPU and ownership checks. It recorded 358 writes and one slow write.

That write took 32.551750 ms elapsed and 3.653250 ms outer-window CPU. Its frame sequence was 52. The source measurement started at sequence 312.

The slow write belongs to a frame with a lower source sequence than the start-cut sequence. This does not align native and page clocks.

The unchanged five-second repeat passed and remains a separate result.

AttemptAccepted FPSNative callsElapsed slow msOuter CPU msSlow sequenceSource start sequence
web-observe5-ncpuv2-a1None35832.551753.6532552312

Scope and references

These records do not establish a garbage collection cause, thermal cause, external camera delivery or hours-long behavior.

No uninstrumented run with identical scheduling conditions is available. The earlier source-budget reports remain separate.

The data retains result, source-manifest, native-receipt and journal digests. The candidate has not shipped as a product update.

ContextResult SHA256Native receipt SHA256Pressure journal SHA256
web4dade0ebba66bfd51e69e3a7c4f4a2cc2513224be3a44321264ba093d884644c749267f7c2248be5819cfa1ab417981e4433513d74400ee486a2e0e4c0beb60d67f3ad48da32ae536c95857a22e61cc6c34697d0bf675e0f5d3f6c81a90536f6
desktop06eb8c2d7725d438d1cc1ae27f85d005c1f69883b6b732079d64d55410df5d841797374563431c9246237bedb5869c1980edc359c707d700641b296b1370fdb1f458b79851100d700100dbbfd61c04d35e0b0466b268060d3028a6f884549c6f

Numeric data · Text report · Checksums

Earlier source-budget report